@article{sparing_visual_2002, title = {Visual cortex excitability increases during visual mental imagery--a {TMS} study in healthy human subjects}, volume = {938}, issn = {0006-8993}, url = {http://www.sciencedirect.com/science/article/B6SYR-45FH251-2/2/f76bbca311201f1302cfab744c761939}, doi = {{10.1016/S0006-8993(02)02478-2}}, abstract = { Previous neuroimaging studies provided evidence that visual mental imagery relies, in part, on the primary visual cortex. We hypothesized that, analogous to the finding that motor imagery increases the excitability of motor cortex, visual imagery should increase visual cortex excitability, as indexed by a decrease in the phosphene threshold {(PT).} In order to test visual cortex excitability, the primary visual cortex was stimulated with transcranial magnetic stimulation {(TMS),} so as to elicite phosphenes in the right lower visual quadrant. Subjects performed a visual imagery task and an auditory control task. We applied {TMS} with increasing intensity to determine the {PT} for each subject. Independent of the quadrant in which subjects placed their visual images, imagery decreased {PT} compared to baseline {PT;} in contrast, the auditory task did not change {PT.} These findings demonstrate for the first time a short-term, task-dependent modulation of {PT.} These results constitute evidence that early visual areas participate in visual imagery processing.}, number = {1-2}, journal = {Brain Research}, author = {Roland Sparing and Felix M. Mottaghy and Giorgio Ganis and William L. Thompson and Rudolf Töpper and Stephen M. Kosslyn and Alvaro {Pascual-Leone}}, month = may, year = {2002}, keywords = {Phosphene {threshold,Primary} visual {cortex,Transcranial} magnetic {stimulation,Visual} mental imagery}, pages = {92--97} }, @article{maeda_556._2000, title = {556. Transcranial magnetic stimulation studies of cortical excitability in depression}, volume = {47}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-403W273-NR/2/ca2b25885b74202ff43af0cf2ffc5a06}, doi = {{10.1016/S0006-3223(00)00858-1}}, number = {8, Supplement 1}, journal = {Biological Psychiatry}, author = {F. Maeda and J. P. Keenan and S. Freund and R. Birnbaum and B. Vaccaro and A. {Pascual-Leone}}, month = apr, year = {2000}, pages = {{S169--S170}} }, @article{gerschlager_rtms_2002, title = {{rTMS} over the cerebellum can increase corticospinal excitability through a spinal mechanism involving activation of peripheral nerve fibres}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-46H6M0J-9/2/3d79bf2894ef277a2a2cbab34c4b5b79}, doi = {{10.1016/S1388-2457(02)00156-6}}, abstract = { Objectives: Single-pulse transcranial magnetic stimulation {(TMS)} over the cerebellum affects corticospinal excitability by a cerebellar and a peripheral mechanism. We have investigated whether any of the long-lasting effects of repetitive {TMS} {(rTMS)} over cerebellum can also be attributed to peripheral effects. Methods: Five hundred conditioning stimuli at 1 Hz were given over either the right cerebellum using a double-cone coil, or over the right posterior neck using a figure-8-coil. Corticospinal excitability was assessed by measuring the amplitude of motor evoked potentials {(MEPs)} evoked in the right and left hand and forearm muscles. Hoffman reflexes {(H-reflex)} were also obtained in the right flexor carpi radialis muscle. Results: {rTMS} over either the right cerebellum or the right posterior neck significantly facilitated {MEPs} in hand and forearm muscles in the right but not in the left arm (n=8) for up to 30 min after the end of the train. {rTMS} (1 Hz) of the right neck area increased the amplitude of the H-reflex (n=5). Conclusions: Much of the persisting effects of {rTMS} over the cerebellum on corticospinal excitability appear to be mediated through stimulation of peripheral rather than central structures. Moreover, the results show that {rTMS} over peripheral areas can cause long-lasting changes in spinal reflexes.}, number = {9}, journal = {Clinical Neurophysiology}, author = {W. Gerschlager and L. O. D. Christensen and S. Bestmann and J. C. Rothwell}, month = sep, year = {2002}, keywords = {Hoffman {reflex,Motor} evoked {potentials,Repetitive} transcranial magnetic stimulation}, pages = {1435--1440} }, @article{khn_pseudo-bilateral_2002, title = {Pseudo-bilateral hand motor responses evoked by transcranial magnetic stimulation in patients with deep brain stimulators}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-4538P7G-5/2/5a62589226316d80d20c317f5accaaf8}, doi = {{10.1016/S1388-2457(01)00731-3}}, abstract = { Objectives: In 3 of 5 patients with dystonia and bilaterally implanted deep brain stimulating electrodes, focal transcranial magnetic stimulation {(TMS)} of one motor cortex elicited bilateral hand motor responses. The aim of this study was to clarify the origin of these ipsilateral responses. Methods: {TMS} and electrical stimulation of corticospinal fibres by the implanted electrodes were performed and the evoked hand motor potentials were analysed. Results: In comparison with responses elicited by contralateral motor cortex stimulation, ipsilateral responses were smaller in amplitude (3.0±1.4 versus 5.8±1.5 {mV),} had shorter peak latencies (first negative peak: 20.9±0.8 versus 25.1±0.4 ms) and were followed by a shorter-lasting silent period (46±4 versus 195±35 ms). Ipsilateral responses following {TMS} had similar peak latencies to responses elicited subcortically by deep brain stimulation {(DBS)} (20.4±0.9 ms). Conclusions: Hand motor responses ipsilateral to {TMS} result from a subcortical activation of corticospinal fibres, via the implanted electrode in the other hemisphere, secondary to currents induced by {TMS} in subcutaneous wire loops that underlie the magnetic coil. Studies of {TMS} in patients with {DBS} have to take this potential source of confounding into account.}, number = {3}, journal = {Clinical Neurophysiology}, author = {A. A. Kühn and T. Trottenberg and A. Kupsch and B. {-U.} Meyer}, month = mar, year = {2002}, keywords = {Deep brain {stimulation,Globus} pallidus {internus,Ipsilateral} hand motor {responses,Magnetic} brain {stimulation,Motor} {cortex,Ventral} intermediate nucleus of the thalamus}, pages = {341--345} }, @article{epstein_localization_1999, title = {Localization and characterization of speech arrest during transcranial magnetic stimulation}, volume = {110}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-3WRJPRJ-8/2/a79f3143d848473aef82764c29746566}, doi = {{10.1016/S1388-2457(99)00047-4}}, abstract = { Objective: To determine the anatomic and physiologic localization of speech arrest induced by repetitive transcranial magnetic stimulation {(rTMS),} and to examine the relationship of speech arrest to language function. Methods: Ten normal, right-handed volunteers were tested in a battery of language tasks during {rTMS.} Four underwent mapping of speech arrest on a 1 cm grid over the left frontal region. Compound motor action potentials from the right face and hand were mapped onto the same grid. Mean positions for speech arrest and muscle activation were identified in two subjects on 3-dimensional {MRI.} Results: All subjects had lateralized arrest of spontaneous speech and reading aloud during {rTMS} over the left posterior-inferior frontal region. Writing, comprehension, repetition, naming, oral praxis, and singing were relatively spared {(P{\textless}.05).} Stimulation on the right during singing abolished melody in two subjects, but minimally affected speech production. The area of speech arrest overlay the caudal portion of the left precentral gyrus, congruous with the region where stimulation produced movement of the right face. Conclusions: The site of magnetic speech arrest appears to be the facial motor cortex. Its characteristics differ from those of classic aphasias, and include a prominent dissociation among different types of speech output.}, number = {6}, journal = {Clinical Neurophysiology}, author = {Charles M. Epstein and Kimford J. Meador and David W. Loring and Randall J. Wright and Joseph D. Weissman and Scott Sheppard and James J. Lah and Frank Puhalovich and Luis Gaitan and Kent R. Davey}, month = jun, year = {1999}, keywords = {Frontal {lobe,Language,Speech,Transcranial} magnetic stimulation}, pages = {1073--1079} }, @article{mottaghy_modulation_2000, title = {Modulation of the neuronal circuitry subserving working memory in healthy human subjects by repetitive transcranial magnetic stimulation}, volume = {280}, issn = {0304-3940}, url = {http://www.sciencedirect.com/science/article/B6T0G-3YJYC89-4/2/cad103b3d25e760a7cfd8d7f58e07b5c}, doi = {{10.1016/S0304-3940(00)00798-9}}, abstract = { We studied the effect of repetitive transcranial magnetic stimulation {(rTMS)} on changes in regional cerebral blood flow {(rCBF)} as revealed by positron emission tomography {(PET)} while subjects performed a 2-back verbal working memory {(WM)} task. {rTMS} to the right or left dorsolateral prefrontal cortex {(DLPFC),} but not to the midline frontal cortex, significantly worsened performance in the {WM} task while inducing significant reductions in {rCBF} at the stimulation site and in distant brain regions. These results for the first time demonstrate the ability of {rTMS} to produce temporary functional lesions in elements of a neuronal network thus changing its distributed activations and resulting in behavioral consequences.}, number = {3}, journal = {Neuroscience Letters}, author = {Felix M. Mottaghy and Bernd J. Krause and Lars J. Kemna and Rudolf Töpper and Lutz Tellmann and Markus Beu and Alvaro {Pascual-Leone} and {Hans-Wilhelm} {Müller-Gärtner}}, month = feb, year = {2000}, keywords = {Dorsolateral prefrontal {cortex,Functional} {lesion,Positron} emission {tomography,Regional} cerebral blood {flow,Repetitive} transcranial magnetic {stimulation,Verbal} working memory}, pages = {167--170} }, @article{foltys_motor_2001, title = {Motor control in simple bimanual movements: a transcranial magnetic stimulation and reaction time study}, volume = {112}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-429XWRH-6/2/4ee7a7ed53281d764fdd2cfec1d8dcb9}, doi = {{10.1016/S1388-2457(00)00539-3}}, abstract = { Objective: Simple reaction time {(RT)} can be influenced by transcranial magnetic stimulation {(TMS)} to the motor cortex. Since {TMS} differentially affects {RT} of ipsilateral and contralateral muscles a combined {RT} and {TMS} investigation sheds light on cortical motor control of bimanual movements. Methods: Ten normal subjects and one subject with congenital mirror movements {(MM)} were investigated with a {RT} paradigm in which they had to move one or both hands in response to a visual go-signal. Suprathreshold {TMS} was applied to the motor cortex ipsilateral or contralateral to the moving hand at various interstimulus intervals {(ISIs)} after presentation of the go-signal. {EMG} recordings from the thenar muscles of both hands were used to determine the {RT.} Results: {TMS} applied to the ipsilateral motor cortex shortened {RT} when {TMS} was delivered simultaneously with the go-signal. With increasing {ISI} between {TMS} and go-signal the {RT} was progressively delayed. This delay was more pronounced if {TMS} was applied contralateral to the moving hand. When normal subjects performed bimanual movements the {TMS-induced} changes in {RT} were essentially the same as if they had used the hand in an unimanual task. In the subject with {MM,} {TMS} given at the time of the go-signal facilitated both the voluntary and the {MM.} With increasing {ISI,} however, {RT} for voluntary movements and {MM} increased in parallel. Conclusions: Ipsilateral {TMS} affects the timing of hand movements to the same extent regardless of whether the hand is engaged in an unimanual or a bimanual movement. It can be concluded, therefore, that in normal subjects simple bimanual movements are controlled by each motor cortex independently. The results obtained in the subject with {MM} are consistent with the hypothesis that mirror movements originate from uncrossed corticospinal fibres. The alternative hypothesis that a deficit in transcallosal inhibition leads to {MM} in the contralateral motor cortex is not compatible with the presented data, because {TMS} applied to the motor cortex ipsilateral to a voluntary moved hand affected voluntary movements and {MM} to the same extent.}, number = {2}, journal = {Clinical Neurophysiology}, author = {Henrik Foltys and Roland Sparing and Babak Boroojerdi and Timo Krings and Ingo G. Meister and Felix M. Mottaghy and Rudolf Töpper}, month = feb, year = {2001}, keywords = {Bimanual {movements,Mirror} {movements,Reaction} {time,Transcranial} magnetic stimulation}, pages = {265--274} }, @article{pascual-leone_transcranial_2000, title = {Transcranial magnetic stimulation in cognitive neuroscience – virtual lesion, chronometry, and functional connectivity}, volume = {10}, url = {http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VS3-402CMNM-F&_user=108429&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000059713&_version=1&_urlVersion=0&_userid=108429&md5=bb8df2cdc2cc9f84b0f133702bfaa80b}, doi = {{10.1016/S0959-4388(00)00081-7}}, abstract = {a Laboratory for Magnetic Brain Stimulation, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, Kirstein Building {KS} 452, Boston, {MA} 02215, {USA} b Department of Experimental Psychology, University of Oxford, Oxford, {UK} c {MRC} Human Movement and Balance Unit, Institute of Neurology, Queen Square, London, {UK} Fifteen years after its introduction by Anthony Barker, transcranial magnetic stimulation {(TMS)} appears to be ‘coming of age’ in cognitive neuroscience and promises to reshape the way we investigate brain–behavior relations. Among the many methods now available for imaging the activity of the human brain, magnetic stimulation is the only technique that allows us to interfere actively with brain function. As illustrated by several experiments over the past couple of years, this property of {TMS} allows us to investigate the relationship between focal cortical activity and behavior, to trace the timing at which activity in a particular cortical region contributes to a given task, and to map the functional connectivity between brain regions. Subject-index terms: Neuroscience The investigative tools used in science determine the kinds of empirical observations that can be made. Very often, the results produced by new tools in the neurosciences force us to re-evaluate models of brain–behavior relationships and even affect the kinds of questions that are asked. For example, over the past decade, the neuroimaging techniques of computerized tomography, magnetic resonance imaging, positron emission tomography {(PET),} magneto-encephalography and electro-encephalography {(EEG)} have shaped the way in which we model behavior. Anatomical neuroimaging techniques have produced ever more detailed descriptions of the extent of lesions produced by brain injury. Combining this knowledge with clinical examination of the affected patients should provide insights into the original function of the damaged brain areas. However such a ‘lesion study approach’ is hampered by the issue of compensatory plasticity, and by the possibility that the disturbance to function may be more, or less, widespread than the anatomical lesion [1]. Functional neuroimaging methods have overcome some of these problems and can demonstrate an association between behavior and patterns of activity in cortical and subcortical structures. Although careful design of experiments may allow us to conclude with reasonable certainty that the correlation of brain activity with behavior is attributable to a causal connection (i.e. that the brain activity causes the behavior), imaging alone will never be able to provide proof of that assertion. Transcranial magnetic stimulation {(TMS)} is based on Faraday’s principles of electromagnetic induction. A pulse of current flowing through a coil of wire generates a magnetic field. If the magnitude of this magnetic field changes in time, then it will induce a secondary current in any nearby conductor. The rate of change of the field determines the size of the current induced. In {TMS} studies, the stimulating coil is held over a subject’s head and as a brief pulse of current is passed through it, a magnetic field is generated that passes through the subject’s scalp and skull with negligible attenuation (only decaying by the square of the distance). This time-varying magnetic field induces a current in the subject’s brain, and this stimulates the neural tissue. In many experiments, single pulses of stimulation are applied. Each of these lasts about 100 μs, so that the effect is similar to stimulating a peripheral nerve with a conventional electric stimulator. To date, the single-pulse technique appears to be completely safe when applied to healthy individuals. It is also possible to apply a series of pulses at rates of up to 50 Hz (this is known as repetitive {TMS,} or {rTMS).} This procedure is more dangerous and can cause seizures even in healthy subjects; because of this risk, safety and ethical guidelines must be followed [2]. Although studies in animal models and, particularly, in neurosurgical patients have provided considerable insight into the mechanisms of action of {TMS} [3, 4, 5, 6, 7 and 8], our knowledge is still limited [1, 9 and 10]: we are not yet able to ascertain precisely the depth of stimulation in the brain, nor its spatial resolution; we are not able to determine which neural elements are the most sensitive to stimulation in a particular area of brain; and we are not certain whether all the effects of stimulation are attributable to activity at the site of the stimulus or whether activity spreads through neural pathways to other more distant sites. One might therefore be tempted to wait for greater insights into the neuronal effects of {TMS} before applying it widely to studies in cognitive science. We would argue that waiting may be desirable, but is not necessary. As we shall see below, the majority of {TMS} experiments in cognitive science rely on the fact that magnetic stimulation of an area of the brain disrupts any processing that is going on at the time. If that processing is contributing to behavior, then we would expect to observe deterioration in the performance of that behavior. From such an observation, we can conclude that there is a functional connection between the activity and the behavior. In this scenario, we need not know precisely which elements in the brain were activated by the stimulus. Any artificially induced synchronized activity in a population of neurones will interfere with their function — at this fundamental level, we can probably trust the technique. In fact, by analogy with the synchronised spike-wave discharges of an epileptic focus, it seems probable that a large magnetic stimulus will synchronously excite a population of neurones. These will fire a rapid series of impulses for a few milliseconds, and then the whole activity will be suppressed by a long-lasting period of {(GABAergic)} inhibition. The whole process may last between 20 and 200 ms, depending on the intensity of the stimulus. In this review, we shall highlight two of the major potential contributions of {TMS} studies to our understanding of cognitive neuroscience: the transient disruption of focal cortical activity to establish the causal role and the timing of the contribution of a given cortical region in a behavior, and the application of {TMS} to the study of functional brain connectivity. What is critical and common to both of these contributions is that they allow us to further our knowledge beyond that which the study of patients can teach us — they allow us to empirically test specific neuropsychologic models and constructs. Applied as single pulses appropriately delivered in time and space, or applied in trains of repetitive stimuli at an appropriate frequency and intensity, {TMS} can be used to transiently disrupt the function of a given cortical target, thus creating a temporary ‘virtual brain lesion’ [1 and 11]. This makes it possible to study two aspects of the contribution of a given cortical region to a specific behavior: ‘what does it do?’ and ‘when does it do it?’. An early example of the use of {TMS} to assess the causal significance between focal brain activity and behavior was the study by Cohen et al. [12] of the role of the visual cortex during tactile Braille reading in early blind subjects. Functional imaging studies of early or congenitally blind subjects reveal that their primary visual cortex can be activated by Braille reading and other tactile discrimination tasks [13]. This activation could be either an epiphenomenon of tactile information processing in blind people (regardless of whether related to compensatory mechanisms or not), or causally related to the tactile spatial discrimination ability of the subjects. Cohen et al. [12 and 14] used {TMS} to disrupt the function of different cortical areas in blind subjects and sighted volunteers while they used their index finger to read Braille or embossed Roman letters. {TMS} of the occipital visual cortex (centred over the striate cortex, area V1) induced reading errors and distorted the tactile perceptions of congenitally or early blind subjects, but did not affect performance in the sighted controls or in those subjects who became blind after age 14 (if the blindness was slowly progressive in onset or if its extent was partial) [14]. Hamilton et al. [15] have reported the notable case of an early blind woman who suffered bilateral occipital damage following an ischemic stroke. She became unable to read Braille despite her somatosensory perception being otherwise unchanged. This experiment of nature parallels the effects of {TMS} and, again, demonstrates that the visual cortex is required for tactile spatial processing by early blind subjects. Other recent examples of studies using ‘virtual lesions’ to establish the causal role of a cortical region for a given behavior are the studies of Kosslyn et al. [16] on primary visual cortex in visual imagery, Ganis et al. [17] on motor cortex in mental rotation, Zangaladze et al. [18] on peristriate visual cortex in tactile discrimination of orientation, and Jahanshahi et al. [19 and 20] on frontal cortex in random number generation. In the majority of these experiments, a series of stimuli was applied at a frequency of 20 Hz over a period of 2 s, with the result that the data could yield information only on the parts of the brain that are important for performing a particular task. However, if single stimuli are applied — which disrupt activity for only a short time — it is possible to obtain information on precisely when activity contributes to task performance (i.e. the ‘chronometry’ of cognition). For example, in a variation on the Braille reading studies [21], real or non-sensical Braille stimuli were presented to the pads of the reading (index) fingers of early blind subjects with a specially designed Braille stimulator. Single-pulse {TMS} to the contralateral somatosensory cortex disrupted detection of Braille stimuli when it was applied at interstimulus intervals of 20 to 40 ms; the subjects did not realize that a peripheral stimulus had been presented. In contrast, {TMS} to the striate cortex disrupted the processing of the Braille stimuli when it was presented at interstimulus intervals of 50 to 80 ms: the subjects typically were aware that a peripheral stimulus had been presented, but were unable to discriminate what particular Braille symbol it was. This suggests that the {TMS} caused interference with their perception of the Braille symbols (i.e. subjects knew that they had been presented with a Braille symbol, but could not tell which one it was). Several other recent studies using {TMS} have provided information about which cortical area contributes to performance in a specific task, and at what precise moment the contribution is critical. Zangaladze et al. [18] investigated both the involvement of peristriate visual cortex activity during discrimination of the orientation of tactile gratings in normal subjects, and the timing of this involvement. It was found that the contribution of the peristriate visual cortex to performance on the task could be abolished by {TMS} stimulation presented 180 ms after presentation of the tactile stimulus — thereby suggesting that the timing of tactile input to the peristriate visual area occurs 180 ms after stimulus presentation. Terao et al. [22] investigated the contributions of the frontal and parietal cortex to an antisaccade task. They delivered focal {TMS} at various time intervals (80, 100, and 120 ms) after target presentation over various sites on the scalp while the subjects performed an antisaccade task. Saccade onset was significantly delayed by {TMS} to frontal and posterior parietal regions of either hemisphere. The frontal region corresponded to the frontal eye field, whereas the parietal region included the posterior parietal cortex. The timing of the {TMS} effect was earlier (80 ms) for the posterior parietal region and later for the frontal region (100 ms). This suggests an information flow from posterior to anterior cortical regions during the presaccadic period. Schulter et al. [23 and 24] studied the timing of the involvement of the premotor and the primary motor cortex in a choice reaction time task. Subjects performed a cued movement task while receiving single-pulse {TMS} to three possible sites: sensorimotor cortex, posterior premotor cortex or anterior premotor cortex. {TMS} slowed movements when applied at 140 ms after the visual cue over the anterior premotor site, at 180 ms after the visual cue over the posterior premotor site, and at 220 ms and later after the visual cue over the sensorimotor cortex. These results are consistent with a change from signal- to movement-related processing when moving from premotor to motor cortex. In a second experiment the authors introduced a preparatory set period between an instruction signal, which informed subjects which movement to make, and a {‘Go’} signal, which informed them when to make the movement. In this case, {TMS} slowed movements equally regardless of whether the anterior premotor or the sensorimotor cortex was targeted. Therefore, the findings suggest that set activity is processed by both premotor and motor cortices. It is possible that {TMS} may be used to treat neuropsychological patients. We shall not address this topic directly, however, as most of the relevant work involves neuropsychiatric disorders and is still preliminary [25, 26 and 27]. Interestingly, {TMS} not only can disrupt, but also can functionally enhance activity in a targeted cortical region [28]. Topper et al. [29] found that the application of a single pulse of {TMS} to Wernicke’s area speeded reaction times for picture naming, suggesting that this behavioral gain resulted from enhanced excitability in Wernicke’s area as a result of {TMS.} However, at the present time it is difficult to understand why the effect was maximal when stimuli were applied 500 ms or 1 s prior to presentation of the picture. Such a long-lasting effect of a single magnetic stimulus of cortical circuitry has never been observed before. One possible mechanism to account for such long delays might be that the effects of {TMS} are not caused by the stimulation of the directly targeted Wernicke’s cortex, but rather are attributable to effects on more distant cortical regions reached by trans-synaptic cortico-cortical effects. {TMS} can also be used to explore the compensatory cortical plasticity that occurs in response to a lesion. Particularly elegant examples of such work are the studies of Olivieri et al. [30 and 31] on neglect. In an initial study [30], they asked normal control subjects to report detection of very weak electrical stimuli applied to the first, third and fifth digits of either hand or both hands. Single-pulse {TMS} over the right parietal cortex 20 or 40 ms after digit stimulation reduced the subjects’ ability to detect input from either hand, particularly if both hands were stimulated at the same time. Applying {TMS} to only the left parietal cortex had a similar but smaller effect, whereas stimulation of frontal cortex had no effect. Olivieri et al. concluded that normal controls have a right hemisphere dominance for stimulus perception, and that parietal regions are active in this process 20 to 40 ms after stimulus presentation. Olivieri et al. [31] then applied {TMS} to patients with right-hemispheric lesions. When stimuli were applied simultaneously to both hands, the patients often failed to detect the stimulus on the left side. Stimulation (at intensities 10\% higher than those used in normal subjects) of left frontal, but not of parietal cortex, significantly reduced the rate of extinction (i.e the lack of detection of the stimulus). Therefore, as in animal models of neglect [32], transient disruption of the healthy hemisphere restores spatial attention to the contralesional side, thereby improving neglect. These results support the notion that spatial attention may be explained in terms of interhemispheric competition between subcortical and cortical structures; this competition may be asymmetrical [33]. Furthermore, it may be possible to use {TMS} — or perhaps {rTMS} — to induce long-lasting changes in cortical excitability for the rehabilitation of neglect patients. {TMS} can also provide insight into brain function beyond that which can be obtained from lesion studies in patients. A good example of {TMS} being used in this way are the recent experiments by Walsh et al. [34 and 35] on parietal cortex function and conjunction search tasks. Consistent with findings in patients with right parietal lesions, they [34] found that {TMS} applied to the right parietal cortex disrupts performance of controls on a color and form conjunction search task. Interestingly, however, they also noted a persistent — though later — engagement of the parietal cortex when no target was given during a trial and the subject decided to terminate the search rather than guess the answer. This study demonstrates the usefulness of {TMS} because the specificity of the contribution of parietal cortex to perceptual learning during conjunction tasks is normally difficult to test in patients, given that lesions cannot be reversed (see [34]). Using {TMS,} however, it is possible to disrupt performance of a novel task while demonstrating the lack of impairment in another, overlearned conjunction task (i.e. a conjunction task in which performance has become partially automatized as a result of extensive practice). Hence, the parietal lobe contribution is specific for performance when a task is novel — or at least not practiced so extensively that it might have become automatized. A final example of how {TMS} studies can take us ‘beyond patients’ is provided by the effects of transient parietal (visual motion area V5) disruption during color and motion conjunction search tasks [35]. The disruption to neural activity caused by {TMS} is both transient and acute, hence not allowing plastic reorganization of the brain. Walsh et al. [35] found that patient {LM,} who has bilateral V5 lesions, is able to perform form and color conjunction tasks. It is not clear, however, what are the effects of the lesions to V5 with respect to {LM’s} relatively preserved abilities. When {TMS} is used to transiently disrupt V5 in normal controls, performance on form and motion conjunction tasks deteriorates, but subjects show improved performance on color and form conjunction tasks. Therefore, {TMS} is providing insights into the interplay between functionally connected areas by unmasking such paradoxical performance improvements. Paus et al. [36, 37 and 38] were the first to introduce the combined techniques of {TMS} and functional neuroimaging as a means of mapping neural connections in the live human brain. They used {TMS} to stimulate directly a selected cortical area; simultaneously, they measured changes in brain activity, indexed by cerebral blood flow {(CBF),} using {PET.} Ilmoniemi et al. [39] used a similar approach for studying cerebral connectivity using a combination of {TMS} and quantitative {EEG.} In their first study, Paus et al. [36] applied {TMS} to the left frontal eye fields and found a significant positive correlation between the number of {TMS} pulses and {CBF} at the stimulation site and, most importantly, in the superior parietal and medial parieto-occipital regions. The pattern of these distal effects was consistent with the known anatomical connectivity of monkey frontal eye fields. The authors conclude that the combination of {TMS} with functional neuroimaging “offers an objective tool for assessing the state of functional connectivity without requiring the subject to engage in any specific behavior” [36]. Curiously, the frontal eye fields are also richly connected to area 46 in the prefrontal cortex and to motor cortical areas, but these were not activated. We wonder whether covert, implicit behavior, such as concentrating on inhibiting eye movements, might prime certain connections and hence influence the effects of {TMS.} In a second study, Paus et al. [37] again used a combination of {TMS} and {PET,} but on the primary motor cortex and using differing numbers of stimuli that were below the motor threshold. In this case, activations were observed at a distance — in the supplementary motor area, the parietal cortex and the contralateral motor and premotor areas. However, unlike the frontal eye fields data, these results showed negative correlations between blood flow and the number of {TMS} pulses. This was interpreted as indicating that the low-intensity stimuli that were applied to the motor cortex had an inhibititory effect in this area. Whatever the explanation, it is a warning that stimulation may have subtly different effects on different regions of the brain. As Lomber [32] has argued in his discussion of experiments using cooling probes, it is important to realize that transient disruption of a given cortical region tells us mostly about the capacity of the rest of the brain to adjust (i.e. react or adapt) to it. Hence, ‘functional connectivity experiments’ combining {TMS} with functional imaging might in fact reveal the capacity of the brain to rapidly adjust to the disruption of a given area in an attempt to maintain function. Mottaghy et al. [40] have recently illustrated this point in a study in which {TMS} and {PET} were combined in order to investigate the role of prefrontal cortex in working memory. Performance in the task is equally disrupted by {TMS} to the left or to the right dorsolateral prefrontal cortex. However, {PET} reveals significant differences in the brain activity associated with task performance between {TMS} applied to the left and to the right side of the brain. These results demonstrate for the first time the ability of {TMS} to produce temporary functional lesions in different elements of a neuronal network, and to demonstrate how such effects are associated with differential behavioral consequences that can be explained on the basis of the pattern of brain activity in the elements of the network that are not directly targeted by {TMS.} So, for example, both left and right prefrontal {TMS} affect performance in the working memory task. However, performance is more impaired, both in severity and duration, following right-sided {TMS.} The {PET} study of the task performance during {TMS} reveals that {TMS} to the left dorsolateral prefrontal cortex only causes significant reductions in cortical activity in the directly targeted prefrontal region. However, {TMS} to the right prefrontal cortex significantly reduces activity in the right prefrontal region, the right fronto-temporal pole, and bilateral parietal regions. These kinds of experiments combining {TMS,} behavioral measures, and functional brain imaging, allow us to model behavior by tracking the coordinated changes of activity over a widely distributed network, and to use {TMS} to transiently modulate elements of the network to evaluate the dependent changes throughout. It is as though we might be lightly tapping elements of a mobile sculpture in order to capture its aesthetic value in the induced swings and sways. Our knowledge about the mechanisms of action of {TMS} is still limited. Nevertheless, its limitations aside, {TMS} provides us with a unique opportunity to study brain–behavior relations. {TMS} can create virtual lesions, thereby allowing us to obtain information about the timing of the contribution of a given cortical region to a specific behavior (‘causal chronometry’). Furthermore, combined with functional neuroimaging, {TMS} can be used to study functional connectivity and, in particular, to study the distributed effects of {TMS} on the neural networks involved in a given behavior. {TMS} is a timely addition to the armamentarium of cognitive neuroscience tools and may change the way we approach problems of linking brain activity with behavior. Supported in part by the General Clinical Research Center at Beth Israel Deaconess Medical Center {(National} Center for Research Resources {MO1} {RR01032)} and grants from the National Institute of Mental Health {(RO1MH57980,} {RO1MH60734)} and the National Eye Institute {(RO1EY12091).} Papers of particular interest, published within the annual period of review, have been highlighted as: }, number = {2}, journal = {Current Opinion in Neurobiology}, author = {Alvaro {Pascual-Leone} and Vincent Walsh and John Rothwell}, month = apr, year = {2000}, pages = {232--237} }, @article{boroojerdi_visual_2002, title = {Visual and motor cortex excitability: a transcranial magnetic stimulation study}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-46H6M0J-K/2/78373944b4d5234fa508b8fc232d1fe4}, doi = {{10.1016/S1388-2457(02)00198-0}}, abstract = { Objectives: Phosphene thresholds {(PTs)} to transcranial magnetic stimulation over the occipital cortex and motor thresholds {(MTs)} have been used increasingly as measures of the excitability of the visual and motor cortex. {MT} has been utilized as a guide to the excitability of other, non-motor cortical areas such as dorsolateral prefrontal cortex. The aims of this study were to compare the {PTs} to {MTs;} to assess their stability across sessions; and to investigate their relation to {MTs.} Methods: {PTs} and {MTs} were determined using focal transcranial magnetic stimulation over the visual and motor cortex. Results: {PTs} were shown to be significantly higher than {MTs.} Both {PTs} and {MTs} were stable across sessions. No correlation between {PTs} and {MTs} could be established. Conclusions: Phosphene threshold is a stable parameter of the visual cortex excitability. {MTs} were not related to the excitability of non-motor cortical areas.}, number = {9}, journal = {Clinical Neurophysiology}, author = {Babak Boroojerdi and Ingo G. Meister and Henrik Foltys and Roland Sparing and Leonardo G. Cohen and Rudolf Töpper}, month = sep, year = {2002}, keywords = {Motor {threshold,Phosphene,Phosphene} {threshold,Transcranial} magnetic {stimulation,Visual} cortex excitability}, pages = {1501--1504} }, @article{han_optimization_2001, title = {Optimization of facilitation related to threshold in transcranial magnetic stimulation}, volume = {112}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-42MFG34-3/2/9fb453a1e44933594f5bf8df727cc580}, doi = {{10.1016/S1388-2457(01)00471-0}}, abstract = { Objectives: To attain the standardized procedure for optimal facilitation, we analyzed motor-evoked potential {(MEP)} responses to the degree of voluntary contraction and stimulus intensity. Methods: Fifteen normal subjects were included. {MEPs} were elicited at thenar muscles during rest and at gradual voluntary contraction {(MVC),} using 10, 30, and 50\% of {MVC.} During rest and each contraction, the excitability threshold at rest {(RET)} and at contraction {(CET)} were determined. Consecutive stimuli were applied, with the intensity of ratio increments (110-150\% of {ET).} Results: The {RET} showed a remarkable decrease after contraction. Shortening of latency reached a saturation level at 10\% of {MVC.} Amplitude reached a saturation level at 30\% of {MVC} with 62.7±8.5\% of the maximum output, which is equal to 140\% intensity of {CET,} and 110\% of {RET.} The {MEP} amplitudes at rest and at 10\% {MVC} were influenced by their {ETs,} but those measured above 30\% of {MVC} were not related. Conclusions: The procedure recommended for optimal facilitation is as follows: to achieve minimal latency of {MEPs,} a minimal contraction (10\% of {MVC)} with {RET} intensity is sufficient and for maximal amplitude, a moderate contraction (30\% of {MVC)} with 110\% of {RET} intensity is adequate.}, number = {4}, journal = {Clinical Neurophysiology}, author = {Tai Ryoon Han and Jin Ho Kim and Jae Young Lim}, month = apr, year = {2001}, keywords = {{Facilitation,Motor} evoked {potential,Transcranial} magnetic {stimulation,Voluntary} contraction}, pages = {593--599} }, @article{wassermann_motor_2001, title = {Motor cortex excitability correlates with an anxiety-related personality trait}, volume = {50}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-43VYG08-B/2/60be583bcddd41b93c52ad540e3abafa}, doi = {{10.1016/S0006-3223(01)01210-0}}, abstract = { Background: In an earlier study comparing obsessive-compulsive disorder {(OCD)} patients to psychiatrically screened normals, we found lowered motor evoked potential {(MEP)} threshold to transcranial magnetic stimulation {(TMS)} and decreased intracortical inhibition in {OCD.} We sought to determine whether this pattern was specific to {OCD.} Methods: We measured the threshold and amplitude of {MEPs} to single and paired (subthreshold-suprathreshold; 3, 4, 10, 15 msec intervals) {TMS} in 46 healthy volunteers (23 women, 23 men) who were given the {NEO-PI-R} personality inventory. Nineteen of the men also received cognitive and motor tests. Results: The paired-pulse conditioned/unconditioned {MEP} amplitude ratios correlated with Neuroticism {(N),} a stable measure of trait-level anxiety and other negative emotions, in the whole sample (r = 0.48; p = 0.0006), and in the men (r = 0.63; p = 0.0009). There were no other significant correlations. Conclusions: This relationship reflects a factor that contributes to both personality and cortical regulation. It was not statistically significant in women, probably because of confounding hormonal influences on excitability. Decreased intracortical inhibition may be related more to trait anxiety and depression, which are high in {OCD,} than to {OCD} itself. However, the {MEP} threshold (significantly lowered in {OCD)} was unrelated to N.}, number = {5}, journal = {Biological Psychiatry}, author = {Eric M. Wassermann and Benjamin D. Greenberg and Margaret B. Nguyen and Dennis L. Murphy}, month = sep, year = {2001}, keywords = {anxiety {disorders,GABA,motor} cortex,obsessive-compulsive disorder,sex {differences,Transcranial} magnetic stimulation}, pages = {377--382} }, @article{huang_case_2004, title = {A case report of repetitive transcranial magnetic stimulation-induced mania}, volume = {6}, url = {http://dx.doi.org/10.1111/j.1399-5618.2004.00145.x}, doi = {10.1111/j.1399-5618.2004.00145.x}, number = {5}, journal = {Bipolar Disorders}, author = {{Chih-Chia} Huang and {Tung-Ping} Su and {Ian-Kai} Shan}, year = {2004}, pages = {444--445} }, @article{mcconnell_transcranial_2001, title = {The transcranial magnetic stimulation motor threshold depends on the distance from coil to underlying cortex: a replication in healthy adults comparing two methods of assessing the distance to cortex}, volume = {49}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-42M788C-8/2/719149da74d63943d1fe09ed0ecd2558}, doi = {{10.1016/S0006-3223(00)01039-8}}, abstract = { {\%Using} transcranial magnetic stimulation {(TMS),} a handheld electrified copper coil against the scalp produces a powerful and rapidly oscillating magnetic field, which in turn induces electrical currents in the brain. The amount of electrical energy needed for {TMS} to induce motor movement (called the motor threshold {[MT]),} varies widely across individuals. The intensity of {TMS} is dosed relative to the {MT.} Kozel et al observed in a depressed cohort that {MT} increases as a function of distance from coil to cortex. This article examines this relationship in a healthy cohort and compares the two methods of assessing distance to cortex. {mSeventeen} healthy adults had their {TMS} {MT} determined and marked with a fiducial. Magnetic resonance images showed the fiducials marking motor cortex, allowing researchers to measure distance from scalp to motor and prefontal cortex using two methods: 1) measuring a line from scalp to the nearest cortex and 2) sampling the distance from scalp to cortex of two 18-mm-square areas. {mConfirming} Kozel's previous finding, we observe that motor threshold increases as distance to motor cortex increased for both methods of measuring distance and that no significant correlation exists between {MT} and prefontal cortex distance. {mDistance} from {TMS} coil to motor cortex is an important determinant of {MT} in healthy and depressed adults. Distance to prefontal cortex is not correlated with {MT,} raising questions about the common practice of dosing prefontal stimulation using {MT} determined over motor cortex.}, number = {5}, journal = {Biological Psychiatry}, author = {Kathleen A. {McConnell} and Ziad Nahas and Ananda Shastri and Jeffrey P. Lorberbaum and F. Andrew Kozel and Daryl E. Bohning and Mark S. George}, month = mar, year = {2001}, keywords = {depression,motor cortex,motor {threshold,MRI,prefrontal} {cortex,Transcranial} magnetic stimulation}, pages = {454--459} }, @article{strens_effects_2002, title = {The effects of subthreshold 1 Hz repetitive {TMS} on cortico-cortical and interhemispheric coherence}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-46C08HT-4/2/4d68e7dca8e920157ea7766a59f96c4e}, doi = {{10.1016/S1388-2457(02)00151-7}}, abstract = { Objectives: Repetitive transcranial magnetic stimulation {(rTMS)} shows promise as a treatment for various movement and psychiatric disorders. Just how {rTMS} may have persistent effects on cortical function remains unclear. We hypothesised that it may act by modulating cortico-cortical and interhemispheric connectivity. To this end we assessed cortico-cortical and interhemispheric coherence before and after low frequency, subthreshold {rTMS} of the left motor cortex. Methods: Fifteen healthy subjects received one train (1 Hz, 90\% of active motor threshold, 1500 stimuli) of {rTMS} to the left motor hand area. Spectral power and coherence estimates were calculated between different electroencephalogram {(EEG)} signals at rest and while muscles of the distal upper limb were tonically contracted. Results: {rTMS} over the left motor hand area caused a significant increase in ipsilateral {EEG-EEG} coherence and in the interhemispheric coherence between motor areas in the alpha band. The effects of {rTMS} lasted up to 25 min post-stimulation. There was no significant change in {EEG-EEG} coherence over the hemisphere contralateral to stimulation. Conclusions: Low frequency, subthreshold {rTMS} of the motor cortex increases ipsilateral cortico-cortical and interhemispheric coherence in the alpha band. This may, in part, mediate the inhibitory effects of low frequency {rTMS.}}, number = {8}, journal = {Clinical Neurophysiology}, author = {Lucy H. A. Strens and Antonio Oliviero and Bastiaan R. Bloem and Willibald Gerschlager and John C. Rothwell and Peter Brown}, month = aug, year = {2002}, keywords = {Cortico-cortical {coherence,Electroencephalogram,Motor} {cortex,Transcranial} magnetic stimulation}, pages = {1279--1285} }, @article{xia_treatment-emergent_2008, title = {{Treatment-Emergent} Mania in Unipolar and Bipolar Depression: Focus on Repetitive Transcranial Magnetic Stimulation}, volume = {11}, url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1630916}, doi = {{10.1017/S1461145707007699}}, number = {01}, journal = {The International Journal of Neuropsychopharmacology}, author = {Guohua Xia and Prashant Gajwani and David J. Muzina and David E. Kemp and Keming Gao and Stephen J. Ganocy and Joseph R. Calabrese}, year = {2008}, pages = {119--130} }, @article{ogiue-ikeda_effect_2003, title = {The effect of repetitive transcranial magnetic stimulation on long-term potentiation in rat hippocampus depends on stimulus intensity}, volume = {993}, number = {1-2}, journal = {Brain Research}, author = {M. {Ogiue-Ikeda} and S. Kawato and S. Ueno}, year = {2003}, pages = {222--226} }, @article{nikouline_role_1999, title = {The role of the coil click in {TMS} assessed with simultaneous {EEG}}, volume = {110}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-3WWVBN3-1/2/414e896043c5b9ff5276938c939d0038}, doi = {{10.1016/S1388-2457(99)00070-X}}, abstract = { Objective: We have used {EEG} to measure effects of air- and bone-conducted sound from the coil in transcranial magnetic stimulation {(TMS).} Methods: Auditory-evoked potentials to {TMS} were recorded in three different experimental conditions: (1) the coil 2 cm above the head, (2) the coil 2 cm above the head but rigidly connected by a plastic piece to the scalp, (3) the coil pressed against the scalp over the motor cortex. Results: The acoustical click from the {TMS} coil evoked large auditory potentials, whose amplitude depended critically on the mechanical contact of the coil with the head. Conclusion: Both air- and bone-conducted sounds have to be taken into account in the design and interpretation of {TMS} experiments.}, number = {8}, journal = {Clinical Neurophysiology}, author = {V. Nikouline and Jarmo Ruohonen and Risto J. Ilmoniemi}, month = aug, year = {1999}, keywords = {Auditory evoked {potentials,Bone} {conduction,Electroencephalography,Transcranial} magnetic stimulation}, pages = {1325--1328} }, @article{lisanby_sham_2001, title = {Sham {TMS:} intracerebral measurement of the induced electrical field and the induction of motor-evoked potentials}, volume = {49}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-42M788C-9/2/2ea2e4931fa094834c7125ea16cac4ea}, doi = {{10.1016/S0006-3223(00)01110-0}}, abstract = { {\%Testing} the therapeutic potential of transcranial magnetic stimulation {(TMS)} in controlled trials requires a valid sham condition. Sham {TMS} is typically administered by tilting the coil 45-90° off the scalp, with one or two wings of the coil touching the scalp. Lack of cortical effects has not been verified. {mWe} compared sham manipulations in their thresholds for eliciting motor-evoked potentials {(MEPs)} in human volunteers and in intracerebral measurements of voltage induced in the prefrontal cortex of a rhesus monkey. {mThree} types of sham (one-wing 45° and 90° and two-wing 90° tilt) induced much lower voltage in the brain than active {TMS} (67-73\% reductions). However, the two-wing 45° sham induced values just 24\% below active {TMS.} This sham was about half as potent in inducing {MEPs} over the motor cortex as active {TMS.} {mSome} sham {TMS} conditions produce substantial cortical stimulation, making it critical to carefully select the sham manipulation for clinical trials.}, number = {5}, journal = {Biological Psychiatry}, author = {Sarah H. Lisanby and David Gutman and Bruce Luber and Charles Schroeder and Harold A. Sackeim}, month = mar, year = {2001}, keywords = {depression,induced current,magnetics,motor threshold {(MT),sham,Transcranial} magnetic stimulation {(TMS)}}, pages = {460--463} }, @article{antal_modulation_2003, title = {Modulation of moving phosphene thresholds by transcranial direct current stimulation of V1 in human}, volume = {41}, issn = {0028-3932}, url = {http://www.sciencedirect.com/science/article/B6T0D-49FR3HB-4/2/75125a5e56b4f66f9d3cfac82ba8a7ad}, doi = {{10.1016/S0028-3932(03)00181-7}}, abstract = { Small moving sensations, so-called moving phosphenes are perceived, when V5, a visual area important for visual motion analysis, is stimulated by transcranial magnetic stimulation {(TMS).} However, it is still a matter of debate if only V5 takes part in movement perception or other visual areas are also involved in this process. In this study we tested the involvement of V1 in the perception of moving phosphenes by applying transcranial direct current stimulation {(tDCS)} to this area. {tDCS} is a non-invasive stimulation technique known to modulate cortical excitability in a polarity-specific manner. Moving and stationary phosphene thresholds {(PT)} were measured by {TMS} before, immediately after and 10, 20 and 30 min after the end of 10 min cathodal and anodal {tDCS} in nine healthy subjects. Reduced {PTs} were detected immediately and 10 min after the end of anodal {tDCS} while cathodal stimulation resulted in an opposite effect. Our results show that the excitability shifts induced by V1 stimulation can modulate moving phosphene perception. {tDCS} elicits transient, but yet reversible effects, thus presenting a promising tool for neuroplasticity research.}, number = {13}, journal = {Neuropsychologia}, author = {Andrea Antal and Tamás Z. Kincses and Michael A. Nitsche and Walter Paulus}, year = {2003}, keywords = {{Human,Phosphenes,Transcranial} direct current {stimulation,Transcranial} magnetic {stimulation,V5,Visual} cortex}, pages = {1802--1807} }, @article{chen_low-frequency_2003, title = {Low-frequency {rTMS} over lateral premotor cortex induces lasting changes in regional activation and functional coupling of cortical motor areas}, volume = {114}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-493HTRY-2/2/ee5687b549aebe88d06fe5a28644d3f2}, doi = {{10.1016/S1388-2457(03)00063-4}}, abstract = { Objective: To study the effect of 0.9 Hz repetitive transcranial magnetic stimulation {(rTMS)} of the lateral premotor cortex on neuronal activity in cortical motor areas during simple motor tasks. Methods: In 8 subjects, electroencephalogram {(EEG)} and electromyogram {(EMG)} were simultaneously recorded during voluntary contractions of the thumb before and after a 15 min train of 0.9 Hz {rTMS} over the left lateral premotor cortex at stimulus intensity of 90\% of active motor threshold. After-effects on cortical motor activity were assessed by measuring the task-related {EEG} power and inter-regional coherence changes, and the {EEG-EMG} coherence {(EMGCoh).} Results: Low-frequency {rTMS} over the premotor cortex gave rise to (i) a reduction of the task-related power decrease in the alpha and beta bands, (ii) a selective increase in the task-related coherence change among cortical motor areas in the upper alpha band, and (iii) a decrease in the cortico-muscular coherence. These effects lasted about 15 min after the end of {rTMS} intervention. Conclusions: The attenuated task-related power changes and decreased {EMGCoh} point to a lasting suppression of voluntary activation of cortical motor areas after {rTMS.} The present data provide an evidence for a transient reorganization of movement-related neuronal activity in the cortical motor areas after 0.9 Hz {rTMS} over the premotor cortex. Significance: Low-frequency {rTMS} changes the regional activation and functional coupling of cortical motor areas as demonstrated by {EEG} analysis.}, number = {9}, journal = {Clinical Neurophysiology}, author = {{Wei-Hung} Chen and Tatsuya Mima and Hartwig R. Siebner and Tatsuhide Oga and Hidemi Hara and Takeshi Satow and Tahamina Begum and Takashi Nagamine and Hiroshi Shibasaki}, month = sep, year = {2003}, keywords = {{Coherence,EEG} power {spectrum,Functional} {reorganization,Motor} cortex {excitability,Premotor} {cortex,Repetitive} transcranial magnetic stimulation}, pages = {1628--1637} }, @article{herwig_spatial_2002, title = {Spatial congruence of neuronavigated transcranial magnetic stimulation and functional neuroimaging}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-45CNHDX-3/2/3c1436e45c17120e9fd7e177baaa32a5}, doi = {{10.1016/S1388-2457(02)00026-3}}, abstract = { Objectives: Transcranial magnetic stimulation {(TMS)} is progressively gaining relevance as a tool in cognitive neuroscience and clinical research. However, most studies in this field do not consider individual anatomy. Neuronavigational devices allow to guide the coil to a specific cortical area, predetermined by functional magnetic resonance imaging {(fMRI).} Therefore, it is crucial to know whether the area of a certain function as identified by {fMRI} corresponds to the area where the {TMS} should be placed in order to influence this function. Methods: We investigated the spatial relation between the cortical area activated by a motor task in {fMRI} and the area of magnetically evoked motor potentials {(MEP)} in 8 subjects, using a spacing of 5×5 mm. A neuronavigational system was adapted for coil positioning and for the registration of the stimulation coordinates. Results: A spatial divergence of the centers of gravity from {fMRI} and {MEP} was found with a mean distance of about 10 mm, with the {MEP} centers being, by a mean derivation of 7.5 mm, consistently anterior to the center of {fMRI} activation. However, regarding {MEP} areas and {fMRI} activities, a large overlap was found for stimulation intensities of both 110 and 120\% motor threshold. Conclusions: The combination of {fMRI} and neuronavigated {TMS} is useful for non-invasive investigation of individual cortical functions predetermined by {fMRI.} Whereas both are spatially by and large congruent, discrepencies in the exact spatial relation between {MEP} and {fMRI} areas should be considered and further studied.}, number = {4}, journal = {Clinical Neurophysiology}, author = {Uwe Herwig and Klaus Kölbel and Arthur P. Wunderlich and Axel Thielscher and Cyrill von Tiesenhausen and Manfred Spitzer and Carlos {Schönfeldt-Lecuona}}, month = apr, year = {2002}, keywords = {Functional magnetic resonance {imaging,Motor} {cortex,Motor} {mapping,Neuronavigation}}, pages = {462--468} }, @article{wu_modification_2000, title = {Modification of the silent period by double transcranial magnetic stimulation}, volume = {111}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-419BFX0-R/2/341208fec3b42b1879c025f2122b68b6}, doi = {{10.1016/S1388-2457(00)00426-0}}, abstract = { Objectives: To study the time course of the changes of the inhibitory network of the human motor system, we investigated the silent period {(SP)} in 7 healthy subjects by double suprathreshold transcranial magnetic stimulation {(TMS).} Methods: {SPs} and motor evoked potentials {(MEPs)} were recorded from the voluntarily activated right abductor digiti minimi muscle. Conditioning and test stimuli were delivered with equal intensity, which was set to yield a baseline {SP} duration of 130 ms by a single pulse, and with various interstimulus intervals {(ISIs).} In addition, a control experiment with adjustment of the intensity of single stimuli was performed. Results: At {ISIs} of 20 and 30 ms the test pulse {SP} duration was prolonged, without increasing the {MEP} amplitude. The {SP} duration shortened at longer {ISIs} and showed a significant depression between {ISIs} of 60-110 ms. The shortened {SP} was accompanied by a diminished {MEP.} The control experiment revealed that the {SPs} evoked by the adjusted pulses were significantly shorter than the test pulse {SPs.} Conclusions: A conditioning stimulus can prolong and shorten the test pulse {SP} duration at different {ISIs.} The prolongation is probably cortically generated, whereas the shortening is likely to occur at a cortical and spinal level.}, number = {10}, journal = {Clinical Neurophysiology}, author = {Tao Wu and Martin Sommer and Frithjof Tergau and Walter Paulus}, month = oct, year = {2000}, keywords = {Double transcranial magnetic {stimulation,Inhibitory} {system,Motor} {cortex,Silent} period}, pages = {1868--1872} }, @article{zwanzger_occurrence_2002, title = {Occurrence of delusions during repetitive transcranial magnetic stimulation {(rTMS)} in major depression}, volume = {51}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-45HVDJC-9/2/5c42dbdf4e3399208d155e73c9b81e25}, doi = {{10.1016/S0006-3223(01)01369-5}}, abstract = { Background: Repetitive transcranial magnetic stimulation {(rTMS)} has been suggested as a potentially useful treatment for major depression. Nonpsychotic depressed patients appear to have a better outcome than those with psychotic symptoms. Methods: We report findings in a patient suffering from recurrent, nonpsychotic major depression {(DSM-IV)} who had 13 daily sessions of {rTMS} monotherapy within a 3 week period. Results: During {rTMS} treatment, the patient developed recurrent severe delusions, which he had never experienced before. Psychotic symptoms remitted quickly with neuroleptic medication. Conclusions: In light of preclinical findings showing increased dopaminergic activity after {rTMS} treatment, occurrence of psychotic symptoms should be considered a potential side effect of {rTMS} treatment.}, number = {7}, journal = {Biological Psychiatry}, author = {Peter Zwanzger and Robin Ella and Martin E. Keck and Rainer Rupprecht and Frank Padberg}, month = apr, year = {2002}, keywords = {delusions,depression,dopamine,psychotic {symptoms,rTMS}}, pages = {602--603} }, @article{shaldivin_transcranial_2001, title = {Transcranial magnetic stimulation in an amphetamine hyperactivity model of mania}, volume = {3}, number = {1}, journal = {Bipolar Disorders}, author = {A. Shaldivin and A. Kaptsan and R. H. Belmaker and H. Einat and N. Grisaru}, year = {2001}, pages = {30--34} }, @article{konstantinidis_rapid_2002, title = {Rapid transcranial magnetic stimulation {(r-TMS):} A novel treatment option for seasonal affective disorder {(SAD)?}}, volume = {12}, number = {1003}, journal = {European Neuropsychopharmacology}, author = {A. Konstantinidis and A. Heiden and J. Stastny and C. Baecker and M. Letmaier and D. Winkler and A. Neumeister and S. Kasper}, year = {2002}, pages = {252--252} }, @article{kessels_spatial_2000, title = {Spatial working memory performance after high-frequency repetitive transcranial magnetic stimulation of the left and right posterior parietal cortex in humans}, volume = {287}, issn = {0304-3940}, url = {http://www.sciencedirect.com/science/article/B6T0G-4182FD6-M/2/6b99903877133490105c385ab9182ffe}, doi = {{10.1016/S0304-3940(00)01146-0}}, abstract = { The effects of high-frequency repetitive transcranial magnetic stimulation {(rTMS)} at the left or right posterior parietal cortex were studied using a spatial working memory task. Eight subjects were stimulated over the P3 and P4 electrode site at 115\% of the motor threshold (frequency 25 Hz, trains of 200 ms) during the 1000-ms delay of the spatial working memory task, or received sham stimulation. It was found that the reaction times were slower during right-parietal {rTMS} than during left-parietal {rTMS.} No differences were found between the percentages correct responses. These results are in line with recent neuroimaging findings and data from patients with cerebral lesions, suggesting that the posterior parietal cortex is especially involved in spatial processing, and provide converging evidence for recent theories on hemispheric specialization.}, number = {1}, journal = {Neuroscience Letters}, author = {Roy P. C. Kessels and Alfredo A. L. {d'Alfonso} and Albert Postma and Edward H. F. de Haan}, month = jun, year = {2000}, keywords = {{Consolidation,Coordinate} {processing,Encoding,Lateralization,Posterior} parietal {cortex,Spatial} working {memory,Transcranial} magnetic stimulation}, pages = {68--70} }, @article{molinuevo_effect_2000, title = {The effect of transcranial magnetic stimulation on reaction time in progressive supranuclear palsy}, volume = {111}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-41JTNGT-J/2/3ee4e9cb00482895b096399a03402e42}, doi = {{10.1016/S1388-2457(00)00443-0}}, abstract = { Objective: Reaction time is shortened when a startling acoustic stimulus {(SAS)} is delivered together with the [`]go' signal in normal subjects and patients with Parkinson's disease {(IPD),} but not in patients with progressive supranuclear palsy {(PSP).} Similar shortening of reaction time has been reported in normal subjects and patients with {IPD} with transcranial magnetic stimulation {(TMS).} In this paper, we analyzed the effect of {TMS} on reaction time in patients with {PSP.} Methods: Six patients with {PSP} received the instruction to extend the wrist to a visual cue. In test trials, the visual signal was accompanied by either a {SAS} or a subthreshold {TMS} applied to the motor area. The same experimental paradigm was applied to 7 patients with {IPD,} and 10 normal subjects. We measured both reaction time and the slope of the initial accelerometric displacement {(SAD).} Results: Neither {TMS} nor {SAS} changed significantly reaction time in {PSP} patients. This observation was in contrast with the marked reaction time shortening induced by both stimuli in a similar amount in normal subjects and patients with {IPD.} Furthermore, {SAS} and {TMS} did not modify the {SAD} in {PSP,} but shortened it significantly in {IPD.} Conclusion: The absence of an effect of {TMS} and {SAS} on reaction time in {PSP} patients suggests that these patients have a dysfunction in the mechanisms of facilitation of reaction time. The fact that {TMS} and {SAS} induced similar effects on reaction time in normal subjects, {IPD} and {PSP} patients indicate the possibility of common mechanisms of action for both types of stimuli.}, number = {11}, journal = {Clinical Neurophysiology}, author = {José L. Molinuevo and Josep {Valls-Solé} and Francesc Valldeoriola}, month = nov, year = {2000}, keywords = {Parkinson's {disease,Progressive} supranuclear {palsy,Reaction} {time,Startling} acoustic {stimulus,Transcranial} magnetic stimulation}, pages = {2008--2013} }, @article{carroll_reliability_2001, title = {Reliability of the input-output properties of the cortico-spinal pathway obtained from transcranial magnetic and electrical stimulation}, volume = {112}, issn = {0165-0270}, url = {http://www.sciencedirect.com/science/article/B6T04-45MCKN2-C/2/515536f44a0e386c31ebbb962a0d8a24}, doi = {{10.1016/S0165-0270(01)00468-X}}, abstract = { The purpose of this experiment was to assess the test-retest reliability of input-output parameters of the cortico-spinal pathway derived from transcranial magnetic {(TMS)} and electrical {(TES)} stimulation at rest and during muscle contraction. Motor evoked potentials {(MEPs)} were recorded from the first dorsal interosseous muscle of eight individuals on three separate days. The intensity of {TMS} at rest was varied from 5\% below threshold to the maximal output of the stimulator. During trials in which the muscle was active, {TMS} and {TES} intensities were selected that elicited {MEPs} of between 150 and 300 {[mu]V} at rest. {MEPs} were evoked while the participants exerted torques up to 50\% of their maximum capacity. The relationship between {MEP} size and stimulus intensity at rest was sigmoidal {(R2=0.97).} Intra-class correlation coefficients {(ICC)} ranged between 0.47 and 0.81 for the parameters of the sigmoid function. For the active trials, the slope and intercept of regression equations of {MEP} size on level of background contraction were obtained more reliably for {TES} {(ICC=0.63} and 0.78, respectively) than for {TMS} {(ICC=0.50} and 0.53, respectively). These results suggest that input-output parameters of the cortico-spinal pathway may be reliably obtained via transcranial stimulation during longitudinal investigations of cortico-spinal plasticity.}, number = {2}, journal = {Journal of Neuroscience Methods}, author = {Timothy J. Carroll and Stephan Riek and Richard G. Carson}, month = dec, year = {2001}, keywords = {Cortical {excitability,Motor} evoked {potentials,Reliability,TES,TMS}}, pages = {193--202} }, @article{loo_transcranial_2000, title = {Transcranial magnetic stimulation {(TMS)} in controlled treatment studies: are some "sham" forms active?}, volume = {47}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-3YMFKRF-7/2/7efe78f8d0881103caff1fc971d014f2}, doi = {{10.1016/S0006-3223(99)00285-1}}, abstract = { Background: Carefully designed controlled studies are essential in further evaluating the therapeutic efficacy of transcranial magnetic stimulation {(TMS)} in psychiatric disorders. A major methodological concern is the design of the "sham" control for {TMS.} An ideal sham would produce negligible cortical stimulation in conjunction with a scalp sensation akin to real treatment. Strategies employed so far include alterations in the position of the stimulating coil, but there has been little systematic study of their validity. In this study, we investigated the effects of different coil positions on cortical activation and scalp sensation. Methods: In nine normal subjects, single {TMS} pulses were administered at a range of intensities with a "figure eight" coil held in various positions over the left primary motor cortex. Responses were measured as motor-evoked potentials in the right first dorsal interosseus muscle. Scalp sensation to {TMS} with the coil in various positions over the prefrontal area was also assessed. Results: None of the coil positions studied met the criteria for an ideal sham. Arrangements associated with a higher likelihood of scalp sensation were also more likely to stimulate the cortex. Conclusions: The choice of a sham for {TMS} involves a trade-off between effective blinding and truly inactive "stimulation." Further research is needed to develop the best sham condition for a range of applications.}, number = {4}, journal = {Biological Psychiatry}, author = {Colleen K. Loo and Janet L. Taylor and Simon C. Gandevia and Benjamin N. {McDarmont} and Philip B. Mitchell and Perminder S. Sachdev}, month = feb, year = {2000}, keywords = {brain,motor cortex,prefrontal {cortex,psychiatry,Transcranial} magnetic stimulation,treatment}, pages = {325--331} }, @article{schambra_modulation_2003, title = {Modulation of excitability of human motor cortex {(M1)} by 1 Hz transcranial magnetic stimulation of the contralateral M1}, volume = {114}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-47F19T3-N/2/de9459c1d967d0e2e86d2e0ecf4654ec}, doi = {{10.1016/S1388-2457(02)00342-5}}, abstract = { Objective: Previous studies demonstrated that single-pulse transcranial magnetic stimulation {(TMS)} of one motor cortex {(M1)} exerts a brief inhibitory effect on the contralateral M1. The purpose of this study was to test the hypothesis that 30 min of 1 Hz {TMS} of M1 will result in a lasting increase in excitability in the contralateral M1. Methods: Healthy volunteers were tested on 2 separate days, before (baseline) and after one of two interventions: (a) stimulation of M1 with 1 Hz {TMS} for 30 min at 115\% of resting motor threshold, and (b) sham stimulation. Recruitment curves to {TMS,} pinch force, and simple reaction time were assessed in the hand contralateral to the unstimulated motor cortex. Results: The main finding of this study was that 30 min of 1 Hz significantly increased recruitment curves in the contralateral motor cortex in the real stimulation condition relative to sham {(P{\textless}0.005,} factorial analysis of variance {(ANOVA)).} This change outlasted the stimulation period for at least 15 min and occurred in the absence of changes in pinch force or reaction time. Conclusions: These results raise the potential for inducing lasting modulation of excitability in M1 by 1 Hz {TMS} of the other M1, a phenomenon possibly reflecting modulation of interhemispheric interactions. Significance: It is conceivable that 1 Hz {TMS} applied to M1 may be used to modulate excitability in the opposite motor cortex for therapeutic purposes.}, number = {1}, journal = {Clinical Neurophysiology}, author = {H. M. Schambra and L. Sawaki and L. G. Cohen}, year = {2003}, keywords = {{Excitability,Motor} {system,Physiology,Transcranial} magnetic stimulation}, pages = {130--133} }, @article{hong_visual_2000, title = {Visual working memory revealed by repetitive transcranial magnetic stimulation}, volume = {181}, issn = {{0022-510X}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/11099712}, abstract = {We evaluated whether repetitive transcranial magnetic stimulation {(rTMS)} could be utilized for studying the hemispheric lateralization and anatomical localization of the cortical areas of the visual system that are concerned with object-related visual working memory. In eight normal volunteers, visual working memory was tested during {rTMS} delivery over nine regions in each hemisphere. Visual working memory was significantly disturbed by {rTMS} over the right hemisphere compared with the left {(P{\textless}0.05).} The disturbance in visual working memory by {rTMS} was significant over the right inferior frontal {(F8),} inferior temporal {(T8),} and middle parietal {(P4)} areas compared with the control region {(P{\textless}0.05).} This study suggests that visual working memory is lateralized to the right hemisphere and localized in the right inferior frontal, inferior temporal, and middle-parietal areas. As a non-invasive tool, {rTMS} may be useful for the functional localization of the working memory system.}, number = {1-2}, journal = {Journal of the Neurological Sciences}, author = {K S Hong and S K Lee and J Y Kim and K K Kim and H Nam}, month = dec, year = {2000}, note = {{PMID:} 11099712}, keywords = {{Adult,Cerebral} {Cortex,Electric} {Stimulation,Functional} {Laterality,Male,Memory,} {Short-Term,Neuropsychological} {Tests,Psychomotor} {Performance,Transcranial} Magnetic {Stimulation,Visual} {Pathways,Visual} Perception}, pages = {50--5} }, @article{foltys_motor_2003, title = {Motor representation in patients rapidly recovering after stroke: a functional magnetic resonance imaging and transcranial magnetic stimulation study}, volume = {114}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-49H0XSH-4/2/497953c6b21507a5ac78f058a17defbb}, doi = {{10.1016/S1388-2457(03)00263-3}}, abstract = { Objective: Neuroimaging studies have suggested an evolution of the brain activation pattern in the course of motor recovery after stroke. Initially poor motor performance is correlated with an recruitment of the uninjured hemisphere that continuously vanished until a nearly normal (contralateral) activation pattern is achieved and motor performance is good. Here we were interested in the early brain activation pattern in patients who showed a good and rapid recovery after stroke. Methods: Ten patients with first-ever ischemic stroke affecting motor areas had to perform self-paced simple or more complex movements with the affected or the unaffected hand during functional magnetic resonance imaging {(fMRI).} The location and number of activated voxels above threshold were determined. To study possible changes in the cortical motor output map the amplitude of the motor evoked potentials {(MEP)} and the extent of the excitable area were determined using transcranial magnetic stimulation {(TMS).} Results: The pattern of activation observed with movements of the affected and the unaffected hand was similar. In the simple motor task significant {(P{\textless}0.05)} increases were found in the primary motor cortex ipsilateral to the movement, the supplementary motor area and the cerebellar hemisphere contralateral to the movement during performance with the affected hand compared to movements with the unaffected hand. When comparing simple with more complex movements performed with either the affected or the unaffected hand, a further tendency to increased activation in motor areas was observed. The amplitude of {MEPs} obtained from the affected hemisphere was smaller and the extent of cortical output maps was decreased compared to the unaffected hemisphere; but none of the patients showed {MEPs} at the affected hand when the ipsilateral unaffected motor cortex was stimulated. Conclusions: Despite a rapid and nearly complete motor recovery the brain activation pattern was associated with increased activity in (bilateral) motor areas as revealed with {fMRI.} {TMS} revealed impaired motor output properties, but failed to demonstrate ipsilateral motor pathways. Successful recovery in our patients may therefore rely on the increased bilateral activation of existing motor networks spared by the injury.}, number = {12}, journal = {Clinical Neurophysiology}, author = {Henrik Foltys and Timo Krings and Ingo G. Meister and Roland Sparing and Babak Boroojerdi and Armin Thron and Rudolf Töpper}, month = dec, year = {2003}, keywords = {Functional magnetic resonance {imaging,Motor} {recovery,Stroke,Transcranial} magnetic stimulation}, pages = {2404--2415} }, @article{kammer_influence_2001, title = {The influence of current direction on phosphene thresholds evoked by transcranial magnetic stimulation}, volume = {112}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-448YK7H-5/2/b6388214c3e9a7f9c93b655c3522657f}, doi = {{10.1016/S1388-2457(01)00673-3}}, abstract = { Objectives: To quantify phosphene thresholds evoked by transcranial magnetic stimulation {(TMS)} in the occipital cortex as a function of induced current direction. Methods: Phosphene thresholds were determined in 6 subjects. We compared two stimulator types {(Medtronic-Dantec} and Magstim) with monophasic pulses using the standard figure-of-eight coils and systematically varied hemisphere (left and right) and induced current direction (latero-medial and medio-lateral). Each measurement was made 3 times, with a new stimulation site chosen for each repetition. Only those stimulation sites were investigated where phosphenes were restricted to one visual hemifield. Coil positions were stereotactically registered. Functional magnetic resonance imaging {(fMRI)} of retinotopic areas was performed in 5 subjects to individually characterize the borders of visual areas; {TMS} stimulation sites were coregistered with respect to visual areas. Results: Despite large interindividual variance we found a consistent pattern of phosphene thresholds. They were significantly lower if the direction of the induced current was oriented from lateral to medial in the occipital lobe rather than vice versa. No difference with respect to the hemisphere was found. Threshold values normalized to the square root of the stored energy in the stimulators were lower with the {Medtronic-Dantec} device than with the Magstim device. {fMRI} revealed that stimulation sites generating unilateral phosphenes were situated at V2 and V3. Variability of phosphene thresholds was low within a cortical patch of 2×2 cm2. Stimulation over V1 yields phosphenes in both visual fields. Conclusions: The excitability of visual cortical areas depends on the direction of the induced current with a preference for latero-medial currents. Although the coil positions used in this study were centered over visual areas V2 and V3, we cannot rule out the possibility that subcortical structures or V1 could actually be the main generator for phosphenes.}, number = {11}, journal = {Clinical Neurophysiology}, author = {Thomas Kammer and Sandra Beck and Michael Erb and Wolfgang Grodd}, month = nov, year = {2001}, keywords = {Functional magnetic resonance {imaging,Human} visual {cortex,Phosphenes,Retinotopic} {map,Threshold,TMS}}, pages = {2015--2021} }, @article{liebetanz_safety_2003, title = {Safety aspects of chronic low-frequency transcranial magnetic stimulation based on localized proton magnetic resonance spectroscopy and histology of the rat brain}, volume = {37}, issn = {0022-3956}, url = {http://www.sciencedirect.com/science/article/B6T8T-4840JFB-5/2/7b40751de637ed9625c6700b94bcdc6e}, doi = {{10.1016/S0022-3956(03)00017-7}}, abstract = { Because repetitive transcranial magnetic stimulation {(rTMS)} is capable of inducing lasting alterations of cortical excitability, it represents a promising therapeutic tool in several neuropsychiatric disorders. However, {rTMS,} especially when applied chronically, may cause harmful effects in the stimulated tissue. To study the safety of chronic {rTMS} we used a novel small stimulation coil, which was specially designed to treat rats, and investigated brain tissue using in vivo localized proton magnetic resonance spectroscopy {(MRS)} and post mortem histological analysis. Histology was based on a modified stereology method in combination with immunohistochemistry applying antibodies against {OX-6,} {OX-42,} {ED,} and {GFAP} to detect any microglial and/or astrocytic activation 48 h after the last {TMS} session. Conscious rats were treated with a daily suprathreshold {rTMS} regimen of 1000 stimuli applied on 5 consecutive days at a frequency of 1 Hz. In comparison with control animals receiving magnetic stimulation over the lumbar spine, quantitative evaluations of cerebral metabolite concentrations by proton {MRS} revealed no significant alterations of N-acetyl-aspartate, creatine and phosphocreatine, choline-containing compounds, myo-inositol, glucose and lactate after chronic {rTMS.} Similarly to the in vivo results, post mortem histology revealed no changes in microglial and astrocytic activation after {rTMS.} In conclusion, these data provide support for the safety of chronic {rTMS.} However, they do not exclude acute changes on neurotransmitters systems or other physiologic responses during or directly after the {rTMS} treatment.}, number = {4}, journal = {Journal of Psychiatric Research}, author = {David Liebetanz and Susanne Fauser and Thomas Michaelis and Boldizsár Czéh and Takashi Watanabe and Walter Paulus and Jens Frahm and Eberhard Fuchs}, year = {2003}, keywords = {Brain {metabolites,Cell} {counting,Glia,Proton} {MR} {spectroscopy,Rat,TMS}}, pages = {277--286} }, @article{herwig_311._2000, title = {311. Neuronavigated transcranial magnetic stimulation in depression}, volume = {47}, number = {{8S1}}, journal = {Biological Psychiatry}, author = {U. Herwig and C. Schönfeldt Lecuona and M. Spitzer}, year = {2000}, pages = {94--94} }, @article{kemna_repetitive_2003, title = {Repetitive transcranial magnetic stimulation induces different responses in different cortical areas: a functional magnetic resonance study in humans}, volume = {336}, issn = {0304-3940}, url = {http://www.sciencedirect.com/science/article/B6T0G-47F7G0W-8/2/701e372f5727134ab7443c95e0b76d2a}, doi = {{10.1016/S0304-3940(02)01195-3}}, abstract = { Repetitive transcranial magnetic stimulation {(TMS)} for 1 s at 4 Hz and 150\% of the individual motor threshold was applied to primary motor cortex and adjacent cortical regions where no motor response could be produced. The hemodynamic reaction was measured using an event-related functional magnetic resonance setup. While all volunteers showed a typical signal increase beneath the coil during motor cortex stimulation, no consistent signal changes were present during frontal or parietal stimulation apart from activation of auditory cortex. The results suggest that neuronal stimulation by {TMS} is followed by an inhibitive phase that compensates for the effect of an initial neuronal activation. It is further concluded that the signal increases during motor cortex fit a sensory feedback from the moving body parts.}, number = {2}, journal = {Neuroscience Letters}, author = {Lars Johann Kemna and Daniel Gembris}, year = {2003}, keywords = {{BOLD} {signal,Frontal} {cortex,Functional} magnetic resonance {imaging,Parietal} {cortex,Sensorimotor} {cortex,Transcranial} magnetic stimulation}, pages = {85--88} }, @article{chen_plasticity_2003, title = {Plasticity of the human motor system following muscle reconstruction: a magnetic stimulation and functional magnetic resonance imaging study}, volume = {114}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-49WG3P3-2/2/c29da8f7dc6798d03ca68b733e4157ad}, doi = {{10.1016/S1388-2457(03)00283-9}}, abstract = { Objective: Although motor system plasticity in response to neuromuscular injury has been documented, few studies have examined recovered and functioning muscles in the human. We examined brain changes in a group of patients who had a muscle transfer. Methods: Transcranial magnetic stimulation {(TMS)} was used to study a unique group of 9 patients who had upper extremity motor function restored using microneurovascular transfer of the gracilis muscle. The findings from the reconstructed muscle were compared to the homologous muscle of the intact arm. One patient was also studied with functional magnetic resonance imaging {(fMRI).} Results: {TMS} showed that the motor threshold and short interval intracortical inhibition was reduced on the transplanted side while at rest but not during muscle activation. The difference in motor threshold decreased with the time since surgery. {TMS} mapping showed no significant difference in the location and size of the representation of the reconstructed muscle in the motor cortex compared to the intact side. In one patient with reconstructed biceps muscle innervated by the intercostal nerves, both {TMS} mapping and {fMRI} showed that the upper limb area rather than the trunk area of the motor cortex controlled the reconstructed muscle. Conclusions: Plasticity occurs in cortical areas projecting to functionally relevant muscles. Changes in the neuronal level are not necessarily accompanied by changes in motor representation. Brain reorganization may involve multiple processes mediated by different mechanisms and continues to evolve long after the initial injury. Significance: Central nervous system plasticity following neuromuscular injury may have functional relevance.}, number = {12}, journal = {Clinical Neurophysiology}, author = {Robert Chen and Dimitri J. Anastakis and Catherine T. Haywood and David J. Mikulis and Ralph T. Manktelow}, month = dec, year = {2003}, keywords = {Functional magnetic resonance {imaging,Injury,Magnetic} {stimulation,Motor} {cortex,Plasticity,Repair}}, pages = {2434--2446} }, @article{dolberg_transcranial_2001, title = {Transcranial magnetic stimulation-induced switch into mania: a report of two cases}, volume = {49}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-42M788C-C/2/43ed61c97b7b1d1ac129bc157b4f48bd}, doi = {{10.1016/S0006-3223(00)01086-6}}, abstract = { {Background:Transcranial} magnetic stimulation is a novel, experimental procedure in the treatment of psychiatric disorders, most notably mood disorders. Transcranial magnetic stimulation is currently being widely studied in other applications, and its efficacies and potential side effects are being investigated. {Methods:Transcranial} magnetic stimulation was administered five times a week for 4 weeks. {Results:In} this report, a manic episode followed treatment with transcranial magnetic stimulation in two patients. {Conclusions:Clinicians} should be aware that, like with other antidepressive treatments, a switch into mania might complicate treatment with transcranial magnetic stimulation in bipolar patients.}, number = {5}, journal = {Biological Psychiatry}, author = {Ornah T. Dolberg and Shaul Schreiber and Leon Grunhaus}, month = mar, year = {2001}, keywords = {antidepressants-adverse effects,bipolar affective disorder,major depressive {disorder,Transcranial} magnetic stimulation}, pages = {468--470} }, @article{satow_nausea_2002, title = {Nausea as a complication of low-frequency repetitive transcranial magnetic stimulation of the posterior fossa}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-46H6M0J-B/2/034ecb8ae349b30fe3c35ef9dbefd1ba}, doi = {{10.1016/S1388-2457(02)00187-6}}, abstract = { Background: Transcranial magnetic stimulation {(TMS)} can non-invasively investigate the function of human brain. However, it can induce a focal pain at the stimulated site on the scalp or seizures when applied with high frequency ({\textgreater}1 Hz). Here we report an induction of nausea as a complication of low-frequency repetitive {TMS} {(rTMS)} of the cerebellum. Subjects and methods: Eight right-handed normal volunteers underwent low-frequency (0.9 Hz) {rTMS} of the right cerebellum. The stimulus intensity was set at 90\% of the resting motor threshold determined by {TMS} to motor cortex. Results: Nausea lasted as long as 10 min after the end of {rTMS} without apparent neurological deficit in two subjects. This symptom was replicated when the same protocol was applied on a different day in the same subjects. Conclusions: Low-frequency {rTMS} of cerebellum is still a safe procedure, but the experimenters should keep in mind the possibility of inducing nausea.}, number = {9}, journal = {Clinical Neurophysiology}, author = {Takeshi Satow and Tatsuya Mima and Hidemi Hara and Tatsuhide Oga and Akio Ikeda and Nobuo Hashimoto and Hiroshi Shibasaki}, month = sep, year = {2002}, keywords = {{Cerebellum,Complication,Low} {frequency,Nausea,Repetitive} transcranial magnetic stimulation}, pages = {1441--1443} }, @article{shimizu_modulation_1999, title = {Modulation of intracortical excitability for different muscles in the upper extremity: paired magnetic stimulation study with focal versus non-focal coils}, volume = {110}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-43MKB85-V/2/7ab5e45914474a920b500bdfbca95a0f}, doi = {{10.1016/S1388-2457(98)00081-9}}, abstract = { Objective: Intracortical excitability was studied for 4 muscles in the upper extremity by paired transcranial magnetic stimulation on the motor cortex, using focal and non-focal coils. Methods: Surface {EMG} responses of two hand and two forearm muscles were simultaneously recorded in 13 healthy subjects, after delivering paired stimuli at interstimulus intervals {(ISIs)} of 1-50 ms using circular and figure-of-8 (focal) coils. The intensities of conditioning and test stimuli were submotor and supramotor thresholds, respectively. Results: Paired stimulation using a circular coil showed constant inhibition at 2 ms {ISI} for all muscles, but not at 5 ms {ISI,} and induced facilitation at 10 ms {ISI.} The results using a focal coil were similar to those with a circular coil at all {ISIs} except at 5 ms {ISI,} where the former showed inhibition. At 20 and 30 ms {ISIs,} there was interindividual variability for both coils, some subjects showing inhibition and others facilitation. Conclusions: The difference of the inhibition at 5 ms {ISI} between using circular and focal coils could be attributed to the cortical mechanism. The inhibitory effect at 2 ms {ISI,} consistently observed for the 4 muscles with both types of coil, could be easily applied to assess the inhibitory intracortical function in patients with neurological diseases.}, number = {3}, journal = {Clinical Neurophysiology}, author = {T. Shimizu and M. M. Filippi and M. G. Palmieri and M. Oliveri and F. Vernieri and P. Pasqualetti and P. M. Rossini}, month = mar, year = {1999}, keywords = {Human motor {cortex,Intracortical} {facilitation,Intracortical} {inhibition,Paired} transcranial magnetic {stimulation,Pyramidal} tract neurons}, pages = {575--581} }, @article{stewart_motor_2001, title = {Motor and phosphene thresholds: a transcranial magnetic stimulation correlation study}, volume = {39}, issn = {0028-3932}, url = {http://www.sciencedirect.com/science/article/B6T0D-427JW9G-B/2/d4bc028ed8835a08abc23568ac9cdf8b}, doi = {{10.1016/S0028-3932(00)00130-5}}, abstract = { Objective: To investigate the stability of visual phosphene thresholds and to assess whether they correlate with motor thresholds. Background: Currently, motor threshold is used as an index of cortical sensitivity so that in transcranial magnetic stimulation {(TMS)} experiments, intensity can be set at a given percentage of this value. It is not known whether this is a reasonable index of cortical sensitivity in non-motor and hence whether it should be used in experiments where other cortical areas are targeted. Previous studies have indicated that phosphene threshold might be a suitable alternative in {TMS} studies of the visual system. Method: Using single pulse {TMS} visual phosphene and motor thresholds were measured in 15 subjects. Both thresholds were retested in seven of these subjects a week later. Result: Visual phosphene thresholds, though stable within subjects across the two sessions, showed greater variability than motor thresholds. There was no correlation between the two measures. Conclusion: {TMS} motor thresholds cannot be assumed to be a guide to visual cortex excitability and by extension are probably an inappropriate guide to the cortical excitability of other non-motor areas of the brain. Phosphene thresholds are proposed as a potential standard for inter-individual comparison in visual {TMS} experiments.}, number = {4}, journal = {Neuropsychologia}, author = {L. M. Stewart and V. Walsh and J. C. Rothwell}, year = {2001}, keywords = {Motor {threshold,Phosphene} {threshold,Transcranial} magnetic stimulation}, pages = {415--419} }, @article{kimbrell_left_2002, title = {Left prefrontal-repetitive transcranial magnetic stimulation {(rTMS)} and regional cerebral glucose metabolism in normal volunteers}, volume = {115}, issn = {0925-4927}, url = {http://www.sciencedirect.com/science/article/B6TBW-46MBFS7-2/2/b0a1369a3a9bc4fdffc4e897a4347780}, doi = {{10.1016/S0925-4927(02)00041-0}}, abstract = { Repetitive transcranial magnetic stimulation {(rTMS)} holds promise as a probe into the pathophysiology and possible treatment of neuropsychiatric disorders. To explore its regional effects, we combined {rTMS} with positron emission tomography {(PET).} Fourteen healthy volunteers participated in a baseline 18-fluorodeoxyglucose {(FDG)} {PET} scan. During a second {FDG} infusion on the same day, seven subjects received 30 min of 1 Hz {rTMS} at 80\% of motor threshold to left prefrontal cortex, and seven other subjects received sham {rTMS} under identical conditions. Global and normalized regional cerebral glucose metabolic rates {(rCMRglu)} from the active and sham conditions were compared to baseline and then to each other. Sham, but not active 1 Hz {rTMS,} was associated with significantly increased global {CMRglu.} Compared to baseline, active {rTMS} induced normalized decreases in {rCMRglu} in right prefrontal cortex, bilateral anterior cingulate, basal ganglia {(L{\textgreater}R),} hypothalamus, midbrain, and cerebellum. Increases in {rCMRglu} were seen in bilateral posterior temporal and occipital cortices. Sham {rTMS} compared to baseline resulted in isolated normalized decreases in {rCMRglu} in left dorsal anterior cingulate and left basal ganglia, and increases in posterior association and occiptal regions. Differences between the 1 Hz active versus sham changes from baseline revealed that active {rTMS} induced relative decrements in {rCMRglu} in the left superior frontal gyrus and increases in the cuneus {(L{\textgreater}R).} One Hertz {rTMS} at 80\% motor threshold over the left prefrontal cortex in healthy subjects compared to sham {rTMS} in another group (each compared to baseline) induced an area of decreased normalized left prefrontal {rCMRglu} not directly under the stimulation site, as well as increases in occipital cortex. While these results are in the predicted direction, further studies using other designs and higher intensities and frequencies of {rTMS} are indicated to better describe the local and distant changes induced by {rTMS.}}, number = {3}, journal = {Psychiatry Research: Neuroimaging}, author = {Timothy A. Kimbrell and Robert T. Dunn and Mark S. George and Aimee L. Danielson and Mark W. Willis and Jennifer D. Repella and Brenda E. Benson and Peter Herscovitch and Robert M. Post and Eric M. Wassermann}, month = oct, year = {2002}, keywords = {{Neurocircuitry,Positron} emission {tomography,Prefrontal} {cortex,rCMRglu,rTMS}}, pages = {101--113} }, @article{stewart_role_2001, title = {The role of transcranial magnetic stimulation {(TMS)} in studies of vision, attention and cognition}, volume = {107}, issn = {0001-6918}, url = {http://www.sciencedirect.com/science/article/B6V5T-42VM8R7-F/2/638727a32085b7b64b2291245b1200c4}, doi = {{10.1016/S0001-6918(01)00035-X}}, number = {1-3}, journal = {Acta Psychologica}, author = {Lauren Stewart and Amanda Ellison and Vincent Walsh and Alan Cowey}, month = apr, year = {2001}, keywords = {Magnetic {stimulation,Phosphenes,Plasticity,Speech} {arrest,Virtual} {lesions,Vision}}, pages = {275--291} }, @article{kojima_excitation_1999, title = {The excitation site of the accessory nerve to the magnetic stimulation - the relationship between the orientation of the magnetic field and the excitation site}, volume = {110}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-3WRJPRJ-C/2/5bcd6f8ede116dc7cd110720bad9bdfc}, doi = {{10.1016/S1388-2457(99)00050-4}}, abstract = { Objective: The relationship between the accessory nerve excitation site and the magnetic field direction was investigated to prove whether the cranial nerve excitation site to the transcranial magnetic stimulation is constant or not. Methods: Compound muscle action potentials {(CMAPs)} elicited by the transcranial magnetic stimulation were recorded from the trapezius muscles of 7 adult cats. The waveforms of {CMAPs} were detected before craniectomy, after craniectomy, and after cutting the accessory nerve at the C1, at the jugular tubercle, and at the jugular foramen. The optimal orientation was determined by rotating the coil clockwise in increments of 22.5° from the rostral direction. Results: The accessory nerve was stimulated by the magnetic stimulation at the C1, at the jugular tubercle or at the jubular foramen, and these excitation sites varied with coil orientation. The average angles of the optimal orientation of the magnetic coil were 77.1° for C1, 122.1-263.6° for the jugular tubercle, and 308.6-32.1° for the jugular foramen. Conclusions: The accessory nerve excitation site varied with the orientation of the magnetic coil. This study suggested the possibility of a variety of the cranial nerve excitation sites to the transcranial magnetic stimulation.}, number = {6}, journal = {Clinical Neurophysiology}, author = {Atsuhiro Kojima and Takayuki Ohira and Masahito Kobayashi and Masato Ochiai and Takeshi Kawase}, month = jun, year = {1999}, keywords = {Accessory {nerve,Coil} {orientation,Excitation} {site,Magnetic} {stimulation,Short} latency response}, pages = {1100--1105} }, @article{serrien_repetitive_2002, title = {Repetitive transcranial magnetic stimulation of the supplementary motor area {(SMA)} degrades bimanual movement control in humans}, volume = {328}, issn = {0304-3940}, url = {http://www.sciencedirect.com/science/article/B6T0G-45WGH3R-4/2/34f9ebc2f3df83fe4e1018d69e78097a}, doi = {{10.1016/S0304-3940(02)00499-8}}, abstract = { Moving the upper limbs at a common tempo according to an in-phase or anti-phase mode represents elementary coordination dynamics. Previously, the role of the supplementary motor area {(SMA)} has been emphasized for successful production of these patterns. The objective of this study was to investigate whether repetitive transcranial magnetic stimulation {(rTMS)} of the {SMA} at 5 Hz can interfere with these isofrequency configurations in the post-stimulation stage. Results showed a deterioration of temporal control as a function of coordinative complexity. This effect was associated with a decrease in the functional coupling between the primary motor cortices, as measured by electroencephalographic coherence. These data suggest that {rTMS} of the {SMA} can modify interhemispheric communication and accordingly modulate interlimb behavior.}, number = {2}, journal = {Neuroscience Letters}, author = {Deborah J. Serrien and Lucy H. A. Strens and Antonio Oliviero and Peter Brown}, month = aug, year = {2002}, keywords = {{Electroencephalography,Interlimb} {coordination,Synchronization}}, pages = {89--92} }, @article{okada_long-term_2002, title = {The long-term high-frequency repetitive transcranial magnetic stimulation does not induce {mRNA} expression of inflammatory mediators in the rat central nervous system}, volume = {957}, issn = {0006-8993}, url = {http://www.sciencedirect.com/science/article/B6SYR-470V343-J/2/9a6d5d7c52ef8271c9e2ae47560f9c70}, doi = {{10.1016/S0006-8993(02)03582-5}}, abstract = { Repetitive transcranial magnetic stimulation {(rTMS)} has been applied for treatment of several diseases such as depression. However, the safety and biological effects of {rTMS} have not been fully elucidated. In this study, the effects of {rTMS} on the levels of inflammatory mediators in the central nervous system {(CNS),} which may be involved in neurodegenerative disorders, were investigated in comparison with the electric convulsive model. Long-term {rTMS} (1500 pulses at 30 Hz/day for series of 7 days) stimulation, which did not elicit convulsion, was given to rats {(rTMS} rats). Single high-frequency electrical stimulation (100 Hz, 0.5-ms pulse width, 1 s duration, 50 {mA),} which induced convulsion, was given to rats {(ES} rats). {mRNA} levels of interleukin {(IL)-1[beta],} {IL-6,} cyclooxygenase {(COX)-2} and inducible nitric oxide synthetase {(iNOS)} in the brain were evaluated by reverse transcription-polymerase chain reaction before and after these stimulations. {mRNA} of {IL-1[beta],} {IL-6} and {COX-2} was induced in the brains of {ES} rats but not in the brains of long-term {rTMS} rats. {mRNA} of {iNOS} was not induced in the brain of long-term {rTMS} rats. These results suggest that long-term {rTMS} may safe and modulate neural function without up-regulation of inflammatory mediators, which may be involved in neurodegenerative disorders.}, number = {1}, journal = {Brain Research}, author = {Kazumasa Okada and Kaoru Matsunaga and Tomoaki Yuhi and Etsushi Kuroda and Uki Yamashita and Sadatoshi Tsuji}, month = dec, year = {2002}, keywords = {{Cyclooxygenase-2,Cytokine,Inducible} nitric oxide {synthetase,Repetitive} transcranial magnetic stimulation}, pages = {37--41} }, @article{wassermann_therapeutic_2001, title = {Therapeutic application of repetitive transcranial magnetic stimulation: a review}, volume = {112}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-43GCBXD-2/2/de71511f43286eee56344e73ec617da3}, doi = {{10.1016/S1388-2457(01)00585-5}}, abstract = { Transcranial magnetic stimulation {(TMS),} a non-invasive means of electrically stimulating neurons in the human cerebral cortex, is able to modify neuronal activity locally and at distant sites when delivered in series or trains of pulses. Data from stimulation of the motor cortex suggest that the type of effect on the excitability of the cortical network depends on the frequency of stimulation. These data, as well as results from studies in rodents, have been generalized across brain areas and species to provide rationales for using repetitive {TMS} {(rTMS)} to treat various brain disorders, most notably depression. Research into clinical applications for {TMS} remains active and has the potential to provide useful data, but, to date, the results of blinded, sham-controlled trials do not provide clear evidence of beneficial effects that replace or even match the effectiveness of conventional treatments in any disorder. In this review, we discuss the clinical and scientific bases for using {rTMS} as treatment, and review the results of trials in psychiatric and neurological disorders to date.}, number = {8}, journal = {Clinical Neurophysiology}, author = {Eric M. Wassermann and Sarah H. Lisanby}, month = aug, year = {2001}, keywords = {Clinical {trials,Depression,Motor} {cortex,Parkinson's} {disease,Prefrontal} {cortex,Treatment}}, pages = {1367--1377} }, @article{kbler_modulation_2002, title = {Modulation of slow cortical potentials by transcranial magnetic stimulation in humans}, volume = {324}, issn = {0304-3940}, url = {http://www.sciencedirect.com/science/article/B6T0G-45CNG1F-9/2/db54e27fe9de309199b74775a94fc217}, doi = {{10.1016/S0304-3940(02)00197-0}}, abstract = { We studied the effects of transcranial magnetic stimulation {(TMS)} on slow cortical potentials {(SCPs)} of the brain elicited during performance of a feedback and reward task. Ten healthy participants were trained to self-regulate their {SCP} amplitude using visual feedback and reward for increased or decreased amplitudes. Subjects participated in 27 runs (each comprising 70 trials) under three different conditions: single-pulse {TMS} delivered with the coil centered over Cz (vertex), over a lateral scalp position {(LSP),} which increased task difficulty, and in the absence of stimulation. Cz stimulation led to a non-significant enhancement of negative {SCPs,} while {LSP} stimulation led to a significant increase of positive {SCPs.} These results are consistent with the idea that enhanced task difficulty, as in {LSP} stimulation, enhances cognitive processing load leading to an increase of positive {SCPs.} Additionally, the data raise the hypothesis that {TMS} delivered to bilateral midcentral regions could modulate the amplitude of negative {SCPs.}}, number = {3}, journal = {Neuroscience Letters}, author = {Andrea Kübler and Konrad Schmidt and Leonardo G. Cohen and Martin Lotze and Susanne Winter and Thilo Hinterberger and Niels Birbaumer}, month = may, year = {2002}, keywords = {Slow cortical {potentials,Transcranial} magnetic stimulation}, pages = {205--208} }, @article{mller_long-term_2000, title = {Long-term repetitive transcranial magnetic stimulation increases the expression of brain-derived neurotrophic factor and cholecystokinin {mRNA,} but not neuropeptide tyrosine {mRNA} in specific areas of rat brain}, volume = {23}, issn = {{0893-133X}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/10882847}, doi = {{10.1016/S0893-133X(00)00099-3}}, abstract = {Repetitive transcranial magnetic stimulation {(rTMS)} is increasingly used as a therapeutic tool in various neurological and psychiatric disorders, and we recently found that it has a neuroprotective effect both in vitro and in vivo. However, the neurochemical mechanisms underlying the therapeutic effects are still unknown. We investigated the effects of long-term {rTMS} on the expression of brain-derived neurotrophic factor {(BDNF),} cholecystokinin {(CCK),} and neuropeptide tyrosine {(NPY)} {mRNA} in rat brain. In situ hybridization revealed a significant increase in {BDNF} {mRNA} in the hippocampal areas {CA3} and {CA3c,} the granule cell layer, as well as in the parietal and the piriform cortex after {rTMS.} {BDNF-like} immunoreactivity was markedly increased in the same areas. A significant increase in {CCK} {mRNA} was observed in all brain regions examined. {NPY} {mRNA} expression, in contrast, was not altered. The present results suggest that {BDNF} may contribute to the neuroprotective effects of {rTMS.} Furthermore, the {rTMS-induced} changes in {BDNF} and {CCK} expression are similar to those reported after antidepressant drug treatment and electroconvulsive seizures, suggesting that a common molecular mechanism may underlie different antidepressant treatment strategies.}, number = {2}, journal = {Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology}, author = {M B Müller and N Toschi and A E Kresse and A Post and M E Keck}, month = aug, year = {2000}, note = {{PMID:} 10882847}, keywords = {{Animals,Brain,Brain-Derived} Neurotrophic {Factor,Cerebral} {Cortex,Cholecystokinin,Dentate} {Gyrus,Electric} {Stimulation,Hippocampus,Male,Neuropeptide} {Y,Olfactory} {Pathways,Parietal} {Lobe,Rats,Rats,} {Wistar,RNA,} {Messenger,Time,Transcranial} Magnetic Stimulation}, pages = {205--15} }, @article{herwig_transcranial_2001, title = {Transcranial magnetic stimulation in therapy studies: examination of the reliability of "standard" coil positioning by neuronavigation}, volume = {50}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-43G2WK9-9/2/463da6118ea1b34cc9f34b3d4ee21d66}, doi = {{10.1016/S0006-3223(01)01153-2}}, abstract = { Transcranial magnetic stimulation is investigated as a new tool in the therapy of depression and other psychiatric disorders. In almost all studies, the dorsolateral prefrontal cortex {(DLPFC)} has been selected as the target site for stimulation. Usually this region was determined by identifying the patient's motor cortex, and from there the coil was placed 5 cm rostrally. The aim of our study was to test the reliability of this standard procedure. A neuronavigational system was used to relate the final coil position after applying the standard procedure to the individual cortical anatomy. In 7 of 22 subjects, the Brodman area 9 of the {DLPFC} was targeted correctly in this manner. In 15 subjects, the center of the coil was found to be located more dorsally (e.g., above the premotor cortex). The current method for locating the {DLPFC} is not precise anatomically and may be improved by navigating procedures taking individual anatomy into account.}, number = {1}, journal = {Biological Psychiatry}, author = {Uwe Herwig and Frank Padberg and Jürgen Unger and Manfred Spitzer and Carlos {Schönfeldt-Lecuona}}, month = jul, year = {2001}, keywords = {coil positioning,dorsolateral prefrontal cortex,magnetic resonance imaging,neuronavigation,therapy {studies,Transcranial} magnetic stimulation}, pages = {58--61} }, @article{tiitinen_separation_1999, title = {Separation of contamination caused by coil clicks from responses elicited by transcranial magnetic stimulation}, volume = {110}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-3WM5BD8-V/2/f95b81082cbdf1116f2a6364fb80d7a9}, doi = {{10.1016/S1388-2457(99)00038-3}}, abstract = { Transcranial magnetic stimulation {(TMS)} is accompanied with loud clicks that evoke auditory responses in the brain, confounding several types of {TMS} studies. We investigated the effects of these clicks with high-resolution {EEG} by applying {TMS} pulses at 3 magnitudes, with the coil placed either at 10 or 50 mm over the subjects' vertex and recording event-related potentials {(ERPs).} The clicks were found to elicit a positively displaced response at 150-250 ms {post-TMS.} Furthermore, clicks were found to interact with simultaneously presented auditory sinewave stimuli, resulting in an amplitude decrease in the auditory N1 response.}, number = {5}, journal = {Clinical Neurophysiology}, author = {Hannu Tiitinen and Juha Virtanen and Risto J. Ilmoniemi and Janne Kamppuri and Marko Ollikainen and Jarmo Ruohonen and Risto Näätänen}, month = may, year = {1999}, keywords = {{Auditory,EEG,Electroencephalogram,ERP,Event-related} {potential,Transcranial} magnetic stimulation}, pages = {982--985} }, @article{nguyen_465._2000, title = {465. Personality traits are correlated with motor cortex excitability: a transcranial magnetic stimulation {(TMS)} study}, volume = {47}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-403W273-JG/2/ae2abf74bdcaf097e867c2428660be8e}, doi = {{10.1016/S0006-3223(00)00735-6}}, number = {8, Supplement 1}, journal = {Biological Psychiatry}, author = {M. Nguyen and B. D. Greenberg and D. L. Murphy and M. J. Smith and E. M. Wassermann}, month = apr, year = {2000}, pages = {S142} }, @article{kanda_transcranial_2003, title = {Transcranial magnetic stimulation {(TMS)} of the sensorimotor cortex and medial frontal cortex modifies human pain perception}, volume = {114}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-484VM43-8/2/5a6f094bc8c48e05186a28e267c3128e}, doi = {{10.1016/S1388-2457(03)00034-8}}, abstract = { Objective: Although recent neuroimaging studies have shown that painful stimuli can produce activity in multiple cortical areas, the question remains as to the role of each area in particular aspects of human pain perception. To solve this problem we used transcranial magnetic stimulation {(TMS)} as an [`]interference approach' tool to test the consequence on pain perception of disrupting activity in several areas of cortex known to be activated by painful input. Methods: Weak {CO2} laser stimuli at an intensity around the threshold for pain were given to the dorsum of the left hand in 9 normal subjects. At variable delays (50, 150, 250, 350 ms) after the onset of the laser stimulus, pairs of {TMS} pulses {(dTMS:} interpulse interval of 50 ms, and stimulus intensity of 120\% resting motor threshold) were applied in separate blocks of trials over either the right sensorimotor cortex {(SMI),} midline occipital cortex {(OCC),} second somatosensory cortex {(SII),} or medial frontal cortex {(MFC).} Subjects were instructed to judge whether or not the stimulus was painful and to point to the stimulated spot on a drawing of subject's hand. Results: Subjects judged that the stimulus was painful on more trials than control when {dTMS} was delivered over {SMI} at 150-200 ms after the laser stimulus; the opposite occurred when {dTMS} was delivered over {MFC} at 50-100 ms. {dTMS} over the {SII} or {OCC} failed to alter the pain threshold. Conclusions: These results suggest that {TMS} to {SMI} can facilitate whereas stimulation over {MFC} suppresses central processing of pain perception. Since there was no effect of {dTMS} at any of the scalp sites on the localization task, the cortical locus for point localization of pain may be different from that for perception of pain intensity or may involve a more complex mechanism than the latter. Significance: This is the first report that {TMS} of {SMI} facilitates while that of {MFC} suppresses the central processing of pain perception. This raises the possibility of using {TMS} as a therapeutic device to control pain.}, number = {5}, journal = {Clinical Neurophysiology}, author = {Masutaro Kanda and Tatsuya Mima and Tatsuhide Oga and Masao Matsuhashi and Keiichiro Toma and Hidemi Hara and Takeshi Satow and Takashi Nagamine and John C. Rothwell and Hiroshi Shibasaki}, month = may, year = {2003}, keywords = {Anterior cingulate {cortex,Facilitation,Inhibition,Pain,Sensorimotor} {cortex,Transcranial} magnetic stimulation {(TMS)}}, pages = {860--866} }, @article{nagel_effect_2003, title = {The effect of transcranial magnetic stimulation over the cerebellum on the synkinesis of coordinated eye and head movements}, volume = {213}, issn = {{0022-510X}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/12873753}, abstract = {We made a study of coordinated saccadic eye and head movements following random and predictable horizontal visual targets by applying transcranial magnetic stimulation {(TMS)} over the cerebellum before the start of the gaze movement. We have found three effects of {TMS} on eye/head movements under these conditions. {SACCADIC} {LATENCY-EFFECT:} When stimulation took place shortly before movements commenced, significantly shorter latencies were found between target presentation and commencement of saccades: For predictable, to a lesser extent for random targets and {TMS} up to 75 ms before start of the saccade, latencies were significantly decreased when compared with no application of {TMS.} Without stimulation, latencies to random targets were within a range of 120-200 ms. {EYE-HEAD} {INTERACTION-EFFECT:} Without {TMS,} for amplitudes greater than 25 degrees, head movements usually preceded eye movements, as expected, especially for predictive responses. With the application of {TMS} shortly after the target display, the number of eye movements which preceded head movements, was significantly increased (p{\textless}0.001), and the delay between eye and head movements was reduced or reversed (p{\textless}0.001), compared with gaze movements without the use of {TMS.} {SACCADIC} {PEAK} {VELOCITY-EFFECT:} Applying transcranial magnetic stimulation at 5-25 ms after the position change of the 60 degrees target, and 50-5 s before the start of eye movement, mean peak velocity of synkinetic saccades increased up to 600 degrees/s, compared with 350-400 degrees/s without the use of {TMS.We} conclude that transient functional cerebellar deficits caused by the application of {TMS} can change the central synkinesis of eye-head coordination.}, number = {1-2}, journal = {Journal of the Neurological Sciences}, author = {M Nagel and W H Zangemeister}, month = sep, year = {2003}, note = {{PMID:} 12873753}, keywords = {{Adult,Cerebellum,Electric} {Stimulation,Fixation,} {Ocular,Head} {Movements,Photic} {Stimulation,Psychomotor} {Performance,Reaction} {Time,Reference} {Values,Saccades,Transcranial} Magnetic Stimulation}, pages = {35--45} }, @article{keck_repetitive_2002, title = {Repetitive transcranial magnetic stimulation increases the release of dopamine in the mesolimbic and mesostriatal system}, volume = {43}, issn = {0028-3908}, url = {http://www.sciencedirect.com/science/article/B6T0C-460WG2G-1/2/d76d275255c7757e23b5c71e5a7017f6}, doi = {{10.1016/S0028-3908(02)00069-2}}, abstract = { Repetitive transcranial magnetic stimulation {(rTMS)} is suggested to be a potentially useful treatment in major depression. In order to optimize {rTMS} for therapeutic use, it is necessary to understand the neurobiological mechanisms involved, particularly the nature of the neurochemical changes induced. Using intracerebral microdialysis in urethane-anesthetized and conscious adult male Wistar rats, we monitored the effects of acute {rTMS} (20 Hz) on the intrahippocampal, intraaccumbal and intrastriatal release patterns of dopamine and its metabolites (homovanillic acid, 3,4-dihydroxyphenylacetic acid). The stimulation parameters were adjusted according to the results of accurate {MRI-based} computer-assisted reconstructions of the current density distributions induced by {rTMS} in the rat brain, ensuring stimulation of frontal brain regions. In the dorsal hippocampus, the shell of the nucleus accumbens and the dorsal striatum the extracellular concentration of dopamine was significantly elevated in response to {rTMS.} Taken together, these data provide the first in vivo evidence that acute {rTMS} of frontal brain regions has a modulatory effect on both the mesolimbic and the mesostriatal dopaminergic systems. This increase in dopaminergic neurotransmission may contribute to the beneficial effects of {rTMS} in the treatment of affective disorders and Parkinson's disease.}, number = {1}, journal = {Neuropharmacology}, author = {M. E. Keck and T. Welt and M. B. Müller and A. Erhardt and F. Ohl and N. Toschi and F. Holsboer and I. Sillaber}, month = jul, year = {2002}, keywords = {{Antidepressant,Biogenic} {amines,Depression,Microdialysis,Monoamines,Parkinson's} disease}, pages = {101--109} }, @article{erfurth_euphoric_2000, title = {Euphoric Mania and Rapid Transcranial Magnetic Stimulation}, volume = {157}, url = {http://ajp.psychiatryonline.org}, doi = {10.1176/appi.ajp.157.5.835-a}, number = {5}, journal = {Am J Psychiatry}, author = {{ANDREAS} {ERFURTH} and {NIKOLAUS} {MICHAEL} and {CHRISTIAN} {MOSTERT} and {VOLKER} {AROLT}}, month = may, year = {2000}, pages = {835--a-836} }, @article{keck_repetitive_2000, title = {Repetitive transcranial magnetic stimulation induces active coping strategies and attenuates the neuroendocrine stress response in rats}, volume = {34}, issn = {0022-3956}, url = {http://www.sciencedirect.com/science/article/B6T8T-41V2998-1/2/4c467f14e13890be0b9d699bc3efa802}, doi = {{10.1016/S0022-3956(00)00028-5}}, abstract = { The effects of repetitive transcranial magnetic stimulation {(rTMS)} on various brain functions were investigated in adult male Wistar rats. The stimulation parameters were adjusted according to the results of accurate computer-assisted, magnetic resonance imaging-based reconstructions of the current density distributions induced by {rTMS} in the rat and human brain, ensuring comparable stimulation patterns in both cases. The animals were subjected to daily {rTMS-treatment} (three trains of 20 Hz; 2.5 s) for 8 weeks from the age of 4 weeks on. In the forced swim test these rats showed a more active stress coping strategy than the control rats. This was accompanied by a significantly attenuated stress-induced elevation of plasma {ACTH} concentrations. Pituitary changes accounting for the attenuation were ruled out by the corticotropin-releasing hormone test. Baseline concentrations of {ACTH} and corticosterone were indistinguishable in the two groups. No changes were found in the anxiety-related behavior of the rats on the elevated plus-maze or in behavior during the social interaction test. Accordingly, the binding characteristics of the benzodiazepine agonist {[3H]flunitrazepam} at the benzodiazepine/[gamma]-aminobutyric acid type A receptor complex were similar in the {rTMS} and control groups. In summary, chronic {rTMS} treatment of frontal brain regions in rats resulted in a change in coping strategy that was accompanied by an attenuated neuroendocrine response to stress, thus revealing parallels to the effects of antidepressant drug treatment.}, number = {4-5}, journal = {Journal of Psychiatric Research}, author = {M. E. Keck and M. Engelmann and M. B. Müller and M. S. H. Henniger and B. Hermann and R. Rupprecht and I. D. Neumann and N. Toschi and R. Landgraf and A. Post}, month = jul, year = {2000}, keywords = {{ACTH,Anxiety,Corticosterone,Forced} swim {test,HPA} {system,rTMS,Stress}}, pages = {265--276} }, @article{evers_impact_2001, title = {The impact of repetitive transcranial magnetic stimulation on pituitary hormone levels and cortisol in healthy subjects}, volume = {66}, issn = {0165-0327}, url = {http://www.sciencedirect.com/science/article/B6T2X-43VJ7XM-C/2/cff31cb75786871e767cac829e88410c}, doi = {{10.1016/S0165-0327(00)00289-5}}, abstract = { Background: Repetitive transcranial magnetic stimulation {(rTMS)} is a new therapeutic tool in the treatment of affective disorders but only few studies on its safety exist. We aimed to determine the impact of {rTMS} on (neuro)endocrinological serum levels by a placebo-controlled cross-over study. Methods: 23 healthy subjects were stimulated by {rTMS} in a typical paradigm used in the treatment of depression (coil placed over left dorsolateral prefrontal cortex, 10 and 20 Hz stimulation). Placebo, infrathreshold, and suprathreshold stimulation were applied in random order. The serum levels of cortisol, prolactin, {FSH,} and {TSH} were measured before and after stimulation. Results: After infrathreshold stimulation, cortisol and {TSH} serum levels decreased mildly but significantly. All other stimulations had no significant impact on hormone levels. In female, but not in male, subjects placebo stimulation yielded a significant increase of prolactin. Conclusions: {rTMS} as applied for the treatment of depression leads to only very mild and safe changes of hormones. These changes, in particular the decrease of cortisol levels, might explain in part the efficacy of {rTMS.}}, number = {1}, journal = {Journal of Affective Disorders}, author = {Stefan Evers and Karin Hengst and Peter W. Pecuch}, month = sep, year = {2001}, keywords = {{Cortisol,FSH,Prolactin,Transcranial} magnetic {stimulation,TSH}}, pages = {83--88} }, @article{hoshiyama_shortening_1999, title = {Shortening of the cortical silent period following transcranial magnetic brain stimulation during an experimental paradigm for generating contingent negative variation {(CNV)}}, volume = {110}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-3WWVBN3-B/2/2cd909b2358c72821903173579aa01be}, doi = {{10.1016/S1388-2457(99)00110-8}}, abstract = { Objectives: We investigated changes in the cortical silent period {(CSP)} following transcranial magnetic cortical stimulation {(TCMS)} during a standard paradigm which was designed to evoke contingent negative variation {(CNV)} in ten normal subjects. Methods: We recorded the motor evoked potentials {(MEP)} and {CSP} during the inter-stimulus interval {(ISI)} of a {CNV} paradigm in ten normal subjects. The {CNV} paradigm consisted of a visual warning stimulus {(S1)} followed by a visual response stimulus {(S2).} The {CSP} following {TCMS} on the hand motor area was recorded from mildly contracted first dorsal interosseous muscles. Results: The {CSP} was significantly shortened during the {ISI} {(P{\textless}0.01,} t test) with a highly significant correlation with the {TCMS} timing during the {ISI} {(P{\textless}0.02,} Spearman's correlation coefficient), while the {MEP} amplitude and latency were unchanged. Conclusions: The results suggested that shortening of the {CSP} was associated with neural processes related to preparation for voluntary movement during the paradigm.}, number = {8}, journal = {Clinical Neurophysiology}, author = {Minoru Hoshiyama and Ryusuke Kakigi}, month = aug, year = {1999}, keywords = {Contingent negative {variation,Cortical} silent {period,Magnetic} cortical {stimulation,Motor} evoked potential}, pages = {1394--1398} }, @article{thoret_repetitive_2002, title = {Repetitive transcranial magnetic stimulation of human area {MT/V5} disrupts perception and storage of the motion aftereffect}, volume = {40}, issn = {0028-3932}, url = {http://www.sciencedirect.com/science/article/B6T0D-473KPJP-9/2/57c993d2c90f3b3b61152ec8a39e95c2}, doi = {{10.1016/S0028-3932(02)00112-4}}, abstract = { Following adaptation to a moving stimulus, the introduction of a stationary pattern creates the illusion of motion. This phenomenon, known as the motion aftereffect {(MAE),} can be delayed by placing a blank storage interval between the adapting and test stimuli. Human motion selective area {MT/V5} has been proposed as the likely neural origin of {MAEs.} To examine the role of {MT/V5} in perceiving and storing {MAEs,} we applied repetitive transcranial magnetic stimulation {(rTMS)} to this area during a 10 s storage interval and while subjects perceived illusory motion. Our results show that {rTMS} disrupts perception of the {MAE} when it is delivered in the early parts of the storage period and when it is applied during the perceptual {MAE} itself. Stimulation of control regions corresponding to V1 or Cz did not affect the {MAE.} In addition, magnetic stimulation of dorsolateral prefrontal and posterior parietal cortices did not disrupt {MAE} perception. These data provide experimental support for the notion that {MT/V5} subserves perception and storage of the motion aftereffect.}, number = {13}, journal = {Neuropsychologia}, author = {Hugo Théoret and Masahito Kobayashi and Giorgio Ganis and Paul Di Capua and Alvaro {Pascual-Leone}}, year = {2002}, keywords = {{Adaptation,Illusory} {motion,Motion} {perception,Visual} cortex}, pages = {2280--2287} }, @article{charlton_prolonged_2003, title = {Prolonged peripheral nerve stimulation induces persistent changes in excitability of human motor cortex}, volume = {208}, issn = {{0022-510X}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/12639729}, abstract = {This study sought to determine whether prolonged peripheral nerve stimulation was effective in inducing persistent "plastic" changes in the excitability of the human motor cortex. The amplitude of the electromyographic response evoked in resting intrinsic hand muscles by focal transcranial magnetic stimulation {(TMS)} was taken as an index of motor cortical excitability. Twelve subjects were stimulated with each of three protocols, one of which was given on each of three separate occasions. The protocols consisted of various schedules of electrical stimulation of the radial and ulnar nerves or the motor point of the first dorsal interosseous muscle {(FDI),} or stimulation of {FDI} motor point paired with low-frequency {TMS.} Amplitudes of {TMS-elicited} motor evoked potentials {(MEPs)} were measured before peripheral stimulation and for 2 h after stimulation. The data from one subject were unusable. In every other subject, all three protocols induced a prolonged, significant facilitation of {MEPs} in at least some of the three intrinsic hand muscles used. In some instances, {MEPs} were not enlarged and occasionally were significantly depressed. Different protocols based on peripheral afferent stimulation can induce plastic changes in the organisation of the motor cortex that persist for at least 2 h.}, number = {1-2}, journal = {Journal of the Neurological Sciences}, author = {C Shona Charlton and Michael C Ridding and Philip D Thompson and Timothy S Miles}, month = apr, year = {2003}, note = {{PMID:} 12639729}, keywords = {{Adult,Analysis} of {Variance,Electric} {Stimulation,Electromyography,Evoked} Potentials, {Motor,Female,Magnetics,Male,Median} {Nerve,Motor} {Cortex,Muscle,} {Skeletal,Neuronal} {Plasticity,Peripheral} {Nerves,Radial} {Nerve,Ulnar} {Nerve,Wrist}}, pages = {79--85} }, @article{franck_left_2003, title = {Left temporoparietal transcranial magnetic stimulation in treatment-resistant schizophrenia with verbal hallucinations}, volume = {120}, issn = {0165-1781}, url = {http://www.sciencedirect.com/science/article/B6TBV-49CRK1S-3/2/8fd9afc7189dbd8ed2fbe16edec157df}, doi = {{10.1016/S0165-1781(03)00148-3}}, abstract = { Left temporoparietal repetitive transcranial magnetic stimulation {(rTMS)} reportedly diminishes verbal hallucinations. A 21-year-old schizophrenic man, who had killed his mother in the belief that she was a demon, failed to respond to combined treatment with a variety of antipsychotic agents. His persistent hallucinations consisted of two voices {(God} and the Devil). As an adjunct to continued antipsychotic medication, the patient received a course of {rTMS:} 10 sessions of {1-Hz} stimulations near Wernicke's area. After {rTMS,} the patient's hallucinations grew less intrusive and he no longer required isolation. Although the improvement could be a delayed effect of medication, further trials of {rTMS} in cases of this type appear justified.}, number = {1}, journal = {Psychiatry Research}, author = {Nicolas Franck and Emmanuel Poulet and {Jean-Louis} Terra and Jean Daléry and Thierry {d'Amato}}, month = aug, year = {2003}, keywords = {Repetitive transmagnetic {stimulation,Scale} for the Assessment of Positive {Symptoms,Schizophrenia,Violence}}, pages = {107--109} }, @article{schlaghecken_slow_2003, title = {Slow frequency repetitive transcranial magnetic stimulation affects reaction times, but not priming effects, in a masked prime task}, volume = {114}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-48S4VC9-B/2/7a2f8bdefb1b56ddf04e0d89918f3674}, doi = {{10.1016/S1388-2457(03)00118-4}}, abstract = { Objective: Slow frequency repetitive transcranial magnetic stimulation {(rTMS)} reduces motor cortex excitability, but it is unclear whether this has behavioural consequences in healthy subjects. Methods: We examined the effects of 1 Hz {rTMS} (train of 20 min; stimulus intensity 80\% of active motor threshold) over left motor or left premotor cortex on performance in a visually cued choice reaction time task, using a [`]masked prime' paradigm to assess whether {rTMS} might affect more automatic motor processes. Twelve healthy volunteers participated. Results: Motor cortex {rTMS} and, to a lesser extent, premotor cortex {rTMS} resulted in a slowing of right (stimulated) hand responses, but not of left (unstimulated) hand responses. In a control experiment, {rTMS} of the left somatosensory cortex did not lead to slower right hand responses. Discussion: We conclude that long trains of low intensity 1 Hz {rTMS} over the motor or premotor cortex can have subtle behavioural consequences outlasting the stimulation. {rTMS} did not affect the modulation of reaction times by subliminal primes, suggesting that priming effects triggered by subliminal primes are not generated at the level of motor or pre-motor cortex.}, number = {7}, journal = {Clinical Neurophysiology}, author = {F. Schlaghecken and A. Münchau and B. R. Bloem and J. Rothwell and M. Eimer}, month = jul, year = {2003}, keywords = {Masked {priming,Motor} {cortex,Motor} {inhibition,Premotor} {cortex,Repetitive} transcranial magnetic stimulation}, pages = {1272--1277} }, @article{ruohonen_transcranial_1998, title = {Transcranial magnetic stimulation: modelling and new techniques [doctoral dissertation]}, journal = {Espoo, Finland: Department of Engineering Physics and Mathematics, Helsinki University of Technology}, author = {J. Ruohonen}, year = {1998} }, @article{mosimann_mood_2000, title = {Mood effects of repetitive transcranial magnetic stimulation of left prefrontal cortex in healthy volunteers}, volume = {94}, issn = {0165-1781}, url = {http://www.sciencedirect.com/science/article/B6TBV-40NMS7V-7/2/9152e319b2e6580536338c5b1b1e7e1f}, doi = {{10.1016/S0165-1781(00)00146-3}}, abstract = { This study investigated the effect of high-frequency repetitive transcranial magnetic stimulation {(HF-rTMS)} of the left prefrontal cortex {(LPFC)} on mood in a sham-controlled crossover design. Twenty-five healthy male subjects received {HF-rTMS} of the {LPFC} in real and sham conditions. Forty trains (frequency 20 Hz, stimulation intensity 100\% of individual motor threshold, train duration 2 s, intertrain interval 28 s) were applied in each session. Mood change from baseline was measured with five visual analog scales {(VAS)} for sadness, anxiety, happiness, tiredness and pain/discomfort. We were unable to demonstrate significant mood changes from baseline on visual analog scales after either sham or real stimulation of {LPFC.} There is insufficient evidence to support the general conclusion that {HF-rTMS} of {LPFC} has mood effects in healthy volunteers. Future studies should be sham-controlled, have larger sample sizes, and strictly stimulate one single region per session in order to exclude interaction effects with the previous stimulation.}, number = {3}, journal = {Psychiatry Research}, author = {Urs P. Mosimann and Tonia A. Rihs and Judith Engeler and {Hans-Ulrich} Fisch and Thomas E. Schlaepfer}, month = jul, year = {2000}, keywords = {{Affect,Prefrontal} {cortex,Transcranial} magnetic {stimulation,Visual} analog scales}, pages = {251--256} }, @article{sackeim_repetitive_2000, title = {Repetitive transcranial magnetic stimulation: what are the next steps?}, volume = {48}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-41NCW2Y-1/2/6b0d8ad848f7cca0e91e277d95e1bf04}, doi = {{10.1016/S0006-3223(00)01064-7}}, number = {10}, journal = {Biological Psychiatry}, author = {Harold A. Sackeim}, month = nov, year = {2000}, pages = {959--961} }, @article{civardi_transcranial_2001, title = {Transcranial Magnetic Stimulation Can Be Used to Test Connections to Primary Motor Areas from Frontal and Medial Cortex in Humans}, volume = {14}, issn = {1053-8119}, url = {http://www.sciencedirect.com/science/article/B6WNP-457D9NJ-S/2/ee7e756e399f0cc899eed6156312c3c2}, doi = {10.1006/nimg.2001.0918}, abstract = { Surface {EMG} responses {(MEPs)} were recorded from the relaxed first dorsal interosseous {(FDI)} of 16 normal subjects following transcranial magnetic stimulation {(TMS)} over the hand area of the primary motor cortex. These test responses were conditioned by a subthreshold stimulus applied 2-15 ms beforehand over a range of anterior or medial sites. Stimuli applied 3-5 cm anterior to the hand motor area (site A) or 6 cm anterior to the vertex on the nasion-inion line (site B) inhibited the test responses at short latency. The largest effect was seen when the interstimulus interval was 6 ms and the intensity of the conditioning stimulus was equal to 0.9× active motor threshold {(AMT)} at the hand area. Increasing the intensity to 1.2× {AMT} produced facilitation. Suppression of surface {EMG} responses was mirrored in the behavior of single motor units. Conditioning stimuli had no effect on responses evoked in the active {FDI} muscle by transcranial electric stimulation of motor cortex nor on forearm flexor H reflexes even though {MEPs} in the same muscle were suppressed at appropriate interstimulus intervals. We conclude that low-intensity {TMS} over presumed premotor areas of frontal cortex can engage corticocortical connections to the primary motor hand area.}, number = {6}, journal = {{NeuroImage}}, author = {Carlo Civardi and Roberto Cantello and Peter Asselman and John C. Rothwell}, month = dec, year = {2001}, pages = {1444--1453} }, @article{peinemann_subthreshold_2000, title = {Subthreshold {5-Hz} repetitive transcranial magnetic stimulation of the human primary motor cortex reduces intracortical paired-pulse inhibition}, volume = {296}, issn = {0304-3940}, url = {http://www.sciencedirect.com/science/article/B6T0G-41SCDR3-6/2/adfef2d0d7480f3df0c6cce202ce667d}, doi = {{10.1016/S0304-3940(00)01616-5}}, abstract = { Paired-pulse transcranial magnetic stimulation {(TMS)} at short interstimulus intervals was employed to investigate short-term effects of {5-Hz} repetitive {TMS} {(rTMS)} over the primary motor hand area {(M1HAND)} on intracortical excitability. In ten healthy individuals, 1250 pulses of {5-Hz} {rTMS} were applied at 90\% of motor resting threshold over the left {M1HAND.} Ten minutes after {5-Hz} {rTMS,} paired-pulse inhibition was significantly reduced, whereas paired-pulse facilitation was not modified. {Sham-rTMS} had no lasting effect on intracortical excitability. These findings suggest that subthreshold {5-Hz} {rTMS} causes a short-term modulation of the excitability of intracortical circuitry in the stimulated {M1HAND.} The lasting effect of subthreshold {5-Hz} {rTMS} on intracortical inhibition provides a useful probe for studying short-term plasticity of the human {M1HAND.}}, number = {1}, journal = {Neuroscience Letters}, author = {Alexander Peinemann and Christian Lehner and Claudia Mentschel and Alexander Münchau and Bastian Conrad and Hartwig Roman Siebner}, month = dec, year = {2000}, keywords = {Intracortical {facilitation,Intracortical} {inhibition,Motor} {cortex,Paired-pulse,Plasticity,Transcranial} magnetic stimulation}, pages = {21--24} }, @article{brighina_magnetic_2000, title = {Magnetic stimulation study during observation of motor tasks}, volume = {174}, issn = {{0022-510X}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/10727697}, abstract = {The aim of the study was to assess if the observation of single or more complex muscle movements activates the premotor cortex in man. We stimulated by transcranial magnetic stimulation the right and left motor cortex recording from the abductor pollicis brevis of eight normal subjects, during observation of different movements performed by the examiner: (1) single movements: thumb abduction, arm elevation; (2) motor sequences: finger opposing movements performed in an ordinate sequence: 1-2, 1-3, 1-4, 1-5, 1-2ellipsis, and in a non-consecutive non-repetitive order: 1-3, 1-5, 1-4, 1-2, 1-5, 1-2ellipsis We found an increased excitability of the right cortex during observation of isolated muscle movement regardless of which muscle is moved. At the stimulation of the left cortex, {MEPs} were significantly increased during observation of complex muscular synergies.}, number = {2}, journal = {Journal of the Neurological Sciences}, author = {F Brighina and V La Bua and M Oliveri and A Piazza and B Fierro}, month = mar, year = {2000}, note = {{PMID:} 10727697}, keywords = {{Adult,Arm,Dominance,} {Cerebral,Electric} {Stimulation,Electromagnetic} {Fields,Evoked} {Potentials,Female,Fingers,Male,Motor} {Activity,Motor} {Cortex,Nerve} {Net,Thumb}}, pages = {122--6} }, @article{fernandez_mapping_2002, title = {Mapping of the human visual cortex using image-guided transcranial magnetic stimulation}, volume = {10}, issn = {{1385-299X}}, url = {http://www.sciencedirect.com/science/article/B6T3N-475BG48-2/2/5037b73da3136a7ee9d4587fdb3f34e3}, doi = {{10.1016/S1385-299X(02)00189-7}}, abstract = { We describe a protocol using transcranial magnetic stimulation {(TMS)} to systematically map the visual sensations induced by focal and non-invasive stimulation of the human occipital cortex. {TMS} is applied with a figure of eight coil to 28 positions arranged in a 2×2-cm grid over the occipital area. A digitizing tablet connected to a {PC} computer running customized software, and audio and video recording are used for detailed and accurate data collection and analysis of evoked phosphenes. A frameless image-guided neuronavigational device is used to describe the position of the actual sites of the stimulation coils relative to the cortical surface. Our results show that {TMS} is able to elicit phosphenes in almost all sighted subjects and in a proportion of blind subjects. Evoked phosphenes are topographically organized. Despite minor inter-individual variations, the mapping results are reproducible and show good congruence among different subjects. This procedure has potential to improve our understanding of physiologic organization and plastic changes in the human visual system and to establish the degree of remaining functional visual cortex in blind subjects. Such a non-invasive method is critical for selection of suitable subjects for a cortical visual prosthesis.}, number = {2}, journal = {Brain Research Protocols}, author = {E. Fernandez and A. Alfaro and J. M. Tormos and R. Climent and M. Martínez and H. Vilanova and V. Walsh and A. {Pascual-Leone}}, month = oct, year = {2002}, keywords = {{Blind,Mapping,Occipital} {cortex,Phosphenes,Transcranial} magnetic stimulation}, pages = {115--124} }, @article{hedges_transcranial_2002, title = {Transcranial magnetic stimulation {(TMS)} effects on testosterone, prolactin, and corticosterone in adult male rats}, volume = {51}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-45BD9YC-B/2/22e355f884080cf6ce540d025d10d6ec}, doi = {{10.1016/S0006-3223(01)01266-5}}, abstract = { Background: Transcranial magnetic stimulation is a relatively new technique for inducing small, localized, and reversible changes in living brain tissue. Although transcranial magnetic stimulation generally results in no immediate changes in plasma corticosterone, prolactin, and testosterone, it normalizes the dexamethasone suppression test in some depressed subjects and has been shown to attenuate stress-induced increases in adrenocorticotropic hormone in rats. Methods: In this study, serum corticosterone and testosterone concentrations were assayed in male rats immediately and 3, 6, 9, 12, 24, and 48 hours following a single transcranial magnetic stimulation or sham application. Serum prolactin concentrations were determined immediately and 2 hours following a one-time application of either transcranial magnetic stimulation or sham. Results: Transcranial magnetic stimulation animals displayed significantly lower corticosterone concentrations at 6 and 24 hours following a single application compared with sham-control values. Transcranial magnetic stimulation also resulted in lower corticosterone concentrations numerically but not statistically in transcranial magnetic stimulation animals immediately after application (p = .089). No significant differences were found between groups for serum prolactin or testosterone levels at any given collection time point. Conclusions: These findings 1) suggest that transcranial magnetic stimulation alters the hypothalamic-pituitary-adrenal stress axis and 2) provide time-course data for the implications of the hormonal mechanism that may be involved in the actions of transcranial magnetic stimulation.}, number = {5}, journal = {Biological Psychiatry}, author = {Dawson W. Hedges and David L. Salyer and Brian J. Higginbotham and Trent D. Lund and James L. Hellewell and David Ferguson and Edwin D. Lephart}, month = mar, year = {2002}, keywords = {corticosterone,hypothalamic-pituitary-adrenal {axis,prolactin,rat,testosterone,Transcranial} magnetic stimulation}, pages = {417--421} }, @article{hoffman_one_2003, title = {One hertz repetitive transcranial magnetic stimulation delivered to brain areas underlying speech perception reduces persistent auditory hallucinations}, volume = {60}, journal = {Schizophr Res}, author = {R. E. Hoffman and K. A. Hawkins and A. W. Anderson and R. Buchanan and K. Wu and M. Hampson and R. Gueorguieva and K. M. Carroll and D. D. Spencer and J. H. Krystal}, year = {2003}, pages = {285--286} }, @article{suga_soleus_2001, title = {The soleus late response elicited by transcranial magnetic stimulation reflects agonist-antagonist postural adjustment in the lower limbs}, volume = {112}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-44BG0R7-1/2/3094514eecb23c8d3a5bbc43821a2baf}, doi = {{10.1016/S1388-2457(01)00689-7}}, abstract = { Objectives: We studied the origin and underlying mechanism of the soleus late response {(SLR)} at a mean latency of 90 ms following transcranial magnetic stimulation. Methods: The soleus primary response {(SPR)} and {SLR} were recorded from the soleus {(SOL)} muscle in 27 normal subjects under various conditions using a double-cone coil. We also tested 28 patients demonstrating neurological disorders with postural disturbance. Results: The amplitude of the {SPR} gradually increased and its latency gradually decreased against the voluntary contraction (0-80\%) of the tibialis anterior {(TA)} muscle. In contrast, the {SLR} amplitude was the greatest at a 20\% {TA} contraction while the {SLR} latency was the shortest at a 40\% {TA} contraction. The preactivation of {SOL} enhanced the {SPR} response but did not evoke the {SLR.} The {SPR} amplitude was significantly augmented while standing, however, the {SLR} amplitude tended to decrease. The {SLR} was never obtained following the stimulation of the brainstem, lumbar roots and peroneal nerve. The {SLR} was abnormal in patients with cerebellar ataxia and Parkinson's disease while the {SPR} was normal. Conclusions: A lack of any correlation between the {SPR} and {SLR} suggests that the {SLR} does not originate in the corticospinal tract. The {SLR} may thus be a polysynaptic response related to the postural control of the agonist and antagonist organization between the {TA} and {SOL.}}, number = {12}, journal = {Clinical Neurophysiology}, author = {Rie Suga and Shozo Tobimatsu and Takayuki Taniwaki and Jun-ichi Kira and Motohiro Kato}, month = dec, year = {2001}, keywords = {Basal {ganglia,Cerebellum,Postural} {adjustment,Soleus} late {response,Transcranial} magnetic stimulation}, pages = {2300--2311} }, @article{daskalakis_effect_2003, title = {Effect of antipsychotics on cortical inhibition using transcranial magnetic stimulation}, volume = {170}, url = {http://dx.doi.org/10.1007/s00213-003-1548-1}, doi = {10.1007/s00213-003-1548-1}, abstract = {Previous studies suggest that antipsychotic medications may alter cortical inhibition {(CI).} The current study was designed to determine if typical or atypical antipsychotics indeed alter {CI} in healthy subjects using three {CI} paradigms as measured with transcranial magnetic stimulation {(TMS):} short interval intracortical inhibition {(SICI),} cortical silent period {(CSP)} and transcallosal inhibition {(TCI).} {CI} was measured before, 6 and 24 h after being randomly assigned to receive a single dose of 2 mg haloperidol ( n=8), 10 mg olanzapine ( n=10) or placebo ( n=9). There was no significant effect on any measure of {CI} at 6 and 24 h after receiving olanzapine, haloperidol or placebo. Moreover, no significant change in the motor threshold was observed across the three medication groups. Therefore, single administration of an antipsychotic has no effect on {CI} or resting motor threshold. Whether chronic, repeated administration of antipsychotics has effects on {CI} requires further investigation.}, number = {3}, journal = {Psychopharmacology}, author = {{ZafirisJ.} Daskalakis and {BruceK.} Christensen and Robert Chen and {PaulB.} Fitzgerald and {RobertB.} Zipursky and Shitij Kapur}, month = nov, year = {2003}, pages = {255--262} }, @article{mottaghy_modulation_2003, title = {Modulation of a brain-behavior relationship in verbal working memory by {rTMS}}, volume = {15}, issn = {0926-6410}, url = {http://www.sciencedirect.com/science/article/B6SYV-46RMXVR-1/2/9332e607252e61287e523313e9f7c1ff}, doi = {{10.1016/S0926-6410(02)00196-9}}, abstract = { We investigated whether the brain-behavior relationship {(BBR)} between regional cerebral blood flow {(rCBF)} as measured by positron emission tomography {(PET)} and individual accuracy in verbal working memory {(WM)} can be modulated by repetitive transcranial magnetic stimulation {(rTMS)} of the left or right middle frontal gyrus {(MFG).} Fourteen right-handed male subjects received a 30-s {rTMS} train (4 Hz, 110\% motor threshold) to the left or right {MFG} during a 2-back {WM} task using letters as stimuli. Simultaneously an {rCBF} {PET} tracer was injected and whole-brain functional images were acquired. A hypothesis-driven region-of-interest-analysis of the left and right {MFG} {BBR} as well as an explorative whole-brain analysis correlating the individual accuracy with {rCBF} was carried out. Without {rTMS} we found a negative {BBR} in the left but no significant {BBR} in the right {MFG.} This negative {BBR} is best explained by an increased effort of volunteers with an inferior task performance. Left-sided {rTMS} led to a shift of the {BBR} towards the superior frontal gyrus {(SFG)} and to a positive {BBR} in anterior parts of the left {SFG.} With {rTMS} of the right {MFG} the {BBR} was posterior and inferior in the left inferior frontal gyrus. Beyond the cognitive subtraction approach this correlation analysis provides information on how the prefrontal cortex is involved based on individual performance in working memory. The results are discussed along the idea of a short-term plasticity in an active neuronal network that reacts to an {rTMS-induced} temporary disruption of two different network modules.}, number = {3}, journal = {Cognitive Brain Research}, author = {Felix M. Mottaghy and Alvaro {Pascual-Leone} and Lars J. Kemna and Rudolf Töpper and Hans Herzog and {Hans-Wilhelm} {Müller-Gärtner} and Bernd J. Krause}, month = feb, year = {2003}, keywords = {{Cognition,Human,Middle} frontal {gyrus,Neuroimaging,rTMS}}, pages = {241--249} }, @article{wassermann_variation_2002, title = {Variation in the response to transcranial magnetic brain stimulation in the general population}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-45Y6NM1-3/2/d61e1f656991e1af083b87beb987563c}, doi = {{10.1016/S1388-2457(02)00144-X}}, abstract = { Objectives: The aim of this study is to describe the variability and other characteristics of the motor evoked potential {(MEP)} to transcranial magnetic stimulation {(TMS)} in a large database. Methods: One hundred fifty one subjects, including 17 sib pairs, free of neurological or psychiatric disease and on no neuroactive medications were studied with uniform techniques. Nineteen were studied on 3 occasions. Measures included {MEP} threshold {(N=141)} during rest and voluntary muscle activation and the response to paired {TMS} (subthreshold conditioning stimulus) at interstimulus intervals {(ISIs)} of 3, 4, 10, and 15 ms {(N=53).} Results: There was a large variability in all the measures. Approximately 40-50\% of this appeared to come from within-subjects variation or experimental error. The {MEP} threshold data were skewed downward, but normalized with log transformation. The paired-pulse ratios (conditioned/unconditioned {MEP)} were normally distributed except those from the 3 ms {ISI} which had no lower tail and could not be normalized. There were subjects showing inhibition and others showing facilitation at all {ISIs.} There were no correlations in any of the data with age or sex, but {MEP} thresholds were highly correlated within sibs. Conclusions: These data should be useful for planning, analyzing, and interpreting {TMS} studies in healthy and patient populations.}, number = {7}, journal = {Clinical Neurophysiology}, author = {Eric M. Wassermann}, month = jul, year = {2002}, keywords = {Individual {differences,Motor} {cortex,Motor} evoked potentials}, pages = {1165--1171} }, @article{sommer_repetitive_2002, title = {Repetitive paired-pulse transcranial magnetic stimulation affects corticospinal excitability and finger tapping in Parkinson's disease}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-45HWX3T-4/2/1733fa7b50e49cea2312b8c37bdf479d}, doi = {{10.1016/S1388-2457(02)00061-5}}, abstract = { Objectives: To study the effect of long trains of a recently established conditioning-test paired-pulse repetitive transcranial magnetic stimulation {(rTMS)} paradigm on corticospinal excitability and finger tapping speed. Methods: We applied 900 inhibiting or facilitating paired-pulses or 900 real or sham single stimuli at 1 Hz over the motor cortex contralateral to the dominant hand of 9 healthy subjects and contralateral to the more affected hand of 11 patients with Parkinson's disease. Results: In both groups, motor evoked potentials {(MEPs)} from suprathreshold pulses were larger after facilitating paired-pulses than after inhibiting paired-pulses. After real single-pulse {rTMS} and after either type of paired-pulse {rTMS} patients showed an increase in finger tapping frequency on the stimulated hand. Tapping was unchanged contralaterally, after sham stimuli, and in controls. Tremor and tapping frequencies were not correlated, nor was the change in {MEP} size correlated to the change in tapping frequency. Conclusions: Repetitive paired-pulses allow selective induction of corticospinal inhibition or facilitation, but do not enhance the transient improvement of finger motility induced by conventional single-pulse {rTMS.}}, number = {6}, journal = {Clinical Neurophysiology}, author = {Martin Sommer and Torsten Kamm and Frithjof Tergau and Gudrun Ulm and Walter Paulus}, month = jun, year = {2002}, keywords = {Motor cortex {excitability,Parkinson's} {disease,Repetitive} transcranial magnetic stimulation}, pages = {944--950} }, @article{george_summary_2001, title = {Summary and Future Directions of Therapeutic Brain Stimulation: Neurostimulation and Neuropsychiatric Disorders, }, volume = {2}, issn = {1525-5050}, url = {http://www.sciencedirect.com/science/article/B6WDT-4BH58JM-1F/2/12fa44128733a8c8c4b1fa4adf0d5711}, doi = {10.1006/ebeh.2001.0202}, abstract = { Technologies that use electromagnetism applied to nervous tissue for the purpose of neurostimulation have made rapid advancements in recent years. This leap forward in brain treatment challenges the traditional categorical divisions between neurologists, psychiatrists, and neurosurgeons. The therapy itself invites a rethinking of terminology as physicians debate its place within standard therapeutic models. Several areas of concern have manifested themselves in regard to this therapy. Physicians must proceed cautiously and work to overcome understandable suspicions about these new developments owing to past abuses involving invasive brain therapies. More information is needed about how the brain works at a systemic level. A better model of how brain stimulation tools function as ablates or augments must be created. Data involving the various techniques of neurostimulation should be meta-analyzed to find commonalities in their mechanisms of action. These technologies are only in their infancy, and the debates and discoveries promise to continue for years to come.}, number = {3, Supplement 0}, journal = {Epilepsy \& Behavior}, author = {Mark S. George}, month = jun, year = {2001}, keywords = {neurostimulation; transcranial magnetic stimulation; vagus nerve; electroconvulsive therapy; magnetic seizure therapy; deep brain stimulation; clinical neuroscience}, pages = {{S95--S100}} }, @article{michael_treatment_2004, title = {Treatment of bipolar mania with right prefrontal rapid transcranial magnetic stimulation}, volume = {78}, issn = {0165-0327}, url = {http://www.sciencedirect.com/science/article/B6T2X-46Y5GVC-4/2/d53696689b3255cb73f27716527faa8b}, doi = {{10.1016/S0165-0327(02)00308-7}}, abstract = { Background: Transcranial magnetic stimulation {(TMS)} has been suggested for the treatment of a variety of {CNS} disorders including depression and mania. Methods: Nine bipolar {(I)} in-patients diagnosed with mania were treated with right prefrontal rapid {TMS} in an open and prospective study. Eight of nine patients received {TMS} as add-on treatment to an insufficient or only partially effective drug therapy. Results: During the 4 weeks of {TMS} treatment a sustained reduction of manic symptoms as measured by the {Bech-Rafaelsen} mania scale {(BRMAS)} was observed in all patients. Limitations: Due to the open and add-on design of the study, a clear causal relationship between {TMS} treatment and reduction of manic symptoms cannot be established. Conclusions: Our data suggest that right prefrontal rapid {TMS} is safe and efficacious in the add-on treatment of bipolar mania showing laterality opposed to the proposed effect of rapid {TMS} in depression.}, number = {3}, journal = {Journal of Affective Disorders}, author = {Nikolaus Michael and Andreas Erfurth}, month = mar, year = {2004}, keywords = {{Laterality,Mania,Prefrontal} {cortex,Transcranial} magnetic stimulation {(TMS),Treatment}}, pages = {253--257} }, @article{kurusu_long-latency_1999, title = {Long-latency reflexes in contracted hand and foot muscles and their relations to somatosensory evoked potentials and transcranial magnetic stimulation of the motor cortex}, volume = {110}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-3XV290T-4/2/32cca41d8037666ca1286ddcb4421db5}, doi = {{10.1016/S1388-2457(99)00166-2}}, abstract = { Objective: The cortical relay time {(CRT)} for V2 of long-latency reflexes {(LLRs)} in the contracted thenar and short toe flexor muscles was studied. Methods: {LLRs} and somatosensory evoked potentials {(SEPs)} were studied by electrical stimulation of the median or posterior tibial nerve. The {CRT} for V2 was calculated by subtracting the onset latency of cortical potentials in {SEPs} and that of motor evoked potentials {(MEPs)} by transcranial magnetic stimulation {(TMS)} from the onset latency of V2 in eight healthy subjects. Results: The {CRT} for the thenar muscles was 11.4±0.9 ms {(mean±SD),} as the onset latency was 48.8±1.4 ms for V2, 16.0±1.2 ms for N20 and 21.3±1.1 ms for {MEP,} respectively. The {CRT} for the short toe flexor muscles was 3.0±1.3 ms, as the onset latency was 80.5±4.5 ms for V2, 35.3±1.8 ms for P38 and 42.2±2.0 ms for {MEP,} respectively. Conclusion: Significantly longer {CRT} for V2 for the thenar muscles {(P{\textless}0.001,} paired Student's t test) may indicate more synaptic relays as compared to that for the short toe flexor muscles.}, number = {12}, journal = {Clinical Neurophysiology}, author = {Koji Kurusu and Jun-ichi Kitamura}, month = dec, year = {1999}, keywords = {Cortical relay {time,Foot} {muscles,Hand} {muscles,Long-latency} reflexes}, pages = {2014--2019} }, @article{mull_transcranial_2001, title = {Transcranial magnetic stimulation of left prefrontal cortex impairs working memory}, volume = {112}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-43RJ9D3-D/2/5ff109d1184811a99986608102c99ddc}, doi = {{10.1016/S1388-2457(01)00606-X}}, abstract = { Objectives: Several lines of evidence suggest that the prefrontal cortex is involved in working memory. Our goal was to determine whether transient functional disruption of the dorsolateral prefrontal cortex {(DLPFC)} would impair performance in a sequential-letter working memory task. Methods: Subjects were shown sequences of letters and asked to state whether the letter just displayed was the same as the one presented 3-back. Single-pulse transcranial magnetic stimulation {(TMS)} was applied over the {DLPFC} between letter presentations. Results: {TMS} applied over the left {DLPFC} resulted in increased errors relative to no {TMS} controls. {TMS} over the right {DLPFC} did not alter working memory performance. Conclusion: Our results indicate that the left prefrontal cortex has a crucial role in at least one type of working memory.}, number = {9}, journal = {Clinical Neurophysiology}, author = {Brendan R. Mull and Masud Seyal}, month = sep, year = {2001}, keywords = {Dorsolateral prefrontal {cortex,Functional} {disruption,Transcranial} magnetic {stimulation,Working} memory}, pages = {1672--1675} }, @article{hermelink_no_2000, title = {No evidence of lateralized effects on mood after slow repetitive transcranial magnetic stimulation {(rTMS)} in healthy volunteers}, volume = {10}, issn = {{0924-977X}}, url = {http://www.sciencedirect.com/science/article/B6T26-443VYY3-9H/2/0d5374d8ec1f23770901f2b46bfa25a1}, doi = {{10.1016/S0924-977X(00)80267-9}}, number = {Supplement 3}, journal = {European Neuropsychopharmacology}, author = {D. Hermelink and G. Juckel and P. Zwanzger and H. Hampel and H. {-J.} Möller and F. Padberg}, month = sep, year = {2000}, pages = {274} }, @article{oliveri_neurophysiological_2000, title = {Neurophysiological evaluation of tactile space perception deficits through transcranial magnetic stimulation}, volume = {5}, issn = {{1385-299X}}, url = {http://www.sciencedirect.com/science/article/B6T3N-3YSXS1K-4/2/8a2e7fa0b5dbdfbf401c4a7590911f79}, doi = {{10.1016/S1385-299X(99)00055-0}}, abstract = { We describe a procedure useful to investigate the contralateral space perception deficits frequently encountered in patients with unilateral right brain damage. In particular, we focused on the phenomenon of extinction, i.e., the failure to perceive a contralesional stimulus only when a symmetrical contralateral stimulus is simultaneously applied. Fifteen right brain- and 15 left brain-damaged patients were examined. Somatosensory perception was evaluated by using a dedicated electronic device able to provide electrical stimuli of variable intensity to digits of one or both hands. The electrical stimulator was able to trigger a magnetic brain stimulator connected with a focal figure of eight coil. Threshold electrical stimuli were delivered to one or both hands of the patients, who were asked to indicate whether they perceived the stimulus (i) and to localise it (them). The electrical stimulator was connected with a magnetic stimulator with an interstimulus interval {(ISI)} of 40 msec (electrical stimulation preceding the transcranial one). Focal threshold transcranial magnetic stimulation {(TMS)} was applied to frontal and parietal scalp sites of the unaffected hemisphere. At each interpulse interval we found that {TMS} of the unaffected hemisphere was associated to a decrease in the level of contralesional extinction. Our method demonstrates that a basic deficit underlying neglect and extinction of contralateral space in unilaterally brain damaged patients is the interhemispheric imbalance between the two hemispheres in directing contralateral attention. A transient interference with the function of the unaffected hemisphere can improve these deficits, suggesting a possible application of {TMS} in the daily clinical practice for speeding up recovery from {neglect.Themes:} Neural basis of {behaviourTopic:} Cognition}, number = {1}, journal = {Brain Research Protocols}, author = {Massimiliano Oliveri and Paolo Maria Rossini and Paola Cicinelli and Raimondo Traversa and Patrizio Pasqualetti and Maria Maddalena Filippi and Carlo Caltagirone}, month = feb, year = {2000}, keywords = {{Extinction,Neglect,Transcranial} magnetic stimulation}, pages = {25--29} }, @article{van_dongen_within_1999, title = {Within patient variability of lower extremity muscle responses to transcranial electrical stimulation with pulse trains in aortic surgery}, volume = {110}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-3WRJPRJ-K/2/c2858f73142e20fb78eff7972dd5a85f}, doi = {{10.1016/S1388-2457(99)00042-5}}, abstract = { Intraoperative recording of myogenic motor responses evoked by transcranial electrical stimulation is a method of controlling the integrity of the motor pathways during clamping of the aorta. It is important to know the within patient variability of the transcranial motor evoked potential {(tcMEP),} before changes within the variability range are interpreted as abnormal during the period of aortic cross clamping. Lower limb muscle responses were obtained in 11 patients, following transcranial electrical stimulation with pulse trains, of 4, 6 and 8 pulses. Under the conditions of partial neuromuscular blockade and a stable low dose propofol/fentanyl/nitrous oxide anaesthetic state, this study shows that multipulse transcranial electrical stimulation reliably produces muscle responses of the lower limb in all patients tested with a coefficient of variation {(CV)} of around 20\%. Eight pulses in the stimulation train produce neurophysiological facilitation that exceeds a 4 pulse train in terms of area under the curve {(AUC)} and response duration. The use of multipulse stimulation rather than double or single pulse stimulation is recommended in order to increase the clinical efficacy of {tcMEP} monitoring in aortic surgery.}, number = {6}, journal = {Clinical Neurophysiology}, author = {Eric P van Dongen and Huub T. ter Beek and Marc A. Schepens and Wim J. Morshuis and Anthonius de Boer and Leon P. Aarts and Eduard H. Boezeman}, month = jun, year = {1999}, keywords = {Intraoperative {monitoring,Motor} evoked {potential,Multipulse} transcranial electrical {stimulation,Partial} neuromuscular {blockade,Thoracoabdominal} aortic aneurysm surgery}, pages = {1144--1148} }, @article{chen_modulation_2000, title = {Modulation of symptomatic palatal tremor by magnetic stimulation of the motor cortex}, volume = {111}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-40MT2S1-6/2/2df0994472c17fbbce7bfa846702be88}, doi = {{10.1016/S1388-2457(00)00301-1}}, abstract = { Objectives: Magnetic stimulation of the motor cortex can be used to determine the involvement of the cortex in rhythmic movement disorders. Symptomatic palatal tremor {(SPT)} is thought to come from a pacemaker that is relatively resistant to internal and external stimulation. In this study, we investigated the effect of magnetic stimulation of motor cortex on {SPT.} Methods: Five male patients, aged 67-79 years, with {SPT} after brain stem infarction or hemorrhage, all had a synchronous mouth angle twitch with the palatal movement. Electromyographic activity was recorded with a monopolar needle electrode from orbicularis oris. In experiment 1, transcranial magnetic stimulation {(TMS)} was delivered at 200\% motor threshold {(MT)} to reset {SPT.} In experiment 2, the effect of {TMS} intensities was studied at 80-240\% {MT} in two {SPT} patients. To determine the influence of the {TMS,} we used the resetting index {(RI).} Results: {TMS} reset the tremor in all 5 {SPT} patients at 200\% {MT} with {RIs} of 0.86-0.96. The latency of the tremor reappearance after {TMS} was longer than the pre-stimulus tremor interval, and the intervals between the subsequent tremor bursts were also prolonged. The degree of tremor resetting was closely correlated with the magnetic stimulus intensity and the latency of the tremor reappearance after {TMS.} Conclusions: Stimulation of the motor cortex may modulate the generator of {SPT.}}, number = {7}, journal = {Clinical Neurophysiology}, author = {{Jen-Tse} Chen and {Hsiang-Yu} Yu and {Zin-An} Wu and {Ko-Pei} Kao and Mark Hallett and {Kwong-Kum} Liao}, month = jul, year = {2000}, keywords = {{Resetting,Symptomatic} palatal {tremor,Transcranial} magnetic stimulation}, pages = {1191--1197} }, @article{davey_modelingeffects_2003, title = {Modeling the effects of electrical conductivity of the head on the induced electric field in the brain during magnetic stimulation}, volume = {114}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-49FGX8P-1/2/2f98b0353283061b4929bef58aca6fe5}, doi = {{10.1016/S1388-2457(03)00240-2}}, abstract = { Objective: The objective of this document is to quantify the effect of changing conductivity within the brain in transcranial magnetic stimulation. Methods: Extreme examples of white and grey matter distributions as well as cerebral spinal fluid are analyzed with numerical boundary element methods to show that the induced E fields for these various distributions vary little from the homogeneous case. Results: Models representative of the brain that demarcate regions of white matter and grey matter add an unnecessary level of complexity to the design and analysis of magnetic stimulators. The induced E field varies little between a precise model with exact placement of white and grey matter from that of its homogeneous counterpart. The E field will increase in white matter, and decrease in grey, but the variation is small. The contour integral of the E field around a closed path is dictated by the flux change through that contour. Discussion: The maximum value of the variation of the electric field between a fully homogeneous medium, and one filled with different conductivity media is 1/2 the conductivity ratio of the media involved. Neuronal stimulation is more likely at the interface between dissimilar mediums, the greatest being between white matter and cerebral spinal fluid. The interface location where no normal electric field exists will witness a localized electric field 51\% greater than the homogeneous E field on the white matter side of that interface. White-grey matter interfaces will have a maximum localized increase in the E field 22.9\% greater than the homogeneous case. Conclusions: Variations in neural intracellular potential during a magnetic stimulation pulse will be small among patients. The most efficient modeling will follow by assuming the medium homogeneous, and noting that perturbations from this result will exist.}, number = {11}, journal = {Clinical Neurophysiology}, author = {Kent Davey and Charles M. Epstein and Mark S. George and Daryl E. Bohning}, month = nov, year = {2003}, pages = {2204--2209} }, @article{george_vagus_2000, title = {Vagus nerve stimulation: a new tool for brain research and therapy*}, volume = {47}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-3YMFKRF-3/2/5de78fb64c27a14f891426a351d3bccb}, doi = {{10.1016/S0006-3223(99)00308-X}}, abstract = { Biological psychiatry has a long history of using somatic therapies to treat neuropsychiatric illnesses and to understand brain function. These methods have included neurosurgery, electroconvulsive therapy, and, most recently, transcranial magnetic stimulation. Fourteen years ago researchers discovered that intermittent electrical stimulation of the vagus nerve produces inhibition of neural processes, which can alter brain electrical activity and terminate seizures in dogs. Since then, approximately 6000 people worldwide have received vagus nerve stimulation for treatment-resistant epilepsy. We review the neurobiology and anatomy of the vagus nerve and provide an overview of the vagus nerve stimulation technique. We also describe the safety and potential utility of vagus nerve stimulation as a neuroscience research tool and as a putative treatment for psychiatric conditions. Vagus nerve stimulation appears to be a promising new somatic intervention that may improve our understanding of brain function and has promise in the treatment of neuropsychiatric disorders.}, number = {4}, journal = {Biological Psychiatry}, author = {Mark S. George and Harold A. Sackeim and A. John Rush and Lauren B. Marangell and Ziad Nahas and Mustafa M. Husain and Sarah Lisanby and Tal Burt and Juliet Goldman and James C. Ballenger}, month = feb, year = {2000}, keywords = {antidepressant,brain stimulation,depression,locus {ceruleus,Vagus} nerve}, pages = {287--295} }, @article{dalfonso_laterality_2000, title = {Laterality effects in selective attention to threat after repetitive transcranial magnetic stimulation at the prefrontal cortex in female subjects}, volume = {280}, number = {3}, journal = {Neuroscience Letters}, author = {A. A. L. {d'Alfonso} and J. van Honk and E. Hermans and A. Postma and E. H. F. de Haan}, year = {2000}, pages = {195--198} }, @article{hoffman_transcranial_1999, title = {Transcranial magnetic stimulation of left temporoparietal cortex in three patients reporting hallucinated "voices"}, volume = {46}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-3WWMMV1-K/2/70a71925723124313e918c46de95f386}, doi = {{10.1016/S0006-3223(98)00358-8}}, abstract = { Background: Prior studies suggest that auditory hallucinations of "voices" arise from activation of speech perception areas of the cerebral cortex. Low frequency transcranial magnetic stimulation {(TMS)} can reduce cortical activation. Methods: We have studied three schizophrenic patients reporting persistent auditory hallucinations to determine if low frequency {TMS} could curtail these experiences. One hertz stimulation of left temporoparietal cortex was compared with sham stimulation using a double-blind, cross-over design. Results: All three patients demonstrated greater improvement in hallucination severity following active stimulation compared to sham stimulation. Two of the three patients reported near total cessation of hallucinations for [greater-or-equal, slanted] 2 weeks. Conclusions: {TMS} may advance our understanding of the mechanism and treatment of auditory hallucinations.}, number = {1}, journal = {Biological Psychiatry}, author = {Ralph E. Hoffman and Nashaat N. Boutros and Robert M. Berman and Elizabeth Roessler and Aysenil Belger and John H. Krystal and Dennis S. Charney}, month = jul, year = {1999}, keywords = {Auditory hallucinations,cerebral cortex,psychosis,schizophrenia,speech processing,transcranial magnetic stimulation}, pages = {130--132} }, @article{gangitano_modulation_2002, title = {Modulation of input-output curves by low and high frequency repetitive transcranial magnetic stimulation of the motor cortex}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-45R7XWT-1/2/8baea86a125727fb44fef3ef9741c765}, doi = {{10.1016/S1388-2457(02)00109-8}}, abstract = { Objectives: Exploring the modulatory effects of different frequencies of repetitive transcranial magnetic stimulation {(rTMS)} on the excitability of the motor cortex as measured by the input-output curve technique {(I-O} curve). Methods: Sixteen healthy subjects participated in this experiment. On two different sessions, conducted 1 week apart, {rTMS} was applied either at a frequency of 20 or 1 Hz at 90\% of individual motor threshold {(MT)} for a total of 1600 pulses each. Before and after {rTMS,} the cortical excitability was assessed by measuring {MT} and the size of motor evoked potentials {(MEPs)} collected at different intensities of stimulation. Results: The analysis on the whole population showed a significant decrease of cortical excitability after 1 Hz {rTMS} and an increase after 20 Hz {rTMS.} A subsequent cluster analysis pointed out the presence of two distinct groups of subjects with opposite responses at the same frequency of stimulation. Significant variations on {MT} were found for both groups only for the facilitatory effect irrespective of the frequency of stimulation. Conclusions: The results provide further insight into interindividual differences in the effects of {rTMS} and suggest the existence of subpopulations with specific patterns of response to {rTMS.}}, number = {8}, journal = {Clinical Neurophysiology}, author = {Massimo Gangitano and Antoni {Valero-Cabré} and José Maria Tormos and Felix Manuel Mottaghy and Jose Rafael Romero and Álvaro {Pascual-Leone}}, month = aug, year = {2002}, keywords = {Cortical {excitability,Input-output} {curve,Repetitive} transcranial magnetic stimulation}, pages = {1249--1257} }, @article{terao_predominant_2000, title = {Predominant activation of I1-waves from the leg motor area by transcranial magnetic stimulation}, volume = {859}, issn = {0006-8993}, url = {http://www.sciencedirect.com/science/article/B6SYR-3YSXPNG-H/2/6dc35626adba1a3968925151e1a8b199}, doi = {{10.1016/S0006-8993(00)01975-2}}, abstract = { We performed transcranial magnetic stimulation {(TMS)} to elucidate the D- and I-wave components comprising the motor evoked potentials {(MEPs)} elicited from the leg motor area, especially at near-threshold intensity. Recordings were made from the tibialis anterior muscle using needle electrodes. A figure-of-eight coil was placed so as to induce current in the brain in eight different directions, starting from the posterior-to-anterior direction and rotating it in 45° steps. The latencies were compared with those evoked by transcranial electrical stimulation {(TES)} and {TMS} using a double cone coil. Although the latencies of {MEPs} ranged from D to I3 waves, the most prominent component evoked by {TMS} at near-threshold intensity represented the I1 wave. With the double cone coil, the elicited peaks always represented I1 waves, and D waves were evoked only at very high stimulus intensities, suggesting a high effectiveness of this coil in inducing I1 waves. Using the figure-of-eight coil, current flowing anteriorly or toward the hemisphere contralateral to the recorded muscle was more effective in eliciting large responses than current flowing posteriorly or toward the ipsilateral hemisphere. The effective directions induced I1 waves with the lowest threshold, whereas the less effective directions elicited I1 and I2 waves with a similar frequency. Higher stimulus intensities resulted in concomitant activation of D through I3 waves with increasing amount of D waves, but still the predominance of I1 waves was apparent. The amount of I waves, especially of I1 waves, was greater than predicted by the hypothesis that {TMS} over the leg motor area activates the output cells directly, but rather suggests predominant transsynaptic activation. The results accord with those of recent human epidural recordings.}, number = {1}, journal = {Brain Research}, author = {Yasuo Terao and Yoshikazu Ugawa and Ritsuko Hanajima and Katsuyuki Machii and Toshiaki Furubayashi and Hitoshi Mochizuki and Hiroyuki Enomoto and Yasushi Shiio and Haruo Uesugi and Nobue K. Iwata and Ichiro Kanazawa}, month = mar, year = {2000}, keywords = {{I-wave,Leg} motor {area,Transcranial} magnetic stimulation}, pages = {137--146} }, @article{liederman_role_2003, title = {The role of motion direction selective extrastriate regions in reading: a transcranial magnetic stimulation study}, volume = {85}, issn = {{0093-934X}}, url = {http://www.sciencedirect.com/science/article/B6WC0-485P7BP-2/2/498d67830938b591caf3c5f82f07b455}, doi = {{10.1016/S0093-934X(02)00550-3}}, abstract = { Why reading ability is correlated with motion processing ability is perplexing. Activity in motion direction processing regions {(Area} {V5/MT+)} was perturbed by means of repetitive transcranial magnetic stimulation {(rTMS)} to examine its effect on reading. A functional probe (significant shortening of the motion aftereffect) was used to identify Area {V5/MT+.} Right-handed participants (8 m, 8 f) received three 7.5 min blocks of {rTMS,} after which two phonological and one orthographic reading tasks were administered. Application of {rTMS} to Area {V5/MT+} (as compared to a {non-rTMS} baseline) significantly decreased performance only during non-word naming. The pattern of naming errors and the absence of deficits on the second phonological task were not consistent with a role for Area {V5/MT+} in phonological decoding. Instead, its role in reading may be limited to image stabilization and/or letter localization.}, number = {1}, journal = {Brain and Language}, author = {Jacqueline Liederman and Janet {McGraw} Fisher and Marcela Schulz and Carolyn Maxwell and Hugo Théoret and Alvaro {Pascual-Leone}}, month = apr, year = {2003}, keywords = {{Dyslexia,Phonological} {processing,Reading,TMS}}, pages = {140--155} }, @article{levkovitz_transcranial_2001, title = {Transcranial magnetic stimulation and antidepressive drugs share similar cellular effects in rat hippocampus}, volume = {24}, issn = {{0893-133X}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/11331140}, doi = {{10.1016/S0893-133X(00)00244-X}}, abstract = {Transcranial magnetic stimulation {(TMS)} has been proposed as a safe and efficient treatment of human clinical depression. Although its antidepressive mechanism of action remained unknown, our previous studies indicate that {TMS} has a long-lasting effect on neuronal excitability in the hippocampus. We now compare the effects of chronic {TMS} with those of the antidepressant drugs desipramine and mianserin. The three treatments did not affect basal conduction in the perforant path to the dentate gyrus, but markedly suppressed paired-pulse and frequency-dependent inhibition, resulting from a reduction in local circuit inhibition in the dentate gyrus. Concomitantly, these treatments enhanced the expression of long-term potentiation in the perforant path synapse in the dentate gyrus. Finally, chronic {TMS} as well as mianserin suppressed the serotonin-dependent, potentiating action of fenfluramine on population spike in the dentate gyrus. Thus, {TMS,} mianserin, and desipramine are likely to affect the same neuronal populations, which may be relevant to their antidepressant action.}, number = {6}, journal = {Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology}, author = {Y Levkovitz and N Grisaru and M Segal}, month = jun, year = {2001}, note = {{PMID:} 11331140}, keywords = {Action {Potentials,Adrenergic} {alpha-Antagonists,Adrenergic} Uptake {Inhibitors,Animals,Antidepressive} {Agents,Desipramine,Electric} {Stimulation,Electric} Stimulation {Therapy,Excitatory} Postsynaptic {Potentials,Fenfluramine,Hippocampus,Long-Term} {Potentiation,Male,Mianserin,Neural} {Inhibition,Neurons,Rats,Rats,} {Long-Evans,Serotonin,Serotonin} Uptake {Inhibitors,Synaptic} {Transmission,Transcranial} Magnetic Stimulation}, pages = {608--16} }, @article{boroojerdi_localization_1999, title = {Localization of the motor hand area using transcranial magnetic stimulation and functional magnetic resonance imaging}, volume = {110}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-3WKY242-J/2/8002f788be2738ce9f12151cfaa88d36}, doi = {{10.1016/S1388-2457(98)00027-3}}, abstract = { Objective: The anatomical location of the motor area of the hand may be revealed using functional magnetic resonance imaging {(fMRI).} The motor cortex representation of the intrinsic hand muscles consists of a knob-like structure. This is omega- or epsilon-shaped in the axial plane and hook-shaped in the sagittal plane. As this knob lies on the surface of the brain, it can be stimulated non-invasively by transcranial magnetic stimulation {(TMS).} It was the aim of our study to identify the hand knob using {fMRI} and to reveal if the anatomical hand knob corresponds to the hand area of the motor cortex, as identified by {TMS,} by means of a frameless {MRI-based} neuronavigation system. Methods: Suprathreshold transcranial magnetic stimuli were applied over a grid on the left side of the scalp of 4 healthy volunteers. The motor evoked potentials {(MEPs)} were recorded from the contralateral small hand muscles, and the centers of gravity {(CoG)} of the {MEPs} were calculated. The exact anatomical localization of each point on the grid was determined using a frameless {MRI-based} neuronavigation system. In each subject, the hand area of the motor cortex was visualized using {fMRI} during sensorimotor activation achieved by clenching the right hand. Results: In all 4 subjects, the activated precentral site in the {fMRI} and the {CoG} of the {MEP} of all investigated muscles lay within the predicted anatomical area, the so-called hand knob. This knob had the form of an omega in two subjects and an epsilon in the other two subjects. Conclusions: {TMS} is a reliable method for mapping the motor cortex. The {CoG} calculated from the motor output maps may be used as an accurate estimation of the location of the represented muscle in the motor cortex.}, number = {4}, journal = {Clinical Neurophysiology}, author = {B. Boroojerdi and H. Foltys and T. Krings and U. Spetzger and A. Thron and R. Töpper}, month = apr, year = {1999}, keywords = {Functional magnetic resonance {imaging,Hand} {knob,Motorcortex} {mapping,Transcranial} magnetic stimulation}, pages = {699--704} }, @article{romero_subthreshold_2002, title = {Subthreshold low frequency repetitive transcranial magnetic stimulation selectively decreases facilitation in the motor cortex}, volume = {113}, issn = {1388-2457}, url = {http://www.sciencedirect.com/science/article/B6VNP-44B24KC-1/2/cf12ac78f33364e29ac79c25bb2bd509}, doi = {{10.1016/S1388-2457(01)00693-9}}, abstract = { Objective: To investigate the modulatory effect of a subthreshold low frequency repetitive transcranial magnetic stimulation {(rTMS)} train on motor cortex excitability. Methods: The study consisted of two separate experiments. Subjects received a 10 min long subthreshold 1 Hz {rTMS} train. In the first experiment, (single pulse paradigm), cortical excitability was assessed by measuring the amplitude of motor evoked potentials {(MEPs)} before and after the {rTMS} train. In the second experiment, a paired pulse paradigm was employed. Results: Corticospinal excitability, as measured by the {MEP} amplitude, was reduced by the {rTMS} train (experiment 1), with a significant effect lasting for about 10 min after the train completion. There was notable inter-individual as well as intra-individual variability in the effect. {rTMS} produced a significant decrease in intra-cortical facilitation as measured by the paired pulse paradigm (experiment 2). This effect lasted for up to 15 min following the train. Intra-cortical inhibition was not significantly affected. Conclusions: Subthreshold low frequency {rTMS} depresses cortical excitability beyond the duration of the train. This effect seems primarily due to cortical dysfacilitation. These results have implications on the therapeutic use of {rTMS.}}, number = {1}, journal = {Clinical Neurophysiology}, author = {Jose Rafael Romero and David Anschel and Roland Sparing and Massimo Gangitano and Alvaro {Pascual-Leone}}, year = {2002}, keywords = {Cortical {excitability,Human} motor {cortex,Intra-cortical} {circuits,Modulation,Repetitive} transcranial magnetic stimulation}, pages = {101--107} }, @article{schreiber_right_2002, title = {Right prefrontal {rTMS} treatment for refractory auditory command hallucinations - a {neuroSPECT} assisted case study}, volume = {116}, issn = {0925-4927}, url = {http://www.sciencedirect.com/science/article/B6TBW-474CXDD-B/2/90ab907f0f7310e4f3b6daa9673168f3}, doi = {{10.1016/S0925-4927(02)00065-3}}, abstract = { Auditory command hallucinations probably arise from the patient's failure to monitor his/her own [`]inner speech', which is connected to activation of speech perception areas of the left cerebral cortex and to various degrees of dysfunction of cortical circuits involved in schizophrenia as supported by functional brain imaging. We hypothesized that rapid transcranial magnetic stimulation {(rTMS),} by increasing cortical activation of the right prefrontal brain region, would bring about a reduction of the hallucinations. We report our first schizophrenic patient affected with refractory command hallucinations treated with 10 Hz {rTMS.} Treatment was performed over the right dorsolateral prefrontal cortex, with 1200 magnetic stimulations administered daily for 20 days at 90\% motor threshold. Regional cerebral blood flow changes were monitored with {neuroSPECT.} Clinical evaluation and scores on the Positive and Negative Symptoms Scale and the Brief Psychiatric Rating Scale demonstrated a global improvement in the patient's condition, with no change in the intensity and frequency of the hallucinations. {NeuroSPECT} performed at intervals during and after treatment indicated a general improvement in cerebral perfusion. We conclude that right prefrontal {rTMS} may induce a general clinical improvement of schizophrenic brain function, without directly influencing the mechanism involved in auditory command hallucinations.}, number = {1-2}, journal = {Psychiatry Research: Neuroimaging}, author = {Shaul Schreiber and Pinhas N. Dannon and Elinor Goshen and Revital Amiaz and Tzila S. Zwas and Leon Grunhaus}, month = nov, year = {2002}, keywords = {Auditory command {hallucinations,Cerebral} {cortex,Rapid} transcranial magnetic {stimulation,Schizophrenia,Single} photon emission computed tomography}, pages = {113--117} }, @article{pridmore_transcranial_2000, title = {Transcranial magnetic stimulation applications and potential use in chronic pain: studies in waiting}, volume = {182}, issn = {{0022-510X}}, url = {http://www.ncbi.nlm.nih.gov/pubmed/11102633}, abstract = {Transcranial magnetic stimulation {(TMS)} is a new technology which uses electromagnetic principles to produce small electrical currents in the cortex. Evidence indicates that {TMS} can produce plastic changes in the {CNS} which are observable at both the cellular and physiological levels. It is proposed that studies are justified to determine whether {TMS} can provide short-term or long-term relief in chronic pain.}, number = {1}, journal = {Journal of the Neurological Sciences}, author = {S Pridmore and G Oberoi}, month = dec, year = {2000}, note = {{PMID:} 11102633}, keywords = {{Animals,Brain,Chronic} {Disease,Electric} Stimulation {Therapy,Electromagnetic} {Phenomena,Glial} Fibrillary Acidic {Protein,Pain,Spinal} Cord}, pages = {1--4} }, @article{speer_opposite_2000, title = {Opposite effects of high and low frequency {rTMS} on regional brain activity in depressed patients}, volume = {48}, issn = {0006-3223}, url = {http://www.sciencedirect.com/science/article/B6T4S-41Y86F8-3/2/e3c562643e8ad9404cb69089a1bdf518}, doi = {{10.1016/S0006-3223(00)01065-9}}, abstract = { Background: High (10-20 Hz) and low frequency (1-5 Hz) repetitive transcranial magnetic stimulation {(rTMS)} have been explored for possible therapeutic effects in the treatment of neuropsychiatric disorders. As part of a double-blind, placebo-controlled, crossover study evaluating the antidepressant effect of daily {rTMS} over the left prefrontal cortex, we evaluated changes in absolute regional cerebral blood flow {(rCBF)} after treatment with 1- and {20-Hz} {rTMS.} Based on preclinical data, we postulated that high frequency {rTMS} would increase and low frequency {rTMS} would decrease flow in frontal and related subcortical circuits. Methods: Ten medication-free, adult patients with major depression (eight unipolar and two bipolar) were serially imaged using {15O} water and positron emission tomography to measure {rCBF.} Each patient was scanned at baseline and 72 hours after 10 daily treatments with {20-Hz} {rTMS} and 10 daily treatments with 1 Hz {rTMS} given in a randomized order. {TMS} was administered over the left prefrontal cortex at 100\% of motor threshold {(MT).} Significant changes in {rCBF} from pretreatment baseline were determined by paired t test. Results: Twenty-hertz {rTMS} over the left prefrontal cortex was associated only with increases in {rCBF.} Significant increases in {rCBF} across the group of all 10 patients were located in the prefrontal cortex {(L} {\textgreater} R), the cingulate gyrus {(L} {\textgreater}{\textgreater} R), and the left amygdala, as well as bilateral insula, basal ganglia, uncus, hippocampus, parahippocampus, thalamus, and cerebellum. In contrast, {1-Hz} {rTMS} was associated only with decreases in {rCBF.} Significant decreases in flow were noted in small areas of the right prefrontal cortex, left medial temporal cortex, left basal ganglia, and left amygdala. The changes in mood following the two {rTMS} frequencies were inversely related (r = -.78, p {\textless} .005, n = 10) such that individuals who improved with one frequency worsened with the other. Conclusions: These data indicate that 2 weeks of daily {20-Hz} {rTMS} over the left prefrontal cortex at 100\% {MT} induce persistent increases in {rCBF} in bilateral frontal, limbic, and paralimbic regions implicated in depression, whereas {1-Hz} {rTMS} produces more circumscribed decreases (including in the left amygdala). These data demonstrate frequency-dependent, opposite effects of high and low frequency {rTMS} on local and distant regional brain activity that may have important implications for clinical therapeutics in various neuropsychiatric disorders.}, number = {12}, journal = {Biological Psychiatry}, author = {Andrew M. Speer and Timothy A. Kimbrell and Eric M. Wassermann and Jennifer D. Repella and Mark W. Willis and Peter Herscovitch and Robert M. Post}, month = dec, year = {2000}, keywords = {depressed,high frequency (20 Hz),low frequency (1 Hz),positron emission tomography,regional cerebral blood {flow,Transcranial} magnetic stimulation}, pages = {1133--1141} }