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1

Transcranial magnetic stimulation: Improved coil design for deep brain investigation  

NASA Astrophysics Data System (ADS)

This paper reports on a design for a coil for transcranial magnetic stimulation. The design shows potential for improving the penetration depth of the magnetic field, allowing stimulation of subcortical structures within the brain. The magnetic and induced electric fields in the human head have been calculated with finite element electromagnetic modeling software and compared with empirical measurements. Results show that the coil design used gives improved penetration depth, but also indicates the likelihood of stimulation of additional tissue resulting from the spatial distribution of the magnetic field.

Crowther, L. J.; Marketos, P.; Williams, P. I.; Melikhov, Y.; Jiles, D. C.; Starzewski, J. H.

2011-04-01

2

Deep transcranial magnetic stimulation as a treatment for psychiatric disorders: a comprehensive review.  

PubMed

Deep transcranial magnetic stimulation (TMS) is a technique of neuromodulation and neurostimulation based on the principle of electromagnetic induction of an electric field in the brain. The coil (H-coil) used in deep TMS is able to modulate cortical excitability up to a maximum depth of 6 cm and is therefore able not only to modulate the activity of the cerebral cortex but also the activity of deeper neural circuits. Deep TMS is largely used for the treatment of drug-resistant major depressive disorder (MDD) and is being tested to treat a very wide range of neurological, psychiatric and medical conditions. The aim of this review is to illustrate the biophysical principles of deep TMS, to explain the pathophysiological basis for its utilization in each psychiatric disorder (major depression, autism, bipolar depression, auditory hallucinations, negative symptoms of schizophrenia), to summarize the results presented thus far in the international scientific literature regarding the use of deep TMS in psychiatry, its side effects and its effects on cognitive functions. PMID:22559998

Bersani, F S; Minichino, A; Enticott, P G; Mazzarini, L; Khan, N; Antonacci, G; Raccah, R N; Salviati, M; Delle Chiaie, R; Bersani, G; Fitzgerald, P B; Biondi, M

2012-05-03

3

Deep transcranial magnetic stimulation for the treatment of auditory hallucinations: a preliminary open-label study  

PubMed Central

Background Schizophrenia is a chronic and disabling disease that presents with delusions and hallucinations. Auditory hallucinations are usually expressed as voices speaking to or about the patient. Previous studies have examined the effect of repetitive transcranial magnetic stimulation (TMS) over the temporoparietal cortex on auditory hallucinations in schizophrenic patients. Our aim was to explore the potential effect of deep TMS, using the H coil over the same brain region on auditory hallucinations. Patients and methods Eight schizophrenic patients with refractory auditory hallucinations were recruited, mainly from Beer Ya'akov Mental Health Institution (Tel Aviv university, Israel) ambulatory clinics, as well as from other hospitals outpatient populations. Low-frequency deep TMS was applied for 10 min (600 pulses per session) to the left temporoparietal cortex for either 10 or 20 sessions. Deep TMS was applied using Brainsway's H1 coil apparatus. Patients were evaluated using the Auditory Hallucinations Rating Scale (AHRS) as well as the Scale for the Assessment of Positive Symptoms scores (SAPS), Clinical Global Impressions (CGI) scale, and the Scale for Assessment of Negative Symptoms (SANS). Results This preliminary study demonstrated a significant improvement in AHRS score (an average reduction of 31.7% ± 32.2%) and to a lesser extent improvement in SAPS results (an average reduction of 16.5% ± 20.3%). Conclusions In this study, we have demonstrated the potential of deep TMS treatment over the temporoparietal cortex as an add-on treatment for chronic auditory hallucinations in schizophrenic patients. Larger samples in a double-blind sham-controlled design are now being preformed to evaluate the effectiveness of deep TMS treatment for auditory hallucinations. Trial registration This trial is registered with clinicaltrials.gov (identifier: NCT00564096).

2011-01-01

4

Deep Transcranial Magnetic Stimulation for treatment-resistant bipolar depression: A case report of acute and maintenance efficacy.  

PubMed

Deep Transcranial Magnetic Stimulation (dTMS) is currently being evaluated as a possible treatment for several neuropsychiatric disorders and has been demonstrated as a safe and effective procedure. This case presents a patient with bipolar depression that has been treated with 20 daily consecutive dTMS sessions and with one dTMS session every 2 weeks for the following 3 months. Depressive symptoms improved rapidly and response was maintained during the next 6 months; cognitive performances also improved. This report suggests that add-on dTMS may help overcoming drug-resistance in bipolar depression and protect from subsequent bipolar episodes of any polarity. PMID:22827578

Bersani, Francesco Saverio; Girardi, Nicoletta; Sanna, Livia; Mazzarini, Lorenzo; Santucci, Chiara; Kotzalidis, Giorgio D; Sani, Gabriele; Rossi, Pietro De; Raccah, Ruggero N; Caltagirone, Saverio Simone; Battipaglia, Mariella; Capezzuto, Silvia; Bersani, Giuseppe; Girardi, Paolo

2012-07-24

5

Deep transcranial magnetic stimulation add-on for the treatment of auditory hallucinations: a double-blind study  

PubMed Central

Background About 25% of schizophrenia patients with auditory hallucinations are refractory to pharmacotherapy and electroconvulsive therapy. We conducted a deep transcranial magnetic stimulation (TMS) pilot study in order to evaluate the potential clinical benefit of repeated left temporoparietal cortex stimulation in these patients. The results were encouraging, but a sham-controlled study was needed to rule out a placebo effect. Methods A total of 18 schizophrenic patients with refractory auditory hallucinations were recruited, from Beer Yaakov MHC and other hospitals outpatient populations. Patients received 10 daily treatment sessions with low-frequency (1 Hz for 10 min) deep TMS applied over the left temporoparietal cortex, using the H1 coil at the intensity of 110% of the motor threshold. Procedure was either real or sham according to patient randomization. Patients were evaluated via the Auditory Hallucinations Rating Scale, Scale for the Assessment of Positive Symptoms-Negative Symptoms, Clinical Global Impressions, and Quality of Life Questionnaire. Results In all, 10 patients completed the treatment (10 TMS sessions). Auditory hallucination scores of both groups improved; however, there was no statistical difference in any of the scales between the active and the sham treated groups. Conclusions Low-frequency deep TMS to the left temporoparietal cortex using the protocol mentioned above has no statistically significant effect on auditory hallucinations or the other clinical scales measured in schizophrenic patients. Trial Registration Clinicaltrials.gov identifier: NCT00564096.

2012-01-01

6

Transcranial magnetic stimulation in ALS  

PubMed Central

Objective: To investigate transcranial magnetic stimulation (TMS) measures as clinical correlates and longitudinal markers of amyotrophic lateral sclerosis (ALS). Methods: We prospectively studied 60 patients with ALS subtypes (sporadic ALS, familial ALS, progressive muscular atrophy, and primary lateral sclerosis) using single pulse TMS, recording from abductor digiti minimi (ADM) and tibialis anterior (TA) muscles. We evaluated three measures: 1) TMS motor response threshold to the ADM, 2) central motor conduction time (CMCT), and 3) motor evoked potential amplitude (correcting for peripheral changes). Patients were evaluated at baseline, compared with controls, and followed every 3 months for up to six visits. Changes were analyzed using generalized estimation equations to test linear trends with time. Results: TMS threshold, CMCT, and TMS amplitude correlated (p < 0.05) with clinical upper motor neuron (UMN) signs at baseline and were different (p < 0.05) from normal controls in at least one response. Seventy-eight percent of patients with UMN (41/52) and 50% (4/8) of patients without clinical UMN signs had prolonged CMCT. All three measures revealed significant deterioration over time: TMS amplitude showed the greatest change, decreasing 8% per month; threshold increased 1.8% per month; and CMCT increased by 0.9% per month. Conclusions: Transcranial magnetic stimulation (TMS) findings, particularly TMS amplitude, can objectively discriminate corticospinal tract involvement in amyotrophic lateral sclerosis (ALS) from controls and assess the progression of ALS. While central motor conduction time and response threshold worsen by less than 2% per month, TMS amplitude decrease averages 8% per month, and may be a useful objective marker of disease progression. GLOSSARY ADM = abductor digiti minimi; ALS = amyotrophic lateral sclerosis; ANOVA = analysis of variance; CI = confidence interval; CMAP = compound motor action potential; CMCT = central motor conduction time; DTR = deep tendon stretch reflex; fALS = familial ALS; GEE = generalized estimation equations; LMN = lower motor neuron; MEP = motor evoked potential; PLS = primary lateral sclerosis; PMA = progressive muscular atrophy; sALS = sporadic ALS; TA = tibialis anterior; TMS = transcranial magnetic stimulation; UMN = upper motor neuron.

Floyd, A G.; Yu, Q P.; Piboolnurak, P; Tang, M X.; Fang, Y; Smith, W A.; Yim, J; Rowland, L P.; Mitsumoto, H; Pullman, S L.

2009-01-01

7

Transcranial magnetic stimulation: the method and application  

Microsoft Academic Search

Summary. Transcranial magnetic stimulation is a noninvasive method for stimulation of brain that is based on the ability of magnetic field to penetrate skull and brain meninges, subsequently inducing electric current in the brain tissues that produces neuronal depolarization and generation of action potentials. Moreover, transcranial magnetic stimulation has effects on neurochemical and synaptic processes in neurons. Due to its

Jacqueline Höppner; Osvaldas Rukš?nas

2006-01-01

8

Transcranial magnetic stimulation for central pain  

Microsoft Academic Search

Transcranial magnetic stimulation recently has emerged as a therapeutic tool in neurology and psychiatry, with contradictory\\u000a results. Central pain, a major chronic pain syndrome affecting millions of people worldwide, has been the focus of a few studies.\\u000a Although transcranial magnetic stimulation has no role in the chronic management of such pain, it has potential as a screening\\u000a procedure for the

Sergio Canavero; Vincenzo Bonicalzi

2005-01-01

9

Transcranial Magnetic Stimulation in Children  

PubMed Central

Developmental disabilities (e.g. attention deficit disorder; cerebral palsy) are frequently associated with deviations of the typical pattern of motor skill maturation. Neurophysiologic tools, such as transcranial magnetic stimulation (TMS), which probe motor cortex function, can potentially provide insights into both typical neuromotor maturation and the mechanisms underlying the motor skill deficits in children with developmental disabilities. These insights may set the stage for finding effective interventions for these disorders. We review the literature pertaining to the use of TMS in pediatrics. Most TMS-evoked parameters show age-related changes in typically developing children and some of these are abnormal in a number of childhood-onset neurological disorders. Although no TMS-evoked parameters are diagnostic for any disorder, changes in certain parameters appear to reflect disease burden or may provide a measure of treatment-related improvement. Furthermore, TMS may be especially useful when combined with other neurophysiologic modalities (e.g. fMRI). However, much work remains to be done to determine if TMS-evoked parameters can be used as valid and reliable biomarkers for disease-burden, the natural history of neurological injury and repair, and the efficacy of pharmacological and rehabilitation interventions.

Garvey, Marjorie A.; Mall, Volker

2008-01-01

10

Three-dimensional distribution of the electric field induced in the brain by transcranial magnetic stimulation using figure-8 and deep H-coils.  

PubMed

The H-coils are a novel development in transcranial magnetic stimulation (TMS), designed to achieve effective stimulation of deep neuronal regions without inducing unbearable fields cortically, thus broadly expanding the potential feasibility of TMS for research and for treating various neurologic disorders. This study compared the field distribution of two H-coil versions, termed H1 and H2, and of a standard figure-of-eight coil. Three-dimensional electrical field distributions of the H1 and H2-coils, designed for effective stimulation of prefrontal regions, and of a standard figure-8 coil, were measured in a head model filled with physiologic saline solution. With stimulator output at 120% of the hand motor threshold, suprathreshold field is induced by the H1-coil at lateral and medial frontal regions at depths of up to 4 to 5 cm, and by the H2-coil at medial prefrontal regions up to 2 to 3 cm, and at lateral frontal regions up to 5 to 6 cm. The figure-8 coil induced suprathreshold field focally under the coil's central segment, at depths of up to 1.5 cm. The ability of the H-coils to stimulate effectively deeper neuronal structures is obtained at the cost of a wider electrical field distribution in the brain. However, the H-coils enable simultaneous stimulation of several brain regions, whereas the depth penetration in each region can be controlled either by adjusting the stimulator output, and/or by varying the distance between various coil elements and the skull. PMID:17277575

Roth, Yiftach; Amir, Alon; Levkovitz, Yechiel; Zangen, Abraham

2007-02-01

11

Transcranial magnetic stimulation and the human brain  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) is rapidly developing as a powerful, non-invasive tool for studying the human brain. A pulsed magnetic field creates current flow in the brain and can temporarily excite or inhibit specific areas. TMS of motor cortex can produce a muscle twitch or block movement; TMS of occipital cortex can produce visual phosphenes or scotomas. TMS can also

Mark Hallett

2000-01-01

12

Pain During Transcranial Magnetic Stimulation in Youth  

PubMed Central

Pain or discomfort at the site of stimulation is a common side effect of transcranial magnetic stimulation. Relevant physiology and predisposing factors have not been adequately described. Literature regarding work with minors is even more limited. The authors present two cases from a child and adolescent neurophysiology transcranial magnetic stimulation protocol and one case from a therapeutic study of repetitive transcranial magnetic stimulation in adolescents with treatment-resistant major depressive disorder. Relevant literature is reviewed. Potential subjects, parents, and study teams should be well aware of this potential side effect in child and adolescent populations. Subjects with anxiety disorders may be prone to pain during these procedures. Further work could assist in identifying predisposed individuals, refining the informed consent process, and implementing procedures to minimize discomfort.

Wall, Christopher A.; King, Jessica D.; Andrew Kozel, F.; Daskalakis, Zafiris J.

2011-01-01

13

Transcranial Magnetic Stimulation Intensities in Cognitive Paradigms  

Microsoft Academic Search

BackgroundTranscranial magnetic stimulation (TMS) has become an important experimental tool for exploring the brain's functional anatomy. As TMS interferes with neural activity, the hypothetical function of the stimulated area can thus be tested. One unresolved methodological issue in TMS experiments is the question of how to adequately calibrate stimulation intensities. The motor threshold (MT) is often taken as a reference

Jakob A. Kaminski; Franziska M. Korb; Arno Villringer; Derek V. M. Ott; Joseph Najbauer

2011-01-01

14

Masking visual stimuli by transcranial magnetic stimulation  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) applied over the occipital pole can suppress visual perception. Since its first description\\u000a in 1989 by Amassian et al., this technique has widely been used to investigate visual processing at the cortical level. This\\u000a article presents a review of experiments masking visual stimuli by TMS. The psychophysical characterization of TMS masking,\\u000a the dependence on stimulus onset asynchrony

Thomas Kammer

2007-01-01

15

Repetitive transcranial magnetic stimulation for ALS  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) of brain can modulate cortical neurotransmission, a novel paradigm of repetitive stimulation termed continuous theta-burst stimulation (cTBS) produces a pronounced and prolonged suppression of motor cortex excitability. The aim of this preliminary study was to investigate whether cTBS of motor cortex could have any beneficial effect in patients with amyotrophic lateral sclerosis (ALS). We performed

Vincenzo Di Lazzaro; Michele Dileone; Fabio Pilato; Paolo Profice; Federico Ranieri; Gabriella Musumeci; Francesco Angelucci; Mario Sabatelli; Pietro A. Tonali

2006-01-01

16

State-Dependency of Transcranial Magnetic Stimulation  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS), a tool that allows noninvasive modulation of cortical neural activity, has become\\u000a an important tool in cognitive \\u0009neuroscience and is being increasingly explored in neurotherapeutics. Amongst the factors\\u000a that are likely to influence its efficacy, the importance of the baseline cortical activation state on the impact of TMS has\\u000a not received much attention. However, this state-dependency

Juha Silvanto; Alvaro Pascual-Leone

2008-01-01

17

Dosimetry of typical transcranial magnetic stimulation devices  

NASA Astrophysics Data System (ADS)

The therapeutic staff using transcranial magnetic stimulation (TMS) devices could be exposed to magnetic pulses. In this paper, dependence of induced currents in real human man model on different coil shapes, distance between the coil and man model as well as the rotation of the coil in space have been investigated by employing impedance method. It was found that the figure-of-eight coil has less leakage magnetic field and low current density induced in the body compared with the round coil. The TMS power supply cables play an important role in the induced current density in human body. The induced current density in TMS operator decreased as the coil rotates from parallel position to perpendicular position. Our present study shows that TMS operator should stand at least 110 cm apart from the coil.

Lu, Mai; Ueno, Shoogo

2010-05-01

18

Cortical excitability changes associated with musical tasks: a transcranial magnetic stimulation study in humans  

Microsoft Academic Search

Neuroimaging studies have suggested differences in cortical activation in human vocalization and musical tasks. However, functional neurophysiological evidence on cortical excitability changes is lacking. We utilized transcranial magnetic stimulation to demonstrate changes in cortical excitability during overt humming and singing tasks. The findings complement those from neuroimaging and support the existence of separate bilateral deep-seated neural networks, as distinct from

Y. L. Lo; S. Fook-Chong; D. P. C. Lau; E. K. Tan

2003-01-01

19

Electroencephalogram and repetitive transcranial magnetic stimulation.  

PubMed

Scalp recordings of the electroencephalogram (EEG) have been used in association with repetitive transcranial magnetic stimulation (rTMS) investigations as a safety measure in monitoring ongoing EEG activity and as a neurophysiologic tool in examining the specific effects induced by the magnetic stimulus on the EEG or evoked potentials (EPs). Medline review on the use of EEG or EPs with rTMS reveals that this area has been largely unexplored. Limited available studies attest to the potential for studies combining EEG/EPs and rTMS to be useful in further elucidating the normal brain physiology. Herein, we report on our experience with continuous EEG sampling combined with rTMS in patients with major depression (n = 14), schizophrenia (n = 7), and obsessive-compulsive disorder (n = 5). Our data support the practice of using continuous EEG monitoring when the stimulation parameters fall outside established safety guidelines. PMID:11126191

Boutros, N N; Berman, R M; Hoffman, R; Miano, A P; Campbell, D; Ilmoniemi, R

2000-01-01

20

Transcranial magnetic stimulation assisted by neuronavigation of magnetic resonance images  

NASA Astrophysics Data System (ADS)

Technological advance has improved the way scientists and doctors can learn about the brain and treat different disorders. A non-invasive method used for this is Transcranial Magnetic Stimulation (TMS) based on neuron excitation by electromagnetic induction. Combining this method with functional Magnetic Resonance Images (fMRI), it is intended to improve the localization technique of cortical brain structures by designing an extracranial localization system, based on Alcauter et al. work.

Viesca, N. Angeline; Alcauter, S. Sarael; Barrios, A. Fernando; González, O. Jorge J.; Márquez, F. Jorge A.

2012-10-01

21

Magnetic shielding requirements for PET detectors during transcranial magnetic stimulation  

Microsoft Academic Search

Trans-cranial magnetic stimulation (TMS) can be used to stimulate the human cerebral cortex to demonstrate the interconnections between different brain regions. Pulses of 200 ?sec, and high magnetic fields 1.5-2.2 Tesla are used for the stimulation. These are sufficient to seriously perturb the operation of the photo-multipliers (PMT) used in positron emission tomography (PET), a functional imaging technique which can

C. J. Thompson; T. Paus; R. Clancy

1997-01-01

22

Transcranial magnetic stimulation studies in Alzheimer's disease.  

PubMed

Although motor deficits affect patients with Alzheimer's disease (AD) only at later stages, recent studies demonstrated that primary motor cortex is precociously affected by neuronal degeneration. It is conceivable that neuronal loss is compensated by reorganization of the neural circuitries, thereby maintaining motor performances in daily living. Effectively several transcranial magnetic stimulation (TMS) studies have demonstrated that cortical excitability is enhanced in AD and primary motor cortex presents functional reorganization. Although the best hypothesis for the pathogenesis of AD remains the degeneration of cholinergic neurons in specific regions of the basal forebrain, the application of specific TMS protocols pointed out a role of other neurotransmitters. The present paper provides a perspective of the TMS techniques used to study neurophysiological aspects of AD showing also that, based on different patterns of cortical excitability, TMS may be useful in discriminating between physiological and pathological brain aging at least at the group level. Moreover repetitive TMS might become useful in the rehabilitation of AD patients. Finally integrated approaches utilizing TMS together with others neuro-physiological techniques, such as high-density EEG, and structural and functional imaging as well as biological markers are proposed as promising tool for large-scale, low-cost, and noninvasive evaluation of at-risk populations. PMID:21760985

Guerra, Andrea; Assenza, Federica; Bressi, Federica; Scrascia, Federica; Del Duca, Marco; Ursini, Francesca; Vollaro, Stefano; Trotta, Laura; Tombini, Mario; Chisari, Carmelo; Ferreri, Florinda

2011-07-06

23

Transcranial Magnetic Stimulation Studies in Alzheimer's Disease  

PubMed Central

Although motor deficits affect patients with Alzheimer's disease (AD) only at later stages, recent studies demonstrated that primary motor cortex is precociously affected by neuronal degeneration. It is conceivable that neuronal loss is compensated by reorganization of the neural circuitries, thereby maintaining motor performances in daily living. Effectively several transcranial magnetic stimulation (TMS) studies have demonstrated that cortical excitability is enhanced in AD and primary motor cortex presents functional reorganization. Although the best hypothesis for the pathogenesis of AD remains the degeneration of cholinergic neurons in specific regions of the basal forebrain, the application of specific TMS protocols pointed out a role of other neurotransmitters. The present paper provides a perspective of the TMS techniques used to study neurophysiological aspects of AD showing also that, based on different patterns of cortical excitability, TMS may be useful in discriminating between physiological and pathological brain aging at least at the group level. Moreover repetitive TMS might become useful in the rehabilitation of AD patients. Finally integrated approaches utilizing TMS together with others neuro-physiological techniques, such as high-density EEG, and structural and functional imaging as well as biological markers are proposed as promising tool for large-scale, low-cost, and noninvasive evaluation of at-risk populations.

Guerra, Andrea; Assenza, Federica; Bressi, Federica; Scrascia, Federica; Del Duca, Marco; Ursini, Francesca; Vollaro, Stefano; Trotta, Laura; Tombini, Mario; Chisari, Carmelo; Ferreri, Florinda

2011-01-01

24

Transcranial Magnetic Stimulation in Child Neurology: Current and Future Directions  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) is a method for focal brain stimulation based on the principle of electromagnetic induction, where small intracranial electric currents are generated by a powerful, rapidly changing extracranial magnetic field. Over the past 2 decades TMS has shown promise in the diagnosis, monitoring, and treatment of neurological and psychiatric disease in adults, but has been used on

Richard E. Frye; Alexander Rotenberg; Molliann Ousley; Alvaro Pascual-Leone

2008-01-01

25

Effects of transcranial magnetic stimulation on EEG activity  

Microsoft Academic Search

The combination of transcranial magnetic stimulation (TMS) and an electroencephalogram (EEG) is an effective tool for investigating the functional connectivity in the brain. This paper investigated cortical reactivity and connectivity by the combination of TMS and EEG. The spontaneous activity of the brain was measured before and after magnetic stimulation. The effect of TMS on alpha activity was investigated. The

Keiji Iramina; Takashi Maeno; Yasuyuki Kowatari; Shoogo Ueno

2002-01-01

26

Transcranial magnetic stimulation induces alterations in brain monoamines  

Microsoft Academic Search

Summary Transcranial magnetic stimulation has been suggested as a possible therapeutic tool in depression. In behavioral models of depression, magnetic stimulation induced similar effects to those of electroconvulsive shock. This study demonstrates the effect of a single session of rapid TMS on tissue monoamines in rat brain. Alterations in monoamines were selective and specific in relation to brain areas and

D. Ben-Shachar; R. H. Belmaker; N. Grisaru; E. Klein

1997-01-01

27

3-dimensional modeling of transcranial magnetic stimulation: Design and application  

Microsoft Academic Search

Over the past three decades, transcranial magnetic stimulation (TMS) has emerged as an effective tool for many research, diagnostic and therapeutic applications in humans. TMS delivers highly localized brain stimulations via non-invasive externally applied magnetic fields. This non-invasive, painless technique provides researchers and clinicians a unique tool capable of stimulating both the central and peripheral nervous systems. However, a complete

Felipe Santiago Salinas

2008-01-01

28

Aging affects transcranial magnetic modulation of hippocampal evoked potentials  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) is being proposed as a method of choice for the treatment of clinical depression, yet its action in the brain is still not well understood. In previous studies we found that TMS has a long-term effect on reactivity of the hippocampus to perforant path stimulation. Since the efficacy of antidepressants is highly age-dependent, we studied possible

Y. Levkovitz; M. Segal

2001-01-01

29

Transcranial magnetic stimulation, synaptic plasticity and network oscillations  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) has quickly progressed from a technical curiosity to a bona-fide tool for neurological research. The impetus has been due to the promising results obtained when using TMS to uncover neural processes in normal human subjects, as well as in the treatment of intractable neurological conditions, such as stroke, chronic depression and epilepsy. The basic principle of

Patricio T Huerta; Bruce T Volpe

2009-01-01

30

Illusory Sensation of Movement Induced by Repetitive Transcranial Magnetic Stimulation  

Microsoft Academic Search

Human movement sense relies on both somatosensory feedback and on knowledge of the motor commands used to produce the movement. We have induced a movement illusion using repetitive transcranial magnetic stimulation over primary motor cortex and dorsal premotor cortex in the absence of limb movement and its associated somatosensory feedback. Afferent and efferent neural signalling was abolished in the arm

Mark Schram Christensen; Jesper Lundbye-Jensen; Michael James Grey; Alexandra Damgaard Vejlby; Bo Belhage; Jens Bo Nielsen

2010-01-01

31

Combining backward masking and transcranial magnetic stimulation in human observers  

Microsoft Academic Search

Both backward masking and transcranial magnetic stimulation (TMS) are capable of hindering perception of a visual target. To study the relationship between these two methods we applied TMS over the occipital pole in combination with the visual backward masking technique shine-through. The recently discovered weak shine-through mask consists of a horizontal grating with 25 vernier elements. In three subjects we

Thomas Kammer; Frank Scharnowski; Michael H. Herzog

2003-01-01

32

Transcranial magnetic stimulation studies of cognition: an emerging field  

Microsoft Academic Search

In this short review, we consider the applica- tion of transcranial magnetic stimulation (TMS) to the study of cognitive function. Following an introduction to the technique, we consider its possible mechanisms of action. We then review the studies that have applied TMS to the investigation of cognition. In the majority of these investigations, TMS has been applied to disrupt function

Marjan Jahanshahi; John Rothwell

2000-01-01

33

Changes of blood lactate levels after repetitive transcranial magnetic stimulation  

Microsoft Academic Search

The objective was to study whether repetitive transcranial magnetic stimulation (rTMS) of the motor cortex could induce modification of peripheral blood lactate values. Nineteen young healthy volunteers were included; during the study, all subjects were at rest, sitting on a comfortable armchair. The muscular activation was evaluated by continuous electromyographic record. TMS was performed by using a circular coil at

Giovanna Alagona; Marinella Coco; Giuseppe Rapisarda; Erminio Costanzo; Tiziana Maci; Domenico Restivo; Antonino Maugeri; Vincenzo Perciavalle

2009-01-01

34

Transcranial magnetic stimulation differentially affects speed and direction judgments  

Microsoft Academic Search

This study was conducted to determine wheth- er humans' judgments about the speed and direction of moving stimuli was differentially affected by transcrani- al magnetic stimulation (TMS). Subjects viewed two successively presented moving stimuli that differed from each other both in speed and direction of motion. Single- pulse TMS was applied either medially (approximately 2 cm above the inion) or

Nestor Matthews; Bruce Luber; Ning Qian; Sarah H. Lisanby

2001-01-01

35

Motor and phosphene thresholds: a transcranial magnetic stimulation correlation study  

Microsoft Academic Search

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

L. M. Stewart; V. Walsh; J. C. Rothwell

2001-01-01

36

Transcranial magnetic stimulation in sport science: A commentary  

Microsoft Academic Search

The aim of this commentary is to provide a brief overview of transcranial magnetic stimulation (TMS) and highlight how this technique can be used to investigate the acute and chronic responses of the central nervous system to exercise. We characterise the neuromuscular responses to TMS and discuss how these measures can be used to investigate the mechanisms of fatigue in

Stuart Goodall; Glyn Howatson; Lee Romer; Emma Ross

2012-01-01

37

Repetitive transcranial magnetic stimulation in anorexia nervosa: A pilot study  

Microsoft Academic Search

The search for new treatments to improve outcome in people with anorexia nervosa continues. This pilot study investigated whether one session of high frequency repetitive transcranial magnetic stimulation (rTMS) delivered to the left dorsolateral prefrontal cortex reduces eating disorder related symptoms following exposure to visual and real food stimuli. Safety and tolerability were also assessed. Ten right-handed people with anorexia

F. Van den Eynde; S. Guillaume; H. Broadbent; I. C. Campbell; U. Schmidt

38

Localization and characterization of speech arrest during transcranial magnetic stimulation  

Microsoft Academic Search

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

Charles M Epstein; Kimford J Meador; David W Loring; Randall J Wright; Joseph D Weissman; Scott Sheppard; James J Lah; Frank Puhalovich; Luis Gaitan; Kent R Davey

1999-01-01

39

Transcranial Magnetic Stimulation Evokes Giant Inhibitory Potentials in Children  

Microsoft Academic Search

The electroencephalographic response to transcranial magnetic stimulation (TMS) recently has been established as a direct parameter of motor cortex excitability. Its N100 component was suggested to reflect an inhibitory response. We investigated influences of cerebral maturation on TMS-evoked N100 in 6- to 10-year-old healthy children. We used a forewarned reaction time (contingent negative variation) task to test the effects of

Stephan Bender; Kristine Basseler; Imke Sebastian; Franz Resch; Thomas Kammer; Rieke Oelkers-Ax; Matthias Weisbrod

2005-01-01

40

Transcranial magnetic stimulation in the treatment of psychiatric disorders  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) is an emerging novel treatment modality for psychiatric disorders, particularly major\\u000a depression. A device for delivery of TMS was approved by the US Food and Drug Administration for treatment of major depressive\\u000a disorder in adults. TMS is being studied for a variety of psychiatric disorders, including obsessivecompulsive disorder, post-traumatic\\u000a stress disorder, and auditory hallucinations in schizophrenia.

Deborah R. Kim; Angeliki Pesiridou; John P. O’Reardon

2009-01-01

41

Rapid rate transcranial magnetic stimulation – a safety study  

Microsoft Academic Search

We assessed the safety of repeated short trains (4 stimuli) of rapid-rate transcranial magnetic stimulation (rrTMS) over the left motor cortex in 6 healthy normal subjects. rrTMS involved two separate blocks of 50 consecutive trains of 4 stimuli at a frequency of 20 Hz and an intensity of 5–10% above active motor threshold. We monitored EEG, and assessed aspects of

Marjan Jahanshahi; Michael C Ridding; Patricia Limousin; Paolo Profice; Wolfgang Fogel; Dirk Dressler; Rebecca Fuller; Richard G Brown; Peter Brown; John C Rothwell

1997-01-01

42

Effect of Vigabatrin on motor responses to transcranial magnetic stimulation  

Microsoft Academic Search

In this study, transcranial magnetic stimulation (TMS) of the hand primary motor area was used to test possible excitability changes induced by the administration of Vigabatrin (Gamma-Vinyl-?-aminobutryic acid;4-amino-hex-5-enoic acid; GVG), a selective GABAergic drug, on cortical inhibitory mechanisms in healthy subjects. In a group of 15 healthy volunteers, the level of motor cortical excitability was studied by means of paired-pulse

Mariangela Pierantozzi; Maria Grazia Marciani; Maria Giuseppina Palmieri; Livia Brusa; Salvatore Galati; Maria Donatella Caramia; Giorgio Bernardi; Paolo Stanzione

2004-01-01

43

Transcranial magnetic motor-evoked potentials in scoliosis surgery.  

PubMed

Spinal cord monitoring using SSEPs is an accepted adjunct in the surgical correction of spinal deformities, but does not directly assess motor function. Motor-evoked potentials have been introduced in an effort to meet this important need. In this series of 18 patients, the feasibility of intraoperative monitoring using transcranial magnetic motor-evoked potentials is documented. The potential value of this neurophysiologic monitoring technique, as well as the pitfalls in interpretation, are reviewed. PMID:8584459

Glassman, S D; Zhang, Y P; Shields, C B; Johnson, J R; Linden, R D

1995-10-01

44

Transcranial static magnetic field stimulation of the human motor cortex  

PubMed Central

Abstract The aim of the present study was to investigate in healthy humans the possibility of a non-invasive modulation of motor cortex excitability by the application of static magnetic fields through the scalp. Static magnetic fields were obtained by using cylindrical NdFeB magnets. We performed four sets of experiments. In Experiment 1, we recorded motor potentials evoked by single-pulse transcranial magnetic stimulation (TMS) of the motor cortex before and after 10 min of transcranial static magnetic field stimulation (tSMS) in conscious subjects. We observed an average reduction of motor cortex excitability of up to 25%, as revealed by TMS, which lasted for several minutes after the end of tSMS, and was dose dependent (intensity of the magnetic field) but not polarity dependent. In Experiment 2, we confirmed the reduction of motor cortex excitability induced by tSMS using a double-blind sham-controlled design. In Experiment 3, we investigated the duration of tSMS that was necessary to modulate motor cortex excitability. We found that 10 min of tSMS (compared to 1 min and 5 min) were necessary to induce significant effects. In Experiment 4, we used transcranial electric stimulation (TES) to establish that the tSMS-induced reduction of motor cortex excitability was not due to corticospinal axon and/or spinal excitability, but specifically involved intracortical networks. These results suggest that tSMS using small static magnets may be a promising tool to modulate cerebral excitability in a non-invasive, painless, and reversible way.

Oliviero, Antonio; Mordillo-Mateos, Laura; Arias, Pablo; Panyavin, Ivan; Foffani, Guglielmo; Aguilar, Juan

2011-01-01

45

Ketamine Increases Human Motor Cortex Excitability to Transcranial Magnetic Stimulation  

PubMed Central

Subanaesthetic doses of the N-methyl-d-aspartate (NMDA) antagonist ketamine have been shown to determine a dual modulating effect on glutamatergic transmission in experimental animals, blocking NMDA receptor activity and enhancing non-NMDA transmission through an increase in the release of endogenous glutamate. Little is known about the effects of ketamine on the excitability of the human central nervous system. The effects of subanaesthetic, graded incremental doses of ketamine (0.01, 0.02 and 0.04 mg kg?1 min?1, i.v.) on the excitability of cortical networks of the human motor cortex were examined with a range of transcranial magnetic and electric stimulation protocols in seven normal subjects. Administration of ketamine at increasing doses produced a progressive reduction in the mean resting motor threshold (RMT) (F(3, 18) = 22.33, P < 0.001) and active motor threshold (AMT) (F(3, 18) = 12.17, P < 0.001). Before ketamine administration, mean RMT ±s.d. was 49 ± 3.3 % of maximum stimulator output and at the highest infusion level it was 42.6 ± 2.6 % (P < 0.001). Before ketamine administration, AMT ±s.d. was 38 ± 3.3 % of maximum stimulator output and at the highest infusion level it was 33 ± 4.4 % (P < 0.002). Ketamine also led to an increase in the amplitude of EMG responses evoked by magnetic stimulation at rest; this increase was a function of ketamine dosage (F(3, 18) = 5.29, P= 0.009). In contrast to responses evoked by magnetic stimulation, responses evoked by electric stimulation were not modified by ketamine. The differential effect of ketamine on responses evoked by magnetic and electric stimulation demonstrates that subanaesthetic doses of ketamine enhance the recruitment of excitatory cortical networks in motor cortex. Transcranial magnetic stimulation produces a high-frequency repetitive discharge of pyramidal neurones and for this reason probably depends mostly on short-lasting AMPA transmission. An increase in this transmission might facilitate the repetitive discharge of pyramidal cells after transcranial magnetic stimulation which, in turn, results in larger motor responses and lower thresholds. We suggest that the enhancement of human motor cortex excitability to transcranial magnetic stimulation is the effect of an increase in glutamatergic transmission at non-NMDA receptors similar to that described in experimental studies.

Lazzaro, V Di; Oliviero, A; Profice, P; Pennisi, M A; Pilato, F; Zito, G; Dileone, M; Nicoletti, R; Pasqualetti, P; Tonali, P A

2003-01-01

46

Transcranial magnetic stimulation (TMS) effects on testosterone, prolactin, and corticosterone in adult male rats  

Microsoft Academic Search

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

Dawson W. Hedges; David L. Salyer; Brian J. Higginbotham; Trent D. Lund; James L. Hellewell; David Ferguson; Edwin D. Lephart

2002-01-01

47

Activation of epileptic foci by transcranial magnetic stimulation: effects on secretion of prolactin and luteinizing hormone  

Microsoft Academic Search

Transient elevation of serum levels of prolactin has been observed following several types of epileptic seizures and after electrical stimulation of limbic temporal lobe structures via implanted electrodes. Transcranial magnetic stimulation has been found to selectively induce epileptiform afterdischarges in the epileptic focus of candidates for epilepsy surgery who suffered from temporal lobe epilepsy. Lateralized serial transcranial magnetic stimulation was

A. Hufnagel; C. E. Elger; D. Klingmüller; S. Zierz; R. Kramer

1990-01-01

48

Transcranial magnetic-stimulation mapping of the cortical topography of the human masseter muscle  

Microsoft Academic Search

The cortical topography of several limb and trunk muscles has been disclosed using transcranial magnetic stimulation, but the corticomotor representation of the human jaw muscles has not yet been described. An experimental paradigm incorporating transcranial magnetic stimulation of verified sites on the scalp was used (a) to determine the cortical topography of the human masseter muscle and (b) to assess

Anne S. McMillan; Catherine Watson; David Walshaw

1998-01-01

49

Increased transcranial magnetic motor threshold after ECT. A case report.  

PubMed

Electroconvulsive therapy (ECT) is a powerful antidepressive treatment, but its mechanism of action remains poorly understood. To clarify the influence of ECT on corticospinal tract excitability we tested the motor threshold, the motor evoked potential (MEP) input/output curve, and the intracortical excitability using transcranial magnetic stimulation in a depressed patient before and after successful treatment with ECT. Resting motor thresholds were increased bilaterally after treatment, and the input/output curve less steep. These results point to a decreased excitability of the corticospinal motor tract after successful ECT. PMID:12451468

Sommer, Martin; Dieterich, Anja; Rüther, Eckart; Paulus, Walter; Wiltfang, Jens

2002-10-01

50

The study of deep brain structures by transcranial duplex sonography and imaging resonance correlation.  

PubMed

Transcranial duplex sonography (TCS) currently provides us with images of deep brain structures with sufficient resolution. We chose 2 sonographic quantitative parameters: the diameter of the third ventricle and a measurement not used by TCS to date, the midbrain area. Their reliability and reproducibility were assessed using magnetic resonance imaging (MRI) as the reference. A total of 99 patients free from neurodegenerative disorders were examined using TCS, and both parameters were measured by 2 independent explorers. Measurements of third-ventricle diameter by TCS showed very good correlation (r = 0.80) and agreement (ICC = 0.89) with measurements obtained by MRI. Measurements of the midbrain area by TCS also provided acceptable values with moderate correlation (r = 0.36) and agreement (ICC = 0.53). Interexplorer correlation values were good (ICC = 0.98 and 0.79 for the third ventricle and midbrain areas, respectively). Further studies will be required to determine the potential diagnostic usefulness of these parameters. PMID:23257352

Sahuquillo, Patricia; Tembl, Jose Ignacio; Parkhutik, Vera; Vázquez, Juan Francisco; Sastre, Isabel; Lago, Aida

2012-12-17

51

Transcranial direct current stimulation and repetitive transcranial magnetic stimulation in consultation-liaison psychiatry.  

PubMed

Patients with clinical diseases often present psychiatric conditions whose pharmacological treatment is hampered due to hazardous interactions with the clinical treatment and/or disease. This is particularly relevant for major depressive disorder, the most common psychiatric disorder in the general hospital. In this context, nonpharmacological interventions could be useful therapies; and, among those, noninvasive brain stimulation (NIBS) might be an interesting option. The main methods of NIBS are repetitive transcranial magnetic stimulation (rTMS), which was recently approved as a nonresearch treatment for some psychiatric conditions, and transcranial direct current stimulation (tDCS), a technique that is currently limited to research scenarios but has shown promising results. Therefore, our aim was to review the main medical conditions associated with high depression rates, the main obstacles for depression treatment, and whether these therapies could be a useful intervention for such conditions. We found that depression is an important and prevalent comorbidity in a variety of diseases such as epilepsy, stroke, Parkinson's disease, myocardial infarction, cancer, and in other conditions such as pregnancy and in patients without enteral access. We found that treatment of depression is often suboptimal within the above contexts and that rTMS and tDCS therapies have been insufficiently appraised. We discuss whether rTMS and tDCS could have a significant impact in treating depression that develops within a clinical context, considering its unique characteristics such as the absence of pharmacological interactions, the use of a nonenteral route, and as an augmentation therapy for antidepressants. PMID:24141608

Valiengo, L C L; Benseñor, I M; Lotufo, P A; Fraguas, R; Brunoni, A R

2013-10-02

52

Transcranial Magnetic Stimulation in Child Neurology: Current and Future Directions  

PubMed Central

Transcranial magnetic stimulation (TMS) is a method for focal brain stimulation based on the principle of electromagnetic induction, where small intracranial electric currents are generated by a powerful, rapidly changing extracranial magnetic field. Over the past 2 decades TMS has shown promise in the diagnosis, monitoring, and treatment of neurological and psychiatric disease in adults, but has been used on a more limited basis in children. We reviewed the literature to identify potential diagnostic and therapeutic applications of TMS in child neurology and also its safety in pediatrics. Although TMS has not been associated with any serious side effects in children and appears to be well tolerated, general safety guidelines should be established. The potential for applications of TMS in child neurology and psychiatry is significant. Given its excellent safety profile and possible therapeutic effect, this technique should develop as an important tool in pediatric neurology over the next decade.

Frye, Richard E.; Rotenberg, Alexander; Ousley, Molliann; Pascual-Leone, Alvaro

2008-01-01

53

Iron-core coils for transcranial magnetic stimulation.  

PubMed

Transcranial magnetic stimulation requires a great deal of power, which mandates bulky power supplies and produces rapid coil heating. The authors describe the construction, modeling, and testing of an iron-core TMS coil that reduces power requirements and heat generation substantially, while improving the penetration of the magnetic field. Experimental measurements and numeric boundary element analysis show that the iron-core stimulation coil induces much stronger electrical fields, allows greater charge recovery, and generates less heat than air-core counterparts when excited on a constant-energy basis. These advantages are magnified in constant-effect comparisons. Examples are given in which the iron-core coil allows more effective operation in research and clinical applications. PMID:12436092

Epstein, Charles M; Davey, Kent R

2002-08-01

54

Abnormal cutaneomotor integration in patients with cerebellar syndromes: a transcranial magnetic stimulation study  

Microsoft Academic Search

Objective: To examine the sensorimotor interactions in cerebellar patients.Methods: We investigated the effects of electrical stimulation of the second (D2) and fifth (D5) fingers on the amplitude of motor evoked potentials (MEPs) in response to transcranial magnetic stimulation and transcranial electrical stimulation (TES) in the relaxed right abductor digiti minimi muscles of 7 patients with cerebellar syndromes and of 14

Stefano Tamburin; Antonio Fiaschi; Annalisa Andreoli; Antonio Forgione; Paolo Manganotti; Giampietro Zanette

2003-01-01

55

Localization of Magnetic Field Structure of Multi-Current Loops on Axisymmetrical Model for Transcranial Magnetic Stimulation  

NASA Astrophysics Data System (ADS)

We calculate magnetic field distributions from multi-current loops for transcranial magnetic stimulation (TMS). In TMS, it is important to produce locally strong magnetic fields and apply eddy-currents only to the aimed cell in a deep region of the brain. First, we investigate the field structure around a single current loop. We find that a single loop generates the convexed field on a certain plane parallel to the loop surface. Second, we study an axisymmetrical model of three-current loops, i.e., a main-coil and two sub-coils, in which the fields are significantly localized in the vertical direction at a symmetrical plane on the central axis compared with that of a single loop.

Okita, Taishi; Takagi, Toshiyuki

2009-01-01

56

Information for assistants of repeated transcranial magnetic stimulation.  

PubMed

Repeated transcranial magnetic stimulation (rTMS) is an exciting new technology being used in psychiatric and neurological research in many centres around the world. rTMS has been accepted as a routine treatment of depression in Canada and Israel. To this point, it has been exclusively conducted by medical officers. As knowledge and experience grows, it is probable that professionals with other backgrounds will have the opportunity to play a role. The aim of this paper is to provide information that will be valuable to assistants. Electromagnetic principles are harnessed to deliver electric currents to localized regions of the cortex. rTMS does not involve anaesthesia or seizure. Side-effects appear to be few. Much remains uncertain, however, even including the most appropriate treatment parameters. PMID:14685956

Pridmore, Saxby; Khan, Umeed; Rosa, Moacyr A; George, Mark S

2003-03-01

57

Repetitive transcranial magnetic stimulation in anorexia nervosa: a pilot study.  

PubMed

The search for new treatments to improve outcome in people with anorexia nervosa continues. This pilot study investigated whether one session of high frequency repetitive transcranial magnetic stimulation (rTMS) delivered to the left dorsolateral prefrontal cortex reduces eating disorder related symptoms following exposure to visual and real food stimuli. Safety and tolerability were also assessed. Ten right-handed people with anorexia nervosa underwent one session of rTMS. Subjective experiences related to the eating disorder (e.g. urge to restrict, feeling full etc.) were assessed before and after rTMS. Non-parametric repeated measures tests were used. rTMS was safe and well-tolerated, and resulted in reduced levels of feeling full, feeling fat and feeling anxious. Thus, rTMS may reduce core symptoms of anorexia nervosa. Future research should establish the therapeutic potential of rTMS in anorexia nervosa. PMID:21880470

Van den Eynde, F; Guillaume, S; Broadbent, H; Campbell, I C; Schmidt, U

2011-08-30

58

Standardization of transcranial magnetic stimulation in the horse.  

PubMed

The influence of coil position on the peak-to-peak amplitude and onset latency of transcranial magnetic motor evoked potentials (MMEPs) in the extensor carpi radialis and cranial tibial muscles of horses was evaluated. Seven different stimulating coil positions were obtained by constructing a frame on the forehead. Two stimulation intensities (80% and 100% of maximal stimulator output) and two different coil currents (clockwise and counter-clockwise) were tested. For both recording sites MMEPs with the shortest onset latency and the largest peak-to-peak amplitude were detected when the coil was placed in the median of the forehead. There was no significant difference between left and right side recordings. The direction of the current flow in the coil had no influence on the onset latency of the MMEPs. PMID:14550735

Nollet, H; Van Ham, L; Dewulf, J; Vanderstraeten, G; Deprez, P

2003-11-01

59

Transcranial magnetic stimulation can measure and modulate learning and memory.  

PubMed

The potential uses for Transcranial Magnetic Stimulation (TMS) in the study of learning and memory range from a method to map the topography and intensity of motor output maps during visuomotor learning to inducing reversible lesions that allow for the precise temporal and spatial dissection of the brain processes underlying learning and remembering. Single-pulse TMS appears to be adequate to examine motor output maps but repetitive TMS (rTMS) appears necessary to affect most cognitive processes in measurable ways. The results we have reviewed in this article indicate that rTMS may have a potential clinical application in patients with epilepsy in whom it is important to identify the lateralization of verbal memory. Single-pulse TMS can help identify changes in motor output maps during training, that may indicate improved or diminished learning and memory processes following a stroke or other neurological insult. Other evidence indicates that rTMS may even have the capability of facilitating various aspects of memory performance. From a research perspective. rTMS has demonstrated site- and time-specific effects primarily in interfering with explicit retrieval of episodic information from long-term memory. rTMS may also be able to modulate retrieval from semantic memory as evidenced by response-time and accuracy changes after rTMS. All these findings suggest that the use of transcranial magnetic stimulation in the study of learning and memory will increase in the future and that it is already a valuable tool in the cognitive neuroscientists' belt. PMID:10080373

Grafman, J; Wassermann, E

1999-02-01

60

Enhancing Warfighter Cognitive Abilities with Transcranial Magnetic Stimulation: A Feasibility Analysis.  

National Technical Information Service (NTIS)

This study examined the feasibility of using transcranial magnetic stimulation (TMS) to enhance warfighter cognitive abilities. An extensive literature review was conducted and several TMS laboratories were visited. Discussions were also held with several...

J. T. Nelson

2007-01-01

61

Repetitive spinal motor neuron discharges following single transcranial magnetic stimulation: relation to dexterity  

Microsoft Academic Search

Transcranial magnetic stimulation allows to study the properties of the human corticospinal tract non-invasively. After a\\u000a single transcranial magnetic stimulus, spinal motor neurons (MNs) sometimes fire not just once, but repetitively. The biological\\u000a significance of such repetitive MN discharges (repMNDs) is unknown. To study the relation of repMNDs to other measures of\\u000a cortico-muscular excitability and to physiological measures of the

W. J. Z’Graggen; A. M. Humm; S. Oppliger-Bachmann; M. Hosang; K. M. Rösler

2008-01-01

62

Effect of Prefrontal Repetitive Transcranial Magnetic Stimulation in Obsessive-Compulsive Disorder: A Preliminary Study  

Microsoft Academic Search

Objective: Prefrontal mechanisms are implicated in obsessive-compulsive disorder. The authors investigated whether prefrontal repetitive transcranial magnetic stimulation influenced obsessive-compulsive disorder symptoms. Method: Twelve patients with obsessive-compulsive disorder were given repetitive transcranial magnetic stimulation (80% motor threshold, 20 Hz\\/2 seconds per minute for 20 minutes) to a right lateral prefrontal, a left lateral prefrontal, and a midoccipital (control) site on separate

Benjamin D. Greenberg; Mark S. George; Juliet D. Martin; Jonathan Benjamin; Thomas E. Schlaepfer; Margaret Altemus; Eric M. Wassermann; Robert M. Post; Dennis L. Murphy

1997-01-01

63

Effects of electric and magnetic transcranial stimulation on long latency reflexes  

Microsoft Academic Search

The interaction of transcranial electric and magnetic brain stimulation with electrically elicited shortand long latency reflexes (LLR) of hand and fore-arm flexor muscles has been investigated in normal subjects. In the first paradigm, the motor potential evoked in thenar muscles by transcranial stimulation was conditioned by median nerve stimulation at various conditioning-test intervals. At short intervals (electric: 5–12.5 ms, magnetic:

G. Deuschl; R. Michels; A. Berardelli; E. Schenck; M. Inghilleri; C. H. Lücking

1991-01-01

64

3D Realistic Head Model Simulation Based on Transcranial Magnetic Stimulation  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) is a powerful, non-invasive tool for investigating functions in the brain. The target inside the head is stimulated with eddy currents induced in the tissue by the time-varying magnetic field. Precise spatial localization of stimulation sites is the key of efficient functional magnetic stimulations. Many researchers devote to magnetic field analysis in empty free space. In

Shuo Yang; Guizhi Xu; Lei Wang; Yong Chen; Huanli Wu; Ying Li; Qingxin Yang

2006-01-01

65

Repetitive Transcranial Magnetic Stimulation Activates Specific Regions in Rat Brain  

NASA Astrophysics Data System (ADS)

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive technique to induce electric currents in the brain. Although rTMS is being evaluated as a possible alternative to electroconvulsive therapy for the treatment of refractory depression, little is known about the pattern of activation induced in the brain by rTMS. We have compared immediate early gene expression in rat brain after rTMS and electroconvulsive stimulation, a well-established animal model for electroconvulsive therapy. Our result shows that rTMS applied in conditions effective in animal models of depression induces different patterns of immediate-early gene expression than does electroconvulsive stimulation. In particular, rTMS evokes strong neural responses in the paraventricular nucleus of the thalamus (PVT) and in other regions involved in the regulation of circadian rhythms. The response in PVT is independent of the orientation of the stimulation probe relative to the head. Part of this response is likely because of direct activation, as repetitive magnetic stimulation also activates PVT neurons in brain slices.

Ji, Ru-Rong; Schlaepfer, Thomas E.; Aizenman, Carlos D.; Epstein, Charles M.; Qiu, Dike; Huang, Justin C.; Rupp, Fabio

1998-12-01

66

THE INFLUENCE OF TRANSCRANIAL THE INFLUENCE OF TRANSCRANIAL MAGNETIC STIMULATION (TMS) ON MEMORY MAGNETIC STIMULATION (TMS) ON MEMORY VLIV TRANSKRANIÁLNÍ MAGNETICKÉ STIMULACE (TMS) NA PAMET  

Microsoft Academic Search

SUMMARY Transcranial magnetic stimulation (TMS) is a new, non-invasive method inducing physiologic changes in relatively small areas of human cerebral cortex. TMS is used to induce artificial cortical lesions and thus affects different cognitive functions which can be further explored. TMS, as applied in cognitive research, is used as single pulse, pair pulse, or rapid-rate pulse (repetitive) TMS. Studies on

COLLEEN DOCKERY

67

Use of Repetitive Transcranial Magnetic Stimulation for Treatment in Psychiatry  

PubMed Central

The potential of noninvasive neurostimulation by repetitive transcranial magnetic stimulation (rTMS) for improving psychiatric disorders has been studied increasingly over the past two decades. This is especially the case for major depression and for auditory-verbal hallucinations in schizophrenia. The present review briefly describes the background of this novel treatment modality and summarizes evidence from clinical trials into the efficacy of rTMS for depression and hallucinations. Evidence for efficacy in depression is stronger than for hallucinations, although a number of studies have reported clinically relevant improvements for hallucinations too. Different stimulation parameters (frequency, duration, location of stimulation) are discussed. There is a paucity of research into other psychiatric disorders, but initial evidence suggests that rTMS may also hold promise for the treatment of negative symptoms in schizophrenia, obsessive compulsive disorder and post-traumatic stress disorder. It can be concluded that rTMS induces alterations in neural networks relevant for psychiatric disorders and that more research is needed to elucidate efficacy and underlying mechanisms of action.

2013-01-01

68

Effect of Transcranial Magnetic Stimulation on Neuronal Networks  

NASA Astrophysics Data System (ADS)

The human brain contains around 100 billion nerve cells controlling our day to day activities. Consequently, brain disorders often result in impairments such as paralysis, loss of coordination and seizure. It has been said that 1 in 5 Americans suffer some diagnosable mental disorder. There is an urgent need to understand the disorders, prevent them and if possible, develop permanent cure for them. As a result, a significant amount of research activities is being directed towards brain research. Transcranial Magnetic Stimulation (TMS) is a promising tool for diagnosing and treating brain disorders. It is a non-invasive treatment method that produces a current flow in the brain which excites the neurons. Even though TMS has been verified to have advantageous effects on various brain related disorders, there have not been enough studies on the impact of TMS on cells. In this study, we are investigating the electrophysiological effects of TMS on one dimensional neuronal culture grown in a circular pathway. Electrical currents are produced on the neuronal networks depending on the directionality of the applied field. This aids in understanding how neuronal networks react under TMS treatment.

Unsal, Ahmet; Hadimani, Ravi; Jiles, David

2013-03-01

69

Aging affects transcranial magnetic modulation of hippocampal evoked potentials.  

PubMed

Transcranial magnetic stimulation (TMS) is being proposed as a method of choice for the treatment of clinical depression, yet its action in the brain is still not well understood. In previous studies we found that TMS has a long-term effect on reactivity of the hippocampus to perforant path stimulation. Since the efficacy of antidepressants is highly age-dependent, we studied possible age-related effects of TMS on hippocampal evoked responses. Young adult (3 months), aging (10 months) and aged (24-26 months) awake rats were subjected to daily TMS for one week, followed by measurements of several parameters of reactivity to perforant path stimulation in the anesthetized rat. TMS did not affect responses of the hippocampus to single perforant path stimulation, but reduced drastically paired-pulse and frequency dependent depression in the young and aging but not the old rats. Likewise, TMS increased LTP expression in the young but not the old rats, and reduced the efficacy of serotonin modulation of reactivity of the hippocampus, in the young but not the old rats. Thus, long term effects of chronic TMS on local GABAergic inhibition are highly age dependent. PMID:11182475

Levkovitz, Y; Segal, M

70

Repetitive Transcranial Magnetic Stimulator with Controllable Pulse Parameters  

PubMed Central

The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10–310 ?s and positive/negative phase amplitude ratio of 1–56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation by up to 82% and 57%, and decreases coil heating by up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3,000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications, and could lead to clinical applications with potentially enhanced potency.

Peterchev, Angel V; Murphy, David L; Lisanby, Sarah H

2013-01-01

71

Transcranial magnetic stimulation and amyotrophic lateral sclerosis: pathophysiological insights  

PubMed Central

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder of the motor neurons in the motor cortex, brainstem and spinal cord. A combination of upper and lower motor neuron dysfunction comprises the clinical ALS phenotype. Although the ALS phenotype was first observed by Charcot over 100?years ago, the site of ALS onset and the pathophysiological mechanisms underlying the development of motor neuron degeneration remain to be elucidated. Transcranial magnetic stimulation (TMS) enables non-invasive assessment of the functional integrity of the motor cortex and its corticomotoneuronal projections. To date, TMS studies have established motor cortical and corticospinal dysfunction in ALS, with cortical hyperexcitability being an early feature in sporadic forms of ALS and preceding the clinical onset of familial ALS. Taken together, a central origin of ALS is supported by TMS studies, with an anterograde transsynaptic mechanism implicated in ALS pathogenesis. Of further relevance, TMS techniques reliably distinguish ALS from mimic disorders, despite a compatible peripheral disease burden, thereby suggesting a potential diagnostic utility of TMS in ALS. This review will focus on the mechanisms underlying the generation of TMS measures used in assessment of cortical excitability, the contribution of TMS in enhancing the understanding of ALS pathophysiology and the potential diagnostic utility of TMS techniques in ALS.

Vucic, Steve; Ziemann, Ulf; Eisen, Andrew; Hallett, Mark; Kiernan, Matthew C

2013-01-01

72

Repetitive transcranial magnetic stimulator with controllable pulse parameters  

NASA Astrophysics Data System (ADS)

The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10-310 µs and positive/negative phase amplitude ratio of 1-56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation up to 82% and 57% and decreases coil heating up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications and could lead to clinical applications with potentially enhanced potency.

Peterchev, Angel V.; Murphy, David L.; Lisanby, Sarah H.

2011-06-01

73

Repetitive transcranial magnetic stimulator with controllable pulse parameters.  

PubMed

The characteristics of transcranial magnetic stimulation (TMS) pulses influence the physiological effect of TMS. However, available TMS devices allow very limited adjustment of the pulse parameters. We describe a novel TMS device that uses a circuit topology incorporating two energy storage capacitors and two insulated-gate bipolar transistor (IGBT) modules to generate near-rectangular electric field pulses with adjustable number, polarity, duration, and amplitude of the pulse phases. This controllable pulse parameter TMS (cTMS) device can induce electric field pulses with phase widths of 10-310 µs and positive/negative phase amplitude ratio of 1-56. Compared to conventional monophasic and biphasic TMS, cTMS reduces energy dissipation up to 82% and 57% and decreases coil heating up to 33% and 41%, respectively. We demonstrate repetitive TMS trains of 3000 pulses at frequencies up to 50 Hz with electric field pulse amplitude and width variability less than the measurement resolution (1.7% and 1%, respectively). Offering flexible pulse parameter adjustment and reduced power consumption and coil heating, cTMS enhances existing TMS paradigms, enables novel research applications and could lead to clinical applications with potentially enhanced potency. PMID:21540487

Peterchev, Angel V; Murphy, David L; Lisanby, Sarah H

2011-05-04

74

ReaChR: a red-shifted variant of channelrhodopsin enables deep transcranial optogenetic excitation.  

PubMed

Channelrhodopsins (ChRs) are used to optogenetically depolarize neurons. We engineered a variant of ChR, denoted red-activatable ChR (ReaChR), that is optimally excited with orange to red light (? ?590-630 nm) and offers improved membrane trafficking, higher photocurrents and faster kinetics compared to existing red-shifted ChRs. Red light is less scattered by tissue and is absorbed less by blood than the blue to green wavelengths that are required by other ChR variants. We used ReaChR expressed in the vibrissa motor cortex to drive spiking and vibrissa motion in awake mice when excited with red light through intact skull. Precise vibrissa movements were evoked by expressing ReaChR in the facial motor nucleus in the brainstem and illumination with red light through the external auditory canal. Thus, ReaChR enables transcranial optical activation of neurons in deep brain structures without the need to surgically thin the skull, form a transcranial window or implant optical fibers. PMID:23995068

Lin, John Y; Knutsen, Per Magne; Muller, Arnaud; Kleinfeld, David; Tsien, Roger Y

2013-09-01

75

Noninvasive techniques for probing neurocircuitry and treating illness: vagus nerve stimulation (VNS), transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS)  

PubMed Central

Although the preceding chapters discuss much of the new knowledge of neurocircuitry of neuropsychiatric diseases, and an invasive approach to treatment, this chapter describes and reviews the noninvasive methods of testing circuit-based theories and treating neuropsychiatric diseases that do not involve implanting electrodes into the brain or on its surface. These techniques are transcranial magnetic stimulation, vagus nerve stimulation, and transcranial direct current stimulation. Two of these approaches have FDA approval as therapies.

George, Mark S; Aston-Jones, Gary

2010-01-01

76

Mood Improvement Following Daily Left Prefrontal Repetitive Transcranial Magnetic Stimulation in Patients With Depression: A Placebo-Controlled Crossover Trial  

Microsoft Academic Search

Objective: Preliminary studies have indicated that daily left prefrontal repetitive transcranial magnetic stimulation might have antidepressant activity. The authors sought to confirm this finding by using a double-blind crossover design. Method: Twelve depressed adults received in random order 2 weeks of active treatment (repetitive transcranial magnetic stimulation, 20 Hz at 80% motor threshold) and 2 weeks of sham treatment. Results:

Mark S. George; Eric M. Wassermann; Tim A. Kimbrell; John T. Little; Wendol E. Williams; Aimee L. Danielson; Benjamin D. Greenberg; Mark Hallett; Robert M. Post

1997-01-01

77

High permeability cores to optimize the stimulation of deeply located brain regions using transcranial magnetic stimulation  

NASA Astrophysics Data System (ADS)

Efficient stimulation of deeply located brain regions with transcranial magnetic stimulation (TMS) poses many challenges, arising from the fact that the induced field decays rapidly and becomes less focal with depth. We propose a new method to improve the efficiency of TMS of deep brain regions that combines high permeability cores, to increase focality and field intensity, with a coil specifically designed to induce a field that decays slowly with increasing depth. The performance of the proposed design was investigated using the finite element method to determine the total electric field induced by this coil/core arrangement on a realistically shaped homogeneous head model. The calculations show that the inclusion of the cores increases the field's magnitude by as much as 25% while also decreasing the field's decay with depth along specific directions. The focality, as measured by the area where the field's norm is greater than 1/\\sqrt 2 of its maximum value, is also improved by as much as 15% with some core arrangements. The coil's inductance is not significantly increased by the cores. These results show that the presence of the cores might make this specially designed coil even more suited for the effective stimulation of deep brain regions.

Salvador, R.; Miranda, P. C.; Roth, Y.; Zangen, A.

2009-05-01

78

Brain Stimulation Techniques Mechanisms and State of the Art of Transcranial Magnetic Stimulation  

Microsoft Academic Search

Summary: In 1985, Barker et al. built a transcranial magnetic stimulation (TMS) device with enough power to stimulate dorsal roots in the spine. They quickly realized that this machine could likely also noninvasively stimulate the superficial cortex in hu- mans. They waited a while before using their device over a human head, fearing that the TMS pulse might magnetically \\

Mark S. George; Ziad Nahas; F. Andrew Kozel; Xingbao Li; Stewart Denslow; Kaori Yamanaka; Alexander Mishory; Milton J. Foust; Daryl E. Bohning

79

ESTIMULACIÓN MAGNETICA TRANSCRANEAL: APLICACIONES EN NEUROCIENCIA COGNITIVA TRANSCRANIAL MAGNETIC STIMULATION: AN APPROACH FROM COGNITIVE NEUROSCIENCE  

Microsoft Academic Search

Objective: In this review we trace some of the mayor developments in the use of Transcranial magnetic stimulation (TMS) as a technique for the investigation of cognitive neuroscience and its application as an assessment and rehabilitation tool in some psychiatric and neurological disorders. Technical aspects and safety studies in animal and humans of the magnetic stimulation are also reviewed. Development:

Beatriz Calvo Merino; Patrick Haggard

80

Transcranial magnetic stimulation of frontal oculomotor regions during smooth pursuit.  

PubMed

Both the frontal eye fields (FEFs) and supplementary eye fields (SEFs) are known to be involved in smooth pursuit eye movements. It has been shown recently that stimulation of the smooth-pursuit area of the FEF [frontal pursuit area (FPA)] in monkey increases the pursuit response to unexpected changes in target motion during pursuit. In the current study, we applied transcranial magnetic stimulation (TMS) to the FPA and SEF in humans during sinusoidal pursuit to assess its effects on the pursuit response to predictable, rather than unexpected, changes in target motion. For the FPA, we found that TMS applied immediately before the target reversed direction increased eye velocity in the new direction, whereas TMS applied in mid-cycle, immediately before the target began to slow, decreased eye velocity. For the SEF, TMS applied at target reversal increased eye velocity in the new direction but had no effect on eye velocity when applied at mid-cycle. TMS of the control region (leg region of the somatosensory cortex) did not affect eye velocity at either point. Previous stimulation studies of FPA during pursuit have suggested that this region is involved in controlling the gain of the transformation of visual signals into pursuit motor commands. The current results suggest that the gain of the transformation of predictive signals into motor commands is also controlled by the FPA. The effect of stimulation of the SEF is distinct from that of the FPA and suggests that its role in sinusoidal pursuit is primarily at the target direction reversal. PMID:16407543

Gagnon, Danny; Paus, Tomás; Grosbras, Marie-Helène; Pike, G Bruce; O'Driscoll, Gillian A

2006-01-11

81

Repetitive transcranial magnetic stimulation for the treatment of chronic tinnitus after traumatic brain injury: a case study.  

PubMed

Tinnitus is a frequent symptom of traumatic brain injury, which is difficult to treat. Repetitive transcranial magnetic stimulation has shown beneficial effects in some forms of tinnitus. However, traumatic brain injury in the past has been considered as a relative contraindication for repetitive transcranial magnetic stimulation because of the increased risk of seizures. Here we present the case of a 53-year-old male patient suffering from severe tinnitus after traumatic brain injury with comorbid depression and alcohol abuse, who received 5 treatment series of repetitive transcranial magnetic stimulation (1 Hz stimulation protocol over left primary auditory cortex, 10 sessions of 2000 stimuli each, stimulation intensity 110% resting motor threshold). Repetitive transcranial magnetic stimulation was tolerated without any side effects and tinnitus complaints (measured by a validated tinnitus questionnaire and numeric rating scales) were improved in a replicable way throughout 5 courses of transcranial magnetic stimulation up to now. PMID:22688213

Kreuzer, Peter Michael; Landgrebe, Michael; Frank, Elmar; Langguth, Berthold

82

Repetitive transcranial magnetic stimulation induces different responses in different cortical areas: a functional magnetic resonance study in humans  

Microsoft Academic Search

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

Lars Johann Kemna; Daniel Gembris

2003-01-01

83

Effects of diazepam, baclofen and thiopental on the silent period evoked by transcranial magnetic stimulation in humans  

Microsoft Academic Search

The cortical silent period evoked by magnetic transcranial stimulation and the peripheral silent period were studied in healthy subjects after intravenous injection of diazepam, baclofen or thiopental. None of the drugs tested changed the peripheral silent period. But, unexpectedly, diazepam significantly shortened the cortical silent period, the inhibitory effect lasting about 30 min. In experiments using paired transcranial stimuli, the

M. Inghilleri; A. Berardelli; P. Marchetti; M. Manfredi

1996-01-01

84

Low and High Frequency Repetitive Transcranial Magnetic Stimulation for the Treatment of Spasticity  

ERIC Educational Resources Information Center

|The development of non-invasive techniques of cortical stimulation, such as transcranial magnetic stimulation (TMS), has opened new potential avenues for the treatment of neuropsychiatric diseases. We hypothesized that an increase in the activity in the motor cortex by cortical stimulation would increase its inhibitory influence on spinal…

Valle, Angela C.; Dionisio, Karen; Pitskel, Naomi Bass; Pascual-Leone, Alvaro; Orsati, Fernanda; Ferreira, Merari J. L.; Boggio, Paulo S.; Lima, Moises C.; Rigonatti, Sergio P.; Fregni, Felipe

2007-01-01

85

Effect of prefrontal transcranial magnetic stimulation on spontaneous truth-telling  

Microsoft Academic Search

Brain-process foundations of deceptive behaviour have become a subject of intensive study both in fundamental and applied neuroscience. Recently, utilization of transcranial magnetic stimulation has enhanced methodological rigour in this research because in addition to correlational studies causal effects of the distinct cortical systems involved can be studied. In these studies, dorsolateral prefrontal cortex has been implied as the brain

Inga Karton; Talis Bachmann

2011-01-01

86

Muscle imaging: Mapping responses to transcranial magnetic stimulation with high-density surface electromyography  

Microsoft Academic Search

Representations of different body parts or muscles in the human primary motor cortex overlap extensively. At the effector level, most muscles are surrounded by and overlap with several neighbours as well. This hampers the assessment of excitability in individual muscles with transcranial magnetic stimulation (TMS), even if so-called “focal” stimulating coils are used. Here we used a novel mapping paradigm

Gijs van Elswijk; Bert U. Kleine; Sebastiaan Overeem; Bertine Eshuis; Karin D. Hekkert; Dick F. Stegeman

2008-01-01

87

The Role of the Dorsolateral Prefrontal Cortex in Bimodal Divided Attention: Two Transcranial Magnetic Stimulation Studies  

Microsoft Academic Search

The neural processes underlying the ability to divide attention between multiple sensory modalities remain poorly understood. To investigate the role of the dorsolateral prefrontal cortex (DLPFC) in bimodal divided attention, we completed two repetitive transcranial magnetic stimulation (rTMS) studies. We tested the hypothesis that the DLPFC is necessary in the ability to divide attention across modalities. This hypothesis originated as

Jennifer Adrienne Johnson; Antonio P. Strafella; Robert J. Zatorre

2007-01-01

88

Transcranial magnetic stimulation applications and potential use in chronic pain: studies in waiting  

Microsoft Academic Search

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

Saxby Pridmore; Gaj’inder Oberoi

2000-01-01

89

Corticomotor control of the genioglossus in awake OSAS patients: a transcranial magnetic stimulation study  

Microsoft Academic Search

BACKGROUND: Upper airway collapse does not occur during wake in obstructive sleep apnea patients. This points to wake-related compensatory mechanisms, and possibly to a modified corticomotor control of upper airway dilator muscles. The objectives of the study were to characterize the responsiveness of the genioglossus to transcranial magnetic stimulation during respiratory and non-respiratory facilitatory maneuvers in obstructive sleep apnea patients,

Wei Wang; Thomas Similowski

2009-01-01

90

Resetting of Orthostatic Tremor Associated With Cerebellar Cortical Atrophy by Transcranial Magnetic Stimulation  

Microsoft Academic Search

Objectives: To investigate the resetting effects of trans- cranial magnetic stimulation over motor cortex on or- thostatic tremor, characterized by high-frequency elec- tromyographic discharges in weight-bearing muscles, particularly orthostatic tremor (OT) associated with cer- ebellar cortical atrophy; and to compare our results with those obtained in primary OT, for which transcranial mag- netic stimulation does not reset tremor. Design: Study

Mario-Ubaldo Manto; Fabrizia Setta; Benjamin Legros; Jean Jacquy; Emile Godaux

1999-01-01

91

Facilitating Effect of 15Hz Repetitive Transcranial Magnetic Stimulation on Tactile Perceptual Learning  

Microsoft Academic Search

Recent neuroimaging studies have revealed that tactile perceptual learning can lead to substantial reorganizational changes of the brain. We report here for the first time that combining high-frequency (15 Hz) repetitive transcranial magnetic stimulation (rTMS) over the primary somatosensory cortex (SI) with tactile discrimination training is capable of facilitating operant perceptual learning. Most notably, increasing the excitability of SI by

Ahmed A. Karim; Anne Schüler; Yiwen Li Hegner; Eva Friedel; Ben Godde

2006-01-01

92

Repetitive Transcranial Magnetic Stimulation to the Primary Motor Cortex Interferes with Motor Learning by Observing  

ERIC Educational Resources Information Center

Neural representations of novel motor skills can be acquired through visual observation. We used repetitive transcranial magnetic stimulation (rTMS) to test the idea that this "motor learning by observing" is based on engagement of neural processes for learning in the primary motor cortex (M1). Human subjects who observed another person learning…

Brown, Liana E.; Wilson, Elizabeth T.; Gribble, Paul L.

2009-01-01

93

Low and High Frequency Repetitive Transcranial Magnetic Stimulation for the Treatment of Spasticity  

ERIC Educational Resources Information Center

The development of non-invasive techniques of cortical stimulation, such as transcranial magnetic stimulation (TMS), has opened new potential avenues for the treatment of neuropsychiatric diseases. We hypothesized that an increase in the activity in the motor cortex by cortical stimulation would increase its inhibitory influence on spinal…

Valle, Angela C.; Dionisio, Karen; Pitskel, Naomi Bass; Pascual-Leone, Alvaro; Orsati, Fernanda; Ferreira, Merari J. L.; Boggio, Paulo S.; Lima, Moises C.; Rigonatti, Sergio P.; Fregni, Felipe

2007-01-01

94

Transcranial magnetic stimulation to right parietal cortex modifies the attentional blink  

Microsoft Academic Search

The ‘attentional blink’ (AB) reflects a limitation in the ability to identify multiple items in a stream of rapidly presented information. Repetitive transcranial magnetic stimulation (rTMS), applied to a site over the right posterior parietal cortex, reduced the magnitude of the AB to visual stimuli, whilst no effect of rTMS was found when stimulation took place at a control site.

Adam C. G. Cooper; Glyn W. Humphreys; Johan Hulleman; Peter Praamstra; Mark Georgeson

2004-01-01

95

Processing of auditory motion in inferior parietal lobule: Evidence from transcranial magnetic stimulation  

Microsoft Academic Search

The neural substrates of auditory motion processing are, at present, still a matter of debate. It has been hypothesized that motion information is, as in the visual system, processed separately from other aspects of auditory information, such as stationary location. Here we aimed to differentiate the location of auditory motion processing in human cortex using low-frequency repetitive transcranial magnetic stimulation

Jörg Lewald; Mario Staedtgen; Roland Sparing; Ingo G. Meister

2011-01-01

96

Functional Connectivity of Human Premotor and Motor Cortex Explored with Repetitive Transcranial Magnetic Stimulation  

Microsoft Academic Search

Connections between the premotor cortex and the primary motor cortex are dense and are important in the visual guidance of arm movements. We have shown previously that it is possi- ble to engage these connections in humans and to measure the net amount of inhibition\\/facilitation from premotor to motor cortex using single-pulse transcranial magnetic stimulation (TMS). The aim of this

A. Munchau; B. R. Bloem; K. Irlbacher; M. R. Trimble; J. C. Rothwell

2002-01-01

97

A transcranial magnetic stimulation study of the ipsilateral silent period in lower limb muscles  

Microsoft Academic Search

The lower limb ipsilateral silent periods (ISP) were determined with transcranial magnetic stimulation in 30 normal subjects using a round coil. The mean duration and transcallosal conduction time were comparable to values obtained from upper limb recordings. No age-related correlation was found for either parameter, corroborating previous imaging and pathological studies of interhemispheric pathways. Our results highlight the feasibilty of

Y. L. Lo; S. Fook-Chong

2004-01-01

98

Transcranial magnetic stimulation-induced ‘visual echoes’ are generated in early visual cortex  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) of the early visual areas can trigger perception of a flash of light, a so-called phosphene. Here we show that a very brief presentation of a stimulus can modulate features of a subsequent TMS-induced phosphene, to a level that participants mistake phosphenes for real stimuli, inducing ‘visual echoes’ of a previously seen stimulus. These ‘echoes’ are

Jacob Jolij; Victor A. F. Lamme

2010-01-01

99

Transcranial magnetic stimulation of the primary motor cortex modulates response interference in a flanker task  

Microsoft Academic Search

In a typical flanker task, responses to a central target (“S” or “N”) are modulated by whether the flankers are compatible (“SSSSS”) or incompatible (“NNSNN”), with increased reaction times and decreased accuracy on incompatible trials. The role of the motor system in response interference under these conditions remains unclear, however. Here we show that transcranial magnetic stimulation (TMS) of the

David Soto; Pedro R. Montoro; Glyn W. Humphreys

2009-01-01

100

Navigated transcranial magnetic stimulation of the primary somatosensory cortex impairs perceptual processing of tactile temporal discrimination  

Microsoft Academic Search

Previous studies indicate that transcranial magnetic stimulation (TMS) with biphasic pulses applied approximately over the primary somatosensory cortex (S1) suppresses performance in vibrotactile temporal discrimination tasks; these previous results, however, do not allow separating perceptual influence from memory or decision-making. Moreover, earlier studies using external landmarks for directing biphasic TMS pulses to the cortex do not reveal whether the changes

Henri Hannula; Tuomas Neuvonen; Petri Savolainen; Taru Tukiainen; Oili Salonen; Synnöve Carlson; Antti Pertovaara

2008-01-01

101

Deficient motor control in children with tic disorder: evidence from transcranial magnetic stimulation  

Microsoft Academic Search

Decreased motor inhibition was reported in adult patients with tic disorder (TD) using the technique of transcranial magnetic stimulation. Since tics usually begin during childhood, motor threshold, cortical silent period (CSP) and intracortical inhibition\\/facilitation were measured in 21 TD children and 25 healthy children aged 10–16 years. In TD children motor threshold was normal. The CSP was significantly shortened compared

Gunther H Moll; Stephan Wischer; Hartmut Heinrich; Frithjof Tergau; Walter Paulus; Aribert Rothenberger

1999-01-01

102

Intracortical inhibitory circuits and sensory input: a study with transcranial magnetic stimulation in humans  

Microsoft Academic Search

We compared intracortical inhibition (ICI) following paired transcranial magnetic stimulation (TMS) (interstimulus interval, ISI: 3 ms) and the inhibition of motor evoked potentials (MEPs) to TMS induced by stimulation of the median nerve (ISI: 200 ms) in six normal subjects. MEPs evoked by focal TMS were recorded in the relaxed opponens pollicis muscle and the size of the conditioned responses

Carlo Trompetto; Alessandro Buccolieri; Giovanni Abbruzzese

2001-01-01

103

Anti-kindling effect of slow repetitive transcranial magnetic stimulation in rats  

Microsoft Academic Search

The cerebrospinal fluid (CSF) of animals exposed to electroconvulsive shock (ECS) has anticonvulsant properties when injected into naive animals. The present study investigated whether the CSF of humans exposed to 1 or 10 Hz repetitive transcranial magnetic stimulation (rTMS) has similar properties. Using a 4 day rat flurothyl kindling seizure model we found that the kindling rate was significantly decreased

David J. Anschel; Alvaro Pascual-Leone; Gregory L. Holmes

2003-01-01

104

The relationship between peripheral and early cortical activation induced by transcranial magnetic stimulation  

Microsoft Academic Search

The purpose of this study was to assess the relationship between peripheral muscle responses (motor evoked potentials, MEP) evoked by transcranial magnetic stimulation (TMS) and the early components of the TMS-evoked EEG response, both of which reflect cortical excitability. Left primary motor cortex of five healthy volunteers was stimulated with 100% of the motor threshold. The relationship between MEP amplitudes

Hanna Mäki; Risto J. Ilmoniemi

2010-01-01

105

Transcranial magnetic stimulation in Alzheimer disease: motor cortex excitability and cognitive severity  

Microsoft Academic Search

To study the possible changes of cortical excitability in the Alzheimer disease (AD) by transcranial magnetic stimulation (TMS) and to evaluate their eventual correlation with its stage twenty-one AD patients and 18 normal controls underwent TMS. Motor threshold, amplitudes of motor evoked potentials (MEPs), central motor conduction time (CMCT) and silent period (SP) were considered. The motor threshold in AD

Giovanna Alagona; Rita Bella; Raffaele Ferri; Anna Carnemolla; Alessandra Pappalardo; Erminio Costanzo; Giovanni Pennisi

2001-01-01

106

Orally administered atropine enhances motor cortex excitability: a transcranial magnetic stimulation study in human subjects  

Microsoft Academic Search

Oral application of atropine was used to test if a modulation of cholinergic neurotransmission changed motor excitability. Healthy volunteers received either 1 or 2 mg atropine. Paired transcranial magnetic stimulation was used to study intracortical inhibition and intracortical facilitation before, 1 h and 24 h after ingestion of atropine. In addition, the silent period, motor threshold, F wave and motor

J Liepert; S Schardt; C Weiller

2001-01-01

107

Postural instability enhances motor responses to transcranial magnetic stimulation in humans  

Microsoft Academic Search

Does the state of postural instability require a high hierarchical level of posture control? Electromyographic (EMG) activity of leg muscles was recorded during transcranial magnetic stimulation (TMS) of the motor cortex and electrical stimulation of the tibial nerve (H-reflex) in healthy subjects standing on a rigid floor and on a rocking platform. In the soleus muscle, TMS-evoked EMG responses increased

I. A. Solopova; O. V. Kazennikov; N. B. Deniskina; Y. S. Levik; Y. P. Ivanenko

2003-01-01

108

Modulation of slow cortical potentials by transcranial magnetic stimulation in humans  

Microsoft Academic Search

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

Andrea Kübler; Konrad Schmidt; Leonardo G. Cohen; Martin Lotze; Susanne Winter; Thilo Hinterberger; Niels Birbaumer

2002-01-01

109

1 Hz repetitive transcranial magnetic stimulation of the unaffected hemisphere ameliorates contralesional visuospatial neglect in humans  

Microsoft Academic Search

The aim of the study was to investigate whether low-frequency repetitive transcranial magnetic stimulation (rTMS) over the unaffected hemisphere can ameliorate visuospatial neglect. We treated three right brain damaged patients with left neglect. 900 pulses (1 Hz frequency) were given over left posterior parietal cortex every other day for 2 weeks. Patients performed a computerized task requiring length judgement of

F. Brighina; E. Bisiach; M. Oliveri; A. Piazza; V. La Bua; O. Daniele; B. Fierro

2003-01-01

110

Studies in Cognition: The Problems Solved and Created by Transcranial Magnetic Stimulation  

Microsoft Academic Search

The application of transcranial magnetic stimulation (TMS) to investigate important questions in cognitive neuroscience has increased considerably in the last few years. TMS can provide substantial insights into the nature and the chronometry of the computations performed by specific cortical areas during various aspects of cognition. However, the use of TMS in cognitive studies has many potential perils and pitfalls.

E. M. Robertson; H. Théoret; A. Pascual-Leone

2003-01-01

111

Phonological and lexical motor facilitation during speech listening: A transcranial magnetic stimulation study  

Microsoft Academic Search

In the present study, we used transcranial magnetic stimulation (TMS) to investigate the influence of phonological and lexical properties of verbal items on the excitability of the tongue’s cortical motor representation during passive listening. In particular, we aimed to clarify if the difference in tongue motor excitability found during listening to words and pseudo-words [Fadiga, L., Craighero, L., Buccino, G.,

Alice C. Roy; Laila Craighero; Maddalena Fabbri-Destro; Luciano Fadiga

2008-01-01

112

Repetitive transcranial magnetic stimulation of the parietal cortex transiently ameliorates phantom limb pain-like syndrome  

Microsoft Academic Search

Objective: Phantom pain is linked to a reorganization of the partially deafferented sensory cortex. In this study we have investigated whether the pain syndrome can be influenced by repetitive transcranial magnetic stimulation (rTMS).Methods: Two patients with a longstanding unilateral avulsion of the lower cervical roots and chronic pain in the arm were studied. As a control the acute effects of

Rudolf Töpper; Henrik Foltys; Ingo G Meister; Roland Sparing; Babak Boroojerdi

2003-01-01

113

The effect of transcranial magnetic stimulation on reaction time in progressive supranuclear palsy  

Microsoft Academic Search

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

José L Molinuevo; Josep Valls-Solé; Francesc Valldeoriola

2000-01-01

114

Parieto-occipital cortex and planning of reaching movements: A transcranial magnetic stimulation study  

Microsoft Academic Search

A large amount of evidence supports a role for the parietal and frontal cortex in the planning of reaching movements. Nevertheless, neither the timing of involvement of these areas nor if and how their activity can be influenced by external stimuli has been clarified. The parieto-occipital cortex has been investigated by applying transcranial magnetic stimulation (TMS) at 25% (Time 1),

Pierpaolo Busan; Fabrizio Monti; Mauro Semenic; Gilberto Pizzolato; Piero Paolo Battaglini

2009-01-01

115

Overclaiming and the medial prefrontal cortex: A transcranial magnetic stimulation study  

Microsoft Academic Search

The tendency to claim more knowledge than one actually has is common and well documented; however, little research has focused on the neural mechanisms that underlie this phenomenon. The goal of the present study was to investigate the cortical correlates of overclaiming. Transcranial magnetic stimulation (TMS) was delivered to the medial prefrontal cortex (MPFC), supplementary motor area, and precuneus during

Franco Amati; Hanna Oh; Virginia S. Y. Kwan; Kelly Jordan; Julian Paul Keenan

2010-01-01

116

Repetitive transcranial magnetic stimulation for negative symptoms of schizophrenia: A randomized controlled pilot study  

Microsoft Academic Search

BackgroundNegative symptoms in schizophrenia are associated with deficits in executive function and frequently prove highly resistant to neuroleptic medication. Using repetitive transcranial magnetic stimulation (rTMS) to activate the prefrontal cortex has been suggested as a treatment for negative symptoms.

Andrew Mogg; Rick Purvis; Savitha Eranti; Faith Contell; John P. Taylor; Timothy Nicholson; Richard G. Brown; Declan M. McLoughlin

2007-01-01

117

Transcranial magnetic stimulation in the treatment of schizophrenic symptoms: A double blind sham controlled study  

Microsoft Academic Search

BackgroundSchizophrenia is a disabling disease with a significant proportion of patients experiencing persistent symptoms. Repetitive transcranial magnetic stimulation (rTMS) is a promising new therapeutic tool that could benefit to schizophrenic patients. In this study we sought to assess the efficacy of active rTMS compared to sham stimulation in the treatment of patients with schizophrenia.

G. Saba; C. M. Verdon; K. Kalalou; J. F. Rocamora; G. Dumortier; R. Benadhira; L. Stamatiadis; E. Vicaut; H. Lipski; D. Januel

2006-01-01

118

Increased positive emotional memory after repetitive transcranial magnetic stimulation over the orbitofrontal cortex  

Microsoft Academic Search

Objective: Several studies have demonstrated increased left orbitofrontal cortex (OFC) activity during negative and depressed mood. These mood states have also been associated with reduced memory for positive emotional stimuli. The aim of the present study was to investigate whether slow, inhibitory repetitive transcranial magnetic stimulation (rTMS) over the left OFC would improve memory for posi- tive material. Methods: We

Dennis J. L. G. Schutter; Jack van Honk

2006-01-01

119

Repetitive Transcranial Magnetic Stimulation to the Primary Motor Cortex Interferes with Motor Learning by Observing  

ERIC Educational Resources Information Center

|Neural representations of novel motor skills can be acquired through visual observation. We used repetitive transcranial magnetic stimulation (rTMS) to test the idea that this "motor learning by observing" is based on engagement of neural processes for learning in the primary motor cortex (M1). Human subjects who observed another person learning…

Brown, Liana E.; Wilson, Elizabeth T.; Gribble, Paul L.

2009-01-01

120

Transcranial magnetic stimulation: a historical evaluation and future prognosis of therapeutically relevant ethical concerns  

Microsoft Academic Search

Transcranial Magnetic Stimulation (TMS) is a non-invasive neurostimulatory and neuromodulatory technique increasingly used in clinical and research practices around the world. Historically, the ethical considerations guiding the therapeutic practice of TMS were largely concerned with aspects of subject safety in clinical trials. While safety remains of paramount importance, the recent US Food and Drug Administration approval of the Neuronetics NeuroStar

Jared C Horvath; Jennifer M Perez; Lachlan Forrow; Felipe Fregni; Alvaro Pascual-Leone

2010-01-01

121

Inter-hemispheric asymmetry of motor corticospinal excitability in major depression studied by transcranial magnetic stimulation  

Microsoft Academic Search

BackgroundImaging and electroencephalographic studies have reported inter-hemispheric asymmetries in frontal cortical regions associated with depression. This study aimed at comparing motor corticospinal excitability assessed by methods of transcranial magnetic stimulation (TMS) between the right and left hemispheres in patients with major depression and healthy controls.

J. P. Lefaucheur; B. Lucas; F. Andraud; J. Y. Hogrel; F. Bellivier; A. Del Cul; A. Rousseva; M. Leboyer; M. L. Paillère-Martinot

2008-01-01

122

Transcranial magnetic stimulation highlights the sensorimotor side of empathy for pain  

Microsoft Academic Search

Pain is intimately linked with action systems that are involved in observational learning and imitation. Motor responses to one's own pain allow freezing or escape reactions and ultimately survival. Here we show that similar motor responses occur as a result of observation of painful events in others. We used transcranial magnetic stimulation to record changes in corticospinal motor representations of

Alessio Avenanti; Domenica Bueti; Gaspare Galati; Salvatore M Aglioti

2005-01-01

123

Validation of surface recordings of the diaphragm response to transcranial magnetic stimulation in humans.  

PubMed

The integrity of the central efferent motor pathways to the diaphragm can be assessed by using transcranial magnetic stimulation to measure the latency of the corresponding motor evoked potentials with surface electrodes. Because transcranial magnetic stimulation does not activate the diaphragm alone, signal contamination is a potential problem. To evaluate this issue, surface diaphragmatic motor-evoked potential latencies were compared with latencies recorded from diaphragm needle in 9 healthy volunteers. Surface latencies of muscles likely to contaminate the diaphragm signals (serratus anterior, pectoralis major, and tranversus abdominis) were also recorded. The latencies in response to nonfocal transcranial stimulation from surface electrodes were not significantly different from the needle ones (17 +/- 1.3 vs. 17.2 +/- 1.1 ms, respectively) but were significantly different from the latencies of the other muscles. In two cases, signal contamination appeared likely (serratus anterior in 1 case, abdominal muscles in 1 case). It is possible to reliably measure the latency of the diaphragm response to transcranial magnetic stimulation with adequately positioned surface electrodes. PMID:12391044

Demoule, Alexandre; Verin, Eric; Locher, Chrystèle; Derenne, Jean-Philippe; Similowski, Thomas

2002-10-11

124

Magnetic transcranial stimulation in healthy humans: influence on the behavior of upper limb motor units  

Microsoft Academic Search

Aim of the study was to analyze the characteristics of motor action potentials recruitment during magnetic trans-cranial stimulation (TCS) of the brain. Coaxial needle recordings from hand and upper limb musculature, as well as surface electrodes were employed in 20 healthy controls during magnetic TCS with regular and figure-of-8 coil in different experimental protocols including: (a) simple reaction time paradigm

P. M. Rossini; M. D. Caramia; C. Iani; M. T. Desiato; G. Sciarretta; G. Bernardi

1995-01-01

125

Treating Auditory Hallucinations by Transcranial Magnetic Stimulation: A Randomized Controlled Cross-Over Trial  

Microsoft Academic Search

Background: In a previous functional magnetic resonance imaging study, the authors succeeded in demonstrating the activation of Heschl’s gyrus during auditory hallucinations (AH). Objectives: This study aims to treat AH specifically by repetitive transcranial magnetic stimulation (rTMS). Methods: 16 patients with AH were included in a randomized, cross-over, sham-controlled trial. 1 Hz rTMS was administered over the left and right

Martin Jandl; Juergen Steyer; Martin Weber; David E. J. Linden; Johannes Rothmeier; Konrad Maurer; Wolfgang P. Kaschka

2006-01-01

126

Transient visual field defects induced by transcranial magnetic stimulation over human occipital pole  

Microsoft Academic Search

Transient visual field defects (VFDs) and phosphenes were induced in normal volunteers by means of transcranial magnetic stimulation\\u000a (TMS) using a circular magnetic coil of 12.5 cm diameter placed with its lower rim 2–4 cm above the inion in the midline.\\u000a Subjects had to detect small, bright dots presented randomly for 14 ms in one of 60 locations on a

Sabine Kastner; Iris Demmer; Ulf Ziemann

1998-01-01

127

Intracranial measurement of current densities induced by transcranial magnetic stimulation in the human brain  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) is a non-invasive technique that uses the principle of electromagnetic induction to generate currents in the brain via pulsed magnetic fields. The magnitude of such induced currents is unknown. In this study we measured the TMS induced current densities in a patient with implanted depth electrodes for epilepsy monitoring. A maximum current density of 12 ?A\\/cm2

Tim Wagner; Massimo Gangitano; Rafael Romero; Hugo Théoret; Masahito Kobayashi; David Anschel; John Ives; Neil Cuffin; Donald Schomer; Alvaro Pascual-Leone

2004-01-01

128

Noninvasive techniques for probing neurocircuitry and treating illness: vagus nerve stimulation (VNS), transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS)  

Microsoft Academic Search

Although the preceding chapters discuss much of the new knowledge of neurocircuitry of neuropsychiatric diseases, and an invasive approach to treatment, this chapter describes and reviews the noninvasive methods of testing circuit-based theories and treating neuropsychiatric diseases that do not involve implanting electrodes into the brain or on its surface. These techniques are transcranial magnetic stimulation, vagus nerve stimulation, and

Mark S George; Gary Aston-Jones

2010-01-01

129

Motor cortex-induced plasticity by noninvasive brain stimulation: a comparison between transcranial direct current stimulation and transcranial magnetic stimulation.  

PubMed

The aim of this study was to test and compare the effects of a within-subject design of repetitive transcranial magnetic stimulation (rTMS) [coupled with sham transcranial direct current stimulation (tDCS)] and tDCS (coupled with sham rTMS) on the motor cortex excitability and also compare the results against sham tDCS/sham rTMS. We conducted a double-blinded, randomized, sham-controlled, cross-over trial. Eleven right-handed, healthy individuals (five women, mean age: 39.8 years, SD 13.4) received the three interventions (cross-over design) in a randomized order: (a) high-frequency (HF) rTMS (+sham tDCS), (b) anodal tDCS (+sham rTMS), and (c) sham stimulation (sham rTMS+sham tDCS). Cortical excitability measurements [motor threshold, motor evoked potential (MEP), intracortical facilitation and inhibition, and transcallosal inhibition] and motor behavioral assessments were used as outcome measures. Between-group analysis of variance showed that MEP amplitude after HF rTMS was significantly higher than MEP amplitude after anodal tDCS (P=0.001). Post-hoc analysis showed a significant increase in MEP amplitude after HF rTMS (25.3%, P=0.036) and a significant decrease in MEP amplitude after anodal tDCS (-32.7%, P=0.001). There was a similar increase in motor function as indexed by Jebsen-Taylor Hand Function Test in the two active groups compared with sham stimulation. In conclusion, here, we showed that although both techniques induced similar motor gains, they induce opposing results in cortical excitability. HF rTMS is associated with an increase in corticospinal excitability, whereas 20 min of tDCS induces the opposite effect. We discuss potential implications of these results to future clinical experiments using rTMS or tDCS for motor function enhancement. PMID:24100412

Simis, Marcel; Adeyemo, Bamidele O; Medeiros, Liciane F; Miraval, Forella; Gagliardi, Rubens J; Fregni, Felipe

2013-12-01

130

The effect of repetitive transcranial magnetic stimulation on motor performance, fatigue and quality of life in amyotrophic lateral sclerosis  

Microsoft Academic Search

BackgroundThe treatment of amyotrophic lateral sclerosis (ALS) is still disappointing. Repetitive transcranial magnetic stimulation (rTMS) has been suggested to modify the rate of disease progression in ALS.

Giampietro Zanette; Antonio Forgione; Paolo Manganotti; Antonio Fiaschi; Stefano Tamburin

2008-01-01

131

Changes in motor cortical excitability induced by high-frequency repetitive transcranial magnetic stimulation of different stimulation durations  

Microsoft Academic Search

ObjectiveTo investigate the changes in cortical excitability of the human motor cortex induced by high-frequency repetitive transcranial magnetic stimulation (rTMS) of different stimulation durations.

Se Hee Jung; Jae Eun Shin; Yong-Seol Jeong; Hyung-Ik Shin

2008-01-01

132

The use of a cap-shaped coil for transcranial magnetic stimulation of the motor cortex.  

PubMed

A cap-shaped coil is introduced as a superior design for inducing transcranial magnetic motor evoked potentials for spinal cord monitoring. Evaluation of the magnetic characteristics of the cap coil showed higher induced electrical fields at and below the depth of the cortical surface, compared to a 9-cm, butterfly-shaped coil. Twenty normal adults were stimulated with the cap coil and a 9-cm round coil in three positions. Compound muscle action potentials were recorded from the left and right abductor digiti minimi and anterior tibialis muscles. The cap coil induced potentials with higher intensities and lower variability between consecutive stimuli. The cap coil was also more able to simultaneously induce motor evoked potentials from the four muscles studied. This coil design should provide superior means of inducing transcranial magnetic motor evoked potentials in multiple muscles. PMID:8408600

Kraus, K H; Gugino, L D; Levy, W J; Cadwell, J; Roth, B J

1993-07-01

133

High frequency transcranial magnetic stimulation mimics the effects of ECS in upregulating astroglial gene expression in the murine CNS  

Microsoft Academic Search

The present study evaluates the consequences of high frequency (25 hz) trans-cranial magnetic stimulation on the expression of glial fibrillary acidic protein (GFAP) in the murine CNS. Trains of transcranial magnetic stimulation (1–30 trains at 25 Hz, 10 s duration) were delivered to mice via 5-cm diameter round coils. The stimulation produced stimulus-locked motor responses but did not elicit behavioral

Minoru Fujiki; Oswald Steward

1997-01-01

134

The effects of L-DOPA and transcranial magnetic stimulation on behavioral reactions in kindled rats.  

PubMed

Acute experiments were performed on rats to produce a model of chronic epileptic activity--pharmacological kindling by repeated doses of picrotoxin (1.0-1.2 mg/kg, i.p.). During the early period following kindling (24 h from the last dose of epileptogen), animals showed decreases in measures of investigative behavior as measured in an open field test, along with reductions in sexual and feeding behavior. The severity of these impairments had decreased by two weeks from the last picrotoxin dose. Both treatment with L-DOPA (100 mg/kg, i.p.) and transcranial magnetic stimulation (20 impulses with induction, peak 1.5 T) were accompanied by increases in measures of investigative, sexual, and feeding behavior in the animals, suggesting that mechanism of action of transcranial magnetic stimulation in relation to kindling-induced behavioral abnormalities is mediated by activation of the dopaminergic system of the brain. PMID:15875494

Godlevskii, L S; Kobolev, E V

2005-03-01

135

Extrageniculate mediation of unconscious vision in transcranial magnetic stimulation-induced blindsight  

PubMed Central

The proposed neural mechanisms supporting blindsight, the above-chance performance of cortically blind patients on forced-choice visual discrimination tasks, are controversial. In this article, we show that although subjects were unable to perceive foveally presented visual stimuli when transcranial magnetic stimulation over the visual cortex induced a scotoma, responses nonetheless were delayed significantly by these unconscious distractors in a directed saccade but not in an indirect manual response task. These results suggest that the superior colliculus, which is involved with sensory encoding as well as with the generation of saccadic eye movements, is mediating the unconscious processing of the transcranial magnetic stimulation-suppressed distractors and implicate a role of the retinotectal pathway in many blindsight phenomena.

Ro, Tony; Shelton, Dominique; Lee, Olivia L.; Chang, Erik

2004-01-01

136

Transcranial magnetic stimulation: studying the brain-behaviour relationship by induction of 'virtual lesions'.  

PubMed Central

Transcranial magnetic stimulation (TMS) provides a non-invasive method of induction of a focal current in the brain and transient modulation of the function of the targeted cortex. Despite limited understanding about focality and mechanisms of action, TMS provides a unique opportunity of studying brain-behaviour relations in normal humans. TMS can enhance the results of other neuroimaging techniques by establishing the causal link between brain activity and task performance, and by exploring functional brain connectivity.

Pascual-Leone, A; Bartres-Faz, D; Keenan, J P

1999-01-01

137

Variability of motor potentials evoked by transcranial magnetic stimulation depends on muscle activation  

Microsoft Academic Search

The purpose of this research was to determine whether motor cortex excitability assessed using transcranial magnetic stimulation (TMS) is less variable when subjects maintain a visually controlled low-level contraction of the muscle of interest. We also examined the dependence of single motor evoked potential (MEP) amplitude on stimulation intensity and pre-stimulus muscle activation level using linear and non-linear multiple regression

Warren G. Darling; Steven L. Wolf; Andrew J. Butler

2006-01-01

138

Diffuse analgesic effects of unilateral repetitive transcranial magnetic stimulation (rTMS) in healthy volunteers  

Microsoft Academic Search

We investigated the analgesic effects of unilateral repetitive transcranial magnetic stimulation (rTMS) of the motor cortex (M1) or dorsolateral prefrontal cortex (DLPFC) in two models of experimental pain in healthy volunteers. Two studies were carried out in parallel in two groups of 26 paid healthy volunteers. The effects of active or sham rTMS (frequency, 10Hz; intensity, 80% resting motor threshold)

Frédéric Nahmias; Claire Debes; Daniel Ciampi de Andrade; Alaa Mhalla; Didier Bouhassira

2009-01-01

139

Role of the Left DLPFC in Endogenous Task Preparation: Experimental Repetitive Transcranial Magnetic Stimulation Study  

Microsoft Academic Search

The precise role of the dorsolateral prefrontal cortex (DLPFC) in attentional set activation is still not entirely clear. Hence, repetitive transcranial magnetic stimulation (rTMS) can be applied to interfere with neural processing to determine whether a specific brain area is required in task performance. In this study, the influence of one session of high-frequency (HF)-rTMS of the left DLPFC on

Marie-Anne Vanderhasselt; Rudi De Raedt; Lemke Leyman; Chris Baeken

2010-01-01

140

Complete suppression of voluntary motor drive during the silent period after transcranial magnetic stimulation  

Microsoft Academic Search

To evaluate changes in the motor system during the silent period (SP) induced by transcranial magnetic stimulation (TMS)\\u000a of the motor cortex, we investigated motor thresholds as parameters of the excitability of the cortico-muscular pathway after\\u000a a suprathreshold conditioning stimulus in the abductor digiti minimi muscle (ADM) of normal humans. Since the unconditioned\\u000a motor threshold was lower during voluntary tonic

Frithjof Tergau; Veronika Wanschura; Monica Canelo; Stephan Wischer; Eric M. Wassermann; Ulf Ziemann; Walter Paulus

1999-01-01

141

Effects of Acute Repetitive Transcranial Magnetic Stimulation on Extracellular Serotonin Concentration in the Rat Prefrontal Cortex  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) changes the function of the cortex. This study clarified the effects of acute rTMS treatment on extracellular serotonin (5-HT) concentrations in the rat prefrontal cortex (PFC) by using in vivo microdialysis methods. Each rat received acute rTMS treatment of the frontal brain at 500 stimuli from twenty trains applied at 25 Hz for 1 s

Manabu Kanno; Machiko Matsumoto; Hiroko Togashi; Mitsuhiro Yoshioka; Yukio Mano

2003-01-01

142

Emotion and motor preparation: A transcranial magnetic stimulation study of corticospinal motor tract excitability  

Microsoft Academic Search

In the present study, we examined whether preparing motor responses under different emotional conditions alters motor evoked\\u000a potentials (MEPs) elicited by transcranial magnetic stimulation delivered to the motor cortex. Analyses revealed three findings:\\u000a (1) Reaction times were expedited during exposure to unpleasant images, as compared with pleasant and neutral images; (2)\\u000a force amplitude was greater during exposure to unpleasant images,

Stephen A. Coombes; Christophe Tandonnet; Hakuei Fujiyama; Christopher M. Janelle; James H. Cauraugh; Jeffery J. Summers

2009-01-01

143

[Repetitive transcranial magnetic stimulation in depression; stimulation of the brain in order to cure the psyche  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) is a non-invasive approach to briefly stimulate or inhibit cortical brain areas. A novel approach entails the delivery of repetitive TMS pulses (rTMS) at a fixed frequency. In rTMS cortical activity is altered beyond the period of actual stimulation. The changes occur locally as well as at a distance in functionally connected brain areas. These features

R. C. G. Helmich; A. H. Snijders; R. J. Verkes; B. R. Bloem

2004-01-01

144

Introducing navigated transcranial magnetic stimulation as a refined brain mapping methodology  

Microsoft Academic Search

.   A major intrinsic limitation of transcranial magnetic stimulation (TMS) to map the human brain lies in the unclear relationship\\u000a between the position of the stimulating coil on the scalp and the underlying stimulated cortex. The relationship between structure\\u000a and function as the major feature constituting a brain mapping modality can therefore not be established. Recent advances\\u000a in image processing

Timo Krings; Keith H. Chiappa; Henrik Foltys; Marcus H. T. Reinges; Rees G. Cosgrove; Armin Thron

2001-01-01

145

Repetitive transcranial magnetic stimulation to SMA worsens complex movements in Parkinson's disease  

Microsoft Academic Search

Objectives: To evaluate the therapeutic potential of repetitive transcranial magnetic stimulation (rTMS) for Parkinson's disease (PD) by delivering stimulation at higher intensity and frequency over longer time than in previous research. Promising beneficial effects on movement during or after rTMS have been reported.Methods: Ten patients with idiopathic PD were enrolled in a randomized crossover study comparing active versus sham rTMS

L. S. Boylan; S. L. Pullman; S. H. Lisanby; K. E. Spicknall; H. A. Sackeim

2001-01-01

146

Modulation of pain perception by transcranial magnetic stimulation of left prefrontal cortex  

Microsoft Academic Search

Evidence by functional imaging studies suggests the role of left dorsolateral prefrontal cortex (DLPFC) in the inhibitory\\u000a control of nociceptive transmission system. Repetitive transcranial magnetic stimulation (rTMS) is able to modulate pain response\\u000a to capsaicin. In the present study, we evaluated the effect of DLPFC activation (through rTMS) on nociceptive control in a\\u000a model of capsaicin-induced pain. The study was

Filippo Brighina; Marina De Tommaso; Francesca Giglia; Simona Scalia; Giuseppe Cosentino; Angela Puma; Maristella Panetta; Giuseppe Giglia; Brigida Fierro

2011-01-01

147

Impact of coil position and electrophysiological monitoring on determination of motor thresholds to transcranial magnetic stimulation  

Microsoft Academic Search

Objective: We compared motor and movement thresholds to transcranial magnetic stimulation (TMS) in healthy subjects and investigated the effect of different coil positions on thresholds and MEP (motor-evoked potential) amplitudes.Methods: The abductor pollicis brevis (APB) ‘hot spot’ and a standard scalp position were stimulated. APB resting motor threshold (APB MEP-MT) defined by the ‘5\\/10’ electrophysiological method was compared with movement

Adriana Bastos Conforto; Werner J Z'Graggen; Alexandra S Kohl; Kai M Rösler; Alain Kaelin-Lang

2004-01-01

148

Chronic repetitive transcranial magnetic stimulation enhances c-fos in the parietal cortex and hippocampus  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) is a novel non-invasive method with anti-depressant properties. However, the mechanism of activation on the cellular level is unknown. Twelve hours after the last chronic rTMS treatment (14 days, once per day, 20 Hz, 10 s, 75% machine output, the transcription factor c-fos was markedly increased in neurons in layers I–IV and VI of the

Armand Hausmann; Carla Weis; Josef Marksteiner; Hartmann Hinterhuber; Christian Humpel

2000-01-01

149

The Cerebellum in Emotion Regulation: A Repetitive Transcranial Magnetic Stimulation Study  

Microsoft Academic Search

Several lines of evidence suggest that the cerebellum may play a role in the regulation of emotion. The aim of this study\\u000a was to investigate the hypothesis that inhibition of cerebellar function using slow repetitive transcranial magnetic stimulation\\u000a (rTMS) would lead to increased negative mood as a result of impaired emotion regulation. In a randomized counterbalanced within-subjects\\u000a design, 12 healthy

Dennis J. L. G. Schutter; Jack van Honk

2009-01-01

150

Effects of low-frequency transcranial magnetic stimulation on motor excitability and basic motor behavior  

Microsoft Academic Search

Objective: To explore effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) of the primary motor cortex (M1) on motor excitability and basic motor behavior in humans.Design and Methods: Seven normal volunteers underwent 1 Hz rTMS of the hand representation of the right M1 for 15 min at an intensity of 115% of the individual resting motor threshold. The effects of

Wolf Muellbacher; Ulf Ziemann; Babak Boroojerdi; Mark Hallett

2000-01-01

151

Priming theta-burst repetitive transcranial magnetic stimulation with low- and high-frequency stimulation  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) can be used to study metaplasticity in human motor cortex. The term metaplasticity\\u000a describes a phenomenon where the prior synaptic history of a pathway can affect the subsequent induction of long-term potentiation\\u000a or depression. In the current study, we investigated metaplasticity in human motor cortex with the use of inhibitory continuous\\u000a theta-burst stimulation (cTBS). cTBS

Gabrielle Todd; Stanley C. Flavel; Michael C. Ridding

2009-01-01

152

Slow repetitive transcranial magnetic stimulation increases somatosensory high-frequency oscillations in humans  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a possible treatment for psychiatric and neurological disorders characterized by focal brain excitability, such as major depression and action myoclonus. However, the mechanism of modulating excitability by rTMS is unclear. We examined the changes in high frequency oscillations (HFOs) of somatosensory evoked potentials (SEPs) before and after slow rTMS over the

Asao Ogawa; Satoshi Ukai; Kazuhiro Shinosaki; Masakiyo Yamamoto; Shunsuke Kawaguchi; Ryouhei Ishii; Masatoshi Takeda

2004-01-01

153

Repetitive transcranial magnetic stimulation protects hippocampal plasticity in an animal model of depression  

Microsoft Academic Search

Despite its therapeutic success in treating mood-related disorders, little is known about the mechanism by which repetitive transcranial magnetic stimulation (rTMS) alters physiological responses of neurons. Using the forced swim test (FST) in rats as a model of depression, we tested the protective effect of rTMS on synaptic plasticity, specifically, on the induction of hippocampal long-term potentiation (LTP). Male Sprague–Dawley

Eun Joo Kim; Woon Ryoung Kim; Sang Eun Chi; Kang Hee Lee; Eun Hye Park; Jeong-Ho Chae; Soon Kwon Park; Hyun Taek Kim; June-Seek Choi

2006-01-01

154

Influence of 5 Hz repetitive transcranial magnetic stimulation on motor learning  

Microsoft Academic Search

The aim of our study was to assess a possible improvement in motor learning induced by 5Hz repetitive transcranial magnetic stimulation (rTMS) of human motor cortex. The same stimulation protocol previously enhanced perceptual learning as assessed by tactile discrimination performance when applied to the human primary somatosensory cortex. We applied 1250 pulses of 5Hz “real” rTMS at 90% of resting

Matthias Sczesny-Kaiser; Martin Tegenthoff; Peter Schwenkreis

2009-01-01

155

Global perception depends on coherent work of bilateral visual cortices: Transcranial magnetic stimulation (TMS) studies  

Microsoft Academic Search

Previous research suggests that the right and left hemispheres dominate global and local perception of hierarchical patterns,\\u000a respectively. The current work examined whether global perception of hierarchical stimuli requires coherent work of bilateral\\u000a visual cortices using transcranial magnetic stimulation (TMS). Subjects discriminated global or local properties of compound\\u000a letters in Experiment 1. Reaction times were recorded when single-pulse real TMS

Xin Zhang; ShiHui Han

2007-01-01

156

Lasting influence of repetitive transcranial magnetic stimulation on intracortical excitability in human subjects  

Microsoft Academic Search

We studied the effects of a train of 30 pulses of repetitive transcranial magnetic stimulation (rTMS) at frequencies of 5 and 15 Hz and at an intensity of 120% of resting motor threshold on human motor cortex excitability. Intracortical inhibition (ICI) and intracortical facilitation (ICF) after rTMS were tested by a conditioning-test designed paired-pulse paradigm. After 15 Hz rTMS, ICI

Tao Wu; Martin Sommer; Frithjof Tergau; Walter Paulus

2000-01-01

157

Effects of repetitive transcranial magnetic stimulation on memory subtypes: a controlled study  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) of human cortex may disrupt or facilitate cortical activity. The aim of the present study was to investigate the consequences of rTMS applied over different cortical areas during various memory tasks, measuring immediate, working and episodic verbal memory. The study was performed in 16 right-handed healthy men. A double-blind, cross-over, within-subject repeated measures design was

L Rami; A Gironell; J Kulisevsky; C Garc??a-Sánchez; M Berthier; A Estévez-González

2003-01-01

158

Repetitive transcranial magnetic stimulation of human MT+ reduces apparent motion perception  

Microsoft Academic Search

We investigated the effects of repetitive transcranial magnetic stimulation (rTMS) over the human cerebral cortex on apparent motion perception. Previous studies have shown that human extrastriate visual area MT+ (V5) processes not only real but also apparent motion. However, the functional relevance of MT+ on long-range apparent motion perception remains unclear. Here, we show direct evidence for the involvement of

Daisuke Matsuyoshi; Nobuyuki Hirose; Tatsuya Mima; Hidenao Fukuyama; Naoyuki Osaka

2007-01-01

159

Repetitive transcranial magnetic stimulation of the supplementary motor area (SMA) degrades bimanual movement control in humans  

Microsoft Academic Search

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

Deborah J Serrien; Lucy H. A Strens; Antonio Oliviero; Peter Brown

2002-01-01

160

The role of motion direction selective extrastriate regions in reading: a transcranial magnetic stimulation study  

Microsoft Academic Search

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 7.5min blocks

Jacqueline Liederman; Janet McGraw Fisher; Marcela Schulz; Carolyn Maxwell; Hugo Théoret; Alvaro Pascual-Leone

2003-01-01

161

Transcranial magnetic stimulation selectively impairs interhemispheric transfer of visuo-motor information in humans  

Microsoft Academic Search

We investigated the cerebral cortical route by which visual information reaches motor cortex when visual signals are used\\u000a for manual responses. Subjects responded unimanually to photic stimuli delivered to the hemifield ipsilateral or contralateral\\u000a to the moving hand. On some trials, trans-cranial magnetic stimulation (TMS) was applied unilaterally over the occiput, with\\u000a the aim of stimulating extrastriate visual areas and

C. A. Marzi; C. Miniussi; A. Maravita; L. Bertolasi; J. C. Rothwell; J. N. Sanes; G. Zanette

1998-01-01

162

Neural Correlates of the Contextual Interference Effect in Motor Learning: A Transcranial Magnetic Stimulation Investigation  

Microsoft Academic Search

The authors applied transcranial magnetic stimulation (TMS) to investigate the causal role of the primary motor cortex (M1) for the contextual-interference effect in motor learning. Previous work using a nonfocal TMS coil suggested a casual role for M1 during high-interference practice conditions, but this hypothesis has not yet been proven. In the 1st experiment, participants practiced 3 rapid elbow flexion–extension

Chien-Ho Lin; Carolee J. Winstein; Beth E. Fisher; Allan D. Wu

2010-01-01

163

Update on Repetitive Transcranial Magnetic Stimulation in Obsessive-Compulsive Disorder: Different Targets  

Microsoft Academic Search

Obsessive-compulsive disorder (OCD) is a chronic, disabling disorder. Ten percent of patients remain treatment refractory\\u000a despite several treatments. For these severe, treatment-refractory patients, repetitive transcranial magnetic stimulation\\u000a (rTMS) has been suggested as a treatment option. Since 1997, in published trials, a total of 110 OCD patients have been treated\\u000a with rTMS. This review aims to provide an update on rTMS

Rianne M. Blom; Martijn Figee; Nienke Vulink; Damiaan Denys

2011-01-01

164

Altered seizure susceptibility after high-frequency transcranial magnetic stimulation in rats  

Microsoft Academic Search

The long-term effect of repetitive transcranial magnetic stimulation (rTMS) on the susceptibility of amygdala kindling was studied. Two weeks after a single high-frequency rTMS train (120 A\\/?s, 20 Hz for 3 s), the rats had a 55% higher threshold for induction of epileptic afterdischarges compared with sham-treated or control rats. However, subsequent kindling revealed no difference between rTMS-treated and control

Ulrich Ebert; Ulf Ziemann

1999-01-01

165

Changes in blood pressure and heart rate by repetitive transcranial magnetic stimulation in rats  

Microsoft Academic Search

We examined whether repetitive transcranial magnetic stimulation (rTMS) could influence blood pressure (BP) and heart rate (HR) in rats and the possible mechanisms involved. In urethane anesthetized Wistar–Kyoto rats, BP and HR were recorded from the femoral artery around the point of rTMS at a frequency of 10 Hz and an intensity of 1.88–2.44 Tesla. rTMS but not sham stimulation

Byungchul Hong; Tomoyuki Kuwaki; Kihwan Ju; Mamoru Kumada; Masami Akai; Shoogo Ueno

2002-01-01

166

Decreased susceptibility to pentylenetetrazol-induced seizures after low-frequency transcranial magnetic stimulation in rats  

Microsoft Academic Search

We studied the effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) on seizure susceptibility in rats. rTMS of 1000 pulses at 0.5 Hz led to a prolonged latency for seizure development after an intraperitoneal injection of pentylenetetrazol. The rTMS effectively prevented the development of status epilepticus of pentylenetetrazol-induced convulsions. These findings indicate that low-frequency rTMS affects the neural excitability, in

Naoki Akamatsu; Yukiko Fueta; Yutaka Endo; Kaoru Matsunaga; Takenori Uozumi; Sadatoshi Tsuji

2001-01-01

167

1Hz low frequency repetitive transcranial magnetic stimulation in children with Tourette's syndrome  

Microsoft Academic Search

The aim of the current study was to assess the efficacy of repetitive transcranial magnetic stimulation (rTMS) over the supplementary motor area (SMA) of the cortex to children with Tourette's syndrome (TS), if rTMS over the SMA had positive effects on ameliorating tics. We designed a pilot open label 12 weeks cohort study to assess the efficacy of rTMS with

Ho Jang Kwon; Won Seok Lim; Myung Ho Lim; Seong Jae Lee; Jung Keun Hyun; Jeong-Ho Chae; Ki Chung Paik

2011-01-01

168

Modulation of monoamine transporter expression and function by repetitive transcranial magnetic stimulation  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) is a new tool for the treatment of neuropsychiatric disorders. However, the mechanisms underlying the effects of rTMS are still unclear. In this study, we analyzed mRNA expression changes of monoamine transporter (MAT) genes, which are targets for antidepressants and psychostimulants. Following a 20-day rTMS treatment, these genes were found to be differentially expressed in

Tetsurou Ikeda; Masaru Kurosawa; Chiharu Uchikawa; Shigeo Kitayama; Nobuyuki Nukina

2005-01-01

169

Cognitive effects of high-frequency repetitive transcranial magnetic stimulation: a systematic review  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) was introduced as a non-invasive tool for the investigation of the motor cortex. The\\u000a repetitive application (rTMS), causing longer lasting effects, was used to study the influence on a variety of cerebral functions.\\u000a High-frequency (>1 Hz) rTMS is known to depolarize neurons under the stimulating coil and to indirectly affect areas being\\u000a connected and related to emotion

Birgit Guse; Peter Falkai; Thomas Wobrock

2010-01-01

170

Depression in Parkinson’s disease: brainstem midline alteration on transcranial sonography and magnetic resonance imaging  

Microsoft Academic Search

Recent studies using transcranial sonography (TCS) have provided evidence of alterations in the mesencephalic midline structures\\u000a in patients with unipolar depression and depression in Parkinson’s disease (PD), suggesting an involvement of the basal limbic\\u000a system in primary and secondary mood disorders. This study tested the hypothesis of brainstem midline abnormality in depression\\u000a and investigated 31 PD patients by magnetic resonance

Daniela Berg; Tillmann Supprian; Erich Hofmann; Björn Zeiler; Andreas Jäger; Klaus W. Lange; Karlheinz Reiners; Thomas Becker; Georg Becker

1999-01-01

171

The effect of repetitive transcranial magnetic stimulation on fear extinction in rats  

Microsoft Academic Search

Facilitating fear extinction is clinically important to improve the efficacy of current exposure therapies for the treatment of anxiety disorders, such as post-traumatic stress disorder (PTSD). The aim of this study was to determine if repeated transcranial magnetic stimulation (rTMS) facilitates fear extinction in rats, especially when paired with exposure to a conditioned stimulus (CS). Thirty-five rats were conditioned to

K. Baek; J.-H. Chae; J. Jeong

172

Selective Priming of Syntactic Processing by Event-Related Transcranial Magnetic Stimulation of Broca's Area  

Microsoft Academic Search

It remains controversial whether Broca's aphasia is an articulatory deficit, a lexical-access problem, or agrammatism. In spite of recent neuroimaging studies, the causal link between cortical activity and linguistic subcomponents has not been elucidated. Here we report an experiment with event-related transcranial magnetic stimulation (TMS) to clarify the role of Broca's area, more specifically, the left inferior frontal gyrus (F3op\\/F3t),

Kuniyoshi L. Sakai; Yasuki Noguchi; Tatsuya Takeuchi; Eiju Watanabe

2002-01-01

173

Does transcranial magnetic stimulation improve the motor symptoms of Parkinson disease?  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) has been used as a potential therapeutic tool in various neurological and psychiatric disorders. We reviewed the effects of rTMS as a treatment of Parkinson disease in this paper. The existing reports have been conflicting regarding the efficacy of the rTMS in PD. The controversy arises from the differences of the stimulation parameters and evaluation

Sadatoshi Tsuji; Naoki Akamatsu

2003-01-01

174

Low-frequency repetitive transcranial magnetic stimulation and off-phase motor symptoms in Parkinson's disease  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) can modulate cortical excitability and activation and consequently may affect clinical symptoms in neurological conditions characterized by altered motor cortex functions. There are conflicting reports whether low-frequency rTMS has any clinical effects in Parkinson's disease (PD).Ten patients with PD had rTMS (1800 stimuli at just below active motor threshold intensity) at 1Hz rate delivered over

Saša R. Filipovi?; John C. Rothwell; Kailash Bhatia

2010-01-01

175

Repetitive Transcranial Magnetic Stimulation for Treating Medication-resistant Depression in Taiwan: A Preliminary Study  

Microsoft Academic Search

Background: We conducted an open trial to evaluate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in medication-resistant depression. This is the first study in Taiwan of rTMS for the treatment of depression. Methods: A 2-week regimen of rTMS (100% of motor threshold, 5 Hz, 8 sec, 40 trains\\/20 min\\/day, 10 weekdays) applied to the left dorsolateral prefrontal cortex was

Chih-Chia Huang; Tung-Ping Su; I-Hua Wei

2005-01-01

176

Contribution of transcranial magnetic stimulation to the understanding of cortical mechanisms involved in motor control  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) was initially used to evaluate the integrity of the corticospinal tract in humans non-invasively. Since these early studies, the development of paired-pulse and repetitive TMS protocols allowed investigators to explore inhibitory and excitatory interactions of various motor and non-motor cortical regions within and across cerebral hemispheres. These applications have provided insight into the intracortical physiological processes

Janine Reis; Orlando B. Swayne; Yves Vandermeeren; Mickael Camus; Michael A. Dimyan; Michelle Harris-Love; Monica A. Perez; John C. Rothwell; Leonardo G. Cohen

2008-01-01

177

Calculating the electric field in real human head by transcranial magnetic stimulation with shield plate  

NASA Astrophysics Data System (ADS)

In this paper, we present a transcranial magnetic stimulation (TMS) system by incorporating a conductive shield plate. The magnetic field, induced current density, and electric field in a real human head were calculated by impedance method and the results were compared with TMS without shielding. Our results show that the field localization can be improved by introducing a conductive shield plate; the stimulation magnitude (depth) in the brain is reduced comparing with the TMS without shielding. The strong magnetic field near the TMS coil is difficult to be efficiently shielded by a thinner conductive shield plate.

Lu, Mai; Ueno, Shoogo

2009-04-01

178

Intracortical inhibition and facilitation of the response of the diaphragm to transcranial magnetic stimulation.  

PubMed

Respiratory muscles respond to a subcortical automatic command and to a neocortical voluntary command. In diseases such as stroke or motor neurone disease, an abnormal diaphragmatic response to single transcranial magnetic stimuli can identify a central source for respiratory disorders, but this is not likely to be the case in disorders affecting intracortical inhibitory and facilitatory mechanisms. This study describes the response of the diaphragm to paired transcranial magnetic stimulation. Thirteen normal subjects were studied (age range, 22 to 43 years; 7 men; phrenic conduction, <6.8 msec; latency of diaphragmatic motor evoked potential, <20.5 msec). Motor evoked potentials in response to paired stimulation were obtained in eight subjects only, with the motor threshold in the remaining five subjects too high to absorb the loss of power inherent in the double-stimulation montage. Interstimulus intervals less than 5 msec resulted in a statistically significant inhibition (p < 0.01 for interstimulus intervals of 1 and 3 ms), whereas intervals longer than 6 msec were facilitatory (maximal, 15 msec). The diaphragmatic pattern matched that of the biceps brachii. The authors conclude that it is possible to study intracortical inhibition and facilitation of diaphragmatic control, although not in all subjects. Technical improvement should alleviate current limitations and make paired transcranial magnetic stimulation a tool to study respiratory muscle abnormalities in settings in which intracortical interactions are important, such as movement disorders. PMID:12684560

Demoule, Alexandre; Verin, Eric; Ross, Ewen; Moxham, John; Derenne, Jean-Philippe; Polkey, Michael I; Similowski, Thomas

2003-02-01

179

Cerebellar transcranial magnetic stimulation impairs verbal working memory  

Microsoft Academic Search

Previous functional magnetic resonance imaging and patient studies indicate cerebellar participation in verbal working memory. In particular, event-related functional magnetic resonance imaging showed superior cerebellar activation during the initial encoding phase of the Sternberg task. This study used functional magnetic resonance imaging-guided trans- cranial magnetic stimulation (TMS) to test whether disruption of the right superior cerebellum (hemispheric lobule VI\\/Crus I)

John E. Desmond; S. H. Annabel Chen; Perry B. Shieh

2005-01-01

180

[ECT versus transcranial magnetic stimulation (TMS): preliminary data of computer modeling].  

PubMed

The essential issue of electroshock therapy (ECT) is the activity of physical stimulus, i.e., the electric current, on the disturbed structures of the brain. ECT sessions--when chronically applied for evoking antidepressive effects--are responsible for the appearance of excessive incitement in the neuronal net in the brain tissue in a form of self-sustaining after-discharge (SSAD) (convulsive attack characteristic for ECT). The study presents the computer research on basic biophysical phenomena of electroshock therapy (flow of electric current in the structures of the head just before convulsive attack). Five-layer 3-D model of the head was created in OPERA-3D (Vector Fields Ltd., Oxford), general 3 dimensional issues solver. Geometrical dimensions and electrophysical properties of each layer correspond with natural properties. The model was subjected to the action of electric stimulation (parameters identical to those applied in clinical conditions). Analysis of the flow in particular layers revealed the crawling/spreading effect present not only in the scalp layer but also in the layer of cerebrospinal fluid. The effect is conditioned by "deeper situated" lesser conduction of electricity-respectively skull bones, brain tissue. Crawling effect is the reason why only 5-15% of the electricity applied on the surface of the head reaches the surface of the brain. Electro-stimulation examinations also showed that the values of the so called density of the current in layers of brain tissue balanced between 1-10 mA/mm2. The current parameters of ECT were effective in evoking subsequent convulsive attack and safe for the brain tissue. The model was subjected to the action of magnetic stimulation according to the parameters of neurologic technique of transcranial magnetic stimulation (TMS). ELECTRA module was used to solve wire-current issues. The examination showed more regular distribution of current vectors in all layers of the head. The density of cerebral cortex was 0.1-1 mA/mm2, confirming markedly lesser current charge than that observed during ECT. The problem of magnetic stimulation efficacy in irritating deep structures of the brain demands further studies. PMID:10776027

Zyss, T; Krawczyk, A; Drzyma?a, P; Starzy?ski, J

181

Fundamentals of Transcranial Electric and Magnetic Stimulation Dose: Definition, Selection, and Reporting Practices  

PubMed Central

The growing use of transcranial electric and magnetic (EM) brain stimulation in basic research and in clinical applications necessitates a clear understanding of what constitutes the dose of EM stimulation and how it should be reported. The biological effects of EM stimulation are mediated through an electromagnetic field injected (via electric stimulation) or induced (via magnetic stimulation) in the body. Therefore, transcranial EM stimulation dose ought to be defined by all parameters of the stimulation device that affect the electromagnetic field generated in the body, including the stimulation electrode or coil configuration parameters: shape, size, position, and electrical properties, as well as the electrode or coil current (or voltage) waveform parameters: pulse shape, amplitude, width, polarity, and repetition frequency; duration of and interval between bursts or trains of pulses; total number of pulses; and interval between stimulation sessions and total number of sessions. Knowledge of the electromagnetic field generated in the body may not be sufficient but is necessary to understand the biological effects of EM stimulation. We believe that reporting of EM stimulation dose should be guided by the principle of reproducibility: sufficient information about the stimulation parameters should be provided so that the dose can be replicated. This paper provides fundamental definition and principles for reporting of dose that encompass any transcranial EM brain stimulation protocol.

Peterchev, Angel V.; Wagner, Timothy A.; Miranda, Pedro C.; Nitsche, Michael A.; Paulus, Walter; Lisanby, Sarah H.; Pascual-Leone, Alvaro; Bikson, Marom

2011-01-01

182

Topographic mapping of trans-cranial magnetic stimulation data on surface rendered MR images of the brain  

Microsoft Academic Search

We present a method for the coregistration and topographic mapping of trans-cranial magnetic stimulation (TCMS) data on surface rendered images of the cortex, derived from Magnetic Resonance Images (MRI). We describe the TCMS procedure and the methods used to locate the TCM stimulation sites in the MRI coordinate system, and the algorithms needed to depict the TCMS distribution as a

K. D. Singh; S. Hamdy; Q. Aziz; D. G. Thompson

1997-01-01

183

Dramatic Response of Resistant Obsessive Compulsive Disorder to Repeated Transcranial Magnetic Stimulation on Right Supplementary Motor Area  

Microsoft Academic Search

The response rate to the treatment of obsessive compulsive disorder (OCD) is 21.6% to 61.3%, which shows a relative resistance to current treatments and a need for novel therapeutic approaches. Here we report a case of resistant OCD with fast and dramatic response to a relatively new method of repeated transcranial magnetic stimulation. In this method a pulse magnetic field

Ali Talaei; Mohammad Morteza-Nia; Ali Saghebi; Amir Rezaei Ardani

184

Combined use of transcranial magnetic stimulation and metal electrode implants: a theoretical assessment of safety considerations  

NASA Astrophysics Data System (ADS)

This paper provides a theoretical assessment of the safety considerations encountered in the simultaneous use of transcranial magnetic stimulation (TMS) and neurological interventions involving implanted metallic electrodes, such as electrocorticography. Metal implants are subject to magnetic forces due to fast alternating magnetic fields produced by the TMS coil. The question of whether the mechanical movement of the implants leads to irreversible damage of brain tissue is addressed by an electromagnetic simulation which quantifies the magnitude of imposed magnetic forces. The assessment is followed by a careful mechanical analysis determining the maximum tolerable force which does not cause irreversible tissue damage. Results of this investigation provide useful information on the range of TMS stimulator output powers which can be safely used in patients having metallic implants. It is shown that conventional TMS applications can be considered safe when applied on patients with typical electrode implants as the induced stress in the brain tissue remains well below the limit of tissue damage.

Golestanirad, Laleh; Rouhani, Hossein; Elahi, Behzad; Shahim, Kamal; Chen, Robert; Mosig, Juan R.; Pollo, Claudio; Graham, Simon J.

2012-12-01

185

Probing thalamic integrity in schizophrenia using concurrent transcranial magnetic stimulation and functional magnetic resonance imaging  

PubMed Central

Context Schizophrenia is a devastating illness with an indeterminate pathophysiology. Several lines of evidence implicate dysfunction in the thalamus, a key node in the distributed neural networks underlying perception, emotion, and cognition. Existing evidence of aberrant thalamic function is based on indirect measures of thalamic activity, but dysfunction has not yet been demonstrated with a causal method. Objective Test the hypothesis that direct physiological stimulation of cortex will produce an abnormal thalamic response in individuals with schizophrenia. Design We stimulated the precentral gyrus with single-pulse transcranial magnetic stimulation (spTMS) and measured the response to this pulse in synaptically-connected regions (thalamus, medial superior frontal cortex [mSFG], insula) using concurrent functional magnetic resonance imaging (fMRI). The mean hemodynamic response from these regions was fit with the sum of two gamma functions and response parameters were compared across groups. Setting Academic research laboratory. Participants Patients with schizophrenia and sex- and age- matched psychiatrically healthy subjects were recruited from the community. Main Outcome Measures Peak amplitude of the thalamic hemodynamic response to spTMS of precentral gyrus. Results spTMS-evoked responses did not differ between groups at the cortical stimulation site. Compared to healthy subjects, schizophrenia patients showed a reduced response to spTMS in the thalamus (P=1.86 × 10?9) and mSFG (P=.02). Similar results were observed in the insula. Sham TMS indicated that these results could not be attributed to indirect effects of TMS coil discharge. Functional connectivity analyses revealed weaker thalamus-mSFG and thalamus-insula connectivity in schizophrenia patients compared to control subjects. Conclusions Individuals with schizophrenia showed reduced thalamic activation in response to direct perturbation delivered to the cortex. These results extend prior work implicating the thalamus in the pathophysiology of schizophrenia and suggest that the thalamus contributes to the patterns of aberrant connectivity characteristic of this disease.

Guller, Yelena; Ferrarelli, Fabio; Shackman, Alexander J.; Sarasso, Simone; Peterson, Michael J.; Langheim, Frederick J.; Meyerand, Mary E.; Tononi, Giulio; Postle, Bradley R.

2012-01-01

186

Energy Efficient Coils for Transcranial Magnetic Stimulation (TMS)  

Microsoft Academic Search

The preoccupation for improving the quality of life, for persons with different handicaps, led to extended research in the area of functional stimulation. Due to its advantages compared to electrical stimulation, magnetic stimulation of the human nervous system is now a common technique in modern medicine. A difficulty of this technique is the need for accurate focal stimulation. Another one

Laura DARABANT; Mihaela PLESA; Radu CIUPA; Octavian Cret; Adrian S. DARABANT

187

Effect of repetitive transcranial magnetic stimulation on rectal function and emotion in humans  

Microsoft Academic Search

Background  A previous brain imaging study demonstrated activation of the right dorsolateral prefrontal cortex (DLPFC) during visceral\\u000a nociception, and this activation was associated with anxiety. We hypothesized that functional modulation of the right DLPFC\\u000a by repetitive transcranial magnetic stimulation (rTMS) can reveal the actual role of right DLPFC in brain–gut interactions\\u000a in humans.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Subjects were 11 healthy males aged 23.5 ± 1.4 (mean ± SE)

Yuuichi AizawaJoe; Joe Morishita; Michiko Kano; Takayuki Mori; Shin-Ichi Izumi; Kenichiro Tsutsui; Toshio Iijima; Motoyori Kanazawa; Shin Fukudo

188

Acute repetitive transcranial magnetic stimulation reactivates dopaminergic system in lesion rats  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) offers potential benefit as a therapeutic treatment for neurological and psychiatric disorders. However, the mechanism underlying the therapeutic effects of rTMS is still unknown. In this study, we investigated the rescue effects of rTMS in the lesioned rats by administering the neurotoxin MPTP (l-methyl-4-phenyl-l,2,3,6-tetrahydropyridine). The rats received rTMS (10 trains of 25pulses\\/s for 8s) 48h

Hirofumi Funamizu; Mari Ogiue-Ikeda; Hideo Mukai; Suguru Kawato; Shoogo Ueno

2005-01-01

189

The Ferrier Lecture 2004 What can transcranial magnetic stimulation tell us about how the brain works?  

PubMed Central

Transcranial magnetic stimulation (TMS) is a technique whereby parts of the cerebral cortex and underlying white matter can be excited by a brief electrical current induced by a similarly brief, rapidly fluctuating magnetic field which is itself produced by rapidly discharging a current through an insulated coil held against the scalp. When combined with magnetic resonance structural and functional images of the subject's brain, the stimulation can be directed at specific cortical areas. Over a period of only 15 years, TMS has revealed hitherto unsuspected aspects of brain function, such as the role of distant parts of the brain in recovery from stroke, and has helped to resolve several previously intractable disputes, such as the neuronal basis of conscious awareness. This article describes and discusses the origins and nature of TMS, its applications and limitations, and its especial usefulness in conjunction with other techniques of evaluating or imaging brain activity.

Cowey, Alan

2005-01-01

190

Deep brain stimulation of both subthalamic nucleus and internal globus pallidus restores intracortical inhibition in Parkinson's disease paralleling apomorphine effects: a paired magnetic stimulation study  

Microsoft Academic Search

Objective: We investigated the effect of bilateral subthalamic nucleus (STN) and internal globus pallidus (GPi) deep brain stimulation (DBS) on intracortical inhibition (ICI) in patients with advanced Parkinson's disease (PD).Methods: The activity of intracortical inhibitory circuits was studied in 4 PD patients implanted with stimulating electrodes both in STN and GPi by means of paired-pulse transcranial magnetic stimulation, delivered in

M Pierantozzi; M. G Palmieri; P Mazzone; M. G Marciani; P. M Rossini; A Stefani; P Giacomini; A Peppe; P Stanzione

2002-01-01

191

Quantitative assessment of myelopathy patients using motor evoked potentials produced by transcranial magnetic stimulation  

PubMed Central

Motor evoked potentials (MEPs) study using transcranial magnetic stimulation (TMS) may give a functional assessment of corticospinal conduction. But there are no large studies on MEPs using TMS in myelopathy patients. The purpose of this study is to confirm the usefulness of MEPs for the assessment of the myelopathy and to investigate the use of MEPs using TMS as a screening tool for myelopathy. We measured the MEPs of 831 patients with symptoms and signs suggestive of myelopathy using TMS. The MEPs from the abductor digiti minimi (ADM) and abductor hallucis (AH) muscles were evoked by transcranial magnetic brain stimulation. Central motor conduction time (CMCT) is calculated by subtracting the peripheral conduction time from the MEP latency. Later, 349 patients had surgery for myelopathy (operative group) and 482 patients were treated conservatively (nonoperative group). CMCTs in the operative group and nonoperative group were assessed. MEPs were prolonged in 711 patients (86%) and CMCTs were prolonged in 493 patients (59%) compared with the control patients. CMCTs from the ADM and AH in the operative group were significantly more prolonged than that in the nonoperative group. All patients in the operative group showed prolongation of MEPs or CMCTs or multiphase of the MEP wave. MEP abnormalities are useful for an electrophysiological evaluation of myelopathy patients. Moreover, MEPs may be effective parameters in spinal pathology for deciding the operative treatment.

Tanaka, Nobuhiro; Nakanishi, Kazuyoshi; Fujimoto, Yoshinori; Sasaki, Hirofumi; Kamei, Naosuke; Hamasaki, Takahiko; Yamada, Kiyotaka; Yamamoto, Risako; Izumi, Bunichiro; Ochi, Mitsuo

2009-01-01

192

Transcranial magnetic stimulation as a prognostic tool in stroke.  

PubMed

Our aims were to evaluate the prognostic usefulness of magnetic motor evoked potentials (MMEPs) in ischemic stroke, to study the evolution of MMEP abnormalities and the relationships between MMEP abnormalities and infarction topography. We prospectively analyzed 50 consecutive ischemic stroke patients who were followed up to 1 year. MMEPs were recorded 1, 3, 30 and 90 days after stroke and we measured amplitudes and latencies/central motor conduction times (CMCTs) of MMEPs from hypothenar, biceps brachiallis, gastrocnemius and quadriceps. Univariate and multivariate analyses of the clinical and MMEPs data were performed. Patients with Rankin 0-3 at 1 year had had acutely MMEPs with shorter latencies and higher amplitudes than patients with Rankin 4-5 or deceased patients. Increased blood pressure correlated with increased survival, whereas increased heart rate and hyperglycemia correlated with increased mortality. The variables infarction size on second CT, age, and first day CMCT-S1 correctly classified 1 year outcome on discriminant analysis. The inclusion of MMEPs values increased the probability of correct classification from 76% to 84%. We conclude that in patients with nondisabling strokes MMEPs may have an independent value in the prediction of prognosis, increasing the accuracy of prognosis calculations made employing clinical and laboratory data. Topography of lesions should be considered when analyzing MMEP abnormalities after stroke. PMID:9094063

D'Olhaberriague, L; Espadaler Gamissans, J M; Marrugat, J; Valls, A; Oliveras Ley, C; Seoane, J L

1997-03-20

193

A stereotactic method for image-guided transcranial magnetic stimulation validated with fMRI and motor-evoked potentials  

Microsoft Academic Search

Transcranial Magnetic Stimulation (TMS) delivers short magnetic pulses that penetrate the skull unattenuated, disrupting neural processing in a noninvasive, reversible way. To disrupt specific neural processes, coil placement over the proper site is critical. Therefore, a neural navigator (NeNa) was developed. NeNa is a frameless stereotactic device using structural and functional magnetic resonance imaging (fMRI) data to guide TMS coil

S. F. W. Neggers; T. R. Langerak; D. J. L. G. Schutter; R. C. W. Mandl; N. F. Ramsey; P. J. J. Lemmens; A. Postma

2004-01-01

194

A Preliminary Transcranial Magnetic Stimulation Study of Cortical Inhibition and Excitability in High-Functioning Autism and Asperger Disorder  

ERIC Educational Resources Information Center

|Aim: Controversy surrounds the distinction between high-functioning autism (HFA) and Asperger disorder, but motor abnormalities are associated features of both conditions. This study examined motor cortical inhibition and excitability in HFA and Asperger disorder using transcranial magnetic stimulation (TMS). Method: Participants were diagnosed…

Enticott, Peter G.; Rinehart, Nicole J.; Tonge, Bruce J.; Bradshaw, John L.; Fitzgerald, Paul B.

2010-01-01

195

Age-Related Functional Changes of Prefrontal Cortex in Long-Term Memory: A Repetitive Transcranial Magnetic Stimulation Study  

Microsoft Academic Search

Neuroimaging findings suggest that the lateralization of prefrontal cortex activation associated with episodic memory performance is reduced by aging. It is still a matter of debate whether this loss of asymmetry during encoding and retrieval reflects compensatory mechanisms or de-differentiation processes. We addressed this issue by the transient interference produced by repetitive transcranial magnetic stimulation (rTMS), which directly assesses causal

Simone Rossi; Carlo Miniussi; Patrizio Pasqualetti; Claudio Babiloni; Paolo M. Rossini; Stefano F. Cappa

2004-01-01

196

Spinal Cord-Evoked Potentials and Muscle Responses Evoked by Transcranial Magnetic Stimulation in 10 Awake Human Subjects  

Microsoft Academic Search

Transcranial magnetic stimulation (TCMS) causes leg muscle contractions, but the neural structures in the brain that are activated by TCMS and their relationship to these leg muscle responses are not clearly understood. To elucidate this, we concomitantly recorded leg muscle responses and thoracic spinal cord-evoked potentials (SCEPs) after TCMS for the first time in 10 awake, neurologically intact human subjects.

David A. Houlden; Michael L. Schwartz; Charles H. Tator; Peter Ashby; William A. MacKay

1999-01-01

197

The NMDA antagonist memantine affects training induced motor cortex plasticity – a study using transcranial magnetic stimulation [ISRCTN65784760  

Microsoft Academic Search

BACKGROUND: Training of a repetitive synchronised movement of two limb muscles leads to short-term plastic changes in the primary motor cortex, which can be assessed by transcranial magnetic stimulation (TMS) mapping. We used this paradigm to study the effect of memantine, a NDMA antagonist, on short-term motor cortex plasticity in 20 healthy human subjects, and we were especially interested in

Peter Schwenkreis; Katja Witscher; Burkhard Pleger; Jean-Pierre Malin; Martin Tegenthoff

2005-01-01

198

Excitatory and inhibitory corticospinal responses to transcranial magnetic stimulation in patients with minor to moderate head injury  

Microsoft Academic Search

OBJECTIVESThe changes in excitatory and inhibitory responses to transcranial magnetic stimulation (TMS), as attested by motor evoked potential (MEP) and silent period (SP) parameters, were compared in patients who sustained minor to moderate head injury.METHODSA total of 38 patients with brain concussion, and diffuse, focal, and combined brain injury and 20 healthy volunteers were examined. The MEPs and SPs were

A V Chistyakov; J F Soustiel; H Hafner; M Trubnik; G Levy; M Feinsod

2001-01-01

199

The Observation of Manual Grasp Actions Affects the Control of Speech: A Combined Behavioral and Transcranial Magnetic Stimulation Study  

ERIC Educational Resources Information Center

Does the mirror system affect the control of speech? This issue was addressed in behavioral and Transcranial Magnetic Stimulation (TMS) experiments. In behavioral experiment 1, participants pronounced the syllable /da/ while observing (1) a hand grasping large and small objects with power and precision grasps, respectively, (2) a foot interacting…

Gentilucci, Maurizio; Campione, Giovanna Cristina; Volta, Riccardo Dalla; Bernardis, Paolo

2009-01-01

200

Cortical Inhibition in Attention Deficit Hyperactivity Disorder: New Insights from the Electroencephalographic Response to Transcranial Magnetic Stimulation  

ERIC Educational Resources Information Center

Attention deficit hyperactivity disorder is one of the most frequent neuropsychiatric disorders in childhood. Transcranial magnetic stimulation studies based on muscle responses (motor-evoked potentials) suggested that reduced motor inhibition contributes to hyperactivity, a core symptom of the disease. Here we employed the N100 component of the…

Bruckmann, Sarah; Hauk, Daniela; Roessner, Veit; Resch, Franz; Freitag, Christine M.; Kammer, Thomas; Ziemann, Ulf; Rothenberger, Aribert; Weisbrod, Matthias; Bender, Stephan

2012-01-01

201

A Preliminary Transcranial Magnetic Stimulation Study of Cortical Inhibition and Excitability in High-Functioning Autism and Asperger Disorder  

ERIC Educational Resources Information Center

Aim: Controversy surrounds the distinction between high-functioning autism (HFA) and Asperger disorder, but motor abnormalities are associated features of both conditions. This study examined motor cortical inhibition and excitability in HFA and Asperger disorder using transcranial magnetic stimulation (TMS). Method: Participants were diagnosed by…

Enticott, Peter G.; Rinehart, Nicole J.; Tonge, Bruce J.; Bradshaw, John L.; Fitzgerald, Paul B.

2010-01-01

202

Laterality effects in selective attention to threat after repetitive transcranial magnetic stimulation at the prefrontal cortex in female subjects  

Microsoft Academic Search

Recently, several experiments have indicated that the left and right prefrontal cortex (PFC) are differently involved in emotional processing. The aim of this study was to investigate the role of the left and right PFC in selective attention to angry faces by using a pictorial emotional Stroop task. Slow repetitive transcranial magnetic stimulation (rTMS) was applied to the left and

Alfredo A. L. d'Alfonso; Jack van Honk; Erno Hermans; Albert Postma; Edward H. F de Haan

2000-01-01

203

Dynamical changes in corticospinal excitability during imagery of unimanual and bimanual wrist movements in humans: a transcranial magnetic stimulation study  

Microsoft Academic Search

This study explored the dynamical changes in corticospinal excitability during the imagination of cyclical unimanual and bimanual wrist flexion–extension movements. Transcranial magnetic stimulation was applied over the left motor cortex to evoke motor evoked potentials in the right wrist flexor and extensor muscles. Findings provided evidence for increased reciprocal excitability changes during imagery of symmetrical in-phase movements as compared to

O. Levin; M. Steyvers; N. Wenderoth; Y. Li; S. P. Swinnen

2004-01-01

204

Plastic changes in interhemispheric inhibition with practice of a two-hand force production task: a transcranial magnetic stimulation study  

Microsoft Academic Search

We studied the effects of practice of an unusual two-hand finger force production task on electromyographic and force responses to transcranial magnetic stimulation (TMS). Prior to practice, force production by a hand resulted in decreased TMS-induced responses in the other hand. After practice, fingers that were explicitly required to produce force during practice showed a significant drop in these inhibitory

Jae Kun Shim; Sun Wook Kim; Seung Ja Oh; Ning Kang; Vladimir M. Zatsiorsky; Mark L. Latash

2005-01-01

205

Enhancement of human motor cortex inhibition by the dopamine receptor agonist pergolide: evidence from transcranial magnetic stimulation  

Microsoft Academic Search

Focal transcranial magnetic stimulation was used to evaluate the effect a single oral dose (0.125 mg) of the dopamine agonist pergolide on the excitability of the motor cortex in five healthy subjects. Resting and active motor thresholds of the abductor digiti minimi muscle were unaffected. The mean duration of the cortical silent period was significantly lengthened by up to 22

Ulf Ziemann; Dirk Bruns; Walter Paulus

1996-01-01

206

Theta burst transcranial magnetic stimulation is associated with increased EEG synchronization in the stimulated relative to unstimulated cerebral hemisphere  

Microsoft Academic Search

Theta burst transcranial magnetic stimulation (TBS) may induce behavioural changes that outlast the stimulation period. The neurophysiological basis of these behavioural changes are currently under investigation. Given the evidence that cortical information processing relies on transient synchronization and desynchronization of neuronal assemblies, we set out to test whether TBS is associated with changes of neuronal synchronization as assessed by surface

Kaspar Schindler; Thomas Nyffeler; Roland Wiest; Martinus Hauf; Johannes Mathis; Ch. W. Hess; René Müri

2008-01-01

207

Transient inhibition of the human motor cortex by capsaicin-induced pain. A study with transcranial magnetic stimulation  

Microsoft Academic Search

Motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) of the left motor cortex were recorded from the right first dorsal interosseous (FDI), abductor pollicis brevis (APB), abductor digiti minimi (ADM), flexor carpi radialis (FCR), extensor carpi radialis (ECR) in 17 normal subjects, before and after painful application of capsaicin on the skin overlying the right FDI and FCR muscles.

Simona Farina; Massimiliano Valeriani; Tiziana Rosso; Salvatore Aglioti; Stefano Tamburin; Antonio Fiaschi; Michele Tinazzi

2001-01-01

208

Facilitative effect of high frequency subthreshold repetitive transcranial magnetic stimulation on complex sequential motor learning in humans  

Microsoft Academic Search

We investigated the effect of repetitive transcranial magnetic stimulation (rTMS) applied to the motor cortex, on the motor learning of sequential finger movements. Fifteen healthy subjects were trained to perform seven sequential finger movements of the left hand. Ten Hertz or sham rTMS with a resting motor threshold of 80% was applied to each subject during the task period. Stimulation

Yun-Hee Kim; Ji-Won Park; Myoung-Hwan Ko; Sung Ho Jang; Peter K. W. Lee

2004-01-01

209

Lower excitability of the corticospinal tract to transcranial magnetic stimulation during lengthening contractions in human elbow flexors  

Microsoft Academic Search

The purpose of this study was to characterize the neuromuscular control during shortening (SHO) and lengthening (LEN) contractions by investigating the input-output (I\\/O) property in the corticospinal tract. To this end, the relation between various stimulus intensities applied via transcranial magnetic stimulation and the size of motor evoked potentials was investigated in six healthy subjects during elbow flexion and extension.

Hirofumi Sekiguchi; Toshitaka Kimura; Kentaro Yamanaka; Kimitaka Nakazawa

2001-01-01

210

Simultaneous recording of slow brain potentials and transcranial magnetic stimulation of hand area in human motor cortex  

Microsoft Academic Search

Recording of slow brain potentials (SPs) and transcranial magnetic stimulation (TCMS) of the human motor cortex were combined to probe the relationship between SP level and excitability of cortical neurons. In experiment 1, TCMS was applied during and shortly after the warning interval in a forewarned reaction time task. Electromyographic (EMG) responses to TCMS increased only slightly during the warning

Udo H. L. Häusler; Werner Lutzenberger; Niels Birbaumer

1995-01-01

211

Impairment of cortical inhibition in writer's cramp as revealed by changes in electromyographic silent period after transcranial magnetic stimulation  

Microsoft Academic Search

Changes in silent period (SP) duration following transcranial magnetic stimulation (TMS) set at 20% above the motor threshold were studied in six subjects suffering from writer's cramp, while performing dystonic movement and during voluntary isometric contraction of the muscles mostly involved in the dystonic movement. Dependency of SP duration on the intensity of preceding muscle contraction was compared on both

S. R Filipovi?; M Ljubisavljevi?; M Svetel; S Milanovi?; A Ka?ar; V. S Kosti?

1997-01-01

212

Repetitive transcranial magnetic stimulation of the motor cortex attenuates pain perception in complex regional pain syndrome type I  

Microsoft Academic Search

In complex regional pain syndrome (CRPS) many clinical symptoms suggest involvement of the central nervous system. Neuropathic pain as the leading symptom is often resistant to therapy. In the present study we investigated the analgesic efficiency of repetitive transcranial magnetic simulation (rTMS) applied to the motor cortex contralateral to the CRPS-affected side. Seven out of ten patients reported decreased pain

Burkhard Pleger; Frank Janssen; Peter Schwenkreis; Birgit Völker; Christoph Maier; Martin Tegenthoff

2004-01-01

213

Central changes in muscle fatigue during sustained submaximal isometric voluntary contraction as revealed by transcranial magnetic stimulation  

Microsoft Academic Search

Changes in responses to transcranial magnetic stimulation (TMS) during submaximal isometric voluntary contraction (60% of maximal voluntary contraction (MVC) of the adductor pollicis muscle and the subsequent recovery period have been studied in healthy volunteers. TMS at twice the motor threshold was applied during the sustained contraction, as well as at rest and during short-lasting (2 s) 60% MVCs before

M. Ljubisavljevi?; S. Milanovi?; S. Radovanovi?; I. Vuk?evi?; V. Kosti?; R. Anastasijevi?

1996-01-01

214

The course of cortico-hypoglossal projections in the human brainstem: Functional testing using transcranial magnetic stimulation  

Microsoft Academic Search

Summary Cortico-hypoglossal projections were investigated in 11 patients with unifocal ischaemic lesions of different brainstem levels using transcranial magnetic stimulation. Lesion topography was documented by MRI studies. In seven patients the projections to the ipsi- and contralateral hypoglossal nuclei were separately affected. Pontine lesions at the ventral paramedian base close to the midline affect the contralateral projections while lateral lesions

W Muellbacher; H. C. Hopf; B. Connemann; H. P. Hundemer; J. Koehler

1996-01-01

215

Cortical Inhibition in Attention Deficit Hyperactivity Disorder: New Insights from the Electroencephalographic Response to Transcranial Magnetic Stimulation  

ERIC Educational Resources Information Center

|Attention deficit hyperactivity disorder is one of the most frequent neuropsychiatric disorders in childhood. Transcranial magnetic stimulation studies based on muscle responses (motor-evoked potentials) suggested that reduced motor inhibition contributes to hyperactivity, a core symptom of the disease. Here we employed the N100 component of the…

Bruckmann, Sarah; Hauk, Daniela; Roessner, Veit; Resch, Franz; Freitag, Christine M.; Kammer, Thomas; Ziemann, Ulf; Rothenberger, Aribert; Weisbrod, Matthias; Bender, Stephan

2012-01-01

216

Human Ventral Parietal Cortex Plays a Functional Role on Visuospatial Attention and Primary Consciousness. A Repetitive Transcranial Magnetic Stimulation Study  

Microsoft Academic Search

In this paper, we used repetitive transcranial magnetic stimulation (rTMS) in 18 normal subjects to investigate whether the ventral posterior parietal cortex (PPC) plays a causal role on visuospatial attention and primary consciousness and whether these 2 functions are linearly correlated with each other. Two distinct experimental conditions involved a similar visual stimuli recognition paradigm. In ''Consciousness'' experiment, number of

Claudio Babiloni; Fabrizio Vecchio; Simone Rossi; Alberto De Capua; Sabina Bartalini; Monica Ulivelli; Paolo Maria Rossini

2006-01-01

217

Coming Unbound: Disrupting Automatic Integration of Synesthetic Color and Graphemes by Transcranial Magnetic Stimulation of the Right Parietal Lobe  

Microsoft Academic Search

In some individuals, a visually presented letter or number automatically evokes the perception of a specific color, an ex- perience known as color-grapheme synesthesia. It has been suggested that parietal binding mechanisms play a role in the phenomenon. We used a noninvasive stimulation technique, transcranial magnetic stimulation (TMS), to determine whether the posterior parietal lobe is critical for the integration

Michael Esterman; Timothy Verstynen; Richard B. Ivry; Lynn C. Robertson

2006-01-01

218

Transcranial Magnetic Stimulation Effects on One-Trial Learning and Response to Anxiogenic Stimuli in Adult Male Rats  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) is a relatively new technique for inducing small, localized, and reversible changes in living brain tissue and has been suggested to have antidepressant properties in humans and animal models of depression. Memory function generally has been found to be unaffected by TMS, although some studies have raised the possibility of memory interference from TMS. Additionally, there

Dawson W. Hedges; Brian J. Higginbotham; David L. Salyer; Trent D. Lund

2005-01-01

219

Modulation of N400 in Chronic Non-Fluent Aphasia Using Low Frequency Repetitive Transcranial Magnetic Stimulation (rTMS)  

ERIC Educational Resources Information Center

|Low frequency Repetitive Transcranial Magnetic Stimulation (rTMS) has previously been applied to language homologues in non-fluent populations of persons with aphasia yielding significant improvements in behavioral language function up to 43 months post stimulation. The present study aimed to investigate the electrophysiological correlates…

Barwood, Caroline H. S.; Murdoch, Bruce E.; Whelan, Brooke-Mai; Lloyd, David; Riek, Stephan; O'Sullivan, John D.; Coulthard, Alan; Wong, Andrew

2011-01-01

220

The Observation of Manual Grasp Actions Affects the Control of Speech: A Combined Behavioral and Transcranial Magnetic Stimulation Study  

ERIC Educational Resources Information Center

|Does the mirror system affect the control of speech? This issue was addressed in behavioral and Transcranial Magnetic Stimulation (TMS) experiments. In behavioral experiment 1, participants pronounced the syllable /da/ while observing (1) a hand grasping large and small objects with power and precision grasps, respectively, (2) a foot interacting…

Gentilucci, Maurizio; Campione, Giovanna Cristina; Volta, Riccardo Dalla; Bernardis, Paolo

2009-01-01

221

Stimulating Conversation: Enhancement of Elicited Propositional Speech in a Patient with Chronic Non-Fluent Aphasia following Transcranial Magnetic Stimulation  

ERIC Educational Resources Information Center

|Although evidence suggests that patients with left hemisphere strokes and non-fluent aphasia who receive 1Hz repetitive transcranial magnetic stimulation (rTMS) over the intact right inferior frontal gyrus experience persistent benefits in naming, it remains unclear whether the effects of rTMS in these patients generalize to other language…

Hamilton, Roy H.; Sanders, Linda; Benson, Jennifer; Faseyitan, Olufunsho; Norise, Catherine; Naeser, Margaret; Martin, Paula; Coslett, H. Branch

2010-01-01

222

Multiplanar transcranial ultrasound imaging: standards, landmarks and correlation with magnetic resonance imaging.  

PubMed

The purpose of this study was to define a standardized multiplanar approach for transcranial ultrasound (US) imaging of brain parenchyma based on matched data from 3-D US and 3-D magnetic resonance imaging (MRI). The potential and limitations of multiple insonation planes in transverse and coronal orientation were evaluated for the visualization of intracranial landmarks in 60 healthy individuals (18 to 83 years old, mean 41.4 years) with sufficient temporal bone windows. Landmarks regularly visualized even in moderate sonographic conditions with identification rates of >75% were mesencephalon, pons, third ventricle, lateral ventricles, falx, thalamus, basal ganglia, pineal gland and temporal lobe. Identification of medulla oblongata, fourth ventricle, cerebellar structures, hippocampus, insula, frontal, parietal and occipital lobes was more difficult (<75%). We hypothesize that multiplanar transcranial US images, with standardized specification of tilt angles and orientation, not only allow comparison with other neuroimaging modalities, but may also provide a more objective framework for US monitoring of cerebral disease than freehand scanning. PMID:15749552

Kern, Rolf; Perren, Fabienne; Kreisel, Stefan; Szabo, Kristina; Hennerici, Michael; Meairs, Stephen

2005-03-01

223

The Neural Bases of Word Encoding and Retrieval: A fMRI-Guided Transcranial Magnetic Stimulation Study  

Microsoft Academic Search

There is evidence that the human prefrontal cortex is asymmetrically involved in long-term episodic memory processing. Moreover,\\u000a abstract and concrete words processing has been reported to differentially involve prefrontal and parietal areas. We implemented\\u000a a two-stages functional magnetic resonance imaging (fMRI)–repetitive transcranial magnetic stimulation (rTMS) paradigm to\\u000a investigate the role of the dorsolateral prefrontal cortices (DLPFCs) and parietal cortices (PARCs)

R. Manenti; M. Tettamanti; M. Cotelli; C. Miniussi; S. F. Cappa

2010-01-01

224

Transcranial magnetic stimulation (TMS) of the human frontal cortex: implications for repetitive TMS treatment of depression  

PubMed Central

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive tool used to manipulate activity in specific neural circuits of the human brain. Clinical studies suggest that, in some patients with major depression, rTMS has the potential to alleviate symptoms that may be related to functional abnormalities in a frontocingulate circuit. This paper reviews the rationale for the use of rTMS in this context. The following topics are discussed: symptoms and cognition in major depression, with special emphasis on the initiation of speech; neuroimaging studies of depression; rTMS as treatment for depression; structure and function of the mid-dorsolateral frontal and anterior cingulate cortices; and combined TMS/positron emission tomography studies of frontocortical connectivity.

Paus, Tomas; Barrett, Jennifer

2004-01-01

225

A Novel Transcranial Magnetic Stimulator Inducing Near Rectangular Pulses with Controllable Pulse Width (cTMS)  

PubMed Central

A novel transcranial magnetic stimulation (TMS) device with controllable pulse width (PW) and near rectangular pulse shape (cTMS) is described. The cTMS device uses an insulated gate bipolar transistor (IGBT) with appropriate snubbers to switch coil currents up to 7 kA, enabling PW control from 5 ?s to over 100 ?s. The near-rectangular induced electric field pulses use 22–34% less energy and generate 67–72% less coil heating compared to matched conventional cosine pulses. CTMS is used to stimulate rhesus monkey motor cortex in vivo with PWs of 20 to 100 ?s, demonstrating the expected decrease of threshold pulse amplitude with increasing PW. The technological solutions used in the cTMS prototype can expand functionality, and reduce power consumption and coil heating in TMS, enhancing its research and therapeutic applications.

Jalinous, Reza; Lisanby, Sarah H.

2013-01-01

226

Chronic repetitive transcranial magnetic stimulation enhances c-fos in the parietal cortex and hippocampus.  

PubMed

Repetitive transcranial magnetic stimulation (rTMS) is a novel non-invasive method with anti-depressant properties. However, the mechanism of activation on the cellular level is unknown. Twelve hours after the last chronic rTMS treatment (14 days, once per day, 20 Hz, 10 s, 75% machine output, the transcription factor c-fos was markedly increased in neurons in layers I-IV and VI of the parietal cortex and in few scattered neurons in the hippocampus of Sprague-Dawley rats. The cortical activation was not blocked by the NMDA antagonist MK-801. The increase of c-fos was not paralleled by an increased glial response and activation of cortical growth factors. Thus, it is concluded that chronic rTMS differentially activates parietal cortical layers and this might be involved in mediating anti-depressant activity in other brain areas. PMID:10762712

Hausmann, A; Weis, C; Marksteiner, J; Hinterhuber, H; Humpel, C

2000-03-29

227

A Study of Temporal Aspect of Posterior Parietal Cortex in Visual Search Using Transcranial Magnetic Stimulation  

NASA Astrophysics Data System (ADS)

It is known that the posterior parietal cortex (PPC) plays a dominant role in spatial processing during visual search. However, the temporal aspect of the PPC is unclear. In the present study, to investigate the temporal aspects of the PPC in feature search, we applied Transcranial Magnetic Stimulation (TMS) over the right PPC with the TMS stimulus onset asynchronies (SOAs) set at 100, 150, 200 and 250 ms after visual search stimulation. We found that when SOA was set at 150 ms, compared to the sham TMS condition, there was a significant elevation in response time when TMS pulses were applied. However, there was no significant difference between the TMS and sham TMS conditions for the other SOA settings. Therefore, we suggest that the spatial processing of feature search is probably processed in the posterior parietal cortex at about 150-170 ms after visual search stimuli presentation.

Ge, Sheng; Matsuoka, Akira; Ueno, Shoogo; Iramina, Keiji

228

Functional Neurosurgery in the Human Thalamus by Transcranial Magnetic Resonance Guided Focused Ultrasound  

NASA Astrophysics Data System (ADS)

Potential applications of Transcranial Magnetic Resonance guided Focused Ultrasound (TcMRgFUS) include treatment of functional brain disorders, such as Parkinson's disease, dystonia and tremor, neurogenic pain and tinnitus, neuropsychiatric disorders and epilepsy. In this study we demonstrate the feasibility of non-invasive TcMRgFUS ablation of clinically well established targets in the human thalamus that are currently accessed stereotactically by interventional strategies based on the concept of the thalamocortical dysrhythmia (TCD). Thermal hotspots suitable for clinical intervention were created successfully in anatomical preparations of human ex-vivo heads under pseudo clinical conditions. The hotspots could be positioned at the target locations as needed and local energy deposition was sufficient to create tissue ablation. Numerical simulations based on these experimental data predict that the acoustic energy needed to create ablative lesions in-vivo will be within limits that can safely applied.

Werner, Beat; Morel, Anne; Jeanmonod, Daniel; Martin, Ernst

2009-04-01

229

Total i.v. anaesthesia for transcranial magnetic evoked potential spinal cord monitoring.  

PubMed

Continuous intraoperative monitoring of transcranial magnetic motor evoked potentials (TcMMEP) can warn the surgeon of motor tract damage more effectively than somatosensory evoked potentials. As a non-invasive technique it is especially useful during post-traumatic internal fixation and is applicable whatever the level of the spinal cord at risk. Inhalation and many i.v. anaesthetics block the single pulse TcMMEP but a total i.v. anaesthetic regimen based on methohexitone, alfentanil and ketamine was effective in seven patients undergoing post-traumatic internal fixation. Consistent TcMMEP of 100-1000 mcV were obtained in all patients, with a latency change of only 2 ms above preoperative values. Good cardiovascular stability was maintained during operation. PMID:8679365

Watt, J W; Fraser, M H; Soni, B M; Sett, P K; Clay, R

1996-06-01

230

Sufentanil and nitrous oxide anaesthesia for the recording of transcranial magnetic motor evoked potentials in dogs.  

PubMed

Transcranial magnetic motor evoked potentials were recorded from the extensor carpi radialis muscle of the forelimbs and from the cranial tibial muscle of the hindlimbs of anaesthetised dogs. The dogs were premedicated with droperidol and fentanyl and a light plane of anaesthesia was induced and maintained with sufentanil and nitrous oxide. The potentials recorded under sufentanil and nitrous oxide anaesthesia were suppressed in comparison with baseline recordings under droperidol and fentanyl sedation: their latencies were significantly increased and their amplitudes significantly decreased (P < 0.05). However, the potentials could be recorded reliably in all the dogs and with very good reproducibility. This narcotic anaesthesia also allowed sensory evoked potentials to be recorded reliably. PMID:8817859

Van Ham, L M; Nijs, J; Mattheeuws, D R; Vanderstraeten, G G

1996-06-29

231

Adapted filter banks for feature extraction in transcranial magnetic stimulation evoked responses.  

PubMed

A novel adaptive and approximate shift-invariant wavelet packet feature extraction scheme for event-related potentials (ERPs) in the electroencephalogram (EEG) is introduced in this paper. In this algorithm, the shift-invariant wavelet packed decomposition is done by integrating a cost function for decimation decision in each sub-band expansion. Additionally, a shape adaptation of the wavelet is implemented to find the best adapted wavelet shape for a given class of ERPs. This scheme is used to analyze the time course of the impact of single-pulse transcranial magnetic stimulation (TMS) to the auditory ERPs. We show that the proposed scheme is able to extract even slightest impacts of TMS, making it a promising tool for the extraction of weak ERPs components, particularly in hybrid TMS-EEG/ERP setups. PMID:21222168

Harris, Arief R; Schwerdtfeger, Karsten; Strauss, Daniel J

2011-01-11

232

Corticospinal excitability during painful self-stimulation in humans: a transcranial magnetic stimulation study.  

PubMed

We investigated changes in the corticospinal pattern of activity in healthy volunteers during sustained noxious and non-noxious mechanical stimulation of the first hand digit, resulting from active (self-stimulation) or passive (externally-induced) pressing against a sharp or blunted tip. The results indicate that, in order to press a finger onto a noxious stimulus with the same force generated to press onto a non-noxious one, the motor cortex adopts a peculiar strategy in terms of recruitment of motor units. This is reflected by an increase of corticospinal excitability (as revealed by motor potentials evoked by transcranial magnetic stimulation of the contralateral primary motor cortex) and EMG activity of agonist muscles, possibly related to an increase of motor unit synchronization. PMID:15135940

Fadiga, Luciano; Craighero, Laila; Dri, Guanita; Facchin, Patrizia; Destro, Maddalena Fabbri; Porro, Carlo A

2004-05-01

233

A transcranial magnetic stimulator inducing near-rectangular pulses with controllable pulse width (cTMS).  

PubMed

A novel transcranial magnetic stimulation (TMS) device with controllable pulse width (PW) and near-rectangular pulse shape (cTMS) is described. The cTMS device uses an insulated gate bipolar transistor (IGBT) with appropriate snubbers to switch coil currents up to 6 kA, enabling PW control from 5 micros to over 100 micros. The near-rectangular induced electric field pulses use 2%-34% less energy and generate 67%-72% less coil heating compared to matched conventional cosine pulses. CTMS is used to stimulate rhesus monkey motor cortex in vivo with PWs of 20 to 100 micros, demonstrating the expected decrease of threshold pulse amplitude with increasing PW. The technological solutions used in the cTMS prototype can expand functionality, and reduce power consumption and coil heating in TMS, enhancing its research and therapeutic applications. PMID:18232369

Peterchev, Angel V; Jalinous, Reza; Lisanby, Sarah H

2008-01-01

234

1-Hz low frequency repetitive transcranial magnetic stimulation in children with Tourette's syndrome.  

PubMed

The aim of the current study was to assess the efficacy of repetitive transcranial magnetic stimulation (rTMS) over the supplementary motor area (SMA) of the cortex to children with Tourette's syndrome (TS), if rTMS over the SMA had positive effects on ameliorating tics. We designed a pilot open label 12 weeks cohort study to assess the efficacy of rTMS with TS at specific regions. We administered rTMS over SMA with slow frequency to children with TS. We examined 10 male children (mean age 11.2 ± 2.0 years) diagnosed with TS according to the Diagnostic and Statistical Manual of Mental Disorders version IV and Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version. Children with TS were treated with active rTMS to the SMA for 10 daily sessions (1 Hz, 100% of motor threshold, and 1200 stimuli/day). All subjects completed the study with no side effects and no worsening of ADHD or depressive and anxiety symptoms. Tic symptoms improved significantly over the 12 weeks of the study. Statistically significant reductions were seen in the Yale Global Tourette's Syndrome Severity Scale (YGTSS) and Clinical Global Impression (CGI). Low-frequency rTMS over the SMA appears to be effective in children with TS. Further studies using repetitive transcranial magnetic stimulation in TS are warranted, using blinded, balanced, and parallel designs. rTMS over the SMA to children with TS might result in a significant clinical improvement and a normalization of both the hemisphere hyperexcitability. PMID:21256925

Kwon, Ho Jang; Lim, Won Seok; Lim, Myung Ho; Lee, Seong Jae; Hyun, Jung Keun; Chae, Jeong-Ho; Paik, Ki Chung

2011-01-21

235

Repetitive spinal motor neuron discharges following single transcranial magnetic stimulation: relation to dexterity.  

PubMed

Transcranial magnetic stimulation allows to study the properties of the human corticospinal tract non-invasively. After a single transcranial magnetic stimulus, spinal motor neurons (MNs) sometimes fire not just once, but repetitively. The biological significance of such repetitive MN discharges (repMNDs) is unknown. To study the relation of repMNDs to other measures of cortico-muscular excitability and to physiological measures of the skill for finely tuned precision movements, we used a previously described quadruple stimulation (QuadS) technique (Z'Graggen et al. 2005) to quantify the amount of repMNDs in abductor digiti minimi muscles (ADMs) on both sides of 20 right-handed healthy subjects. Skillfulness for finger precision movements of both hands was assessed using a finger tapping task. In 16 subjects, a follow-up examination was performed after training of either precision movements (n = 8) or force (n = 8) of the left ADM. The size of the QuadS response (amplitude and area ratios) was greater in the dominant right hand than in the left hand (QuadS amplitude ratio: 47.1 +/- 18.1 versus 37.7 +/- 22.0%, Wilcoxon test: P < 0.05; QuadS area ratio: 49.7 +/- 16.2% versus 36.9 +/- 23.0%, Wilcoxon test: P < 0.05), pointing to a greater amount of repMNDs. Moreover, the QuadS amplitude and area increased significantly after finger precision training, but not after force training. This increase of repMNDs correlated significantly with the increase in performance in the finger tapping task. Our results demonstrate that repMNDs are related to handedness and therefore probably reflect supraspinal excitability differences. The increase of repMNDs after skills training but not after force training supports the hypothesis of a supraspinal origin of repMNDs. PMID:18463857

Z'Graggen, W J; Humm, A M; Oppliger-Bachmann, S; Hosang, M; Rösler, K M

2008-05-08

236

Cortico-Cortical Modulation Induced by 1-Hz Repetitive Transcranial Magnetic Stimulation of the Temporal Cortex  

PubMed Central

Background and Purpose Repetitive transcranial magnetic stimulation (rTMS) has potential as a noninvasive neuromodulation treatment method for various neuropsychiatric disorders, and repeated sessions of rTMS are more likely to enhance the therapeutic efficacy. This study investigated neurophysiologic and spatiodynamic changes induced by repeated 1-Hz rTMS of the temporal cortex using transcranial magnetic stimulation (TMS) indices and fluorodeoxyglucose positron emission tomography (FDG-PET). Methods Twenty-seven healthy subjects underwent daily 1-Hz active or sham rTMS of the right temporal cortex for 5 consecutive days. TMS indices of motor cortical excitability were measured in both hemispheres daily before and after each rTMS session, and 2 weeks after the last stimulation. FDG-PET was performed at baseline and after the 5 days of rTMS sessions. Results All subjects tolerated all of the sessions well, with only three of them (11.1%) reporting mild transient side effects (i.e., headache, tinnitus, or local irritation). One-Hz rTMS decreased motor evoked potential amplitudes and delayed cortical silent periods in the stimulated hemisphere. Statistical parametric mapping of FDG-PET data revealed a focal reduction of glucose metabolism in the stimulated temporal area and an increase in the bilateral precentral, ipsilateral superior and middle frontal, prefrontal and cingulate gyri. Conclusions Repeated rTMS sessions for 5 consecutive days were tolerated in all subjects, with only occasional minor side effects. Focal 1-Hz rTMS of the temporal cortex induces cortico-cortical modulation with widespread functional changes in brain neural networks via long-range neural connections.

Lee, Mina; Kim, Song E; Kim, Won Sup; Han, Jooman; Kim, Hee Jin; Kim, Bom Sahn; Kim, Ji Young; Hong, Seung Bong; Kim, Byung Gon

2013-01-01

237

Effects of droperidol, pentobarbital, and ketamine on myogenic transcranial magnetic motor-evoked responses in humans.  

PubMed

Myogenic motor-evoked responses to transcranial magnetic stimulation of the motor cortex (tcmag-MERs) may become clinically useful for the noninvasive assessment of motor pathway conduction during surgery. However, application is hindered because most anesthetic regimens result in severe depression of tcmag-MER amplitudes. As part of our systematic attempts to identify anesthetic agents and supplements suitable for use during tcmag-MER recording, we studied the effect of bolus doses of pentobarbital (1.5 mg/kg), droperidol (0.07 mg/kg), or ketamine (1 mg/kg), administered intravenously, on compound muscle action potentials to transcranial magnetic stimulation in five healthy volunteers. The doses were chosen to be comparable with doses that might be suitable for supplementation of a nitrous oxide/opioid anesthetic technique. Droperidol administration resulted in sustained amplitude depression of both tibialis and adductor pollicis tc-MERs to 30 +/- 9% and 39 +/- 14% of baseline (P < 0.01). Tcmag-MER amplitude changes after pentobarbital were variable, ranging from no change to substantial amplitude depression (to 20% of baseline) in two subjects. In contrast, ketamine administration did not result in significant amplitude depression. In three subjects, tibialis anterior amplitude increased to 150 to 220% of control values in the first 10 minutes after ketamine. Onset latency was unchanged after any drug. These data indicate that tcmag-MERs are moderately depressed after droperidol and pentobarbital but well preserved after ketamine. Ketamine may be a more suitable supplement to opioid/nitrous oxide anesthesia than droperidol or pentobarbital. PMID:7885550

Kalkman, C J; Drummond, J C; Patel, P M; Sano, T; Chesnut, R M

1994-12-01

238

Meta-analysis of the effects of repetitive transcranial magnetic stimulation (rTMS) on negative and positive symptoms in schizophrenia  

Microsoft Academic Search

BackgroundA growing body of evidence suggests that repetitive transcranial magnetic stimulation (rTMS) can alleviate negative and positive symptoms of refractory schizophrenia. However, trials to date have been small and results are mixed.

Catarina Freitas; Felipe Fregni; Alvaro Pascual-Leone

2009-01-01

239

Applications of transcranial magnetic stimulation and magnetic seizure therapy in the study and treatment of disorders related to cerebral aging  

PubMed Central

Transcranial magnetic stimulation (TMS) can be used to probe cortical function and treat neuropsychiatric illnesses. TMS has demonstrated neuroplastic effects akin to long-term potentiation and long-term depression, and therapeutic applications are in development for post-stroke recovery, Alzheimer's disease, and depression in seniors. Here, we discuss two new directions of TMS research relevant to cerebral aging and cognition. First, we introduce a paradigm for enhancing cognitive reserve, based on our research in sleep deprivation. Second, we discuss the use of magnetic seizure therapy (MST) to spare cognitive functions relative to conventional electroconvulsive therapy, and as a means of providing a more potent antidepressant treatment when subconvulsive TMS has shown modest efficacy in seniors. Whether in the enhancement of cognition as a treatment goal, or in the reduction of amnesia as a side effect, these approaches to the use of TMS and MST merit further exploration regarding their clinical potential.

Luber, Bruce; McClintock, Shawn M.; Lisanby, Sarah H.

2013-01-01

240

flexTMS--a novel repetitive transcranial magnetic stimulation device with freely programmable stimulus currents.  

PubMed

Transcranial magnetic stimulation (TMS) is able to noninvasively excite neuronal populations due to brief magnetic field pulses. The efficiency and the characteristics of stimulation pulse shapes influence the physiological effect of TMS. However, commercial devices allow only a minimum of control of different pulse shapes. Basically, just sinusoidal and monophasic pulse shapes with fixed pulse widths are available. Only few research groups work on TMS devices with controllable pulse parameters such as pulse shape or pulse width. We describe a novel TMS device with a full-bridge circuit topology incorporating four insulated-gate bipolar transistor (IGBT) modules and one energy storage capacitor to generate arbitrary waveforms. This flexible TMS (flexTMS ) device can generate magnetic pulses which can be adjusted with respect to pulse width, polarity, and intensity. Furthermore, the equipment allows us to set paired pulses with a variable interstimulus interval (ISI) from 0 to 20 ms with a step size of 10  ?s. All user-defined pulses can be applied continually with repetition rates up to 30 pulses per second (pps) or, respectively, up to 100 pps in theta burst mode. Offering this variety of flexibility, flexTMS will allow the enhancement of existing TMS paradigms and novel research applications. PMID:22531742

Gattinger, Norbert; Moessnang, Georg; Gleich, Bernhard

2012-04-18

241

Measurements of evoked electroencephalograph by transcranial magnetic stimulation applied to motor cortex and posterior parietal cortex  

NASA Astrophysics Data System (ADS)

To investigate the functional connectivity, the evoked potentials by stimulating at the motor cortex, the posterior parietal cortex, and the cerebellum by transcranial magnetic stimulation (TMS) were measured. It is difficult to measure the evoked electroencephalograph (EEG) by the magnetic stimulation because of the large artifact induced by the magnetic pulse. We used an EEG measurement system with sample-and-hold circuit and an independent component analysis to eliminate the electromagnetic interaction emitted from TMS. It was possible to measure EEG signals from all electrodes over the head within 10 ms after applying the TMS. When the motor area was stimulated by TMS, the spread of evoked electrical activity to the contralateral hemisphere was observed at 20 ms after stimulation. However, when the posterior parietal cortex was stimulated, the evoked electrical activity to the contralateral hemisphere was not observed. When the cerebellum was stimulated, the cortical activity propagated from the stimulated point to the frontal area and the contralateral hemisphere at around 20 ms after stimulation. These results suggest that the motor area has a strong interhemispheric connection and the posterior parietal cortex has no interhemispheric connection.

Iwahashi, Masakuni; Koyama, Yohei; Hyodo, Akira; Hayami, Takehito; Ueno, Shoogo; Iramina, Keiji

2009-04-01

242

Stroke recovery can be enhanced by using repetitive transcranial magnetic stimulation (rTMS).  

PubMed

Post-stroke recovery is based on plastic changes in the central nervous system that can compensate the loss of activity in affected brain regions. In particular, monohemispheric stroke is thought to result in disinhibition of the contralesional unaffected hemisphere. Neurorehabilitation programs improve function partly by enhancing cortical reorganization. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive way of producing potent changes in cortical excitability. Therefore, the application of rTMS was recently proposed to promote functional recovery in stroke patients, owing to the induced neuroplasticity. This review discusses the first clinical results that were obtained by rTMS in patients with post-stroke motor deficit, visuospatial neglect, or aphasia. These results are promising and depend on the site and frequency of stimulation. In summary, functional recovery might be obtained either when rTMS is applied at low-frequency (around 1 Hz) over the disinhibited, unaffected hemisphere in order to restore defective inhibition or when rTMS is applied at high-frequency (5 Hz or more) over the affected hemisphere in order to reactivate hypoactive regions. The overall procedure remains to be optimized, in particular regarding the number of rTMS sessions and the time of rTMS application after stroke. Cortical stimulation is an exciting perspective for improving functional recovery from stroke. Transient application of non-invasive transcranial stimulation during the time of the rehabilitation process will be preferable to the temporary implantation of epidural cortical electrodes, as recently proposed. Therefore, in the future, acute or recent stroke might be a major indication of rTMS in neurological practice. PMID:17046605

Lefaucheur, J-P

2006-08-30

243

Short term synchronization of human motor units and their responses to transcranial magnetic stimulation.  

PubMed Central

1. The voluntary discharge characteristics, short term synchronization, coherence and responses to transcranial magnetic stimulation of a sample of twenty-two pairs of simultaneously recorded low threshold motor units in the right human first dorsal interosseus muscle have been determined. 2. Peristimulus time histograms and cumulative sums (cusums) of motor unit discharge showed either excitatory or inhibitory responses to cortical stimuli. Over the whole motor unit sample, the primary excitatory response had a mean onset of 24.6 ms and the inhibitory response a mean onset of 31.0 ms. Responses of pairs of motor units to magnetic stimulation could be dissimilar; at some stimulus intensities one of the motor unit pair could be excited by the stimulus whilst the other was inhibited. 3. Most pairs of motor units showed short term synchrony in their voluntary discharge, but the same motor units driven by magnetic cortical stimuli showed little tendency to discharge together more frequently than would be predicted from their independent behaviour. This held true for discharges in both the early primary excitatory peak and in the later secondary peak in peristimulus time histograms. 4. Series of magnetic stimuli, causing either excitation or inhibition of individual tonically active motor units, had no effect on the size of the central peak of the cross-correlogram of the motor unit pair. However, frequency analysis of pairs of motor unit spike trains showed an increase in coherence in the 16-32 Hz band during magnetic stimulation. 5. It is concluded that, whilst many corticospinal fibres branch extensively within motoneurone pools, there are also fast conducting corticomotoneuronal fibres allowing the independent monosynaptic activation of individual motoneurones. 6. It is also suggested that during sustained voluntary tonic activity, magnetic stimuli applied to the brain can increase the synchrony in common input fibres to pairs of motoneurones. Images Figure 3

Mills, K R; Schubert, M

1995-01-01

244

Risk and safety of repetitive transcranial magnetic stimulation: report and suggested guidelines from the International Workshop on the Safety of Repetitive Transcranial Magnetic Stimulation, June 5–7, 1996  

Microsoft Academic Search

Single-pulse transcranial magnetic stimulation (TMS) is a safe and useful tool for investigating various aspects of human neurophysiology, particularly corticospinal function, in health and disease. Repetitive TMS (rTMS), however, is a more powerful and potentially dangerous modality, capable of regionally blocking or facilitating cortical processes. Although there is evidence that rTMS is useful for treating clinical depression, and possibly other

Eric M. Wassermann

1998-01-01

245

The right dorsolateral prefrontal cortex is essential in time reproduction: an investigation with repetitive transcranial magnetic stimulation  

Microsoft Academic Search

This study used repetitive transcranial magnetic stimulation (rTMS) to investigate the roles of the right dorsolateral prefrontal cortex (DLPFC) and supplementary motor area (SMA) in short (500 ms) and long (2 s) interval timing. The results were compared with rTMS over the leg area of motor cortex, an area not thought to be involved with time estimation. rTMS was delivered during one

Catherine R. G. Jones; Karin Rosenkranz; John C. Rothwell; Marjan Jahanshahi

2004-01-01

246

Effects of repetitive transcranial magnetic stimulation over dorsolateral prefrontal and posterior parietal cortex on memory-guided saccades  

Microsoft Academic Search

We investigated the role of the dorsolateral prefrontal cortex (DLPFC) and the posterior parietal cortex (PPC) in a visuospatial\\u000a delayed-response task in humans. Repetitive transcranial magnetic stimulation (20?Hz, 0.5?s) was used to interfere temporarily\\u000a with cortical activity in the DLPFC and PPC during the delay period. Omnidirectional memory-guided saccades with a 3-s delay\\u000a were used as a quantifiable motor response

Stephan A. Brandt; Christoph J. Ploner; Bernd-Ulrich Meyer; Stefanie Leistner; Arno Villringer

1998-01-01

247

Consensus paper on short-interval intracortical inhibition and other transcranial magnetic stimulation intracortical paradigms in movement disorders.  

PubMed

In this article we reviewed the results obtained with the technique of paired-pulse transcranial magnetic stimulation (TMS) in normal subjects and in patients with movement disorders (Parkinson's disease, dystonia, chorea, Tourette's syndrome, myoclonus, essential tremor, and ataxia). Results on short-interval intracortical inhibition (SICI), intracortical facilitation (ICF) and long-interval intracortical inhibition (LICI) are reported and discussed for each type of movement disorder. PMID:20633384

Berardelli, Alfredo; Abbruzzese, Giovanni; Chen, Robert; Orth, Michael; Ridding, Michael C; Stinear, Cathy; Suppa, Antonio; Trompetto, Carlo; Thompson, Philip D

2008-07-01

248

Antioxidant-Like Effects and Protective Action of Transcranial Magnetic Stimulation in Depression Caused by Olfactory Bulbectomy  

Microsoft Academic Search

We studied the effects of transcranial magnetic stimulation (TMS, 60 Hz and 0.7 mT for 4 h\\/day for 14 days) on oxidative and\\u000a cell damage caused by olfactory bulbectomy (OBX) in Wistar rats. The levels of lipid peroxidation products and caspase-3 were\\u000a enhanced by OBX, whereas it prompted a reduction in reduced glutathione (GSH) content and antioxidative enzymes activities.\\u000a The treatment with TMS reverted

Inmaculada TassetReneDrucker-Colõ ´; René Drucker-Colín; José Peña; Ignacio Jimena; Pedro Montilla; Francisco Javier Medina; Isaac Túnez

2010-01-01

249

Sensitivity of transcranial magnetic stimulation of cortico-bulbar vs. cortico-spinal tract involvement in Amyotrophic Lateral Sclerosis (ALS)  

Microsoft Academic Search

Background An upper motor neuron (UMN) lesion in amyotrophic lateral sclerosis (ALS) is often difficult to identify because clinical\\u000a signs may be discrete or masked by severe simultaneous LMN lesions. We compared the diagnostic sensitivity of transcranial\\u000a magnetic stimulation (TMS) to cranial muscles and limb muscles in the detection of UMN lesions. Design We investigated corticobulbar and corticospinal tract function

Peter P. Urban; S. Wicht; H. C. Hopf

2001-01-01

250

Modulation of corticospinal activity by strong emotions evoked by pictures and classical music: a transcranial magnetic stimulation study  

Microsoft Academic Search

Using transcranial magnetic stimulation and skin conductance responses, we sought to clarify if, and to what extent, emotional experiences of di¡erent valences and intensity activate the hand^ motor system and the associated corticospinal tract. For that purpose, we applied a newly developed method to evoke strong emotional experiences by the simultaneous presentation of musi- calandpictorialstimuliofcongruentemotionalvalence.Weuncov- ered enhanced motor-evoked potentials, irrespective

Thomas Baumgartner; Matthias Willi

2007-01-01

251

Neurogenic pain relief by repetitive transcranial magnetic cortical stimulation depends on the origin and the site of pain  

Microsoft Academic Search

Objective: Drug resistant neurogenic pain can be relieved by repetitive transcranial magnetic stimulation (rTMS) of the motor cortex. This study was designed to assess the influence of pain origin, pain site, and sensory loss on rTMS efficacy.Patients and methods: Sixty right handed patients were included, suffering from intractable pain secondary to one of the following types of lesion: thalamic stroke,

J-P Lefaucheur; X Drouot; I Menard-Lefaucheur; F Zerah; B Bendib; P Cesaro; Y Keravel; J-P Nguyen

2004-01-01

252

Using pre-treatment electroencephalography data to predict response to transcranial magnetic stimulation therapy for major depression  

Microsoft Academic Search

We investigate the use of machine learning methods based on the pre-treatment electroencephalograph (EEG) to predict response to repetitive transcranial magnetic stimulation (rTMS), which is a non-pharmacological form of therapy for treating major depressive disorder (MDD). The learning procedure involves the extraction of a large number of candidate features from EEG data, from which a very small subset of most

Ahmad Khodayari-Rostamabad; James P. Reilly; Gary M. Hasey; Hubert de Bruin; Duncan MacCrimmon

2011-01-01

253

Combination of 5 Hz repetitive transcranial magnetic stimulation (rTMS) and tactile coactivation boosts tactile discrimination in humans  

Microsoft Academic Search

A combination of 5 Hz repetitive transcranial magnetic stimulation (rTMS) over the left primary somatosensory cortex together with tactile coactivation applied to the right index-finger representation (coac+rTMS) boosted tactile discrimination ability tested on the right index-finger. Applying coactivation alone caused a 0.25 mm lowering in tactile discrimination thresholds. In contrast, after coac+rTMS we found a significant further improvement of discrimination

Patrick Ragert; Hubert R. Dinse; Burkhard Pleger; Claudia Wilimzig; Elke Frombach; Peter Schwenkreis; Martin Tegenthoff

2003-01-01

254

Spike-timing-related plasticity is preserved in Parkinson's disease and is enhanced by dopamine: Evidence from transcranial magnetic stimulation  

Microsoft Academic Search

We sought to investigate the effects of dopamine on motor cortical plasticity in Parkinson's disease (PD) using a novel interventional transcranial magnetic stimulation protocol that targets spike-timing-dependent plasticity (iTMS). Six patients (3F, mean age 62 years) with mild-moderate PD (mean disease duration 6 years, UPDRS-off 13, UPDRS-on 3, H&Y stage 2, daily levodopa dosage 450mg) were studied off and on

Julian P. Rodrigues; Susan E. Walters; Rick Stell; Frank L. Mastaglia; Gary W. Thickbroom

2008-01-01

255

Increased intracortical inhibition in middle-aged humans; a study using paired-pulse transcranial magnetic stimulation  

Microsoft Academic Search

Using single and paired-pulse transcranial magnetic stimulation we compared the cortical excitability in two different age groups of healthy subjects (mean±SD age: 28.5±5.2 vs. 56.1±4.9 years). Motor evoked potentials were recorded from right extensor and flexor carpi radialis muscles. The effect of paired-pulse stimulation was assessed by the ratio conditioned\\/unconditioned response area with interstimulus intervals of 3 and 13 ms

Andon R Kossev; Christoph Schrader; Jan Däuper; Reinhard Dengler; Jens D Rollnik

2002-01-01

256

Subthreshold 5Hz repetitive transcranial magnetic stimulation of the human primary motor cortex reduces intracortical paired-pulse inhibition  

Microsoft Academic Search

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

Alexander Peinemann; Christian Lehner; Claudia Mentschel; Alexander Münchau; Bastian Conrad; Hartwig Roman Siebner

2000-01-01

257

Lack of effects of low frequency repetitive transcranial magnetic stimulation on alpha rhythm phase synchronization in migraine patients  

Microsoft Academic Search

The study aimed to test the modulation induced by 1Hz repetitive Transcranial Magnetic Stimulation (rTMS) of the occipital cortex on the alpha phase synchronization under repetitive flash stimuli in 15 migraine without aura patients compared to 10 controls. The EEG was recorded by 7 channels, while flash stimuli were delivered at 9, 18, 21 and 24Hz in basal, rTMS (15min

Marina de Tommaso; Sebastiano Stramaglia; Filippo Brighina; Brigida Fierro; Vito Devito Francesco; Orlando Todarello; Claudia Serpino; M. Pellicoro

2011-01-01

258

Changes to cold detection and pain thresholds following low and high frequency transcranial magnetic stimulation of the motor cortex  

Microsoft Academic Search

There is some evidence that repetitive transcranial magnetic stimulation (rTMS) can alleviate the experience of chronic pain. The mechanisms by which rTMS may induce pain relief, however, are unknown. The present study examined whether a session of rTMS would produce sensory threshold changes in healthy individuals. Detection and pain thresholds for cold sensations were compared following low frequency (1Hz) (Experiment

Jeff Summers; Sama Johnson; Saxby Pridmore; Gajinder Oberoi

2004-01-01

259

Two periods of processing in the (circum)striate visual cortex as revealed by transcranial magnetic stimulation  

Microsoft Academic Search

To determine the timing of visual processing in the (circum)striate visual cortex, we examined the effect of single pulse transcranial magnetic stimulation over the occipital pole of healthy subjects who were engaged in a forced-choice visual letter identification task.Single letters, subtending a visual angle of 0.35°, were foveally presented for 10 ms and were immediately followed by a mask. We

Erik Corthout; Bob Uttl; Ulf Ziemann; Alan Cowey; Mark Hallett

1998-01-01

260

Time course of the state-dependent effect of transcranial magnetic stimulation in the TMS-adaptation paradigm  

Microsoft Academic Search

The transcranial magnetic stimulation (TMS)-adaptation paradigm, based on the state-dependency of TMS effects, may become a useful tool for differential stimulation of functionally distinct neural populations within the stimulated region. Here we investigated, in the context of motion perception, the time course of state-dependent TMS effects in this paradigm. After adapting to a motion stimulus, subjects were asked to perform

Zaira Cattaneo; Juha Silvanto

2008-01-01

261

Modulation of the neuronal circuitry subserving working memory in healthy human subjects by repetitive transcranial magnetic stimulation  

Microsoft Academic Search

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

Felix M. Mottaghy; Bernd J. Krause; Lars J. Kemna; Rudolf Töpper; Lutz Tellmann; Markus Beu; Alvaro Pascual-Leone; Hans-Wilhelm Müller-Gärtner

2000-01-01

262

Transcranial magnetic stimulation (TMS) applied to left dorsolateral prefrontal cortex disrupts verbal working memory performance in humans  

Microsoft Academic Search

Working memory refers to the temporary maintenance and processing of information and involves executive processes that manipulate the contents of the working memory. The role of the executive function in the human left dorsolateral prefrontal cortex (LDLPFC) was explored using transcranial magnetic stimulation (TMS) after confirming the LDLPFC activation using fMRI. We applied double-pulse TMS having a 100-ms inter-pulse interval

Naoyuki Osaka; Yuki Otsuka; Nobuyuki Hirose; Takashi Ikeda; Tatsuya Mima; Hidenao Fukuyama; Mariko Osaka

2007-01-01

263

Evaluating the role of prefrontal and parietal cortices in memory-guided response with repetitive transcranial magnetic stimulation  

Microsoft Academic Search

The dorsolateral prefrontal cortex (dlPFC) plays an important role in working memory, including the control of memory-guided response. In this study, with 24 subjects, we used high frequency repetitive transcranial magnetic stimulation (rTMS) to evaluate the role of the dlPFC in memory-guided response to two different types of spatial working memory tasks: one requiring a recognition decision about a probe

Massihullah Hamidi; Giulio Tononi; Bradley R. Postle

2009-01-01

264

Mechanisms of Action Underlying the Effect of Repetitive Transcranial Magnetic Stimulation on Mood: Behavioral and Brain Imaging Studies  

Microsoft Academic Search

In a set of experiments, we applied 10-Hz repetitive transcranial magnetic stimulation (rTMS) over the left mid-dorsolateral frontal cortex (MDLFC) to investigate rTMS-induced changes in affective state and neural activity in healthy volunteers. In Experiment 1, we combined 10-Hz rTMS with a speech task to examine rTMS-induced changes in paralinguistic aspects of speech production, an affect-relevant behavior strongly linked to

Jennifer Barrett; Valeria Della-Maggiore; Philippe A Chouinard; Tomáš Paus

2004-01-01

265

Theta burst transcranial magnetic stimulation for the treatment of auditory verbal hallucinations: Results of a randomized controlled study.  

PubMed

One Hertz (1 Hz) repetitive transcranial magnetic stimulation (rTMS) is an effective therapy for auditory verbal hallucinations (AVH). Theta burst protocols (TBS) show longer after-effects. This single-blind, randomized controlled study compared continuous TBS with 1Hz rTMS in a 10-day treatment. Patients were diagnosed with schizophrenia or schizoaffective disorder. TBS demonstrated equal clinical effects compared to 1Hz TMS. PMID:23648282

Kindler, Jochen; Homan, Philipp; Flury, Richard; Strik, Werner; Dierks, Thomas; Hubl, Daniela

2013-05-04

266

Slow frequency repetitive transcranial magnetic stimulation affects reaction times, but not priming effects, in a masked prime task  

Microsoft Academic Search

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,

F. Schlaghecken; A. Munchau; B. r. Bloem; J. Rothwell; M. Eimer

2003-01-01

267

Transcranial magnetic stimulation as a tool for understanding neurophysiology in Huntington's disease: A review.  

PubMed

Structural and functional magnetic resonance imaging modalities have been critical in advancing our understanding of the neuroanatomical and pathophysiological changes that emerge during the premanifest and symptomatic stages of Huntington's disease (HD). However, the relationship between underlying neuropathology and the motor, cognitive and behavioural changes associated with the disorder still remain poorly understood. Less conventional technologies, such as transcranial magnetic stimulation (TMS) and electroencephalography (EEG), provide a unique opportunity to further investigate the causal relationships between targeted neural circuits and objective neurophysiological responses together with overt behaviours. In this review, we discuss previous successful applications of TMS in other neurological disorders and its prospective use in HD. We also address the added value of multimodal TMS techniques, such as TMS-EEG, in investigating the integrity of neural networks in non-motor regions in HD. We conclude that neurophysiological outcome measures are likely to contribute towards characterising further the trajectory of decline across functional domains in HD, enhance understanding of underlying neural mechanisms, and offer new avenues for elucidating sensitive endophenotypic biomarkers of disease progression. PMID:23727400

Philpott, April L; Fitzgerald, Paul B; Cummins, Tarrant D R; Georgiou-Karistianis, Nellie

2013-05-29

268

Effect of transcranial magnetic stimulation on single-unit activity in the cat primary visual cortex  

PubMed Central

Transcranial magnetic stimulation (TMS) has become a well established procedure for testing and modulating the neuronal excitability of human brain areas, but relatively little is known about the cellular processes induced by this rather coarse stimulus. In a first attempt, we performed extracellular single-unit recordings in the primary visual cortex (area 17) of the anaesthetised and paralysed cat, with the stimulating magnetic field centred at the recording site (2 × 70 mm figure-of-eight coil). The effect of single biphasic TMS pulses, which induce a lateral-to-medial electric current within the occipital pole of the right hemisphere, was tested for spontaneous as well as visually evoked activity. For cat visual cortex we found that a single TMS pulse elicited distinct episodes of enhanced and suppressed activity: in general, a facilitation of activity was found during the first 500 ms, followed thereafter by a suppression of activity lasting up to a few seconds. Strong stimuli exceeding 50 % of maximal stimulator output could also lead to an early suppression of activity during the first 100–200 ms, followed by stronger (rebound) facilitation. Early suppression and facilitation of activity may be related to a more or less direct stimulation of inhibitory and excitatory interneurons, probably with different thresholds. The late, long-lasting suppression is more likely to be related to metabotropic or metabolic processes, or even vascular responses. The time course of facilitation/inhibition may provide clues regarding the action of repetitive TMS application.

Moliadze, Vera; Zhao, Yongqiang; Eysel, Ulf; Funke, Klaus

2003-01-01

269

Cerebral blood flow identifies responders to transcranial magnetic stimulation in auditory verbal hallucinations  

PubMed Central

Auditory hallucinations comprise a critical domain of psychopathology in schizophrenia. Repetitive transcranial magnetic stimulation (TMS) has shown promise as an intervention with both positive and negative reports. The aim of this study was to test resting-brain perfusion before treatment as a possible biological marker of response to repetitive TMS. Twenty-four medicated patients underwent resting-brain perfusion magnetic resonance imaging with arterial spin labeling (ASL) before 10 days of repetitive TMS treatment. Response was defined as a reduction in the hallucination change scale of at least 50%. Responders (n=9) were robustly differentiated from nonresponders (n=15) to repetitive TMS by the higher regional cerebral blood flow (CBF) in the left superior temporal gyrus (STG) (P<0.05, corrected) before treatment. Resting-brain perfusion in the left STG predicted the response to repetitive TMS in this study sample, suggesting this parameter as a possible bio-marker of response in patients with schizophrenia and auditory hallucinations. Being noninvasive and relatively easy to use, resting perfusion measurement before treatment might be a clinically relevant way to identify possible responders and nonresponders to repetitive TMS.

Homan, P; Kindler, J; Hauf, M; Hubl, D; Dierks, T

2012-01-01

270

Cerebral blood flow identifies responders to transcranial magnetic stimulation in auditory verbal hallucinations.  

PubMed

Auditory hallucinations comprise a critical domain of psychopathology in schizophrenia. Repetitive transcranial magnetic stimulation (TMS) has shown promise as an intervention with both positive and negative reports. The aim of this study was to test resting-brain perfusion before treatment as a possible biological marker of response to repetitive TMS. Twenty-four medicated patients underwent resting-brain perfusion magnetic resonance imaging with arterial spin labeling (ASL) before 10 days of repetitive TMS treatment. Response was defined as a reduction in the hallucination change scale of at least 50%. Responders (n=9) were robustly differentiated from nonresponders (n=15) to repetitive TMS by the higher regional cerebral blood flow (CBF) in the left superior temporal gyrus (STG) (P<0.05, corrected) before treatment. Resting-brain perfusion in the left STG predicted the response to repetitive TMS in this study sample, suggesting this parameter as a possible bio-marker of response in patients with schizophrenia and auditory hallucinations. Being noninvasive and relatively easy to use, resting perfusion measurement before treatment might be a clinically relevant way to identify possible responders and nonresponders to repetitive TMS. PMID:23168989

Homan, P; Kindler, J; Hauf, M; Hubl, D; Dierks, T

2012-11-20

271

The influence of sulcus width on simulated electric fields induced by transcranial magnetic stimulation.  

PubMed

Volume conduction models can help in acquiring knowledge about the distribution of the electric field induced by transcranial magnetic stimulation. One aspect of a detailed model is an accurate description of the cortical surface geometry. Since its estimation is difficult, it is important to know how accurate the geometry has to be represented. Previous studies only looked at the differences caused by neglecting the complete boundary between cerebrospinal fluid (CSF) and grey matter (Thielscher et al 2011 NeuroImage 54 234-43, Bijsterbosch et al 2012 Med. Biol. Eng. Comput. 50 671-81), or by resizing the whole brain (Wagner et al 2008 Exp. Brain Res. 186 539-50). However, due to the high conductive properties of the CSF, it can be expected that alterations in sulcus width can already have a significant effect on the distribution of the electric field. To answer this question, the sulcus width of a highly realistic head model, based on T1-, T2- and diffusion-weighted magnetic resonance images, was altered systematically. This study shows that alterations in the sulcus width do not cause large differences in the majority of the electric field values. However, considerable overestimation of sulcus width produces an overestimation of the calculated field strength, also at locations distant from the target location. PMID:23787706

Janssen, A M; Rampersad, S M; Lucka, F; Lanfer, B; Lew, S; Aydin, U; Wolters, C H; Stegeman, D F; Oostendorp, T F

2013-06-21

272

The influence of sulcus width on simulated electric fields induced by transcranial magnetic stimulation  

NASA Astrophysics Data System (ADS)

Volume conduction models can help in acquiring knowledge about the distribution of the electric field induced by transcranial magnetic stimulation. One aspect of a detailed model is an accurate description of the cortical surface geometry. Since its estimation is difficult, it is important to know how accurate the geometry has to be represented. Previous studies only looked at the differences caused by neglecting the complete boundary between cerebrospinal fluid (CSF) and grey matter (Thielscher et al 2011 NeuroImage 54 234–43, Bijsterbosch et al 2012 Med. Biol. Eng. Comput. 50 671–81), or by resizing the whole brain (Wagner et al 2008 Exp. Brain Res. 186 539–50). However, due to the high conductive properties of the CSF, it can be expected that alterations in sulcus width can already have a significant effect on the distribution of the electric field. To answer this question, the sulcus width of a highly realistic head model, based on T1-, T2- and diffusion-weighted magnetic resonance images, was altered systematically. This study shows that alterations in the sulcus width do not cause large differences in the majority of the electric field values. However, considerable overestimation of sulcus width produces an overestimation of the calculated field strength, also at locations distant from the target location.

Janssen, A. M.; Rampersad, S. M.; Lucka, F.; Lanfer, B.; Lew, S.; Aydin, Ü.; Wolters, C. H.; Stegeman, D. F.; Oostendorp, T. F.

2013-07-01

273

Repetitive transcranial magnetic stimulation causes a short-term increase in the duration of the cortical silent period in patients with Parkinson's disease  

Microsoft Academic Search

In ten patients with Parkinson's disease (PD) and ten age-matched healthy controls, we applied 15 30-s trains of subthreshold 5-Hz repetitive transcranial magnetic stimulation (rTMS) over the primary motor hand area. Ten minutes after rTMS, PD patients showed a significant prolongation of the transcranially evoked silent period (SP) in the contralateral first dorsal interosseus muscle, whereas the SP remained unchanged

Hartwig Roman Siebner; Claudia Mentschel; Carola Auer; Christian Lehner; Bastian Conrad

2000-01-01

274

[Computer modelling of electroconvulsive treatment and transcranial magnetic stimulation--an explanation of poor efficacy of the magnetic method].  

PubMed

With help of informatics technology it is possible to simulate various physiological processes in virtual models of biological structures. In a created realistic model of the human head we made some comparative investigations over physical phenomena accompanying the electroconvulsive treatment ECT and transcranial magnetic stimulation TMS--two methods with confirmed (ECT) or presumable (TMS) antidepressant efficacy. The present investigations are a continuation of the earlier conducted study in the simple spherical model of the head. Investigations confirmed, that magnetic stimulation TMS generates a considerably weaker current flow in the brain than it is present in electroconvulsive technique. Applying of such weak stimulation in modus,,at haphazard", i.e. on the brain area which does not need to be metabolically disturbed in this patient--cannot cause an antidepressant effect at all. The results of the investigations explain not only the safety of the magnetic method, but the weak effectiveness of this method. The authors propose some methods for improvement of TMS efficacy. PMID:21449167

Zyss, Tomasz; Krawczyk, Andrzej; Zieba, Andrzej; Dudek, Dominika; Hese, Robert T; Drzyma?a, Pawe?; Wiak, S?awomir; Sawicki, Bartosz; Starzy?ski, Jacek; Szmur?o, Robert; Wincenciak, Stanis?aw

275

Responses of the diaphragm to transcranial magnetic stimulation during wake and sleep in humans.  

PubMed

The human ventilation depends on bulbospinal and corticospinal commands. This study assessed their interactions in five healthy volunteers (two men, age 25-35) through the description of diaphragm and abductor pollicis brevis (APB) motor potentials (DiMEPs, abpMEPs) evoked by transcranial magnetic stimulation (TMS) during relaxed expiration and tidal inspiration and during wake and sleep. NREM decreased corticospinal excitability and REM further did so, for both the diaphragm and the APB. During wake, inspiration shortened supine DiMEPs latencies (expiration 18.56+/-1.90ms; inspiration 17.37+/-1.48ms, P<0.001). This persisted during sleep in an augmented manner (expiration: 21.05+/-1.39ms; inspiration 18.69+/-1.17ms, P=0.002). Inspiration had no effect on apbMEPs during wake and sleep. In conclusion: (1) the tidal bulbospinal input to phrenic motoneurones is sufficient to modulate the throughput of the corticospinal pathway to these neurones; (2) this modulation is best seen after the sleep related removal of corticospinal and/or afferent inputs. PMID:16406377

Mehiri, Selma; Straus, Christian; Arnulf, Isabelle; Attali, Valérie; Zelter, Marc; Derenne, Jean-Philippe; Similowski, Thomas

2006-01-10

276

Sensorimotor Plasticity after Music-Supported Therapy in Chronic Stroke Patients Revealed by Transcranial Magnetic Stimulation  

PubMed Central

Background Several recently developed therapies targeting motor disabilities in stroke sufferers have shown to be more effective than standard neurorehabilitation approaches. In this context, several basic studies demonstrated that music training produces rapid neuroplastic changes in motor-related brain areas. Music-supported therapy has been recently developed as a new motor rehabilitation intervention. Methods and Results In order to explore the plasticity effects of music-supported therapy, this therapeutic intervention was applied to twenty chronic stroke patients. Before and after the music-supported therapy, transcranial magnetic stimulation was applied for the assessment of excitability changes in the motor cortex and a 3D movement analyzer was used for the assessment of motor performance parameters such as velocity, acceleration and smoothness in a set of diadochokinetic movement tasks. Our results suggest that the music-supported therapy produces changes in cortical plasticity leading the improvement of the subjects' motor performance. Conclusion Our findings represent the first evidence of the neurophysiological changes induced by this therapy in chronic stroke patients, and their link with the amelioration of motor performance. Further studies are needed to confirm our observations.

Amengual, Julia L.; Rojo, Nuria; Veciana de las Heras, Misericordia; Marco-Pallares, Josep; Grau-Sanchez, Jennifer; Schneider, Sabine; Vaquero, Lucia; Juncadella, Montserrat; Montero, Jordi; Mohammadi, Bahram; Rubio, Francisco; Rueda, Nohora; Duarte, Esther; Grau, Carles; Altenmuller, Eckart; Munte, Thomas F.; Rodriguez-Fornells, Antoni

2013-01-01

277

Potentiation of quantitative electroencephalograms following prefrontal repetitive transcranial magnetic stimulation in patients with major depression.  

PubMed

The long-lasting effects of repetitive transcranial magnetic stimulation (rTMS) on electroencephalogram (EEG) activity are not clear. We aimed to investigate the cumulative rTMS effects on EEG and clinical outcomes in patients with major depression. Twenty-five patients with medication-resistant depression underwent 10 daily rTMS sessions over the left dorsolateral prefrontal cortex. We measured resting EEG and spectrum-power before and after the rTMS course. Clinical efficacy was evaluated with the Hamilton's Depression Rating Scale (HAM-D) and Wisconsin Card Sorting Test (WCST). In an ANOVA model, including all prefrontal electrodes, post hoc analyses revealed significant time effects on the theta (F1,24=7.89, P=0.010; +43%), delta (F1,24=6.58, P=0.017; +26%), and alpha (F1,24=4.64, P=0.042; 31%) bands without site specificity. Clinical correlations were observed between F4 alpha power increases and improvements in HAM-D retardation, F3 alpha power increases and improvements of the absolute changes in perseveration and error number on the WCST, and C3 and C4 theta power increases and improvements of the percent change in perseveration and error number on the WCST following rTMS. Consecutive prefrontal rTMS could induce long-lasting EEG potentiations beyond the aftereffects, resulting in improved cognitive and depressive symptoms. PMID:23827366

Noda, Yoshihiro; Nakamura, Motoaki; Saeki, Takashi; Inoue, Misa; Iwanari, Hideo; Kasai, Kiyoto

2013-07-01

278

Mapping early changes of cortical motor output after subcortical stroke: a transcranial magnetic stimulation study.  

PubMed

After acute stroke several changes in cortical excitability occur involving affected (AH) and unaffected hemisphere (UH) but whether they contribute to motor recovery is still controversial. We performed transcranial magnetic stimulation mapping of several upper limb muscles over the two hemispheres in thirteen patients at 4-12 days from subcortical stroke and after 1 month. The occurrence of mirror movements (MMs) on the healthy side during contraction of paretic muscles was measured. At baseline, cortical excitability parameters over the AH decreased in comparison with controls, while excitability over the UH increased correlating with severity of motor deficits of the affected arm at baseline as well as with poor recovery. At follow-up, map parameters of the UH became closer to those of controls independently from recovery, while for the AH the number of responsive sites increased significantly. Ipsilateral motor evoked responses (iMEPs) in the affected arm were never elicited. We observed an early impairment in dexterity of the ipsilesional hand that recovered over-time but persistently differed in comparison with controls. MMs occurrence increased at baseline correlating with reduced cortical excitability of the AH as well as with increased map density over the UH. The acute increased excitability of the UH after stroke has a negative prognostic value on recovery and negatively affects motor performance of the ipsilesional hand. Moreover, the absence of iMEPs and the normalization of motor cortical excitability at follow-up indicate that the UH primary motor area does not contribute to recovery. PMID:22776700

Chieffo, Raffaella; Inuggi, Alberto; Straffi, Laura; Coppi, Elisabetta; Gonzalez-Rosa, Javier; Spagnolo, Francesca; Poggi, Antonella; Comi, Giancarlo; Comola, Mauro; Leocani, Letizia

2012-06-28

279

Therapeutic Effects of Individualized Alpha Frequency Transcranial Magnetic Stimulation (?TMS) on the Negative Symptoms of Schizophrenia  

PubMed Central

Previous research in clinical electroencephalography (EEG) has demonstrated that reduction of alpha frequency (8–13 Hz) EEG activity may have particular relevance to the negative symptoms of schizophrenia. Repetitive Transcranial Magnetic Stimulation (rTMS) was utilized to investigate this relationship by assessing the therapeutic effects of stimulation set individually at each subject's peak alpha frequency (?TMS). Twenty-seven subjects, with predominantly negative symptom schizophrenia, received 2 weeks of daily treatment with either ?TMS, 3 Hz, 20 Hz, or sham stimulation bilaterally over the dorsolateral prefrontal cortex. Individualized ?TMS demonstrated a significantly larger (F 3,33 = 4.7, p = .007) therapeutic effect (29.6% reduction in negative symptoms) than the other 3 conditions (< 9%). Furthermore, these clinical improvements were found to be highly correlated (r = 0.86, p = .001) with increases (34%) in frontal alpha amplitude following ?TMS. These results affirm that the resonant features of alpha frequency EEG play an important role in the pathophysiology of schizophrenia and merit further investigation as a particularly efficacious frequency for rTMS treatments.

Jin, Yi; Potkin, Steven G.; Kemp, Aaron S.; Huerta, Steven T.; Alva, Gustavo; Thai, Trung Minh; Carreon, Danilo; Bunney, William E.

2006-01-01

280

Transcranial magnetic stimulation for the prediction and enhancement of rehabilitation treatment effects  

PubMed Central

In this update on rehabilitation technology, transcranial magnetic stimulation (TMS), a technique that allows non-invasive stimulation of the brain, is examined. The background and basic principles of TMS are reviewed and its usefulness as a tool to inform and possibly augment the rehabilitation process is discussed. The 3 main paradigms by which TMS is applied, 1) physiological measurement, 2) disruption/virtual lesion studies and 3) modulation of cortical excitability, are discussed relative to the types of scientific information each paradigm can provide and their potential clinical usefulness in the future. One of the more exciting prospects is that, when combined with rehabilitation training, TMS modulation of cortical excitability could potentially enhance the effects of rehabilitation and lead to greater levels of recovery than are currently attainable with rehabilitation alone. It is concluded that current studies must focus on the mechanisms of recovery based on the specific structures and processes affected by the disorder and the neural effects of specific rehabilitation interventions in order for the potential of TMS-augmented rehabilitation to be realized.

Harris-Love, Michelle

2012-01-01

281

Safety of Theta Burst Transcranial Magnetic Stimulation: A systematic review of the literature  

PubMed Central

Theta Burst Stimulation (TBS) protocols have recently emerged as a method to transiently alter cortical excitability in the human brain through repetitive transcranial magnetic stimulation (rTMS). TBS involves applying short trains of stimuli at high frequency repeated at intervals of 200ms. Because rTMS is known to carry a risk of seizures, safety guidelines have been established. TBS has the theoretical potential of conferring an even higher risk of seizure than other rTMS protocols because it delivers high frequency bursts. In light of the recent report of a seizure induced by TBS, the safety of this new protocol deserves consideration. We performed an English language literature search, and reviewed all studies published from May 2004-December 2009 in which TBS was applied. The adverse events were documented and crude risk was calculated. The majority of adverse events attributed to TBS were mild and occurred in 5% of subjects. Based on this review, TBS appears to be a safe and efficacious technique. However, given its novelty, it should be applied with caution. Additionally, this review highlights the need for rigorous documentation of adverse events associated with TBS, as well as intensity dosing studies to assess the seizure risk associated with various stimulation parameters (e.g. frequency, intensity, location).

Oberman, Lindsay; Edwards, Dylan; Eldaief, Mark; Pascual-Leone, Alvaro

2011-01-01

282

Recurrent CSPs after Transcranial Magnetic Stimulation of Motor Cortex in Restless Legs Syndrome  

PubMed Central

Aims. The aim of this study was to investigate the motor control and central silent period (CSP) in restless legs syndrome (RLS). Methods. Transcranial magnetic stimulation was focused on the dominant and nondominant hemispheric areas of motor cortex in six subjects with RLS and six controls. The responses were recorded on the contralateral abductor digiti minimi (ADM) and tibialis anterior (TA) muscles with intramuscular needle electrodes. Results. No significant differences were found in the motor conduction or central motor conduction time, in the latency, or in the duration of the CSPs between or within the groups, but multiple CSPs were observed in both groups. The number of the CSPs was significantly higher in both ADMs and in the dominant TA (P ? 0.01) in the RLS group compared to the controls. Conclusion. Descending motor pathways functioned correctly in both groups. The occurrence of the recurrent CSPs predominantly in the RLS group could be a sign of a change of function in the inhibitory control system. Further research is needed to clarify the role of the intramuscular recording technique and especially the role of the subcortical generators in the feedback regulation of the central nervous system in RLS.

Ahlgren-Rimpilainen, Aulikki; Lauerma, Hannu; Kahkonen, Seppo; Markkula, Juha; Rimpilainen, Ilpo

2012-01-01

283

Accelerated repetitive transcranial magnetic stimulation (aTMS) for treatment-resistant depression  

PubMed Central

Background Repetitive transcranial magnetic stimulation (rTMS) has shown safety and efficacy for treatment-resistant depression (TRD) but requires daily treatment over 4–6 weeks. Accelerated TMS, with all treatments delivered over a few days, would have significant advantages in terms of access and patient acceptance. Methods Open-label accelerated TMS (aTMS), consisting of 15 rTMS sessions administered over 2 days, was tested in 14 depressed patients not responding to at least one antidepressant medication. Effects on depression, anxiety and cognition were assessed the day following treatment, then after 3 and 6 weeks. Results No seizure activity was observed, and only one patient had a serious adverse event (increased suicidal ideation). Two patients failed to complete a full course of aTMS treatments, and 36% did not complete all study visits. Depression and anxiety significantly decreased following aTMS treatments, and improvements persisted 3 and 6 weeks later. Response rates immediately following treatment, and at 3 and 6 weeks, were 43%, 36% and 36%, respectively. Remission rates at the same timepoints were 29%, 36% and 29%. Conclusions Accelerated TMS demonstrated an excellent safety profile with efficacy comparable to that achieved daily rTMS in other trials. Limitations primarily include open-label treatment and a small sample size.

Holtzheimer, Paul E.; McDonald, William M.; Mufti, Mustafa; Kelley, Mary E.; Quinn, Sinead; Corso, German; Epstein, Charles M.

2010-01-01

284

An Open Study of Repetitive Transcranial Magnetic Stimulation in Treatment-Resistant Depression with Parkinson's Disease  

PubMed Central

Objective Major depression is a common concomitant of chronic central nervous system disorders, notably Parkinson’s disease (PD). Repetitive transcranial magnetic stimulation (rTMS) has been investigated as a potential treatment for depression in PD and for the movement disorder of PD, but comprehensive testing in multiple areas of performance has seldom been carried out within a single study. We studied the effect of left dorsolateral prefrontal rTMS on several different functional domains. Methods Fourteen PD patients with treatment-resistant depression entered an open, 10-day inpatient study of 10-Hertz rTMS, undergoing extensive psychiatric, neuropsychological, and motor testing from baseline to 6 weeks after treatment. Motor testing included a defined “off” state. Results rTMS was well-tolerated. Highly significant improvement in depression scores was seen three days and 3-6 weeks after treatment. Improvement was also found in anxiety, movement scores (especially in the off state), and some neuropsychological measures. We found no evidence of increased risk from rTMS in this population. Conclusions Further controlled trials of rTMS in PD appear worthwhile, and should include a defined “off” state. Significance TMS may be beneficial for depressed PD patients in multiple functional domains.

Epstein, Charles M.; Evatt, Marian L.; Funk, Agnes; Girard-Siqueira, Lhys; Lupei, Nichole; Slaughter, Larisa; Athar, Saima; Green, Joanne; McDonald, William; DeLong, Mahlon R.

2007-01-01

285

Quantifying uncertainty in Transcranial Magnetic Stimulation - A high resolution simulation study in ICBM space.  

PubMed

Transcranial Magnetic Stimulation offers enormous potential for noninvasive brain stimulation. While it is known that brain tissue significantly "reshapes" induced field and charge distributions, most modeling investigations to-date have focused on single-subject data with limited generality. Further, the effects of the significant uncertainties which exist in the simulation (i.e. brain conductivity distributions) and stimulation (e.g. coil positioning and orientations) setup have not been quantified. In this study, we construct a high-resolution anisotropic head model in standard ICBM space, which can be used as a population-representative standard for bioelectromagnetic simulations. Further, we employ Monte-Carlo simulations in order to quantify how uncertainties in conductivity values propagate all the way to induced field and currents, demonstrating significant, regionally dependent dispersions in values which are commonly assumed "ground truth". This framework can be leveraged in order to quantify the effect of any type of uncertainty in noninvasive brain stimulation and bears relevance in all applications of TMS, both investigative and therapeutic. PMID:23366117

Toschi, Nicola; Keck, Martin E; Welt, Tobias; Guerrisi, Maria

2012-01-01

286

Citalopram for continuation therapy following repetitive transcranial magnetic stimulation (rTMS) in vascular depression  

PubMed Central

Objectives We previously reported that repetitive transcranial magnetic stimulation (rTMS) produced a response rate of 39.4% among 62 patients with treatment resistant vascular depression. The current study was undertaken to assess the outcome of continuation therapy to prevent relapse among these patients during 9 weeks after completion of rTMS. Design Patients were randomly assigned to 18,000 pulses of rTMS given over 3 weeks or sham treatment using double blind methods. Following rTMS, all patients were given 20 mg per day of citalopram for 9 weeks and reevaluated at 3, 6 and 9 weeks. Setting Outpatient continuation treatment trial. Participants Patients with vascular depression (n=62), as determined by MRI hyperintensities and/or 3 or more clinical risk factors for vascular disease without other major medical illness, were recruited. They had onset of major depression after age 50 and failed at least one trial of antidepressants. Intervention Following rTMS or sham treatment, all treatment responders were given citalopram for 9 weeks. Results Among the 33 patients given rTMS, 13 responded (i.e. >50% decline in Hamilton Depression Scale score). Of these 13, all completed the 9 weeks of continuation treatment. There were 9 patients who continued to be responders and 4 who had a relapse of depression. Conclusion More effective methods are needed to treat elderly patients with treatment resistant vascular depression and to prevent relapse among treatment responders.

Tenev, Veselin; Robinson, Robert G.; Jorge, Ricardo E.

2009-01-01

287

Assessing temporal processing of facial emotion perception with transcranial magnetic stimulation  

PubMed Central

The ability to process facial expressions can be modified by altering the spatial frequency of the stimuli, an effect that has been attributed to differential properties of visual pathways that convey different types of information to distinct brain regions at different speeds. While this effect suggests a potential influence of spatial frequency on the processing speed of facial emotion, this hypothesis has not been examined directly. We addressed this question using a facial emotion identification task with photographs containing either high spatial frequency (HSF), low spatial frequency (LSF), or broadband spatial frequency (BSF). Temporal processing of emotion perception was manipulated by suppressing visual perception with a single-pulse transcranial magnetic stimulation (TMS), delivered to the visual cortex at six intervals prior to (forward masking) or following (backward masking) stimulus presentation. Participants performed best in the BSF, followed by LSF, and finally HSF condition. A spatial frequency by forward/backward masking interaction effect demonstrated reduced performance in the forward masking component in the BSF condition and a reversed performance pattern in the HSF condition, with no significant differences between forward and backward masking in the LSF condition. Results indicate that LSF information may play a greater role than HSF information in emotional processing, but may not be sufficient for fast conscious perception of emotion. As both LSF and HSF filtering reduced the speed of extracting emotional information from faces, it is possible that intact BSF faces have an inherent perceptual advantage and hence benefit from faster temporal processing.

Rassovsky, Yuri; Lee, Junghee; Nori, Poorang; D Wu, Allan; Iacoboni, Marco; Breitmeyer, Bruno G; Hellemann, Gerhard; Green, Michael F

2013-01-01

288

Two means of suppressing visual awareness: a direct comparison of visual masking and transcranial magnetic stimulation.  

PubMed

Visual masking and visual suppression by transcranial magnetic stimulation (TMS) are both widely utilized in cognitive neuroscience to investigate a wide range of processes. However, the neural processes affected by visual masking and TMS remain unclear. We compared para- and metacontrast masking with TMS-induced suppression of visibility in a within-subjects design where participants were asked to detect and rate the visibility of a stimulus. TMS pulses applied 75-109 msec after the onset of the visual stimulus reduced the subjective visibility of the target. Even when the TMS pulses completely eliminated the conscious perception of the target, unconscious location detection was possible. The visual masking condition yielded similar results: metacontrast did not eliminate unconscious location detection even when the target was reported not seen at all. As the first target-related signals were likely to reach the visual cortex before TMS pulses started to modulate target visibility, we suggest that TMS and metacontrast masking affected neural signals subsequent to the target's transient onset-response. This implies that a preserved onset-response is sufficient for unconscious processing of stimulus attributes, but not for conscious perception. PMID:21232737

Railo, Henry; Koivisto, Mika

2010-12-16

289

Neuronavigated transcranial magnetic stimulation suggests that area V2 is necessary for visual awareness.  

PubMed

The primary visual cortex (V1) has been shown to be critical for visual awareness, but the importance of other low-level visual areas has remained unclear. To clarify the role of human cortical area V2 in visual awareness, we applied transcranial magnetic stimulation (TMS) over V2 while participants were carrying out a visual discrimination task and rating their subjective awareness. Individual retinotopic maps and modelling of the TMS-induced electric field in V1, V2 and V3d ensured that the electric field was at or under the phosphene threshold level in V1 and V3d, whereas in V2 it was at the higher suppressive level. As earlier shown for the V1, our results imply that also V2 is necessary for conscious visual experience. Visual awareness of stimulus presence was completely suppressed when the TMS pulse was delivered 44-84 ms after the onset of visual stimulus. Visual discrimination and awareness of stimulus features was impaired when the TMS pulse was delivered 44-104 ms after the visual stimulus onset. These results suggest that visual awareness cannot be generated without an intact V2. PMID:22465860

Salminen-Vaparanta, Niina; Koivisto, Mika; Noreika, Valdas; Vanni, Simo; Revonsuo, Antti

2012-03-24

290

What have We Learned from "Perturbing" the Human Cortical Motor System with Transcranial Magnetic Stimulation?  

PubMed Central

The purpose of this paper is twofold. First, we will review different approaches that one can use with transcranial magnetic stimulation (TMS) to study both its effects on motor behavior and on neural connections in the human brain. Second, we will present evidence obtained in TMS-based studies showing that the dorsal premotor area (PMd), the ventral premotor area (PMv), the supplementary motor area (SMA), and the pre-supplementary motor area (pre-SMA) each have different roles to play in motor behavior. We highlight the importance of the PMd in response selection based on arbitrary cues and in the control of arm movements, the PMv in grasping and in the discrimination of bodily actions, the SMA in movement sequencing and in bimanual coordination, and the pre-SMA in cognitive control. We will also discuss ways in which TMS can be used to chart “true” cerebral reorganization in clinical populations and how TMS might be used as a therapeutic tool to facilitate motor recovery after stroke. We will end our review by discussing some of the methodological challenges and future directions for using this tool in basic and clinical neuroscience.

Chouinard, Philippe A.; Paus, Tomas

2010-01-01

291

Stochastic resonance effects reveal the neural mechanisms of transcranial magnetic stimulation  

PubMed Central

Transcranial magnetic stimulation (TMS) is a popular method for studying causal relationships between neural activity and behavior. However its mode of action remains controversial, and so far there is no framework to explain its wide range of facilitatory and inhibitory behavioral effects. While some theoretical accounts suggests that TMS suppresses neuronal processing, other competing accounts propose that the effects of TMS result from the addition of noise to neuronal processing. Here we exploited the stochastic resonance phenomenon to distinguish these theoretical accounts and determine how TMS affects neuronal processing. Specifically, we showed that online TMS can induce stochastic resonance in the human brain. At low intensity, TMS facilitated the detection of weak motion signals but with higher TMS intensities and stronger motion signals we found only impairment in detection. These findings suggest that TMS acts by adding noise to neuronal processing, at least in an online TMS protocol. Importantly, such stochastic resonance effects may also explain why TMS parameters that under normal circumstances impair behavior, can induce behavioral facilitations when the stimulated area is in an adapted or suppressed state.

Schwarzkopf, Dietrich Samuel; Silvanto, Juha; Rees, Geraint

2011-01-01

292

Disruption of Saccadic Adaptation with Repetitive Transcranial Magnetic Stimulation of the Posterior Cerebellum in Humans  

PubMed Central

Saccadic eye movements are driven by motor commands that are continuously modified so that errors created by eye muscle fatigue, injury, or—in humans—wearing spectacles can be corrected. It is possible to rapidly adapt saccades in the laboratory by introducing a discrepancy between the intended and actual saccadic target. Neurophysiological and lesion studies in the non-human primate as well as neuroimaging and patient studies in humans have demonstrated that the oculomotor vermis (lobules VI and VII of the posterior cerebellum) is critical for saccadic adaptation. We studied the effect of transiently disrupting the function of posterior cerebellum with repetitive transcranial magnetic stimulation (rTMS) on the ability of healthy human subjects to adapt saccadic eye movements. rTMS significantly impaired the adaptation of the amplitude of saccades, without modulating saccadic amplitude or variability in baseline conditions. Moreover, increasing the intensity of rTMS produced a larger impairment in the ability to adapt saccadic size. These results provide direct evidence for the role of the posterior cerebellum in man and further evidence that TMS can modulate cerebellar function.

Miall, R. Chris

2010-01-01

293

Transcranial magnetic stimulation and brain atrophy: a computer-based human brain model study  

PubMed Central

This paper is aimed at exploring the effect of cortical brain atrophy on the currents induced by transcranial magnetic stimulation (TMS). We compared the currents induced by various TMS conditions on several different MRI derived finite element head models of brain atrophy, incorporating both decreasing cortical volume and widened sulci. The current densities induced in the cortex were dependent upon the degree and type of cortical atrophy and were altered in magnitude, location, and orientation when compared to healthy head models. Predictive models of the degree of current density attenuation as a function of the scalp-to-cortex distance were analyzed, concluding that those which ignore the electromagnetic field–tissue interactions lead to inaccurate conclusions. Ultimately, the precise site and population of neural elements stimulated by TMS in an atrophic brain cannot be predicted based on healthy head models which ignore the effects of the altered cortex on the stimulating currents. Clinical applications of TMS should be carefully considered in light of these findings.

Eden, Uri; Fregni, Felipe; Valero-Cabre, Antoni; Ramos-Estebanez, Ciro; Pronio-Stelluto, Valerie; Grodzinsky, Alan; Zahn, Markus; Pascual-Leone, Alvaro

2012-01-01

294

Chronometry of parietal and prefrontal activations in verbal working memory revealed by transcranial magnetic stimulation.  

PubMed

We explored the temporal dynamics of parietal and prefrontal cortex involvement in verbal working memory employing single-pulse transcranial magnetic stimulation (TMS). In six healthy volunteers the left or right inferior parietal and prefrontal cortex was stimulated with the aid of a frameless stereotactic system. TMS was applied at 10 different time points 140-500 ms into the delay period of a two-back verbal working memory task. A choice reaction task was used as a control task. Interference with task accuracy was induced by TMS earlier in the parietal cortex than in the prefrontal cortex and earlier over the right than the left hemisphere. This suggests a propagation of information flow from posterior to anterior cortical sites converging in the left prefrontal cortex. Significant interference with reaction time was observed after 180 ms with left prefrontal cortex stimulation. These effects were not observed in the control task, underlining the task specificity of our results. We propose that the interference with right-sided prefrontal cortex stimulation leads to impaired performance due to disturbed input into the left prefrontal cortex, whereas left-sided TMS interferes directly with the final information processing. Left- and right-sided brain areas might be involved in parallel processing of semantic and object features of the stimuli, respectively. PMID:12667834

Mottaghy, F M; Gangitano, M; Krause, B J; Pascual-Leone, A

2003-03-01

295

Dissociable networks control conflict during perception and response selection: a transcranial magnetic stimulation Study.  

PubMed

Current models of conflict processing propose that cognitive control resolves conflict in the flanker task by enhancing task-relevant stimulus processing at a perceptual level. However, because conflicts occur at both a perceptual and a response selection level in that task, we tested the hypothesis of conflict-specific control networks for perceptual and response selection conflicts using transcranial magnetic stimulation (TMS). TMS of the presupplementary motor area selectively disrupted the processing of response selection conflict, whereas TMS of the posterior intraparietal sulcus/inferior parietal lobule interfered with perceptual conflict processing. In more detail, the presupplementary motor area seems to resolve response selection conflict mainly when no conflicts have occurred in the previous trial. In contrast, the posterior intraparietal sulcus/inferior parietal lobule may resolve perceptual conflicts selectively when a conflict has occurred in the previous trial. The current data show the need for revising models of cognitive control by providing evidence for the existence of conflict-specific control networks resolving conflict at different processing levels. PMID:23536079

Soutschek, Alexander; Taylor, Paul C J; Müller, Hermann J; Schubert, Torsten

2013-03-27

296

Can transcranial magnetic stimulation be used to evaluate patients with narcolepsy?  

PubMed

Narcolepsy is a rare, chronic sleep disorder characterized by excessive daytime sleepiness, cataplexy and other manifestations of dissociated rapid eye movement in sleep. We assessed the utility of transcranial magnetic stimulation (TMS) as an objective tool to elucidate the cortical excitability changes and also to analyze its role in assessing the treatment efficacy in narcolepsy. Eight patients with narcolepsy under our regular follow-up from 2000 to 2009 at our Sleep disorder clinic were chosen. All of them underwent polysomnography, multiple sleep latency tests and TMS. Resting motor threshold (RMT), cortical silent period (CSP) and central motor conduction time (CMCT) were assessed using TMS in both drug-naïve and post-treatment states. Eight controls were also subjected to all the three investigations. Appropriate statistical methods were used. The mean RMT (%) pre-treatment was higher in narcolepsy patients than that in controls, and it normalized following treatment. CSP and CMCT were unaffected in narcolepsy patients as compared to controls. This study shows that the cortical excitability is significantly low in narcolepsy patients. This motor cortex hypoexcitability becomes normal with the institution of treatment, pari passu with the control of symptoms. In future, TMS may be considered as an effective tool for documenting the treatment efficacy in patients with narcolepsy. PMID:23192441

Vijayakumari, Anupa A; Khan, Fayaz R; Varma, Ravi Prasad; Radhakrishnan, Ashalatha

2012-11-29

297

Motor neuron disease: usefulness of transcranial magnetic stimulation in improving the diagnosis.  

PubMed

Clinical upper motor neuron (UMN) involvement is sometimes difficult to detect in motor neuron disease (MND). For this reason we performed transcranial magnetic stimulation (TMS) to find out whether this technique may be useful in revealing signs of pyramidal tract impairment. Fifty-five MND patients, clinically divided into 22 amyotrophic lateral sclerosis (ALS), 18 ALS with probable UMN signs (ALS-PUMNS), 10 pure lower motor neuron syndrome (LMNS), and 5 progressive bulbar palsy (PBP), underwent standard TMS, recording from abductor digiti minimi and flexor allucis muscles. Prolongation of cortical motor evoked potential (MEP) latency and central conduction time (CCT) and absent MEP were considered as pathologic. ALS-PUMNS and LMNS patients were clinically reclassified after 1 year. TMS was abnormal in 95.4% of ALS, 72.2% of ALS-PUMNS, 50% of LMNS and 20% of PBP. Correlations between TMS parameters and both clinical signs of UMN involvement and disease severity were highly significant. TMS showed a high sensitivity, but lacked specificity. After 1 year, 11 patients among the ALS-PUMNS group were clinically reclassified as definite ALS: all of them had shown TMS abnormalities at the first examination. In conclusion, TMS provides important diagnostic information for an early prediction of ALS in those MND patients presenting with clinically equivocal UMN impairment. PMID:10400213

Miscio, G; Pisano, F; Mora, G; Mazzini, L

1999-05-01

298

Efficacy of repetitive transcranial magnetic stimulation in the treatment of patients with chronic primary insomnia.  

PubMed

This study assessed the efficacy of repetitive transcranial magnetic stimulation (rTMS) in the treatment of patients with chronic primary insomnia. Hundred and twenty patients with chronic primary insomnia were randomly assigned to three study groups (n = 40 per group): rTMS, medication, or psychotherapy treatment (both latter as controls). The treatments proceeded for 2 weeks, after which treatment efficacies were assessed in each study group based on changes in polysomnography parameters, Pittsburgh sleep quality index, and indices of HPA and HPT axes (serum cortisol, adrenocorticotropic hormone, highly sensitive thyrotropin, free T3, and free T4). Further, the relapse and recurrence rates within 3 months after respective treatments were also measured. rTMS treatment significantly better (p < 0.05) improved stage III sleep and REM sleep cycle compared with both control groups. Further, rTMS treatment group was more advantageous in improving the indices of HPA and HPT axes (p < 0.05 vs. both control groups). In addition, the relapse and recurrence rates were also the lowest in rTMS treatment group. In conclusion, rTMS treatment is more advantageous than both medication and psychotherapy treatments in improving the sleep architecture. Further, rTMS significantly decreases the body awakening level and provides a better long-term treatment effect. PMID:23797608

Jiang, Cheng-gang; Zhang, Ting; Yue, Fa-guo; Yi, Ming-ling; Gao, Dong

2013-09-01

299

Effects of repetitive transcranial magnetic stimulation on clinical, social, and cognitive performance in postpartum depression  

PubMed Central

Background: This randomized, placebo-controlled, double-blind pilot study evaluated the impact of repetitive transcranial magnetic stimulation (rTMS) on clinical, cognitive, and social performance in women suffering with postpartum depression. Methods: Fourteen patients were randomized to receive 20 sessions of sham rTMS or active 5 Hz rTMS over the left dorsolateral prefrontal cortex. Psychiatric clinical scales and a neuropsychological battery were applied at baseline (pretreatment), week 4 (end of treatment), and week 6 (follow-up, posttreatment week 2). Results: The active rTMS group showed significant improvement 2 weeks after the end of rTMS treatment (week 6) in Hamilton Depression Rating Scale (P = 0.020), Global Assessment Scale (P = 0.037), Clinical Global Impression (P = 0.047), and Social Adjustment Scale-Self Report-Work at Home (P = 0.020). Conclusion: This study suggests that rTMS has the potential to improve the clinical condition in postpartum depression, while producing marginal gains in social and cognitive function.

Myczkowski, Martin Luiz; Dias, Alvaro Machado; Luvisotto, Tatiana; Arnaut, Debora; Bellini, Bianca Boura; Mansur, Carlos Gustavo; Renno, Joel; Tortella, Gabriel; Ribeiro, Philip Leite; Marcolin, Marco Antonio

2012-01-01

300

Can sleep disturbance in depression predict repetitive transcranial magnetic stimulation (rTMS) treatment response?  

PubMed

Treatment for depression is not effective in all patients and it is therefore important to identify factors that can be used to tailor treatments. One potential factor is insomnia. Several repetitive transcranial magnetic stimulation (rTMS) studies have reported on this symptom, however, they did not take into account the presence of hypersomnia or that insomnia was related to their outcome measure. Our aim was to investigate whether baseline sleep disruption was related to rTMS treatment response. We pooled data from four clinical trials using rTMS to treat depression, including 139 subjects in data analysis. Insomnia was measured using the Hamilton Depression Rating Scale (HamD) sleep questions and hypersomnia from the Beck Depression Inventory (BDI). To reduce the possible impact of insomnia on our treatment response outcome we created an adjusted HamD score which omitted sleep items. Sleep disturbances were common in our study: 66% had insomnia and 38% hypersomnia. Using regression analysis with our adjusted HamD score we found no relation between baseline insomnia or hypersomnia and rTMS treatment response. Our data are consistent with previous studies; however, this is the first rTMS study to our knowledge that has attempted to dissociate baseline insomnia from the HamD outcome measure and to report no relationship between hypersomnia and rTMS outcome. PMID:23726870

Lowe, Alex; Rajaratnam, Shantha M W; Hoy, Kate; Taffe, John; Fitzgerald, Paul B

2013-05-30

301

The effects of propofol on rat transcranial magnetic motor evoked potentials.  

PubMed

INTRAOPERATIVE MONITORING OF motor evoked potentials (MEPs) may become a valuable test of spinal cord function during surgery. Unfortunately, MEP responses are affected by most common anesthetics. We studied the effect of intravenous propofol on transcranial magnetic MEPs (tcMMEPs) in the rat. Baseline tcMMEPs were recorded before administration of the drug. Each rat then received three induction doses of propofol, 10, 5, and 5 mg/kg (totaling 10, 15, and 20 mg/kg) and three successive 20-minute infusion doses at rates of 10, 20, and 40 mg/kg/h, respectively. An MEP intensity series was performed after each induction dose, during each infusion, and during a 20-minute recovery period. tcMMEPs recorded during the induction period demonstrated a significant, dose-dependent increase in onset latency and a marked decrease in amplitude. Infusion tcMMEPs displayed increased onset latencies but demonstrated a significant change in amplitudes only after the largest infusion dose. The MEPs approached baseline levels after discontinuation of the propofol. This study demonstrates that tcMMEPs can be successfully recorded from the rat during propofol anesthesia. PMID:8559347

Fishback, A S; Shields, C B; Linden, R D; Zhang, Y P; Burke, D

1995-11-01

302

Corticospinal facilitation during observation of graspable objects: a transcranial magnetic stimulation study.  

PubMed

In 1979, Gibson first advanced the idea that the sight of graspable objects automatically activates in the observer the repertoire of actions necessary to interact with them, even in the absence of any intention to act ("affordance effect"). The neurophysiological substrate of this effect was later identified in a class of bimodal neurons, the so-called "canonical" neurons, located within monkey premotor cortex. In humans, even if different behavioral studies supported the existence of affordance effect, neurophysiological investigations exploring its neural substrates showed contradictory results. Here, by means of Transcranial Magnetic Stimulation (TMS), we explored the time-course of the "affordance effect" elicited by the observation of everyday-life graspable objects on motor cortex of resting observers. We recorded motor evoked potentials (MEP) from three intrinsic hand muscles (two "synergic" for grasping, OP and FDI and one "neutral", ADM). We found that objects' vision determined an increased excitability at 120 milliseconds after their presentation. Moreover, this modulation was proved to be specific to the cortical representations of synergic muscles. From an evolutionary perspective, this timing perfectly fits with a fast recruitment of the motor system aimed at rapidly and accurately choosing the appropriate motor plans in a competitive environment filled with different opportunities. PMID:23145052

Franca, Michele; Turella, Luca; Canto, Rosario; Brunelli, Nicola; Allione, Luisa; Andreasi, Nico Golfré; Desantis, Marianna; Marzoli, Daniele; Fadiga, Luciano

2012-11-08

303

The influence of hand posture on corticospinal excitability during motor imagery: a transcranial magnetic stimulation study.  

PubMed

In order to study the interaction between proprioceptive information and motor imagery, we herein investigate how compatible and incompatible postural signals influence corticospinal excitability during the mental simulation of hand movements. Subjects were asked to imagine themselves joining the tips of the thumb and the little finger while they maintained one of the two following hand postures: posture A (PA, compatible), little finger, index and thumb extended, the remaining fingers flexed; or posture B (PB, incompatible), index and thumb extended, other fingers flexed. All subjects rated the imagined finger opposition movements as easier to perform when the hand was kept in PA than in PB (P < 0.01) and the correlation between the duration of motor imagery and movement execution was also higher for PA than PB (P < 0.01). For each posture, motor evoked potentials (MEPs) elicited by focal transcranial magnetic stimulation (TMS) of the left motor cortex were recorded from the right opponens pollicis muscle during both motor imagery (MI) and rest (R) conditions. MEP area varied according to the hand posture: PA induced a higher increase in corticospinal excitability, when compared with PB. These results indicate that the actual limb posture affects the process of motor imagery. The source of this postural modulation effect is discussed. PMID:15142965

Vargas, C D; Olivier, E; Craighero, L; Fadiga, L; Duhamel, J R; Sirigu, A

2004-05-13

304

First preoperative functional mapping via navigated transcranial magnetic stimulation in a 3-year-old boy.  

PubMed

Preoperative functional mapping in children younger than 5 years old remains a challenge. Awake functional MRI (fMRI) is usually not an option for these patients. Except for a description of passive fMRI in sedated patients and magnetoencephalography, no other noninvasive mapping method has been reported as a preoperative diagnostic tool in children. Therefore, invasive intraoperative direct cortical stimulation remains the method of choice. To the authors' knowledge, this is the first case of a young child undergoing preoperative functional motor cortex mapping with the aid of navigated transcranial magnetic stimulation (nTMS). In this 3-year-old boy with a rolandic ganglioglioma, awake preoperative mapping was performed using nTMS. A precise location of Broca area 4 could be established. The surgical approach was planned according to the preoperative findings. Intraoperative direct cortical stimulation verified the location of the nTMS hotspots, and complete resection of the precentral tumor was achieved. Navigated TMS is a precise tool for preoperative motor cortex mapping and is feasible even in very young pediatric patients. In children for whom performing the fMRI motor paradigm is challenging, nTMS is the only available option for functional mapping. PMID:22656259

Coburger, Jan; Karhu, Jari; Bittl, Markus; Hopf, Nikolai J

2012-06-01

305

Kernohan's notch phenomenon demonstrated by diffusion tensor imaging and transcranial magnetic stimulation.  

PubMed

Kernohan's notch phenomenon is the ipsilateral hemiplegia caused by compression of the contralateral cerebral peduncle against the tentorial edge by a supratentorial mass. Diffusion tensor imaging (DTI) and transcranial magnetic stimulation (TMS) could be useful for exploring the state of the corticospinal tract (CST). This report attempts to demonstrate Kernohan's notch phenomenon in a patient with subdural haematoma by using DTI and TMS. One patient and six normal control subjects were recruited. The patient showed severe right hemiplegia even though the subdural haematoma was located in the right hemisphere. Brain CT at the time of onset showed right transtentorial herniation, and T2 weighted images at 6 weeks after onset showed a leucomalacic lesion on the left cerebral peduncle. DTI and TMS were performed at 6 weeks after onset. The fractional anisotrophy value of the left midbrain and medulla of the patient was found to be decreased in comparison with that of the control subjects. On fibre tractography for the CST, an interruption was observed in the left midbrain and medulla. The motor evoked potential obtained from the right hand muscle showed delayed latency, low amplitude and a higher excitatory threshold, thus indicating that the CST of the left hemisphere had been damaged. It seems that the CST had been damaged at the left midbrain, although subdural haematoma and transtentorial herniation had occurred in the right hemisphere in this patient. This report demonstrates Kernohan's notch phenomenon in this patient using DTI and TMS. PMID:18940992

Yoo, W-K; Kim, D-S; Kwon, Y H; Jang, S H

2008-11-01

306

Recurrent CSPs after Transcranial Magnetic Stimulation of Motor Cortex in Restless Legs Syndrome.  

PubMed

Aims. The aim of this study was to investigate the motor control and central silent period (CSP) in restless legs syndrome (RLS). Methods. Transcranial magnetic stimulation was focused on the dominant and nondominant hemispheric areas of motor cortex in six subjects with RLS and six controls. The responses were recorded on the contralateral abductor digiti minimi (ADM) and tibialis anterior (TA) muscles with intramuscular needle electrodes. Results. No significant differences were found in the motor conduction or central motor conduction time, in the latency, or in the duration of the CSPs between or within the groups, but multiple CSPs were observed in both groups. The number of the CSPs was significantly higher in both ADMs and in the dominant TA (P ? 0.01) in the RLS group compared to the controls. Conclusion. Descending motor pathways functioned correctly in both groups. The occurrence of the recurrent CSPs predominantly in the RLS group could be a sign of a change of function in the inhibitory control system. Further research is needed to clarify the role of the intramuscular recording technique and especially the role of the subcortical generators in the feedback regulation of the central nervous system in RLS. PMID:23213521

Ahlgrén-Rimpiläinen, Aulikki; Lauerma, Hannu; Kähkönen, Seppo; Markkula, Juha; Rimpiläinen, Ilpo

2012-11-19

307

Human cortical theta reactivity to high-frequency repetitive transcranial magnetic stimulation.  

PubMed

Electroencephalography (EEG) can directly monitor the temporal progression of cortical changes induced by repetitive Transcranial Magnetic Stimulation (rTMS) and facilitate the understanding of cortical and subcortical influences in the genesis of oscillations. In this combined rTMS/EEG study, we aimed to investigate changes in oscillatory activity after high-frequency (?11 Hz) rTMS relative to the number of applied pulses. Twenty intermittent trains of 20 or 60 rTMS pulses were delivered over the human primary motor cortex at rest and tuned to individual mu frequency. The regional and interregional oscillatory neural activity after stimulation were evaluated using event-related power (ERPow) and event-related coherence (ERCoh) transformations. The most prominent changes for ERPow were observed in the theta band (4-7 Hz), as an increase in ERPow up to 20 s following 60 rTMS pulses, whereas ERPow increases were smaller in mu (10-12 Hz) and beta (13-30 Hz). ERCoh revealed that rTMS 60 modulated the connectivity in the theta band for up to 20 s. The topography of mu and theta changes were not identical; mu was more focal and theta was more global. Our data suggested the presence of independent cortical theta and mu generators with different reactivity to rTMS but could not rule out possible thalamocortical contributions in generating theta and mu over the motor network. PMID:21823206

Azila Noh, Nor; Fuggetta, Giorgio

2011-08-05

308

Fast multigrid-based computation of the induced electric field for transcranial magnetic stimulation.  

PubMed

In transcranial magnetic stimulation (TMS), the distribution of the induced electric field, and the affected brain areas, depends on the position of the stimulation coil and the individual geometry of the head and brain. The distribution of the induced electric field in realistic anatomies can be modelled using computational methods. However, existing computational methods for accurately determining the induced electric field in realistic anatomical models have suffered from long computation times, typically in the range of tens of minutes or longer. This paper presents a matrix-free implementation of the finite-element method with a geometric multigrid method that can potentially reduce the computation time to several seconds or less even when using an ordinary computer. The performance of the method is studied by computing the induced electric field in two anatomically realistic models. An idealized two-loop coil is used as the stimulating coil. Multiple computational grid resolutions ranging from 2 to 0.25 mm are used. The results show that, for macroscopic modelling of the electric field in an anatomically realistic model, computational grid resolutions of 1 mm or 2 mm appear to provide good numerical accuracy compared to higher resolutions. The multigrid iteration typically converges in less than ten iterations independent of the grid resolution. Even without parallelization, each iteration takes about 1.0 s or 0.1 s for the 1 and 2 mm resolutions, respectively. This suggests that calculating the electric field with sufficient accuracy in real time is feasible. PMID:23128377

Laakso, Ilkka; Hirata, Akimasa

2012-11-06

309

A Comprehensive Study of Repetitive Transcranial Magnetic Stimulation in Parkinson's Disease  

PubMed Central

The clinical benefits of repetitive transcranial magnetic stimulation (rTMS) for Parkinson's disease (PD) remain controversial. We performed a comprehensive study to examine whether rTMS is a safe and effective treatment for PD. Twelve PD patients received rTMS once a week. The crossover study design consisted of 4-week sham rTMS followed by 4-week real rTMS. The Unified Parkinson's Disease Rating Scale (UPDRS), Modified Hoehn and Yahr Stage, Schwab and England ADL Scale, Actigraph, Mini-Mental State Examination, Hamilton Depression Scale, Wechsler Adult Intelligence Scale-revised, and cerebral blood flow (CBF) and cerebrospinal fluid (CSF) examinations were used to evaluate the rTMS effects. Under both drug-on and drug-off conditions, the real rTMS improved the UPDRS scores significantly, while the sham rTMS did not. There were no significant changes in the results of the neuropsychological tests, CBF and CSF. rTMS seems to be a safe and effective therapeutic option for PD patients, especially in a wearing-off state.

Kimura, Hideki; Kurimura, Masayuki; Kurokawa, Katsurou; Nagaoka, Utako; Arawaka, Shigeki; Wada, Manabu; Kawanami, Toru; Kurita, Keiji; Kato, Takeo

2011-01-01

310

Impaired cortical inhibition in adult ADHD patients: a study with transcranial magnetic stimulation.  

PubMed

The aim of this study was to analyze motor inhibition and facilitation of adult ADHD patients using double pulse transcranial magnetic stimulation (TMS). Twenty-six right handed adult ADHD patients according to DSM-IV were investigated and compared to 26 age and sex-matched controls. In the left hemisphere, mean motor inhibition was 0.53 +/- 0.33 (mean +/- SD) in ADHD patients and 0.34 +/- 0.16 (mean +/- SD) in controls (p = 0.012). There were no significant differences in motor excitability concerning facilitation or in the right hemisphere. Decreased motor inhibition correlated with a higher symptom score derived from the Wender Reimherr Interview (WRI) (p = 0.28; p = 0.04) and also with self rated hyperactivity/impulsivity symptoms (p = 0.30; p = 0.03). In conclusion, decreased motor inhibition in adult ADHD corroborate similar findings in children with ADHD (Moll et al., 2000) and reflect disturbed impulsivity and hyperactivity on a neurophysiological level. PMID:17982907

Schneider, M; Retz, W; Freitag, C; Irsch, J; Graf, P; Retz-Junginger, P; Rösler, M

2007-01-01

311

Role of Repetitive Transcranial Magnetic Stimulation in Maintenance Treatment of Resistant Depression  

PubMed Central

Troublesome side-effects and lack of efficacy of the pharmacotherapy are the two major limitations in the depression treatment. Inspite of the established modalities like switching, combination and augmentation, using pharmacological and non-pharmacological agents, nearly one-third patients do not achieve complete remission. Repetitive Transcranial Magnetic Stimulation (rTMS) is one such somatic treatment which has been extensively studied for treatment for acute depression. Drop-out rates due to adverse effects have been found to be extremely low. However, literature regarding the role of rTMS in maintenance treatment in recurrent depression is scarce, and there is no existing literature from India. In this case-report we highlight the role of rTMS in the maintenance treatment of TRD in a patient who has been followed up for about three years (four episodes). Emphasis is placed on improvement in symptoms and functioning without use of any pharmacological treatment. Further, the need for systematic study and standardization of various aspects of rTMS therapy for maintenance treatment is emphasised.

Chatterjee, Biswadip; Kumar, Nand; Jha, Shailesh

2012-01-01

312

Motor evoked potentials by transcranial magnetic stimulation in healthy elderly people.  

PubMed

Abstract Introduction: Transcranial magnetic stimulation (TMS) is a non-invasive, safe, and painless method for evaluating the corticospinal pathway. The population of older adults is growing, along with the prevalence of neurological diseases common to this group. Latency and amplitude of motor evoked potentials (MEPs) vary among healthy subjects and no reference normal values for MEPs in healthy older adults are available. Objective: To create a reference value for MEPs by TMS for healthy older adults. Methods: Descriptive study in 36 healthy 70-year-old and older subjects. A 90-mm circular coil Magstim® magnetic stimulator was applied over Cz and Fz. Recording was done in the abductor pollicis brevis and tibialis anterior muscles, at rest and during sustained tonic contraction. Central motor conduction time (CMCT) was derived from MEP latency and peripheral motor conduction time (PMCT). Values were related to age, gender, standing height, and knee height. Results: Mean age was 73.3?±?2.4 years (58% female). In the upper extremity, average MEP latency was 23.3?±?1.9?ms at rest and 19.9?±?1.9?ms during tonic contraction. In the lower extremity, average MEP latency was 30.6?±?2.5?ms at rest and 27.2?±?2.3?ms during tonic contraction. There was a significant correlation between MEP latency and standing height, greater in the lower extremities. Female gender appeared as an independent factor determining lower MEP latency, but not CMCT, in upper and lower extremities. Conclusion: We have provided clinically useful reference values for MEPs by TMS in healthy adults older than 70 years of age. As in the younger population, standing height is important in defining normal MEPs. The difference between genders might be due to the lower height of women. PMID:23767989

Matamala, José Manuel; Núñez, Carolina; Lera, Lydia; Verdugo, Renato J; Sánchez, Hugo; Albala, Cecilia; Castillo, José Luis

2013-06-14

313

Avaliação de fatores associados à duração do tratamento com a estimulação magnética transcraniana repetitiva na depressão An evaluation of factors affecting duration of treatment with repetitive transcranial magnetic stimulation for depression  

Microsoft Academic Search

Objective: To investigate the effects of repetitive transcranial magnetic stimulation in patients with major depression who were submitted to this treatment during the period from 2000 to 2006. Methods: A retrospective study with 204 patients who underwent treatment with repetitive transcranial magnetic stimulation, collecting data from those who experienced remission (defined as a HDRS score equal to or lower than

Roni Broder Cohen; Felipe Fregni; Paulo Sergio Boggio

2007-01-01

314

Facilitation of the diaphragm response to transcranial magnetic stimulation by increases in human respiratory drive.  

PubMed

The human respiratory neural drive has an automatic component (bulbospinal pathway) and a volitional component (corticospinal pathway). The aim of this study was to assess the effects of a hypercapnia-induced increase in the automatic respiratory drive on the function of the diaphragmatic corticospinal pathway as independently as possible of any other influence. Thirteen healthy volunteers breathed room air and then 5 and 7% hyperoxic CO2. Cervical (cms) and transcranial (tms) magnetic stimulations were performed during early inspiration and expiration. Transdiaphragmatic pressure (Pdi) and surface electromyogram of the diaphragm (DiEMG) and of the abductor pollicis brevis (apbEMG) were recorded in response to cms and tms. During inspiration, Pdi,cms was unaffected by CO2, but Pdi,tms increased significantly with 7% CO2. During expiration, Pdi,cms was significantly reduced by CO2, whereas Pdi,tms was preserved. DiEMG,tms latencies decreased significantly during early inspiration and expiration (air vs. 5% CO2 and air vs. 7% CO2). DiEMG,tms amplitude increased significantly in response to early expiration-tms (air vs. 5% CO2 and air vs. 7% CO2) but not in response to early inspiration-tms. DiEMG,cms latencies and amplitudes were not affected by CO2 whereas 7% CO2 significantly increased the apbEMG,cms latency. The apbEMG,tms vs. apbEMG,cms latency difference was unaffected by CO2. In conclusion, increasing the automatic drive to breathe facilitates the response of the diaphragm to tms, during both inspiration and expiration. This could allow the corticospinal drive to breathe to keep the capacity to modulate respiration in conditions under which the automatic respiratory control is stimulated. PMID:15133007

Straus, C; Locher, C; Zelter, M; Derenne, J-P; Similowski, T

2004-05-07

315

Muscle imaging: mapping responses to transcranial magnetic stimulation with high-density surface electromyography.  

PubMed

Representations of different body parts or muscles in the human primary motor cortex overlap extensively. At the effector level, most muscles are surrounded by and overlap with several neighbours as well. This hampers the assessment of excitability in individual muscles with transcranial magnetic stimulation (TMS), even if so-called "focal" stimulating coils are used. Here we used a novel mapping paradigm based on high-density surface electromyography (HD-sEMG) to investigate the spatial selectivity of TMS in the forearm musculature. In addition, we tested the hypothesis that selective stimulation can be improved by a voluntary background contraction of the target muscle. We mapped and compared the topographies of motor evoked potential (MEP) amplitudes during rest and during background contractions of two forearm muscles (extensor carpi radialis and extensor digitorum communis). The MEP topographies were also compared to the amplitude topography of voluntary EMG. The results indicate that under many conditions a large proportion of the MEP activity recorded at the surface originated from the target muscle's neighbours. There was a systematic relationship between TMS intensity and the topographic distribution of MEP responses during voluntary contraction. With increasing stimulus intensity, the MEP topography deviated increasingly more from the topography of voluntary EMG. We conclude that when standard EMG montages are used, the recorded MEPs are not necessarily evoked in the target muscle alone. Stimulation during a voluntary background contraction of the target muscle may enhance the selectivity of TMS. It however remains essential to use stimulus intensities as low as possible, to minimize the contribution of surrounding non-target muscles to the MEP. PMID:18387593

van Elswijk, Gijs; Kleine, Bert U; Overeem, Sebastiaan; Eshuis, Bertine; Hekkert, Karin D; Stegeman, Dick F

2007-12-23

316

Long Lasting Modulation of Cortical Oscillations after Continuous Theta Burst Transcranial Magnetic Stimulation  

PubMed Central

Transcranial magnetic theta burst stimulation (TBS) differs from other high-frequency rTMS protocols because it induces plastic changes up to an hour despite lower stimulus intensity and shorter duration of stimulation. However, the effects of TBS on neuronal oscillations remain unclear. In this study, we used electroencephalography (EEG) to investigate changes of neuronal oscillations after continuous TBS (cTBS), the protocol that emulates long-term depression (LTD) form of synaptic plasticity. We randomly divided 26 healthy humans into two groups receiving either Active or Sham cTBS as control over the left primary motor cortex (M1). Post-cTBS aftereffects were assessed with behavioural measurements at rest using motor evoked potentials (MEPs) and at active state during the execution of a choice reaction time (RT) task in combination with continuous electrophysiological recordings. The cTBS-induced EEG oscillations were assessed using event-related power (ERPow), which reflected regional oscillatory activity of neural assemblies of ? (4–7.5 Hz), low ? (8–9.5 Hz), µ (10–12.5 Hz), low ? (13–19.5 Hz), and high ? (20–30 Hz) brain rhythms. Results revealed 20-min suppression of MEPs and at least 30-min increase of ERPow modulation, suggesting that besides MEPs, EEG has the potential to provide an accurate cortical readout to assess cortical excitability and to investigate the interference of cortical oscillations in the human brain post-cTBS. We also observed a predominant modulation of ? frequency band, supporting the hypothesis that cTBS acts more on cortical level. Theta oscillations were also modulated during rest implying the involvement of independent cortical theta generators over the motor network post cTBS. This work provided more insights into the underlying mechanisms of cTBS, providing a possible link between synchronised neural oscillations and LTD in humans.

Noh, Nor Azila; Fuggetta, Giorgio; Manganotti, Paolo; Fiaschi, Antonio

2012-01-01

317

The contribution of transcranial magnetic stimulation in the functional evaluation of microcircuits in human motor cortex  

PubMed Central

Although transcranial magnetic stimulation (TMS) activates a number of different neuron types in the cortex, the final output elicited in corticospinal neurones is surprisingly stereotyped. A single TMS pulse evokes a series of descending corticospinal volleys that are separated from each other by about 1.5 ms (i.e., ~670 Hz). This evoked descending corticospinal activity can be directly recorded by an epidural electrode placed over the high cervical cord. The earliest wave is thought to originate from the direct activation of the axons of fast-conducting pyramidal tract neurones (PTN) and is therefore termed “D” wave. The later waves are thought to originate from indirect, trans-synaptic activation of PTNs and are termed “I” waves. The anatomical and computational characteristics of a canonical microcircuit model of cerebral cortex composed of layer II and III and layer V excitatory pyramidal cells, inhibitory interneurons, and cortico-cortical and thalamo-cortical inputs can account for the main characteristics of the corticospinal activity evoked by TMS including its regular and rhythmic nature, the stimulus intensity-dependence and its pharmacological modulation. In this review we summarize present knowledge of the physiological basis of the effects of TMS of the human motor cortex describing possible interactions between TMS and simple canonical microcircuits of neocortex. According to the canonical model, a TMS pulse induces strong depolarization of the excitatory cells in the superficial layers of the circuit. This leads to highly synchronized recruitment of clusters of excitatory neurons, including layer V PTNs, and of inhibitory interneurons producing a high frequency (~670 Hz) repetitive discharge of the corticospinal axons. The role of the inhibitory circuits is crucial to entrain the firing of the excitatory networks to produce a high-frequency discharge and to control the number and magnitude of evoked excitatory discharge in layer V PTNs. In summary, simple canonical microcircuits of neocortex can explain activation of corticospinal neurons in human motor cortex by TMS.

Di Lazzaro, Vincenzo; Ziemann, Ulf

2013-01-01

318

Complete suppression of voluntary motor drive during the silent period after transcranial magnetic stimulation.  

PubMed

To evaluate changes in the motor system during the silent period (SP) induced by transcranial magnetic stimulation (TMS) of the motor cortex, we investigated motor thresholds as parameters of the excitability of the cortico-muscular pathway after a suprathreshold conditioning stimulus in the abductor digiti minimi muscle (ADM) of normal humans. Since the unconditioned motor threshold was lower during voluntary tonic contraction than at rest (31.9+/-5.4% vs. 45.6+/-7.5%), it is suggested that the difference between active and resting motor threshold indicates the magnitude of the voluntary drive on the cortico-muscular pathway. Therefore, we compared conditioned resting and active motor threshold (cRMT and cAMT) during the SP. cRMT showed an intensity-dependent period of elevation of more than 200 ms in duration and approximately 17% of the maximum stimulator output above the unconditioned threshold, due to decreased excitability of the cortico-muscular pathway after the conditioning stimulus. Some 3040 ms after the conditioning stimulus, cAMT approximated cRMT, indicating complete suppression of the voluntary motor drive. This suppression did not start directly after the conditioning stimulus since cAMT was still significantly lower than the cRMT within the first 30-40 ms. Threshold elevation was significantly longer than the SP (220+/-41 vs. 151+/-28 ms). Recovery of the voluntary motor drive started late in the SP and was nearly complete at the end of the SP, although thresholds were still significantly elevated. We conclude that the SP is largely due to a suppression of voluntary motor drive, while the threshold elevation is a different inhibitory phenomenon that is of less importance for the generation of the SP, at least in its late part. It is argued that the pathway of fast cortico-spinal fibers activated by TMS is partially different from the pathway involved in the maintenance of tonic voluntary muscle activation. PMID:10090656

Tergau, F; Wanschura, V; Canelo, M; Wischer, S; Wassermann, E M; Ziemann, U; Paulus, W

1999-02-01

319

[Possibilities of transcranial magnetic therapy and color and rhythm therapy in rehabilitation of ischemic stroke].  

PubMed

One hundred and sixteen post-stroke patients were studied in the early rehabilitation period. All patients were divided into 4 groups: 3 main and 1 control groups. Three main groups (87 patients) received transcranial magnetic therapy (TMT) and/or color and rhythm therapy (CRT) along with traditional treatment and the control group (29 patients) received only basic therapy. TMT was conducted using bitemporal technique, running regime with modulation frequency 1-10 Hz. In CRT, the alternating stimulation of the right and left eye with green and/or blue color with a period of 2-4 s and duration of luminescence 1s was applied. Each of 3 main groups received 2 treatment sessions with an interval of 1,5 month (1st - TMT, 2nd - CRT, 3rd - TMT + CRT). After the treatment, the marked positive changes were seen in all main groups, in particular in group 3. The improvement of neurologic symptoms on the B. Lindmark scale was higher by 9,5% in group 3 compared to the control one, on the Barthel index - by 8,8%, on MMSE and A. Luria and Schulte test - by 5,4 and 14,3%, respectively. Rheographic and encephalographic study revealed the significant improvement of hemodynamics and alpha-rhythm differentiation, decrease of patients with dysrhythmia by 14,6% in group 3 as compared to the control group. The best results were seen in the combination of TMT and CRT, TMT exerted a higher effect on the hemodynamics and CRT - on the psychoemotional state. Both therapies were well tolerated and had no side-effects. PMID:19672234

Sholomov, I I; Cherevashchenko, L A; Suprunov, O V; Ra?gorondski?, Iu M

2009-01-01

320

Therapeutic application of transcranial magnetic stimulation in Parkinson's disease: The contribution of expectation  

PubMed Central

Repetitive transcranial magnetic stimulation (rTMS) is a valuable probe of brain function. Ever since its adoption as a research tool, there has been great interest regarding its potential clinical role. Presently, it is unclear whether rTMS will have some role as an alternative treatment for neuropsychiatric and neurological disorders such as Parkinson’s disease (PD). To date, studies addressing the contribution of placebo during rTMS are missing. The placebo effect has been shown to be associated either with release of dopamine in the striatum or with changes in brain glucose metabolism. The main objective of this study was to test whether, in patients with PD, the expectation of therapeutic benefit from rTMS, which actually was delivered only as sham rTMS (placebo-rTMS) induced changes in striatal [11C] raclopride binding potentials (BP) as measured with positron emission tomography (PET). Placebo-rTMS induced a significant bilateral reduction in [11C] raclopride BP in dorsal and ventral striatum as compared to the baseline condition. This reduction BP is indicative of an increase in dopamine neurotransmission. The changes in [11C] raclopride binding were more evident in the hemisphere contralateral to the more affected side supporting the hypothesis that the more severe the symptoms, the greater the drive for symptom relief, and therefore the placebo response. This is the first study addressing the placebo contribution during rTMS. While our results seem to confirm earlier evidence that expectation induces dopaminergic placebo effects, they also suggest the importance of placebo-controlled studies for future clinical trials involving brain stimulation techniques.

Strafella, Antonio P.; Ko, Ji Hyun; Monchi, Oury

2010-01-01

321

Seizure suppression by EEG-guided repetitive transcranial magnetic stimulation in the rat  

PubMed Central

Objective To test the anticonvulsive potential of a range of repetitive transcranial magnetic stimulation (rTMS) frequencies by novel methods for simultaneous EEG and rTMS in a rat seizure model. Methods Seizures were triggered by intraperitoneal kainic acid (KA; 10 mg/kg). Rats (n = 21) were divided into three groups in which individual seizures were treated with rTMS trains at one of three frequencies: 0.25, 0.5 or 0.75 Hz. EEG was continuously viewed by an operator who identified each seizure onset. Consecutive seizures in each animal were (1) treated with active rTMS, (2) treated with sham rTMS, or (3) were untreated. EEG was re-analyzed post hoc by visual inspection, and seizure durations were compared within and between treatment groups. Results KA-induced seizures were abbreviated by 0.75 Hz (P = 0.019) and 0.5 Hz (P = 0.033) active EEG-guided rTMS. In contrast, neither active 0.25 Hz rTMS nor the control conditions affected seizure duration (P > 0.2). Conclusions We demonstrate that EEG-guided rTMS can suppress seizures in the rat KA epilepsy model, and that the effect is frequency dependent, with 0.75 and 0.5 Hz rTMS being superior to 0.25 Hz rTMS. Significance These data support the use of rat seizure models in translational research aimed at evaluation and development of effective rTMS anticonvulsive protocols. We also offer a proof of principle that real-time analysis of EEG can be used to guide rTMS to suppress individual seizures.

Rotenberg, Alexander; Muller, Paul; Birnbaum, Daniel; Harrington, Michael; Riviello, James J.; Pascual-Leone, Alvaro; Jensen, Frances E.

2009-01-01

322

Responses of single motor units in human masseter to transcranial magnetic stimulation of either hemisphere  

PubMed Central

The corticobulbar inputs to single masseter motoneurons from the contra- and ipsilateral motor cortex were examined using focal transcranial magnetic stimulation (TMS) with a figure-of-eight stimulating coil. Fine-wire electrodes were inserted into the masseter muscle of six subjects, and the responses of 30 motor units were examined. All were tested with contralateral TMS, and 87 % showed a short-latency excitation in the peristimulus time histogram at 7.0 ± 0.3 ms. The response was a single peak of 1.5 ± 0.2 ms duration, consistent with monosynaptic excitation via a single D- or I1-wave volley elicited by the stimulus. Increased TMS intensity produced a higher response probability (n = 13, paired t test, P < 0.05) but did not affect response latency. Of the remaining motor units tested with contralateral TMS, 7 % did not respond at intensities tested, and 7 % had reduced firing probability without any preceding excitation. Sixteen of these motor units were also tested with ipsilateral TMS and four (25 %) showed short-latency excitation at 6.7 ± 0.6 ms, with a duration of 1.5 ± 0.3 ms. Latency and duration of excitatory peaks for these four motor units did not differ significantly with ipsilateral vs. contralateral TMS (paired t tests, P > 0.05). Of the motor units tested with ipsilateral TMS, 56 % responded with a reduced firing probability without a preceding excitation, and 19 % did not respond. These data suggest that masseter motoneurons receive monosynaptic input from the motor cortex that is asymmetrical from each hemisphere, with most low threshold motoneurons receiving short-latency excitatory input from the contralateral hemisphere only.

Pearce, Sophie L; Miles, Timothy S; Thompson, Philip D; Nordstrom, Michael A

2003-01-01

323

Bidirectional long-term motor cortical plasticity and metaplasticity induced by quadripulse transcranial magnetic stimulation  

PubMed Central

Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising tool to induce plastic changes that are thought in some cases to reflect N-methyl-d-aspartate-sensitive changes in synaptic efficacy. As in animal experiments, there is some evidence that the sign of rTMS-induced plasticity depends on the prior history of cortical activity, conforming to the Bienenstock–Cooper–Munro (BCM) theory. However, experiments exploring these plastic changes have only examined priming-induced effects on a limited number of rTMS protocols, often using designs in which the priming alone had a larger effect than the principle conditioning protocol. The aim of this study was to introduce a new rTMS protocol that gives a broad range of after-effects from suppression to facilitation and then test how each of these is affected by a priming protocol that on its own has no effect on motor cortical excitability, as indexed by motor-evoked potential (MEP). Repeated trains of four monophasic TMS pulses (quadripulse stimulation: QPS) separated by interstimulus intervals of 1.5–1250 ms produced a range of after-effects that were compatible with changes in synaptic plasticity. Thus, QPS at short intervals facilitated MEPs for more than 75 min, whereas QPS at long intervals suppressed MEPs for more than 75 min. Paired-pulse TMS experiments exploring intracortical inhibition and facilitation after QPS revealed effects on excitatory but not inhibitory circuits of the primary motor cortex. Finally, the effect of priming protocols on QPS-induced plasticity was consistent with a BCM-like model of priming that shifts the crossover point at which synaptic plasticity reverses from depression to potentiation. The broad range of after-effects produced by the new rTMS protocol opens up new possibilities for detailed examination of theories of metaplasticity in humans.

Hamada, Masashi; Terao, Yasuo; Hanajima, Ritsuko; Shirota, Yuichiro; Nakatani-Enomoto, Setsu; Furubayashi, Toshiaki; Matsumoto, Hideyuki; Ugawa, Yoshikazu

2008-01-01

324

Cortical excitability in juvenile myoclonic epileptic patients and their asymptomatic siblings: a transcranial magnetic stimulation study.  

PubMed

In this study, we aimed to evaluate motor cortical excitability changes in patients with juvenile myoclonic epilepsy (JME) and their asymptomatic siblings (AS) using single-pulse transcranial magnetic stimulation (spTMS). 21 patients with JME and their 21 AS were compared to 20 healthy controls. All of JME patients were receiving antiepileptic therapy and their seizures were well controlled. Firstly, standard EEG examinations and then TMS studies were performed. Resting motor threshold (RMT), motor evoked potential (MEP) amplitudes, the durations of central motor conduction time (CMCT) and cortical silent period (CSP) were measured. After TMS studies, EEG recordings were repeated in an hour to evaluate any effect of TMS study on EEG. There were no significant differences between the first and second EEG recordings. No seizures were recorded during and after the TMS study. RMT was found higher in JME patients than AS and normal controls. There were no significant differences between cortical MEP amplitudes and MEP amplitude/CMAP (compound muscle action potential) amplitude ratio in all three groups. CMCT duration was shorter in JME patients than AS. CSP durations of JME patients were found to be longer than controls. In AS, CSP durations were also found to be longer than controls but this difference was not found statistically significant. Our results suggested that although high MT may be related to antiepileptic therapy, the prolongation of CSP duration may reflect impairment of supraspinal and/or intracortical inhibitory mechanism in JME. To eliminate the drug effect, further studies are needed in newly diagnosed JME patients without medication and large series of their asymptomatic siblings. PMID:19297206

Akgun, Yasemin; Soysal, Aysun; Atakli, Dilek; Yuksel, Burcu; Dayan, Cengiz; Arpaci, Baki

2009-03-17

325

The Effect of Daily Prefrontal Repetitive Transcranial Magnetic Stimulation Over Several Weeks on Resting Motor Threshold  

PubMed Central

Background: The resting motor threshold (rMT) is an important factor in the selection of treatment intensity for patients receiving repetitive transcranial magnetic stimulation (rTMS). In many clinical studies to date, due to concerns about potential drift, the rMT has been routinely re-measured weekly or every fifth session. Objective: Our aim is to investigate whether ongoing treatment with rTMS affects the rMT, the degree of change, and whether frequent remeasurement is needed. Methods: Clinical data were drawn from 50 medication free patients receiving treatment for major depression with rTMS in a large U.S. NIH-sponsored multisite study. Four measurements of rMT were obtained including before and after the double blind phase, followed by weekly measurements during the open phase. Active treatment consisted of 75 four second trains of 10Hz stimulation applied over 37.5 minutes with the coil over the left DLPFC at 120% rMT. Results: For the group as a whole, there was no significant change in the rMT during a minimum of 2 weeks of treatment with prefrontal rTMS (p=0.911, one way ANOVA). The average within-subject coefficient of variation was 6.58%. On average the last rMT was 2.45% less than the baseline rMT (range 32.3% increase, 40.6% decrease). Conclusion: Daily left prefrontal rTMS over several weeks as delivered in this trial does not cause systematic changes in rMT. While most subjects had <10% variance in rMT over time, 5 subjects had changes of ?20% from baseline, raising dosing and safety issues if undetected. We recommend that clinical trials of rTMS have periodic retesting of rMT, especially if the dose is at or near the edge of the TMS safety tables.

Zarkowski, Paul; Navarro, Rita; Pavlicova, Martina; George, Mark S.; Avery, David

2009-01-01

326

Phonological and lexical motor facilitation during speech listening: a transcranial magnetic stimulation study.  

PubMed

In the present study, we used transcranial magnetic stimulation (TMS) to investigate the influence of phonological and lexical properties of verbal items on the excitability of the tongue's cortical motor representation during passive listening. In particular, we aimed to clarify if the difference in tongue motor excitability found during listening to words and pseudo-words [Fadiga, L., Craighero, L., Buccino, G., Rizzolatti, G., 2002. Speech listening specifically modulates the excitability of tongue muscles: a TMS study. European Journal of Neuroscience 15, 399-402] is due to lexical frequency or to the presence of a meaning per se. In order to do this, we investigated the time-course of tongue motor-evoked potentials (MEPs) during listening to frequent words, rare words, and pseudo-words embedded with a double consonant requiring relevant tongue movements for its pronunciation. Results showed that at the later stimulation intervals (200 and 300 ms from the double consonant) listening to rare words evoked much larger MEPs than listening to frequent words. Moreover, by comparing pseudo-words embedded with a double consonant requiring or not tongue movements, we found that a pure phonological motor resonance was present only 100 ms after the double consonant. Thus, while the phonological motor resonance appears very early, the lexical-dependent motor facilitation takes more time to appear and depends on the frequency of the stimuli. The present results indicate that the motor system responsible for phonoarticulatory movements during speech production is also involved during speech listening in a strictly specific way. This motor facilitation reflects both the difference in the phonoarticulatory characteristics and the difference in the frequency of occurrence of the verbal material. PMID:18440210

Roy, Alice C; Craighero, Laila; Fabbri-Destro, Maddalena; Fadiga, Luciano

2008-03-18

327

Repetitive transcranial magnetic stimulation of Broca's area affects verbal responses to gesture observation.  

PubMed

The aim of the present study was to determine whether Broca's area is involved in translating some aspects of arm gesture representations into mouth articulation gestures. In Experiment 1, we applied low-frequency repetitive transcranial magnetic stimulation over Broca's area and over the symmetrical loci of the right hemisphere of participants responding verbally to communicative spoken words, to gestures, or to the simultaneous presentation of the two signals. We performed also sham stimulation over the left stimulation loci. In Experiment 2, we performed the same stimulations as in Experiment 1 to participants responding with words congruent and incongruent with gestures. After sham stimulation voicing parameters were enhanced when responding to communicative spoken words or to gestures as compared to a control condition of word reading. This effect increased when participants responded to the simultaneous presentation of both communicative signals. In contrast, voicing was interfered when the verbal responses were incongruent with gestures. The left stimulation neither induced enhancement on voicing parameters of words congruent with gestures nor interference on words incongruent with gestures. We interpreted the enhancement of the verbal response to gesturing in terms of intention to interact directly. Consequently, we proposed that Broca's area is involved in the process of translating into speech aspects concerning the social intention coded by the gesture. Moreover, we discussed the results in terms of evolution to support the theory [Corballis, M. C. (2002). From hand to mouth: The origins of language. Princeton, NJ: Princeton University Press] proposing spoken language as evolved from an ancient communication system using arm gestures. PMID:16839281

Gentilucci, Maurizio; Bernardis, Paolo; Crisi, Girolamo; Dalla Volta, Riccardo

2006-07-01

328

Electric field depth-focality tradeoff in transcranial magnetic stimulation: simulation comparison of 50 coil designs  

PubMed Central

Background Various transcranial magnetic stimulation (TMS) coil designs are available or have been proposed. However, key coil characteristics such as electric field focality and attenuation in depth have not been adequately compared. Knowledge of the coil focality and depth characteristics can help TMS researchers and clinicians with coil selection and interpretation of TMS studies. Objective To quantify the electric field focality and depth of penetration of various TMS coils. Methods The electric field distributions induced by 50 TMS coils were simulated in a spherical human head model using the finite element method. For each coil design, we quantified the electric field penetration by the half-value depth, d1/2, and focality by the tangential spread, S1/2, defined as the half-value volume (V1/2) divided by the half-value depth, S1/2 = V1/2/d1/2. Results The 50 TMS coils exhibit a wide range of electric field focality and depth, but all followed a depth–focality tradeoff: coils with larger half-value depth cannot be as focal as more superficial coils. The ranges of achievable d1/2 are similar between coils producing circular and figure-8 electric field patterns, ranging 1.0–3.5 cm and 0.9–3.4 cm, respectively. However, figure-8 field coils are more focal, having S1/2 as low as 5 cm2 compared to 34 cm2 for circular field coils. Conclusions For any coil design, the ability to directly stimulate deeper brain structures is obtained at the expense of inducing wider electrical field spread. Novel coil designs should be benchmarked against comparison coils with consistent metrics such as d1/2 and S1/2.

Deng, Zhi-De; Lisanby, Sarah H.; Peterchev, Angel V.

2012-01-01

329

Transcranial magnetic stimulation of visual cortex in migraine patients: a systematic review with meta-analysis.  

PubMed

We systematically reviewed the literature to evaluate the prevalence of phosphenes and the phosphene threshold (PT) values obtained during single-pulse transcranial magnetic stimulation (TMS) in adults with migraine. Controlled studies measuring PT by single-pulse TMS in adults with migraine with or without aura (MA, MwA) were systematically searched. Prevalence of phosphenes and PT values were assessed calculating mean difference (MD) and odds ratio (OR) with 95 % confidence intervals (CI). Ten trials (277 migraine patients and 193 controls) were included. Patients with MA had statistically significant lower PT compared with controls when a circular coil was used (MD -28.33; 95 % CI -36.09 to -20.58); a similar result was found in MwA patients (MD -17.12; 95 % CI -23.81 to -10.43); using a figure-of-eight coil the difference was not statistically significant. There was a significantly higher phosphene prevalence in MA patients compared with control subjects (OR 4.21; 95 % CI 1.18-15.01). No significant differences were found either in phosphene reporting between patients with MwA and controls, or in PT values obtained with a figure-of-eight coil in MA and MwA patients versus controls. Overall considered, these results support the hypothesis of a primary visual cortex hyper-excitability in MA, providing not enough evidence for MwA. A significant statistical heterogeneity reflects clinical and methodological differences across studies, and higher temporal variabilities among PT measurements over time, related to unstable excitability levels. Patients should therefore be evaluated in the true interictal period with an adequate headache-free interval. Furthermore, skull thickness and ovarian cycle should be assessed as possible confounding variables, and sham stimulation should be performed to reduce the rate of false positives. Phosphene prevalence alone cannot be considered a measure of cortical excitability, but should be integrated with PT evaluation. PMID:22535147

Brigo, Francesco; Storti, Monica; Nardone, Raffaele; Fiaschi, Antonio; Bongiovanni, Luigi Giuseppe; Tezzon, Frediano; Manganotti, Paolo

2012-04-27

330

Long lasting modulation of cortical oscillations after continuous theta burst transcranial magnetic stimulation.  

PubMed

Transcranial magnetic theta burst stimulation (TBS) differs from other high-frequency rTMS protocols because it induces plastic changes up to an hour despite lower stimulus intensity and shorter duration of stimulation. However, the effects of TBS on neuronal oscillations remain unclear. In this study, we used electroencephalography (EEG) to investigate changes of neuronal oscillations after continuous TBS (cTBS), the protocol that emulates long-term depression (LTD) form of synaptic plasticity. We randomly divided 26 healthy humans into two groups receiving either Active or Sham cTBS as control over the left primary motor cortex (M1). Post-cTBS aftereffects were assessed with behavioural measurements at rest using motor evoked potentials (MEPs) and at active state during the execution of a choice reaction time (RT) task in combination with continuous electrophysiological recordings. The cTBS-induced EEG oscillations were assessed using event-related power (ERPow), which reflected regional oscillatory activity of neural assemblies of ? (4-7.5 Hz), low ? (8-9.5 Hz), µ (10-12.5 Hz), low ? (13-19.5 Hz), and high ? (20-30 Hz) brain rhythms. Results revealed 20-min suppression of MEPs and at least 30-min increase of ERPow modulation, suggesting that besides MEPs, EEG has the potential to provide an accurate cortical readout to assess cortical excitability and to investigate the interference of cortical oscillations in the human brain post-cTBS. We also observed a predominant modulation of ? frequency band, supporting the hypothesis that cTBS acts more on cortical level. Theta oscillations were also modulated during rest implying the involvement of independent cortical theta generators over the motor network post cTBS. This work provided more insights into the underlying mechanisms of cTBS, providing a possible link between synchronised neural oscillations and LTD in humans. PMID:22496893

Noh, Nor Azila; Fuggetta, Giorgio; Manganotti, Paolo; Fiaschi, Antonio

2012-04-04

331

High-rate repetitive transcranial magnetic stimulation in migraine prophylaxis: a randomized, placebo-controlled study.  

PubMed

Repetitive transcranial magnetic stimulation (rTMS) is an emerging treatment for pain but there is no class 1 study on its role in migraine prophylaxis. In this study we report the efficacy and safety of high-rate rTMS in migraine prophylaxis. Adult migraine patients having >4 attacks/month were randomized to high-rate rTMS or sham stimulation. Stimulation in the form of 10 Hz rTMS, 600 pulses in 10 trains were delivered to the hot spot of the right abductor digiti minimi in 412 s. Three sessions were delivered on alternate days. The outcome was defined at 1 month. The primary outcome measures were reduction in headache frequency and severity >50 % as assessed by the Visual Analogue Scale (VAS). The secondary outcome measures were functional disability, rescue medication and adverse events. Fifty patients each were randomized to rTMS or sham stimulation. The baseline characteristics of rTMS and sham stimulation groups were similar. At 1 month, headache frequency (78.7 vs. 33.3 %; P = 0.0001) and VAS score (76.6 vs. 27.1 %; P = 0.0001) improved significantly in the patients receiving rTMS compared to those in the sham stimulation group. Functional disability also improved significantly in rTMS group (P = 0.0001). Only one patient following rTMS developed transient drowsiness and was withdrawn from the study. This study provides evidence of the efficacy and safety of 10 Hz rTMS in migraine prophylaxis. PMID:23963471

Misra, Usha K; Kalita, Jayantee; Bhoi, Sanjeev K

2013-08-21

332

Seizure with single-pulse transcranial magnetic stimulation in a 35-year-old otherwise-healthy patient with bipolar disorder.  

PubMed

This case report describes a patient who developed a seizure with single-pulse transcranial magnetic stimulation during motor threshold estimation. The patient had no history of seizures in the past and no gross neurologic deficits. The only possible seizure-provoking factors were modest doses of lithium and chlorpromazine, which the patient was on, and family history of seizure in a brother. This report aims to highlight the fact that single-pulse transcranial magnetic stimulation may provoke a seizure even in the absence of gross neurologic abnormality. PMID:16127313

Tharayil, Biju Sunny; Gangadhar, B N; Thirthalli, Jagadisha; Anand, L

2005-09-01

333

A cerebellar-like terminal and postural tremor induced in normal man by transcranial magnetic stimulation.  

PubMed

Trains of repetitive transcranial magnetic stimulation (TMS) at 10-30 Hz and intensities of 90-120% motor threshold were delivered through a figure of eight coil over the motor cortex while normal subjects made either rapid, self-terminated (ballistic) wrist movements or maintained the position of their wrist at a fixed angle. Movement kinematics and EMG activity in antagonistic forearm muscles were analysed. In the ballistic task, repetitive TMS had little effect on the velocity or acceleration of the initial segment of the movement, although it induced large terminal oscillations (tremor) around the target position at frequencies between 4.4 and 7.2 Hz. The likelihood that tremor would occur increased with increasing stimulus intensities or frequencies. It was maximal with stimulation over the forearm area, and decreased with stimulation over the leg area, or over parietal sites; there was no tremor during stimulation of cervical nerve roots. The frequency of the induced tremor was independent of the rate of stimulation and did not depend on the presence of excitatory and inhibitory motor responses to the stimulus. Stimulation could also induce tremor of the same frequency in the fixed task, but only during co-contraction of forearm muscles. The amplitude of tremor was proportional to the level of co-contraction. Clinically, the tremor induced by repetitive TMS appeared very similar to cerebellar tremors. In order to confirm this we investigated two cerebellar patients, one with autosomal dominant cerebellar ataxia and the other with multiple sclerosis. Both of them had a terminal tremor of 6-7 Hz in the wrist movement task. In the holding task, the amplitude of their postural tremor increased with the level of co-contraction in forearm muscles. Since the frequency of repetitive TMS-induced tremor was independent of stimulus parameters, we conclude that it represents some intrinsic property of the CNS. We suggest that the tremor is caused by disruption of cortical processes involved in terminating a voluntary movement or maintaining a posture. Similarities to cerebellar patients suggest that repetitive TMS may cause tremor by interfering with adaptive cerebellar afferent inflow to motor cortex. Repetitive TMS-induced tremor, therefore, may represent a model of some forms of cerebellar tremor in man. PMID:10430838

Topka, H; Mescheriakov, S; Boose, A; Kuntz, R; Hertrich, I; Seydel, L; Dichgans, J; Rothwell, J

1999-08-01

334

Evaluation of transcranial magnetic stimulation for investigating transmission in descending motor tracts in the rat.  

PubMed

In the rat, non-invasive transcranial magnetic stimulation (TMS) has shown promise for evaluation of transmission through the spinal cord before and after repair strategies, but it is still unclear which pathways are activated by TMS. The aim of the present study was therefore to identify these pathways and to analyse the effect of TMS on spinal neurons. In 19 rats, TMS evoked responses bilaterally in forelimb (biceps brachii; BB) and hindlimb muscles (tibialis anterior). The latency and amplitude of these motor-evoked responses (MEPs) were highly variable and depended strongly on the coil position and the stimulation intensity. The most frequently observed latencies for the BB MEPs could be divided into three groups: 3-6 ms, 8-12 ms and 14-18 ms. Lesions in the dorsal columns, which destroyed the corticospinal tract at C2 and C5, significantly depressed MEPs in the mid- and high-latency ranges, but not those in the low-latency range. Lesions in the dorsolateral funiculus, which interrupted the rubrospinal tract, had no effect on MEPs in any of the latency ranges. By contrast, bilateral lesion of the reticulospinal tract and other ventro-laterally located descending pathways abolished all responses. Intracellular recordings from 54 cervical motoneurons in five rats revealed that TMS evoked excitatory postsynaptic potentials (EPSPs) at latencies that corresponded well with those of the BB MEPs. The short-latency EPSPs had rise times of around 1 ms, suggesting that they were mediated by a monosynaptic pathway. EPSPs with longer latencies had considerably longer rise times, which indicated conduction through polysynaptic pathways. Selective electrical stimulation of the pyramidal tract in the brainstem was performed in seven rats, where intracellular recordings from 70 motoneurons revealed that the earliest EPSPs and MEPs evoked by TMS were not mediated by the corticospinal tract, but by other descending motor pathways. Together, these results showed that in the rat TMS activates several descending pathways that converge on common spinal interneurons and motoneurons. Our observations confirm that the corticospinal tract has weak (and indirect) projections to cervical spinal motoneurons. PMID:17328776

Nielsen, J B; Perez, M A; Oudega, M; Enriquez-Denton, M; Aimonetti, J-M

2007-02-01

335

Focality assessment in transcranial magnetic stimulation with double and cone coils.  

PubMed

To evaluate the performance with respect to selectivity of the effect of the wings bending in the cone coil relative to the double coil in transcranial magnetic stimulation. The focal area and the width vector of the central lobe of the induced electrical field distributed along an elliptic surface approximating the cortex were computed for four coil models. The models represented the real coils, the double B70 and the cone B80 Medtronic, and their corresponding simulated flat coils (B70flat and B80flat). A response function was evaluated in 10 subjects for distal and proximal muscles of the upper limb by stimulation of the motor cortex along a line approximating the central sulcus. The width of the response function, at the level of the center of gravity, provided a quantitative measure for coil focality. The focal area for B70, B70flat, B80, and B80flat calculated from the model was 31.4, 32.2, 94.4, and 50.6 cm2, respectively. The width of the central lobe along the stimulation line was: 36.2, 37, 46, and 48.6 mm, respectively. Mean values of focality measure obtained experimentally were in distal muscles, 5.06 RPU (relative position units) for B70 and 5.99 RPU for B80; in proximal muscles, 4.11 RPU for B70 and 5.13 RPU for B80, with a mean RPU value of 11.13 mm. The difference, a 19% focality measure increase in B80 relative to B70 in distal muscles, was statistically significant (P < 0.001). The focality was demonstrated to be highest for the double coil. The width of the central lobe of the induced electrical field distribution is well reflected in the width of the response function. The increase in B80 is mainly due to wing geometry and relative placement of wings and is not due to the wing bending. The width of the central lobe characterizes the spread of the induced current below the wing junction, and it is a better focality estimator than the focal area for cone coils. PMID:17016158

Lontis, Eugen R; Voigt, Michael; Struijk, Johannes J

2006-10-01

336

Changes in Visual Responses in the Feline dLGN: Selective Thalamic Suppression Induced by Transcranial Magnetic Stimulation of V1  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) of the cortex can modify activity noninvasively and produce either excitatory or inhibitory effects, depending on stimulus parameters. Here we demonstrate controlled inhibitory effects on the large corticogeniculate feedback pathway from primary visual cortex to cells of the dorsal lateral geniculate nucleus (dLGN) that are focal and reversible—induced by either single pulses or trains of pulses

Carmen de Labra; Casto Rivadulla; Kenneth Grieve; Jorge Marino; Nelson Espinosa; Javier Cudeiro

2007-01-01

337

The role of the dorsolateral prefrontal cortex in retrieval from long-term memory depends on strategies: a repetitive transcranial magnetic stimulation study  

Microsoft Academic Search

The ability to associate a name to a face is a crucially relevant task in daily life. In this study, we investigated the neuronal basis of face-name retrieval in young subjects using repetitive transcranial magnetic stimulation (rTMS) over the left or right dorsolateral prefrontal cortex (DLPFC). The experimental task was composed of two study phases: an encoding phase and a

R. Manenti; M. Cotelli; M. Calabria; C. Maioli; C. Miniussi

2010-01-01

338

Changes of motor cortical excitability in human subjects from wakefulness to early stages of sleep: a combined transcranial magnetic stimulation and electroencephalographic study  

Microsoft Academic Search

The effect of sleep on human motor cortical excitability was investigated by evaluating the latency and amplitude of motor evoked potentials in ten subjects using transcranial magnetic stimulation. Motor evoked potentials and electroencephalographic data were recorded simultaneously and analyzed. Recordings were performed before, during and after a sleep period. A significant decrease in motor evoked potentials amplitude and a slight

Paolo Manganotti; Giorgio Fuggetta; Antonio Fiaschi

2004-01-01

339

Loss of the muscle silent period evoked by transcranial magnetic stimulation of the motor cortex in patients with cervical cord lesions  

Microsoft Academic Search

The silent period following motor evoked potentials in small hand muscles after transcranial magnetic stimulation (TMS) of the human motor cortex is considered to be cortical origin. The authors report three patients with cervical spinal cord lesions who showed loss of the cortical silent period (CSP) after TMS. One patient had traumatic cervical cord injury, and the other two patients

Toshio Shimizu; Taro Hino; Tetsuo Komori; Shunsaku Hirai

2000-01-01

340

Increased facilitation of the primary motor cortex following 1 Hz repetitive transcranial magnetic stimulation of the contralateral cerebellum in normal humans  

Microsoft Academic Search

Connections between the cerebellum and the contralateral motor cortex are dense and important, but their physiological significance is difficult to measure in humans. We have studied a group of 10 healthy subjects to test whether a modulation of the excitability of the left cerebellum can affect the excitability of the contralateral motor cortex. We used repetitive transcranial magnetic stimulation (rTMS)

Massimiliano Oliveri; Giacomo Koch; Sara Torriero; Carlo Caltagirone

2005-01-01

341

Low-Frequency Repetitive Transcranial Magnetic Stimulation and Intensive Occupational Therapy for Poststroke Patients with Upper Limb Hemiparesis: Preliminary Study of a 15-Day Protocol  

ERIC Educational Resources Information Center

|The purpose of the study was to determine the safety and feasibility of a 15-day protocol of low-frequency repetitive transcranial magnetic stimulation (rTMS) combined with intensive occupational therapy (OT) on motor function and spasticity in hemiparetic upper limbs in poststroke patients. Fifteen poststroke patients (age at study entry 55…

Kakuda, Wataru; Abo, Masahiro; Kobayashi, Kazushige; Momosaki, Ryo; Yokoi, Aki; Fukuda, Akiko; Ishikawa, Atsushi; Ito, Hiroshi; Tominaga, Ayumi

2010-01-01

342

Repetitive Transcranial Magnetic Stimulation for the Treatment of Major Depressive Disorder  

PubMed Central

Executive Summary Objective This review was conducted to assess the effectiveness of repetitive transcranial magnetic stimulation (rTMS) in the treatment of major depressive disorder (MDD). The Technology rTMS is a noninvasive way to stimulate nerve cells in areas of the brain. During rTMS, an electrical current passes through a wire coil placed over the scalp. The current induces a magnetic field that produces an electrical field in the brain that then causes nerve cells to depolarize, resulting in the stimulation or disruption of brain activity. Researchers have investigated rTMS as an option to treat MDD, as an add-on to drug therapy, and, in particular, as an alternative to electroconvulsive therapy (ECT) for patients with treatment-resistant depression. The advantages of rTMS over ECT for patients with severe refractory depression are that general anesthesia is not needed, it is an outpatient procedure, it requires less energy, the simulation is specific and targeted, and convulsion is not required. The advantages of rTMS as an add-on treatment to drug therapy may include hastening of the clinical response when used with antidepressant drugs. Review Strategy The Medical Advisory Secretariat used its standard search strategy to locate international health technology assessments and English-language journal articles published from January 1996 to March 2004. Summary of Findings Some early meta-analyses suggested rTMS might be effective for the treatment of MDD (for treatment-resistant MDD and as an add-on treatment to drug therapy for patients not specifically defined as treatment resistant). There were, however, several crucial methodological limitations in the included studies that were not critically assessed. These are discussed below. Recent meta-analyses (including 2 international health technology assessments) have done evidence-based critical analyses of studies that have assessed rTMS for MDD. The 2 most recent health technology assessments (from the Oxford Cochrane Collaboration and the Norwegian Centre for Health Technology Assessment) concluded that there is no evidence that rTMS is effective for the treatment of MDD, either as compared with a placebo for patients with treatment-resistant or nontreatment-resistant MDD, or as an alternative to ECT for patients with treatment-resistant MDD. This mainly due to the poor quality of the studies. The major methodological limitations were identified in older meta-analyses, recent health technology assessments, and the most recently published trials (Level 2–4 evidence) on the effectiveness of rTMS for MDD are discussed below. Small sample size was a limitation acknowledged by many of the authors. There was also a lack of a priori sample size calculation or justification. Biased randomization may have been a problem. Generally, the published reports lacked detailed information on the method of allocation concealment used. This is important because it is impossible to determine if there was a possible influence (direct or indirect) in the allocation of the patients to different treatment groups. The trials were single blind, evaluated by external blinded assessors, rather than double blind. Double blinding is more robust, because neither the participants nor the investigators know which participants are receiving the active treatment and which are getting a placebo. Those administering rTMS, however, cannot be blinded to whether they are administering the active treatment or a placebo. There was patient variability among the studies. In some studies, the authors said that patients were “medication resistant,” but the definitions of resistant, if provided, were inconsistent or unclear. For example, some described “medication resistant” as failing at least one trial of drugs during the current depressive episode. Furthermore, it was unclear if the term “medication resistant” referred to antidepressants only or to combinations of antidepressants and other drug augmentation strategies (such as neuroleptics, benzodiazepine

2004-01-01

343

An integrated computer-controlled system for assisting researchers in cortical excitability studies by using transcranial magnetic stimulation.  

PubMed

Transcranial magnetic stimulation (TMS) is the most important technique currently available to study cortical excitability. Additionally, TMS can be used for therapeutic and rehabilitation purposes, replacing the more painful transcranial electric stimulation (TES). In this paper we present an innovative and easy-to-use tool that enables neuroscientists to design, carry out and analyze scientific studies based on TMS experiments for both diagnostic and research purposes, assisting them not only in the practicalities of administering the TMS but also in each step of the entire study's workflow. One important aspect of this tool is that it allows neuroscientists to specify research designs at will, enabling them to define any parameter of a TMS study starting from data acquisition and sample group definition to automated statistical data analysis and RDF data storage. It also supports the diagnosing process by using on-line support vector machines able to learn incrementally from the diseases instances that are continuously added into the system. The proposed system is a neuroscientist-centred tool where the protocols being followed in TMS studies are made explicit, leaving to the users flexibility in exploring and sharing the results, and providing assistance in managing the complexity of the final diagnosis. This type of tool can make the results of medical experiments more easily exploitable, thus accelerating scientific progress. PMID:22172294

Giordano, D; Kavasidis, I; Spampinato, C; Bella, R; Pennisi, G; Pennisi, M

2011-12-14

344

The Effect of a Series of Repetitive Transcranial Magnetic Stimulations of the Motor Cortex on Central Pain After Spinal Cord Injury  

Microsoft Academic Search

Defrin R, Grunhaus L, Zamir D, Zeilig G. The effect of a series of repetitive transcranial magnetic stimula- tions of the motor cortex on central pain after spinal cord injury. Arch Phys Med Rehabil 2007;88:1574-80. Objective: To study the analgesic effect of repetitive trans- cranial magnetic stimulation (rTMS) of the motor cortex on central pain in patients with chronic spinal

Ruth Defrin; Leon Grunhaus; Doron Zamir; Gabi Zeilig

345

Imaging functional activation of the auditory cortex during focal repetitive transcranial magnetic stimulation of the primary motor cortex in normal subjects  

Microsoft Academic Search

Positron emission tomography (PET) during focal repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising approach to study cortical connectivity in awake humans. However, the noise caused by the discharging magnetic coil might have confounding effects on the rTMS-related cortical activation pattern. In twelve healthy volunteers, 18-fluoro-2-deoxy-d-glucose (18FDG) PET was employed to visualize the functional activation of the primary

Hartwig Roman Siebner; Martin Peller; Frode Willoch; Carola Auer; Peter Bartenstein; Alexander Drzezga; Markus Schwaiger; Bastian Conrad

1999-01-01

346

Effect of Transcranial Magnetic Stimulation on Short and Long-Term Memory in Healthy Subjects and Patients with Parkinson’s Disease  

Microsoft Academic Search

The effect of transcranial magnetic stimulation (TMS) of the right and the left frontotemporal areas on the short- and long-term verbal memory was studied in healthy subjects and patients with Parkinson’s disease. TMS with a magnetic induction of more than 1.2 T at 10 Hz was found to affect the short-term memory when applied to the left frontotemporal area and

R. F. Gimranov; E. A. Mal’tseva

2005-01-01

347

A transcranial magnetic stimulation study of the effect of visual orientation on the putative human mirror neuron system.  

PubMed

Mirror neurons are a class of motor neuron that are active during both the performance and observation of behavior, and have been implicated in interpersonal understanding. There is evidence to suggest that the mirror response is modulated by the perspective from which an action is presented (e.g., egocentric or allocentric). Most human research, however, has only examined this when presenting intransitive actions. Twenty-three healthy adult participants completed a transcranial magnetic stimulation experiment that assessed corticospinal excitability whilst viewing transitive hand gestures from both egocentric (i.e., self) and allocentric (i.e., other) viewpoints. Although action observation was associated with increases in corticospinal excitability (reflecting putative human mirror neuron activity), there was no effect of visual perspective. These findings are discussed in the context of contemporary theories of mirror neuron ontogeny, including models concerning associative learning and evolutionary adaptation. PMID:24137125

Burgess, Jed D; Arnold, Sara L; Fitzgibbon, Bernadette M; Fitzgerald, Paul B; Enticott, Peter G

2013-10-16

348

A Neuronal Network Model for Simulating the Effects of Repetitive Transcranial Magnetic Stimulation on Local Field Potential Power Spectra  

PubMed Central

Repetitive transcranial magnetic stimulation (rTMS) holds promise as a non-invasive therapy for the treatment of neurological disorders such as depression, schizophrenia, tinnitus, and epilepsy. Complex interdependencies between stimulus duration, frequency and intensity obscure the exact effects of rTMS stimulation on neural activity in the cortex, making evaluation of and comparison between rTMS studies difficult. To explain the influence of rTMS on neural activity (e.g. in the motor cortex), we use a neuronal network model. The results demonstrate that the model adequately explains experimentally observed short term effects of rTMS on the band power in common frequency bands used in electroencephalography (EEG). We show that the equivalent local field potential (eLFP) band power depends on stimulation intensity rather than on stimulation frequency. Additionally, our model resolves contradictions in experiments.

Bey, Alina; Leue, Stefan; Wienbruch, Christian

2012-01-01

349

A transcranial magnetic stimulation study of the effect of visual orientation on the putative human mirror neuron system  

PubMed Central

Mirror neurons are a class of motor neuron that are active during both the performance and observation of behavior, and have been implicated in interpersonal understanding. There is evidence to suggest that the mirror response is modulated by the perspective from which an action is presented (e.g., egocentric or allocentric). Most human research, however, has only examined this when presenting intransitive actions. Twenty-three healthy adult participants completed a transcranial magnetic stimulation experiment that assessed corticospinal excitability whilst viewing transitive hand gestures from both egocentric (i.e., self) and allocentric (i.e., other) viewpoints. Although action observation was associated with increases in corticospinal excitability (reflecting putative human mirror neuron activity), there was no effect of visual perspective. These findings are discussed in the context of contemporary theories of mirror neuron ontogeny, including models concerning associative learning and evolutionary adaptation.

Burgess, Jed D.; Arnold, Sara L.; Fitzgibbon, Bernadette M.; Fitzgerald, Paul B.; Enticott, Peter G.

2013-01-01

350

Probing V5/MT excitability with transcranial magnetic stimulation following visual motion adaptation to random and coherent motion.  

PubMed

The response to stimulating the visual cortex with transcranial magnetic stimulation (TMS) depends on its initial activation state, for example, visual motion adaptation biases perceived TMS-induced phosphene characteristics (e.g., color). We quantified this state dependence by assessing the probability of reporting a phosphene (P(?) ) with "threshold" TMS (i.e., the TMS intensity producing P(?) = 0.5 at baseline) following visual motion adaptation to a random dot motion display. Postadaptation, P(?) was increased, and this effect was confined to the adapted neuronal population. We then adapted subjects using a population of moving dots of fixed average motion direction with standard deviations (SD) ranging from 1° to 128° (SD fixed for a given trial). P(?) was significantly increased at all dot motion SDs except SD = 1°. Neuronal adaptation increases the susceptibility of the neuronal population to activation by threshold intensity TMS. Thus the process of neuronal adaption is not necessarily synonymous with a downmodulation of neuronal excitability. PMID:21950994

Guzman-Lopez, Jessica; Silvanto, Juha; Yousif, Nada; Nousi, Sofia; Quadir, Shamim; Seemungal, Barry M

2011-09-01

351

Novel Therapeutic Strategies for Alcohol and Drug Addiction: Focus on GABA, Ion Channels and Transcranial Magnetic Stimulation  

PubMed Central

Drug addiction represents a major social problem where addicts and alcoholics continue to seek and take drugs despite adverse social, personal, emotional, and legal consequences. A number of pharmacological compounds have been tested in human addicts with the goal of reducing the level or frequency of intake, but these pharmacotherapies have often been of only moderate efficacy or act in a sub-population of humans. Thus, there is a tremendous need for new therapeutic interventions to treat addiction. Here, we review recent interesting studies focusing on gamma-aminobutyric acid receptors, voltage-gated ion channels, and transcranial magnetic stimulation. Some of these treatments show considerable promise to reduce addictive behaviors, or the early clinical studies or pre-clinical rationale suggest that a promising avenue could be developed. Thus, it is likely that within a decade or so, we could have important new and effective treatments to achieve the goal of reducing the burden of human addiction and alcoholism.

Addolorato, Giovanni; Leggio, Lorenzo; Hopf, F Woodward; Diana, Marco; Bonci, Antonello

2012-01-01

352

Repetitive transcranial magnetic stimulation of the unaffected hemisphere in a patient who was forced to use the affected hand.  

PubMed

We present a case report of a 56-yr-old chronic stroke patient with right hemiparesis who was treated with repetitive transcranial magnetic stimulation (rTMS) therapy. Before stroke, the patient had suffered an accident that led to paralysis and contracture of the left upper limb, and, subsequently, he was forced to use only his right upper limb for routine activities, despite right hemiparesis. We performed subthreshold rTMS (1 Hz, 25 mins) and sham stimulation of the contralesional primary motor cortex (M1) at different times. Immediately after rTMS, the patient was able to write characters with increased speed and accuracy, and this effect continued for more than 7 days; however, this was not the case after sham stimulation. Moreover, the writing practice after rTMS improved the patient's pinch force. PMID:18158432

Takeuchi, Naoyuki; Toshima, Masahiko; Chuma, Takayo; Matsuo, Yuichiro; Ikoma, Katsunori

2008-01-01

353

Disturbance of visual search by stimulating to posterior parietal cortex in the brain using transcranial magnetic stimulation  

NASA Astrophysics Data System (ADS)

In this study, we applied a transcranial magnetic stimulation (TMS) to investigate the temporal aspect for the functional processing of visual attention. Although it has been known that right posterior parietal cortex (PPC) in the brain has a role in certain visual search tasks, there is little knowledge about the temporal aspect of this area. Three visual search tasks that have different difficulties of task execution individually were carried out. These three visual search tasks are the ``easy feature task,'' the ``hard feature task,'' and the ``conjunction task.'' To investigate the temporal aspect of the PPC involved in the visual search, we applied various stimulus onset asynchronies (SOAs) and measured the reaction time of the visual search. The magnetic stimulation was applied on the right PPC or the left PPC by the figure-eight coil. The results show that the reaction times of the hard feature task are longer than those of the easy feature task. When SOA=150 ms, compared with no-TMS condition, there was a significant increase in target-present reaction time when TMS pulses were applied. We considered that the right PPC was involved in the visual search at about SOA=150 ms after visual stimulus presentation. The magnetic stimulation to the right PPC disturbed the processing of the visual search. However, the magnetic stimulation to the left PPC gives no effect on the processing of the visual search.

Iramina, Keiji; Ge, Sheng; Hyodo, Akira; Hayami, Takehito; Ueno, Shoogo

2009-04-01

354

Magnetic Properties and Mineralogy of Four Deep-Sea Cores.  

National Technical Information Service (NTIS)

Ferromagnetic minerals have been extracted from 17 samples from four deep-sea cores. Measurements of bulk susceptibility and saturation isothermal remanent magnetization were used as semiquantitative indicators of the efficiency of the described technique...

W. Lowrie M. Jacobs R. Lovlie

1972-01-01

355

The Effect of Variation in Permittivity of Different Tissues on Induced Electric Field in the Brain during Transcranial Magnetic Stimulation  

NASA Astrophysics Data System (ADS)

Estimation of electric field in the brain during Transcranial Magnetic Stimulation (TMS) requires knowledge of the electric property of brain tissue. Grey and white matters have unusually high relative permittivities of ˜ 10^6 at low frequencies. However, relative permittivity of cerebrospinal fluid is ˜ 10^2. With such a variation it is necessary to consider the effect of boundaries. A model consisting of 2 hemispheres was used in the model with the properties of one hemisphere kept constant at ?1=0.1Sm-1 and ?r1= 10 while the properties of the second hemisphere were changed kept at ?2=0.1Sm-1 to 2Sm-1 and ?r2= 10^2 to 10^5. A 70 mm diameter double coil was used as the source of the magnetic field. The amplitude of the current in the coil was 5488 A at a frequency of 2.9 kHz. The results show that the electric field, E induced during magnetic stimulation is independent of the relative permittivity, ?r and varies with the conductivity. Thus the variation in E, calculated with homogeneous and heterogeneous head models was due to variation in conductivity of the tissues and not due to variation in permittivities.

Hadimani, Ravi L.; Porzig, Konstantin; Crowther, Lawrence J.; Brauer, Hartmut; Toepfer, Hannes; Jiles, David C.

2013-03-01

356

Test-retest assessment of cortical activation induced by repetitive transcranial magnetic stimulation with brain atlas-guided optical topography  

NASA Astrophysics Data System (ADS)

Repetitive transcranial magnetic stimulation (rTMS) is a technology that stimulates neurons with rapidly changing magnetic pulses with demonstrated therapeutic applications for various neuropsychiatric disorders. Functional near-infrared spectroscopy (fNIRS) is a suitable tool to assess rTMS-evoked brain responses without interference from the magnetic or electric fields generated by the TMS coil. We have previously reported a channel-wise study of combined rTMS/fNIRS on the motor and prefrontal cortices, showing a robust decrease of oxygenated hemoglobin concentration (?[HbO2]) at the sites of 1-Hz rTMS and the contralateral brain regions. However, the reliability of this putative clinical tool is unknown. In this study, we develop a rapid optical topography approach to spatially characterize the rTMS-evoked hemodynamic responses on a standard brain atlas. A hemispherical approximation of the brain is employed to convert the three-dimensional topography on the complex brain surface to a two-dimensional topography in the spherical coordinate system. The test-retest reliability of the combined rTMS/fNIRS is assessed using repeated measurements performed two to three days apart. The results demonstrate that the ?[HbO2] amplitudes have moderate-to-high reliability at the group level; and the spatial patterns of the topographic images have high reproducibility in size and a moderate degree of overlap at the individual level.

Tian, Fenghua; Kozel, F. Andrew; Yennu, Amarnath; Croarkin, Paul E.; McClintock, Shawn M.; Mapes, Kimberly S.; Husain, Mustafa M.; Liu, Hanli

2012-11-01

357

Measuring and manipulating brain connectivity with resting state functional connectivity magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS)  

PubMed Central

Both resting state functional magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS) are increasingly popular techniques that can be used to non-invasively measure brain connectivity in human subjects. TMS shows additional promise as a method to manipulate brain connectivity. In this review we discuss how these two complimentary tools can be combined to optimally study brain connectivity and manipulate distributed brain networks. Important clinical applications include using resting state fcMRI to guide target selection for TMS and using TMS to modulate pathological network interactions identified with resting state fcMRI. The combination of TMS and resting state fcMRI has the potential to accelerate the translation of both techniques into the clinical realm and promises a new approach to the diagnosis and treatment of neurological and psychiatric diseases that demonstrate network pathology.

Fox, Michael D.; Halko, Mark A.; Eldaief, Mark C.; Pascual-Leone, Alvaro

2012-01-01

358

The Effects of Theta Burst Transcranial Magnetic Stimulation over the Human Primary Motor and Sensory Cortices on Cortico-Muscular Coherence  

Microsoft Academic Search

Recent studies proposed a new paradigm of repetitive transcranial magnetic stimulation (rTMS), “theta burst stimulation” (TBS);\\u000a to primary motor cortex (M1) or sensory cortex (S1) can influence cortical excitability in humans. Particularly it has been\\u000a shown that TBS can induce the long-lasting effects with the stimulation duration shorter than those of conventional rTMSs.\\u000a However, in those studies, effects of TBS

Murat Saglam; Kaoru Matsunaga; Yuki Hayashida; Nobuki Murayama; Ryoji Nakanishi

2007-01-01

359

Opposite impact on 14 C-2-deoxyglucose brain metabolism following patterns of high and low frequency repetitive transcranial magnetic stimulation in the posterior parietal cortex  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) appears capable of modulating human cortical excitability beyond the duration\\u000a of the stimulation train. However, the basis and extent of this “off-line” modulation remains unknown. In a group of anesthetized\\u000a cats, we applied patterns of real or sham focal rTMS to the visuo-parietal cortex (VP) at high (HF) or low (LF) frequency\\u000a and recorded brain

Antoni Valero-Cabré; Bertram R. Payne; Alvaro Pascual-Leone

2007-01-01

360

The effect of short-duration bursts of high-frequency, low-intensity transcranial magnetic stimulation on the human motor cortex  

Microsoft Academic Search

Objective: To explore the effect of applying a short burst of high-frequency repetitive transcranial magnetic stimulation (rTMS) to the human motor cortex as a preparatory investigation before attempting theta burst stimulation in humans.Methods: Five or15 pulses of 50 Hz rTMS were given at 50–80% active motor threshold (AMT). The time course of changes in motor-evoked potential (MEP) size and short

Ying-Zu Huang; John C Rothwell

2004-01-01

361

Impact of repetitive transcranial magnetic stimulation of the parietal cortex on metabolic brain activity: a 14 C-2DG tracing study in the cat  

Microsoft Academic Search

Transcranial magnetic stimulation (TMS) is increasingly utilized in clinical neurology and neuroscience. However, detailed knowledge of the impact and specificity of the effects of TMS on brain activity remains unresolved. We have used 14C-labeled deoxyglucose (14C-2DG) mapping during repetitive TMS (rTMS) of the posterior and inferior parietal cortex in anesthetized cats to study, with exquisite spatial resolution, the local and

Antoni Valero-Cabré; Bertram R. Payne; Jarrett Rushmore; Stephen G. Lomber; Alvaro Pascual-Leone

2005-01-01

362

Abnormal increase in the corticomotor output to the affected hand during repetitive transcranial magnetic stimulation of the primary motor cortex in patients with writer's cramp  

Microsoft Academic Search

In fourteen right-handed patients with writer's cramp and 10 right-handed controls, 10 trains of suprathreshold 1 Hz repetitive transcranial magnetic stimulation (rTMS) were applied over the left primary motor hand area. Each rTMS train lasted for a minute with an intertrain interval of 10 s. The motor evoked potentials (MEPs) were recorded from the relaxed contralateral first dorsal interosseus muscle.

Hartwig Roman Siebner; Carola Auer; Bastian Conrad

1999-01-01

363

Deactivation and activation of left frontal lobe during and after low-frequency repetitive transcranial magnetic stimulation over right prefrontal cortex: A near-infrared spectroscopy study  

Microsoft Academic Search

The effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) over the right frontal lobe on the function of the left frontal lobe were examined by near-infrared spectroscopy (NIRS) in eleven healthy subjects. rTMS applied 5cm anterior to the motor cortex at 1Hz and approximately 50% of the motor threshold intensity (MT) for 60s resulted in a significantly larger decrease in

Naoki Hanaoka; Yoshiyuki Aoyama; Masaki Kameyama; Masato Fukuda; Masahiko Mikuni

2007-01-01

364

Transcranial magnetic stimulation of the posterior parietal cortex delays the latency of both isolated and combined vergence–saccade movements in humans  

Microsoft Academic Search

To explore the 3D visual environment most frequently we make combined saccade–vergence eye movements. We studied the effect of transcranial magnetic stimulation (TMS) of the right posterior parietal cortex (rPPC) on such combined eye movements versus isolated saccade and vergence. In the main experiment, TMS was applied on the rPPC 80, 90 or 100 ms after target onset. In a

Qing Yang; Olivier Coubard; Gintautas Daunys; Christophe Orssaud

2004-01-01

365

Asymmetric responses to repetitive transcranial magnetic stimulation (rTMS) over the left and right primary motor cortex in a patient with lateralized progressive limb-kinetic apraxia  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (5Hz-rTMS, 10 stimuli, 120% resting motor threshold intensity, RMT) produces in healthy subjects a progressive facilitation of motor-evoked potential (MEP) amplitude probably through a short-term enhancement of cortical excitatory interneurones. We had the opportunity to investigate the effect of 5Hz-rTMS delivered over the right and left primary motor cortex (M1) in a patient with limb-kinetic apraxia

Francesca Gilio; Elisa Iacovelli; Antonella Conte; Vittorio Frasca; Maria Gabriele; Elena Giacomelli; Chiara Marini Bettolo; Nicola Scaldaferri; Alessandro Trebbastoni; Massimiliano Prencipe; Maurizio Inghilleri

2008-01-01

366

Spatial working memory performance after high-frequency repetitive transcranial magnetic stimulation of the left and right posterior parietal cortex in humans  

Microsoft Academic Search

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

Roy P. C Kessels; Alfredo A. L d'Alfonso; Albert Postma; Edward H. F de Haan

2000-01-01

367

Sustained increase of somatosensory cortex excitability by 5 Hz repetitive transcranial magnetic stimulation studied by paired median nerve stimulation in humans  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) has been shown to alter cortical processing within primary motor cortex dependent on the choice of stimulation variables. However, little is known about the effects of TMS in other cortical areas such as the primary somatosensory cortex (SI). Here we asked whether high-frequency (5 Hz) rTMS applied over the left SI evokes sustained changes in

Patrick Ragert; Michael Becker; Martin Tegenthoff; Burkhard Pleger; Hubert R. Dinse

2004-01-01

368

Beneficial effect of repetitive transcranial magnetic stimulation combined with cognitive training for the treatment of Alzheimer’s disease: a proof of concept study  

Microsoft Academic Search

The current drug treatment for Alzheimer’s disease (AD) is only partially and temporary effective. Transcranial magnetic stimulation\\u000a (TMS) is a non-invasive technique that generates an electric current inducing modulation in cortical excitability. In addition,\\u000a cognitive training (COG) may improve cognitive functions in AD. Our aim was to treat AD patients combining high-frequency\\u000a repetitive TMS interlaced with COG (rTMS-COG). Eight patients

Jonathan Bentwich; Evgenia Dobronevsky; Sergio Aichenbaum; Ran Shorer; Ruth Peretz; Michael Khaigrekht; Revital Gandelman Marton; Jose M. Rabey

2011-01-01

369

Rapid-rate transcranial magnetic stimulation of animal auditory cortex impairs short-term but not long-term memory formation  

Microsoft Academic Search

Bilateral rapid-rate transcranial magnetic stimulation (rTMS) of gerbil auditory cortex with a miniature coil device was used to study short-term and long-term effects on discrimination learning of frequency-modulated tones. We found previously that directional discrimination of frequency modulation (rising vs. falling) relies on auditory cortex processing and that formation of its memory depends on local protein synthesis. Here we show

Hong Wang; Xu Wang; Wolfram Wetzel; Henning Scheich

2006-01-01

370

High-frequency transcranial magnetic stimulation of the supplementary motor area reduces bimanual coupling during anti-phase but not in-phase movements  

Microsoft Academic Search

Previous electrophysiological and neuroimaging studies have provided evidence that the supplementary motor area (SMA) has\\u000a an important role in the control of bimanual coordination. The present experiment investigated the effects of high-frequency\\u000a repetitive transcranial magnetic stimulation (rTMS) over the SMA region on kinematic variables during cyclical bimanual coordination,\\u000a with a particular focus on the quality of coordination. Subjects performed metronome-paced

Maarten Steyvers; Seiji Etoh; Dieter Sauner; Oron Levin; Hartwig R. Siebner; Stephan P. Swinnen; John C. Rothwell

2003-01-01

371

Effect of high frequency repetitive transcranial magnetic stimulation on reaction time, clinical features and cognitive functions in patients with Parkinson’s disease  

Microsoft Academic Search

The aim of the present study was to investigate the effects of one session of high-frequency repetitive transcranial magnetic\\u000a stimulation (rTMS) applied over the left dorsal premotor cortex (PMd) and left dorsolateral prefrontal cortex (DLPFC) on choice\\u000a reaction time in a noise-compatibility task, and cognitive functions in patients with Parkinson’s disease (PD). Clinical motor\\u000a symptoms of PD were assessed as

Silvie Sedlá?ková; Irena Rektorová; Hana Srovnalová; Ivan Rektor

2009-01-01

372

Effect of transcranial magnetic stimulation on the expression of c-Fos and brain-derived neurotrophic factor of the cerebral cortex in rats with cerebral infarct  

Microsoft Academic Search

Summary  The effect of transcranial magnetic stimulation (TMS) on the neurological functional recovery and expression of c-Fos and\\u000a brain-derived neurotrophic factor (BDNF) of the cerebral cortex in rats with cerebral infarction was investigated. Cerebral\\u000a infarction models were established by using left middle cerebral artery occlusion (MCAO) and were randomly divided into a\\u000a model group (n=40) and a TMS group (n=40). TMS

Xiaoqiao Zhang; Yuanwu Mei; Chuanyu Liu; Shanchun Yu

2007-01-01

373

Repetitive transcranial magnetic stimulation for the treatment of negative symptoms in residual schizophrenia: rationale and design of a sham-controlled, randomized multicenter study  

Microsoft Academic Search

Current meta-analysis revealed small, but significant effects of repetitive transcranial magnetic stimulation (rTMS) on negative\\u000a symptoms in patients with schizophrenia. There is a need for further controlled, multicenter trials to assess the clinical\\u000a efficacy of rTMS on negative symptoms in schizophrenia in a larger sample of patients. The objective of this multicenter,\\u000a randomized, sham-controlled, rater- and patient-blind clinical trial is

Joachim Cordes; P. Falkai; B. Guse; A. Hasan; T. Schneider-Axmann; M. Arends; G. Winterer; W. Wölwer; E. Ben Sliman; M. Ramacher; C. Schmidt-Kraepelin; C. Ohmann; B. Langguth; M. Landgrebe; P. Eichhammer; E. Frank; J. Burger; G. Hajak; M. Rietschel; T. Wobrock

2009-01-01

374

Effect of the stimulus frequency and pulse number of repetitive transcranial magnetic stimulation on the inter-reversal time of perceptual reversal on the right superior parietal lobule  

Microsoft Academic Search

The aim of this study is to investigate the effect of the stimulus frequency and pulses number of repetitive transcranial magnetic stimulation (rTMS) on the inter-reversal time (IRT) of perceptual reversal on the right superior parietal lobule (SPL). The spinning wheel illusion was used as the ambiguous figures stimulation in this study. To investigate the rTMS effect over the right

Kazuhisa Nojima; Sheng Ge; Yoshinori Katayama; Shoogo Ueno; Keiji Iramina

2010-01-01

375

Characterisation of paired-pulse transcranial magnetic stimulation conditions yielding intracortical inhibition or I-wave facilitation using a threshold-hunting paradigm  

Microsoft Academic Search

Short-interval, paired-pulse transcranial magnetic stimulation (TMS) is usually used to demonstrate intracortical inhibition.\\u000a It was shown recently that with short-interval, paired-pulse TMS a facilitation – called intracortical I-wave facilitation\\u000a – can also be demonstrated. It was the aim of this study to investigate which stimulus conditions lead to intracortical inhibition\\u000a and what conditions yield an intracortical I-wave facilitation in a

Friedemann Awiszus; Helmut Feistner; Dietmar Urbach; Hugh Bostock

1999-01-01

376

Effect of low-frequency transcranial magnetic stimulation on an affective go\\/no-go task in patients with major depression: Role of stimulation site and depression severity  

Microsoft Academic Search

Repetitive transcranial magnetic stimulation (rTMS) holds promise as a therapeutic tool in major depression. However, a means to assess the effects of a single rTMS session on mood to guide subsequent sessions would be desirable. The present study examined the effects of a single rTMS session on an affective go\\/no-go task known to measure emotional–cognitive deficits associated with major depression.

Felix Bermpohl; Felipe Fregni; Paulo S. Boggio; Gregor Thut; Georg Northoff; Patricia T. M. Otachi; Sergio P. Rigonatti; Marco A. Marcolin; Alvaro Pascual-Leone

2006-01-01

377

Movement and afferent representations in human motor areas: a simultaneous neuroimaging and transcranial magnetic/peripheral nerve-stimulation study  

PubMed Central

Neuroimaging combined with transcranial magnetic stimulation (TMS) to primary motor cortex (M1) is an emerging technique that can examine motor-system functionality through evoked activity. However, because sensory afferents from twitching muscles are widely represented in motor areas the amount of evoked activity directly resulting from TMS remains unclear. We delivered suprathreshold TMS to left M1 or gave electrical right median nerve stimulation (MNS) in 18 healthy volunteers while simultaneously conducting functional magnetic resonance imaging and monitoring with electromyography (EMG). We examined in detail the localization of TMS-, muscle afferent- and superficial afferent-induced activity in M1 subdivisions. Muscle afferent- and TMS-evoked activity occurred mainly in rostral M1, while superficial afferents generated a slightly different activation distribution. In 12 participants who yielded quantifiable EMG, differences in brain activity ascribed to differences in movement-size were adjusted using integrated information from the EMGs. Sensory components only explained 10–20% of the suprathreshold TMS-induced activity, indicating that locally and remotely evoked activity in motor areas mostly resulted from the recruitment of neural and synaptic activity. The present study appears to justify the use of fMRI combined with suprathreshold TMS to M1 for evoked motor network imaging.

Shitara, H.; Shinozaki, T.; Takagishi, K.; Honda, M.; Hanakawa, T.

2013-01-01

378

Movement and afferent representations in human motor areas: a simultaneous neuroimaging and transcranial magnetic/peripheral nerve-stimulation study.  

PubMed

Neuroimaging combined with transcranial magnetic stimulation (TMS) to primary motor cortex (M1) is an emerging technique that can examine motor-system functionality through evoked activity. However, because sensory afferents from twitching muscles are widely represented in motor areas the amount of evoked activity directly resulting from TMS remains unclear. We delivered suprathreshold TMS to left M1 or gave electrical right median nerve stimulation (MNS) in 18 healthy volunteers while simultaneously conducting functional magnetic resonance imaging and monitoring with electromyography (EMG). We examined in detail the localization of TMS-, muscle afferent- and superficial afferent-induced activity in M1 subdivisions. Muscle afferent- and TMS-evoked activity occurred mainly in rostral M1, while superficial afferents generated a slightly different activation distribution. In 12 participants who yielded quantifiable EMG, differences in brain activity ascribed to differences in movement-size were adjusted using integrated information from the EMGs. Sensory components only explained 10-20% of the suprathreshold TMS-induced activity, indicating that locally and remotely evoked activity in motor areas mostly resulted from the recruitment of neural and synaptic activity. The present study appears to justify the use of fMRI combined with suprathreshold TMS to M1 for evoked motor network imaging. PMID:24062660

Shitara, H; Shinozaki, T; Takagishi, K; Honda, M; Hanakawa, T

2013-09-17

379

Where does transcranial magnetic stimulation (TMS) stimulate? Modelling of induced field maps for some common cortical and cerebellar targets.  

PubMed

Computational models have been be used to estimate the electric and magnetic fields induced by transcranial magnetic stimulation (TMS) and can provide valuable insights into the location and spatial distribution of TMS stimulation. However, there has been little translation of these findings into practical TMS research. This study uses the International 10-20 EEG electrode placement system to position a standard figure-of-eight TMS coil over 13 commonly adopted targets. Using a finite element method and an anatomically detailed and realistic head model, this study provides the first pictorial and numerical atlas of TMS-induced electric fields for a range of coil positions. The results highlight the importance of subject-specific gyral folding patterns and of local thickness of subarachnoid cerebrospinal fluid (CSF). Our modelling shows that high electric fields occur primarily on the peaks of those gyri which have only a thin layer of CSF above them. These findings have important implications for inter-individual generalizability of the TMS-induced electric field. We propose that, in order to determine with accuracy the site of stimulation for an individual subject, it is necessary to solve the electric field distribution using subject-specific anatomy obtained from a high-resolution imaging modality such as MRI. PMID:22678596

Bijsterbosch, Janine D; Barker, Anthony T; Lee, Kwang-Hyuk; Woodruff, P W R

2012-06-08

380

3D modeling of the total electric field induced by transcranial magnetic stimulation using the boundary element method  

NASA Astrophysics Data System (ADS)

Transcranial magnetic stimulation (TMS) delivers highly localized brain stimulations via non-invasive externally applied magnetic fields. This non-invasive, painless technique provides researchers and clinicians with a unique tool capable of stimulating both the central and peripheral nervous systems. However, a complete analysis of the macroscopic electric fields produced by TMS has not yet been performed. In this paper, we addressed the importance of the secondary E-field created by surface charge accumulation during TMS using the boundary element method (BEM). 3D models were developed using simple head geometries in order to test the model and compare it with measured values. The effects of tissue geometry, size and conductivity were also investigated. Finally, a realistically shaped head model was used to assess the effect of multiple surfaces on the total E-field. Secondary E-fields have the greatest impact at areas in close proximity to each tissue layer. Throughout the head, the secondary E-field magnitudes typically range from 20% to 35% of the primary E-field's magnitude. The direction of the secondary E-field was generally in opposition to the primary E-field; however, for some locations, this was not the case (i.e. going from high to low conductivity tissues). These findings show that realistically shaped head geometries are important for accurate modeling of the total E-field.

Salinas, F. S.; Lancaster, J. L.; Fox, P. T.

2009-06-01

381

Descending spinal cord volleys evoked by transcranial magnetic and electrical stimulation of the motor cortex leg area in conscious humans  

PubMed Central

Descending corticospinal volleys evoked after transcranial magnetic or electrical stimulation of the leg area of the motor cortex were recorded from an electrode in the spinal epidural space of six conscious patients who had electrodes implanted for treatment of chronic pain, and from one anaesthetised patient undergoing surgery for a spinal tumour. At threshold, the shortest-latency volley (L1 volley) was evoked by stimulation with an anode 2 cm lateral to the vertex. Anodal stimulation at the vertex also elicited a volley at this latency in two patients, but in the other patients the first volley evoked appeared 1—1.3 ms later (L2 volley), at the same latency as the initial volley evoked by magnetic stimulation. High-intensity stimulation of any type could evoke both the L1 and L2 waves as well as later ones (L3, L4, etc.) that had a periodicity of about 1.5 ms. Voluntary contraction increased the amplitude of the L2 and later volleys, but had no effect on the L1 volley. Intracortical inhibition between pairs of magnetic stimuli resulted in clear suppression of the L4 and later waves. The L2 and L3 waves were unaffected. In the anaesthetised patient the L1 volley occurred 1.7 ms later than the volley produced by transmastoid stimulation of the corticospinal pathways in the brainstem. The L1 volley is likely to be a D wave produced by the direct activation of pyramidal axons in the subcortical white matter; the L2 and later volleys are likely to be I waves produced by the trans-synaptic activation of corticospinal neurones. The implication is that electrical stimulation with an anode at the vertex is more likely to evoke I waves preferentially than stimulation over the hand area. A more secure way to ensure D wave activation of corticospinal fibres from the leg area is to place the anode 2 cm lateral to the vertex.

Lazzaro, V Di; Oliviero, A; Profice, P; Meglio, M; Cioni, B; Tonali, P; Rothwell, J C

2001-01-01

382

Recovery from object substitution masking induced by transient suppression of visual motion processing: a repetitive transcranial magnetic stimulation study.  

PubMed

Object substitution masking is a form of visual backward masking in which a briefly presented target is rendered invisible by a lingering mask that is too sparse to produce lower image-level interference. Recent studies suggested the importance of an updating process in a higher object-level representation, which should rely on the processing of visual motion, in this masking. Repetitive transcranial magnetic stimulation (rTMS) was used to investigate whether functional suppression of motion processing would selectively reduce substitution masking. rTMS-induced transient functional disruption of cortical area V5/MT+, which is important for motion analysis, or V1, which is reciprocally connected with V5/MT+, produced recovery from masking, whereas sham stimulation did not. Furthermore, masking remained undiminished following rTMS over the region 2 cm posterior to V5/MT+, ruling out nonspecific effects of real stimulation and confirming regional specificity of the rTMS effect. The results suggest that object continuity via the normal function of the visual motion processing system might in part contribute to this masking. The relation of these findings to the reentrant processing view of object substitution masking and other visual phenomena is discussed. PMID:18085959

Hirose, Nobuyuki; Kihara, Ken; Mima, Tatsuya; Ueki, Yoshino; Fukuyama, Hidenao; Osaka, Naoyuki

2007-12-01

383

The effect of an anesthetic induction dose of midazolam on motor potentials evoked by transcranial magnetic stimulation in the monkey.  

PubMed

The effect of a hypnotic dose (0.5 mg/kg) of midazolam (MDZ) on motor evoked potentials (MEPs) was examined in 12 monkeys. MEPs were elicited by transcranial magnetic stimulation (TMS) and the resultant potentials recorded from abductor pollicis brevis (APB) and anterior tibialis (AT) muscles contralateral to the stimulation site. After administration of MDZ, sequential MEP recordings were obtained at postinduction, hypnosis, awakening, emergence, and recovery periods. The results were compared with control values using one-way analysis of variance and Tukey's post-hoc test. Under hypnosis, MEP reproducibility was problematic as the potentials were occasionally ill identified and questionable. MDZ resulted in marked MEP scalp field reduction, coil demography alteration, stimulation threshold elevation, and amplitude suppression (p <0.01). Latency response was unaltered. During hypnosis, awakening, and recovery periods, the mean APB and AT thresholds were elevated by 39, 23, and 0% and by 60, 34, and 4% respectively; while APB and AT amplitudes were depressed by 95, 86, and 53% and by 99, 91, and 60%, respectively. We conclude that an induction dose of MDZ can produce profound and prolonged attenuation of TMS MEPs. The drug inhibitory effect on MEPs may persist after recovery. Anesthetic doses of MDZ should cautiously be used in the settings of MEP monitoring. PMID:15815379

Ghaly, R F; Stone, J L; Levy, W J; Kartha, R; Aldrete, A; Brunner, E B; Roccaforte, P

1991-03-01

384

Effects of successive repetitive transcranial magnetic stimulation on motor performances and brain perfusion in idiopathic Parkinson's disease.  

PubMed

We studied the effects of 0.2 Hz repetitive transcranial magnetic stimulation (rTMS) successively performed 6 times for 2 weeks in 12 patients with idiopathic Parkinson's disease (PD). Ten patients received rTMS to the bilateral frontal cortex (frontal rTMS) and six patients received rTMS to the bilateral occipital cortex (occipital rTMS). Before and after rTMS, we evaluated regional cerebral blood flow (rCBF) using 99m-Tc-ECD single photon emission computed tomography (SPECT) and clinical tests. In an analysis with statistic parametric mapping, both frontal and occipital rTMS reduced rCBF in the cortical areas around the stimulated site. The activities of daily living (ADL) and motor scores of Unified Parkinson's Disease Rating Scale (UPDRS), pronation-supination movements, and buttoning up significantly improved after frontal rTMS than before it, while occipital rTMS had no significant effects in clinical tests.The findings of the present study suggest that successive 0.2 Hz rTMS has outlasting inhibitory effects on neuronal activity around the stimulated cortical areas. Because there were no significant relations between improved clinical tests and reduced rCBF, we speculate that the indirect effects of 0.2 Hz rTMS on subcortical structures are related to improved parkinsonian symptoms. Further studies recruiting large numbers of subjects are required to confirm the efficacy of 0.2 Hz rTMS on PD. PMID:12686400

Ikeguchi, Michiko; Touge, Tetsuo; Nishiyama, Yoshihiro; Takeuchi, Hiroaki; Kuriyama, Shigeki; Ohkawa, Motoomi

2003-05-15

385

The perceived position of moving objects: transcranial magnetic stimulation of area MT+ reduces the flash-lag effect.  

PubMed

How does the visual system assign the perceived position of a moving object? This question is surprisingly complex, since sluggish responses of photoreceptors and transmission delays along the visual pathway mean that visual cortex does not have immediate information about a moving object's position. In the flash-lag effect (FLE), a moving object is perceived ahead of an aligned flash. Psychophysical work on this illusion has inspired models for visual localization of moving objects. However, little is known about the underlying neural mechanisms. Here, we investigated the role of neural activity in areas MT+ and V1/V2 in localizing moving objects. Using short trains of repetitive Transcranial Magnetic Stimulation (TMS) or single pulses at different time points, we measured the influence of TMS on the perceived location of a moving object. We found that TMS delivered to MT+ significantly reduced the FLE; single pulse timings revealed a broad temporal tuning with maximum effect for TMS pulses, 200 ms after the flash. Stimulation of V1/V2 did not significantly influence perceived position. Our results demonstrate that area MT+ contributes to the perceptual localization of moving objects and is involved in the integration of position information over a long time window. PMID:22302116

Maus, Gerrit W; Ward, Jamie; Nijhawan, Romi; Whitney, David

2012-02-02

386

A transcranial magnetic stimulation study of the effects of cannabis use on motor cortical inhibition and excitability.  

PubMed

Active compounds in cannabis such as tetrahydrocannabinol (THC) interact with the inhibitory neurotransmitter delta-aminobutyric acid (GABA) but little is known about the functional effects of cannabis on human cortical brain processes. Therefore, the aim of the study was to investigate whether patients with chronic cannabis use demonstrate abnormalities in cortical inhibition or excitability. In all, 42 chronic cannabis using subjects (divided into heavy and light using subjects) and 19 controls were included in the study. Single and paired pulse transcranial magnetic stimulation were used to assess a number of parameters of cortical inhibition and cortical excitability. In addition, psychomotor function and THC plasma levels were measured. Both cannabis using groups (heavy and light use) demonstrated a reduction in short interval cortical inhibition compared with healthy controls, but there was no difference in other measures of cortical inhibition or cortical excitability. There was also no difference between the two groups on measures of psychomotor performance. Chronic cannabis use is associated with a reduction in cortical inhibition potentially related to activity at the GABA(A) receptors. Further research is required to explore whether this results from chronic cannabis use or reflects an underlying predisposition to developing chronic substance use problems. PMID:19571796

Fitzgerald, Paul B; Williams, Suzanne; Daskalakis, Zafiris J

2009-07-01

387

Automated-Parameterization of the Motor Evoked Potential and Cortical Silent Period Induced by Transcranial Magnetic Stimulation  

PubMed Central

Objective To standardize the characterization of motor evoked potential (MEP) and cortical silent period (CSP) recordings elicited with transcranial magnetic stimulation (TMS). Methods A computer-based, automated-parameterization program (APP) was developed and tested which provides a comprehensive set of electromyography (EMG) magnitude and temporal measures. The APP was tested using MEP, CSP, and isolated CSP (iCSP) TMS stimulus-response data from a healthy adult population (N = 13). Results The APP had the highest internal reliability (Cronbach’s alpha = .98) for CSP offset time compared with two prominent automated methods. The immediate post-CSP EMG recovery level was 49% higher than the pre-TMS EMG level. MEP size (peak amplitude, mean amplitude, peak-to-peak amplitude, and area) correlated higher with effective E-field (Eeff) than other intensity measures (r ? 0.5 vs. r ? 0.3) suggesting that Eeff is better suited for standardizing MEP stimulus-response relationships. Conclusions The APP successfully characterized individual and mean epochs containing MEP, CSP, and iCSP responses. The APP provided common signal and temporal measures consistent with previous studies and novel additional parameters. Significance: With the use of the APP modeling method and the Eeff, a standard approach for the analysis and reporting of MEP-CSP complex and iCSP measurements is achievable.

Rabago, Christopher A.; Lancaster, Jack L.; Narayana, Shalini; Zhang, Wei; Fox, Peter T.

2009-01-01

388

Disrupted Central Inhibition after Transcranial Magnetic Stimulation of Motor Cortex in Schizophrenia with Long-Term Antipsychotic Treatment  

PubMed Central

Aims. Schizophrenia is a neuropsychiatric disorder associated with mental and motor disturbances. We aimed to investigate motor control, especially central silent period (CSP) in subjects with schizophrenia (n = 11) on long-term antipsychotic treatment compared to healthy controls (n = 9). Methods. Latency and duration of motor evoked potentials (MEPs) and CSPs were measured with the help of single pulse transcranial magnetic stimulation (TMS) and intramuscular electrodes. After stimulation of the dominant and nondominant motor cortex of abductor digiti minimi (ADM) and tibialis anterior (TA) muscle areas, respective responses were measured on the contralateral side. Results. MEPs did not differ significantly between the groups. Multiple CSPs were found predominantly in subjects with schizophrenia, which showed a higher number of CSPs in the dominant ADM and the longest summarized duration of CSPs in the nondominant ADM (P < 0.05) compared to controls. Conclusions. There were multiple CSPs predominantly in the upper extremities and in the dominant body side in subjects with schizophrenia. Behind multiple CSPs may lie an impaired regulation of excitatory or inhibitory neurotransmitter systems in central motor pathways. Further research is needed to clarify the role of the intramuscular recording methods and the effect of antipsychotics on the results.

Lauerma, Hannu; Kahkonen, Seppo

2013-01-01

389

Baseline and Treatment-Emergent EEG Biomarkers of Antidepressant Medication Response Do Not Predict Response to Repetitive Transcranial Magnetic Stimulation.  

PubMed

There has been a surge of interest in biomarkers that can rapidly predict or assess response to psychiatric treatment, as the current standard practice of extended therapeutic trials is often dissatisfying to both clinicians and patients. Electroencephalographic (EEG) biomarkers in particular have been proposed as an inexpensive yet rapid way of determining whether a patient is responding to an intervention, usually before subjective mood improvement occurs. However, even the most well-reported EEG algorithms have not been subjected to independent replication, limiting their clinical generalizability. It is also unclear whether those biomarkers can generalize beyond their original study population, e.g. to patients undergoing somatic treatments for depression. We report here analysis of EEG data from the pivotal OPT-TMS study of transcranial magnetic stimulation (rTMS) for major depressive disorder. In this dataset, previously reported biomarkers of medication response showed no significant correlation with eventual response to rTMS treatment. Furthermore, EEG power in multiple bands measured at baseline and throughout the treatment course did not correlate with or predict either binary (response/nonresponse) or continuous (Hamilton Rating Scale for Depression) outcome measures. While somewhat limited by technical difficulties in data collection, these analyses are adequately powered to detect clinically relevant biomarkers. We believe this highlights a need for wider-scale independent replication of previous EEG biomarkers, both in pharmacotherapy and neuromodulation. PMID:23763894

Widge, Alik S; Avery, David H; Zarkowski, Paul

2013-05-28

390

Transcranial magnetic stimulation as an investigative tool for motor dysfunction and recovery in stroke: an overview for neurorehabilitation clinicians  

PubMed Central

Rationale An improved understanding of motor dysfunction and recovery after stroke has important clinical implications that may lead to the design of more effective rehabilitation strategies for patients with hemiparesis. Scope Transcranial magnetic stimulation (TMS) is a safe and painless tool that has been used in conjunction with other existing diagnostic tools to investigate motor pathophysiology in stroke patients. Since TMS emerged over two decades ago, its application in clinical and basic neuroscience has expanded worldwide. TMS can quantify the corticomotor excitability properties of clinically affected and unaffected muscles, and probe local cortical networks, as well as remote but functionally related areas. This provides novel insight into the physiology of neural circuits underlying motor dysfunction, and brain reorganization during the motor recovery process. This important tool needs to be used with caution by clinical investigators, its limitations need to be understood and the results should be interpreted along with clinical evaluation in this patient population. Summary In this review, we provide an overview of the rationale, implementation and limitations of TMS to study stroke motor physiology. This knowledge may be useful to guide future rehabilitation treatments by assessing and promoting functional plasticity.

Cortes, Mar; Black-Schaffer, Randie M; Edwards, Dylan J

2012-01-01

391

Using repetitive transcranial magnetic stimulation to study the underlying neural mechanisms of human motor learning and memory  

PubMed Central

In the last two decades, there has been a rapid development in the research of the physiological brain mechanisms underlying human motor learning and memory. While conventional memory research performed on animal models uses intracellular recordings, microfusion of protein inhibitors to specific brain areas and direct induction of focal brain lesions, human research has so far utilized predominantly behavioural approaches and indirect measurements of neural activity. Repetitive transcranial magnetic stimulation (rTMS), a safe non-invasive brain stimulation technique, enables the study of the functional role of specific cortical areas by evaluating the behavioural consequences of selective modulation of activity (excitation or inhibition) on memory generation and consolidation, contributing to the understanding of the neural substrates of motor learning. Depending on the parameters of stimulation, rTMS can also facilitate learning processes, presumably through purposeful modulation of excitability in specific brain regions. rTMS has also been used to gain valuable knowledge regarding the timeline of motor memory formation, from initial encoding to stabilization and long-term retention. In this review, we summarize insights gained using rTMS on the physiological and neural mechanisms of human motor learning and memory. We conclude by suggesting possible future research directions, some with direct clinical implications.

Censor, Nitzan; Cohen, Leonardo G

2011-01-01

392

Attenuation of spinal cord injury-induced astroglial and microglial activation by repetitive transcranial magnetic stimulation in rats.  

PubMed

Spinal cord injury (SCI) causes not only loss of sensory and motor function below the level of injury but also chronic pain, which is difficult and challenging of the treatment. Repetitive transcranial magnetic stimulation (rTMS) to the motor cortex, of non-invasive therapeutic methods, has the motor and sensory consequences and modulates pain in SCI-patients. In the present study, we studied the effectiveness of rTMS and the relationship between the modulation of pain and the changes of neuroglial expression in the spinal cord using a rat SCI-induced pain model. Elevated expressions of Iba1 and GFAP, specific microglial and astrocyte markers, was respectively observed in dorsal and ventral horns at the L4 and L5 levels in SCI rats. But in SCI rats treated with 25 Hz rTMS for 8 weeks, these expressions were significantly reduced by about 30%. Our finding suggests that this attenuation of activation by rTMS is related to pain modulation after SCI. Therefore, rTMS might provide an alternative means of attenuating neuropathic pain below the level of SCI. PMID:23399872

Kim, Ji Young; Choi, Gyu-Sik; Cho, Yun-Woo; Cho, Heekyung; Hwang, Se-Jin; Ahn, Sang-Ho

2013-01-29

393

Using pre-treatment electroencephalography data to predict response to transcranial magnetic stimulation therapy for major depression.  

PubMed

We investigate the use of machine learning methods based on the pre-treatment electroencephalograph (EEG) to predict response to repetitive transcranial magnetic stimulation (rTMS), which is a non-pharmacological form of therapy for treating major depressive disorder (MDD). The learning procedure involves the extraction of a large number of candidate features from EEG data, from which a very small subset of most statistically relevant features is selected for further processing. A statistical prediction model based on mixture of factor analysis (MFA) model is constructed from a training set that classifies the respective subject into responder and non-responder classes. A leave-2-out (L2O) cross-validation procedure is used to evaluate the prediction performance. This pilot study involves 27 subjects who received either left high-frequency (HF) active rTMS therapy or simultaneous left HF and right low-frequency active rTMS therapy. Our results indicate that it is possible to predict rTMS treatment efficacy of either treatment modality with a specificity of 83% and a sensitivity of 78%, for a combined accuracy of 80%. PMID:22255807

Khodayari-Rostamabad, Ahmad; Reilly, James P; Hasey, Gary M; deBruin, Hubert; MacCrimmon, Duncan

2011-01-01

394

Motor demand-dependent improvement in accuracy following low-frequency transcranial magnetic stimulation of left motor cortex  

PubMed Central

The role of primary motor cortex (M1) in the control of voluntary movements is still unclear. In brain functional imaging studies of unilateral hand performance, bilateral M1 activation is inconsistently observed, and disruptions of M1 using repetitive transcranial magnetic stimulation (rTMS) lead to variable results in the hand motor performance. As the motor tasks differed qualitatively in these studies, it is conceivable that M1 contribution differs depending on the level of skillfulness. The objective of the present study was to determine whether M1 contribution to hand motor performance differed depending on the level of precision of the motor task. Here, we used low-frequency rTMS of left M1 to determine its effect on the performance of a pointing task that allows the parametric increase of the level of precision and thereby increase the level of required precision quantitatively. We found that low-frequency rTMS improved performance in both hands for the task with the highest demand on precision, whereas performance remained unchanged for the tasks with lower demands. These results suggest that the functional relevance of M1 activity for motor performance changes as a function of motor demand. The bilateral effect of rTMS to left M1 would also support the notion of M1 functions at a higher level in motor control by integrating afferent input from nonprimary motor areas.

Hines, Benjamin; Shuster, Linda; Pergami, Paola; Mathes, Adam

2011-01-01

395

Unilateral repetitive transcranial magnetic stimulation of the motor cortex does not affect cognition in patients with fibromyalgia.  

PubMed

Repetitive transcranial magnetic stimulation (rTMS) induces changes in neuronal activity that may affect cognition. We assessed cognitive functions, in patients with fibromyalgia participating in a sham-controlled randomized trial of rTMS for pain management. We randomly assigned 38 non depressed fibromyalgia patients (American College of Rheumatology criteria) to the active (n = 20) and sham (n = 18) rTMS treatment groups, in a double-blind manner. rTMS was applied to the left primary motor cortex (10 Hz at 80% of rest motor threshold). Neuropsychological tests were performed immediately before stimulation, to evaluate episodic memory, selective and divided attention and executive functions at baseline, week 3 (after 7 rTMS sessions) and week 11 (after 11 rTMS sessions). The actively treated and sham-treated groups were similar in terms of clinical and neuropsychological variables at baseline. No difference in overall neuropsychological performance with respect to baseline was found between these two groups, but a significant improvement over time was observed in the rTMS group, for several measurements of attention/executive function (the Symbol Digit Modalities Test and the Stroop Color Word Test). Unilateral rTMS of the motor cortex over a three-month period did not modify cognitive functions in patients with chronic pain. rTMS may have mild beneficial cognitive effects, but confirmation is required in larger groups of patients. PMID:23079535

Baudic, Sophie; Attal, Nadine; Mhalla, Alaa; Ciampi de Andrade, Daniel; Perrot, Serge; Bouhassira, Didier

2012-10-15

396

Immediate plasticity in the motor pathways after spinal cord hemisection: implications for transcranial magnetic motor-evoked potentials.  

PubMed

The present study evaluates motor functional recovery after C2 spinal cord hemisection with or without contralateral brachial root transection, which causes a condition that is similar to the crossed phrenic phenomenon on rats. Descending motor pathways, including the reticulospinal extrapyramidal tract and corticospinal pyramidal tracts, were evaluated by transcranial magnetic motor-evoked potentials (mMEPs) and direct cortical electrical motor-evoked potentials (eMEP), respectively. All MEPs recorded from the left forelimb were abolished immediately after the left C2 hemisection. Left mMEPs recovered dramatically immediately after contralateral right brachial root transection. Corticospinal eMEPs never recovered, regardless of transection. The facilitation of mMEPs in animals that had undergone combined contralateral root transection was well correlated with open-field behavioral motor performance. Both electrophysiological and neurological facilitations were significantly attenuated by the selective serotonin synthesis inhibitor para-chlorophenylalanine (p-CPA). These results suggest that serotonergic reticulospinal fibers located contralateral to hemisection contribute to the behavioral and electrophysiological improvement that immediately follows spinal cord injury (SCI). PMID:15144873

Fujiki, Minoru; Kobayashi, Hidenori; Inoue, Ryo; Ishii, Keisuke

2004-06-01

397

Effect of fatiguing maximal voluntary contraction on excitatory and inhibitory responses elicited by transcranial magnetic motor cortex stimulation.  

PubMed

Vertex transcranial magnetic stimulation (TMS) elicited tibialis anterior motor evoked potentials (MEPs) and silent periods (SPs) that were recorded during and following isometric maximal volitional contraction (MVC). During MVC in 6 healthy subjects, MEP amplitudes in the exercised muscle showed an increasing trend from an initial value of 4539 +/- 809 muV (mean +/- SE) to 550 +/- 908 muV (P < 0.13) while force and EMG decreased (P < 0.01). Also, SP duration increased from 165 +/- 37 ms to 231 +/- 32 ms (P < 0.01). Thus, during a fatiguing MVC both excitatory and inhibitory TMS-induced responses increased. TMS delivered during repeated brief 10% MVC contractions before and after a fatiguing MVC in 5 subjects, showed no change in MEP amplitude but SP duration was prolonged after MVC. This SP prolongation was focal to the exercised muscle. Silent periods recorded after pyramidal tract stimulation were unchanged following the MVC. These results suggest that MEP and SP might have common sources of facilitation during an MVC and that inhibitory mechanisms remain focally augmented following a fatiguing MVC. PMID:8756168

McKay, W B; Stokic, D S; Sherwood, A M; Vrbova, G; Dimitrijevic, M R

1996-08-01

398

The silent period after transcranial magnetic stimulation is of exclusive cortical origin: evidence from isolated cortical ischemic lesions in man.  

PubMed

In two representative patients suffering from focal isolated ischemic lesions of the arm-associated (patient 1) or leg-associated (patient 2) primary motor cortex excitatory responses (motor evoked potentials, MEPs) and inhibitory phenomena (silent period, SP) following transcranial magnetic motor cortex stimulation (TMS) are demonstrated. Furthermore, supramaximal peripheral nerve stimulations for testing spinal inhibitory actions were performed. Results were compared to a control group of 12 normal subjects. In patient 1, SP induced by TMS in the clinically affected left extensor carpi radialis muscle (ECR) was lacking in the presence of an only marginally reduced MEP and a normal spinal silent period in this muscle. Normal MEPs and SP durations were observed in the right ECR and in the first dorsal interosseus (FDI) and anterior tibial (TA) muscles on both sides. Similarly, in patient 2 a loss of SP induced by TMS in the clinically affected right TA was observed with normal SP durations in the left TA and both FDI muscles and normal MEP amplitudes in all muscles studied. It is concluded that both early and late phases of SP induced by TMS are of cortical origin and generated in the primary motor cortex. PMID:7877758

Schnitzler, A; Benecke, R

1994-10-10

399

Stump nerve signals during transcranial magnetic motor cortex stimulation recorded in an amputee via longitudinal intrafascicular electrodes.  

PubMed

Do central and peripheral motor pathways associated with an amputated limb retain at least some functions over periods of years? This problem could be addressed by evaluating the response patterns of nerve signals from peripheral motor fibers during transcranial magnetic stimulation (TMS) of corticospinal tracts. The aim of this study was to record for the first time TMS-related responses from the nerves of a left arm stump of an amputee via intrafascicular longitudinal flexible multi-electrodes (tfLIFE4) implanted for a prosthetic hand control. After tfLIFE4 implant in the stump median and ulnar nerves, TMS impulses of increasing intensity were delivered to the contralateral motor cortex while tfLIFE4 recordings were carried out. Combining TMS of increasing intensity and tfLIFE4 electrodes recordings, motor nerve activity possibly related to the missing limb motor control and selectively triggered by brain stimulation without significant electromyographic contamination was identified. These findings are entirely original and indicate that tfLIFE4 signals are clearly driven from M1 stimulation, therefore witnessing the presence in the stump nerves of viable motor signals from the CNS possibly useful for artificial prosthesis control. PMID:21390489

Rossini, P M; Rigosa, Jacopo; Micera, Silvestro; Assenza, Giovanni; Rossini, Luca; Ferreri, Florinda

2011-03-10

400

The observation of manual grasp actions affects the control of speech: a combined behavioral and Transcranial Magnetic Stimulation study.  

PubMed

Does the mirror system affect the control of speech? This issue was addressed in behavioral and Transcranial Magnetic Stimulation (TMS) experiments. In behavioral experiment 1, participants pronounced the syllable /da/ while observing (1) a hand grasping large and small objects with power and precision grasps, respectively, (2) a foot interacting with large and small objects and (3) differently sized objects presented alone. Voice formant 1 was higher when observing power as compared to precision grasp, whereas it remained unaffected by observation of the different types of foot interaction and objects alone. In TMS experiment 2, we stimulated hand motor cortex, while participants observed the two types of grasp. Motor Evoked Potentials (MEPs) of hand muscles active during the two types of grasp were greater when observing power than precision grasp. In experiments 3-5, TMS was applied to tongue motor cortex of participants silently pronouncing the syllable /da/ and simultaneously observing power and precision grasps, pantomimes of the two types of grasps, and differently sized objects presented alone. Tongue MEPs were greater when observing power than precision grasp either executed or pantomimed. Finally, in TMS experiment 6, the observation of foot interaction with large and small objects did not modulate tongue MEPs. We hypothesized that grasp observation activated motor commands to the mouth as well as to the hand that were congruent with the hand kinematics implemented in the observed type of grasp. The commands to the mouth selectively affected postures of phonation organs and consequently basic features of phonological units. PMID:19654016

Gentilucci, Maurizio; Campione, Giovanna Cristina; Dalla Volta, Riccardo; Bernardis, Paolo

2009-08-03

401

Left dorsolateral prefrontal transcranial magnetic stimulation (TMS): sleep factor changes during treatment in patients with pharmacoresistant major depressive disorder.  

PubMed

As they alleviate major depressive disorder, antidepressant therapies may improve associated sleep disturbances, but may also have inherent sedating or activating properties. We examined sleep changes during a multicenter, sham-controlled, trial of transcranial magnetic stimulation (TMS) therapy for pharmacoresistant MDD. Medication-free outpatients (N=301) were randomized to receive active (N=155) or sham (N=146) TMS for 6 weeks. Depression severity was rated with the Montgomery-Asberg Depression Rating Scale, the 24-item Hamilton Depression Scale (HAMD), and the Inventory of Depressive Symptoms-Self Report (IDS-SR). Assessments were performed at baseline, 2, 4, and 6 week time points. Sleep was assessed using the HAMD and IDS-SR sleep factors; comparison between treatment groups employed ANCOVA model. No significant differences were identified between the active and sham treatment groups in either the HAMD or IDS-SR sleep factor scores at any time during treatment. Sleep difficulty as an adverse event over the length of the study did not differ between active and sham treatment. Stratified by end of acute treatment responder status, there was a statistically significant improvement in both the HAMD sleep factor score and the IDS-SR sleep factor during acute treatment in both the active and sham treatment conditions. TMS exerts no intrinsic effect upon sleep in patients with MDD. PMID:23021320

Rosenquist, Peter B; Krystal, Andrew; Heart, Karen L; Demitrack, Mark A; McCall, W Vaughn

2012-09-25

402

Disruption of the right temporoparietal junction with transcranial magnetic stimulation reduces the role of beliefs in moral judgments.  

PubMed

When we judge an action as morally right or wrong, we rely on our capacity to infer the actor's mental states (e.g., beliefs, intentions). Here, we test the hypothesis that the right temporoparietal junction (RTPJ), an area involved in mental state reasoning, is necessary for making moral judgments. In two experiments, we used transcranial magnetic stimulation (TMS) to disrupt neural activity in the RTPJ transiently before moral judgment (experiment 1, offline stimulation) and during moral judgment (experiment 2, online stimulation). In both experiments, TMS to the RTPJ led participants to rely less on the actor's mental states. A particularly striking effect occurred for attempted harms (e.g., actors who intended but failed to do harm): Relative to TMS to a control site, TMS to the RTPJ caused participants to judge attempted harms as less morally forbidden and more morally permissible. Thus, interfering with activity in the RTPJ disrupts the capacity to use mental states in moral judgment, especially in the case of attempted harms. PMID:20351278

Young, Liane; Camprodon, Joan Albert; Hauser, Marc; Pascual-Leone, Alvaro; Saxe, Rebecca

2010-03-29

403

Assessing the effects of electroconvulsive therapy on cortical excitability by means of transcranial magnetic stimulation and electroencephalography.  

PubMed

Electroconvulsive therapy (ECT) has significant short-term antidepressant effects on drug-resistant patients with severe major depression. Animal studies have demonstrated that electroconvulsive seizures produce potentiation-like synaptic remodeling in both sub-cortical and frontal cortical circuits. However, the electrophysiological effects of ECT in the human brain are not known. In this work, we evaluated whether ECT induces a measurable change in the excitability of frontal cortical circuits in humans. Electroencephalographic (EEG) potentials evoked by transcranial magnetic stimulation (TMS) were collected before and after a course of ECT in eight patients with severe major depression. Cortical excitability was measured from the early and local EEG response to TMS. Clinical assessment confirmed the beneficial effects of ECT on depressive symptoms at the group level. TMS/EEG measurements revealed a clear-cut increase of frontal cortical excitability after ECT as compared to baseline, that was significant in each and every patient. The present findings corroborate in humans the idea that ECT may produce synaptic potentiation, as previously observed in animal studies. Moreover, results suggest that TMS/EEG may be employed in depressed patients to monitor longitudinally the electrophysiological effects of different therapeutic neuromodulators, e.g. ECT, repetitive TMS, and sleep deprivation. To the extent that depression involves an alteration of frontal cortical excitability, these measurements may be used to guide and evaluate treatment progression over time at the single-patient level. PMID:23053600

Casarotto, Silvia; Canali, Paola; Rosanova, Mario; Pigorini, Andrea; Fecchio, Matteo; Mariotti, Maurizio; Lucca, Adelio; Colombo, Cristina; Benedetti, Francesco; Massimini, Marcello

2012-10-09

404

The effect of music on corticospinal excitability is related to the perceived emotion: a transcranial magnetic stimulation study.  

PubMed

Transcranial magnetic stimulation (TMS) and neuroimaging studies suggest a functional link between the emotion-related brain areas and the motor system. It is not well understood, however, whether the motor cortex activity is modulated by specific emotions experienced during music listening. In 23 healthy volunteers, we recorded the motor evoked potentials (MEP) following TMS to investigate the corticospinal excitability while subjects listened to music pieces evoking different emotions (happiness, sadness, fear, and displeasure), an emotionally neutral piece, and a control stimulus (musical scale). Quality and intensity of emotions were previously rated in an additional group of 30 healthy subjects. Fear-related music significantly increased the MEP size compared to the neutral piece and the control stimulus. This effect was not seen with music inducing other emotional experiences and was not related to changes in autonomic variables (respiration rate, heart rate). Current data indicate that also in a musical context, the excitability of the corticomotoneuronal system is related to the emotion expressed by the listened piece. PMID:22405960

Giovannelli, Fabio; Banfi, Chiara; Borgheresi, Alessandra; Fiori, Elisa; Innocenti, Iglis; Rossi, Simone; Zaccara, Gaetano; Viggiano, Maria Pia; Cincotta, Massimo

2012-02-10

405

Magnetic reconnection associated fluctuations in the deep magnetotail: ARTEMIS results  

NASA Astrophysics Data System (ADS)

On the basis of ARTEMIS two-probe mission magnetic reconnection (MR) outflow associated magnetic fluctuations and turbulence are analyzed on 19 February 2011. In the deep-tail, at distances between X = 45 - 51 RE, evidence for reconnection associated plasma sheet thinning was found, accompanied by heating of the plasma sheet. Correlated flow and field reversals and the large-scale Hall-effect signatures indicated the presence of the reconnection X-line. Within fast reconnection plasma outflows, magnetic fluctuations exhibit the same spectral scaling features and kinked spectra as magnetic fluctuations in the solar wind or in various parts of geospace. It was shown that the proton scale magnetic fluctuations are constrained by oblique firehose, proton cyclotron and mirror instability thresholds. For parallel plasma ?|| > 1, where the thresholds converge, perpendicular magnetic fluctuations are enhanced. Magnetic compressibility decreases with the distance to the neutral sheet, however, near the instability thresholds it is comparable to the values obtained in the solar wind.

Vörös, Z.

2011-11-01

406

Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research?  

PubMed Central

This article is based on a consensus conference, which took place in Certosa di Pontignano, Siena (Italy) on March 7–9, 2008, intended to update the previous safety guidelines for the application of transcranial magnetic stimulation (TMS) in research and clinical settings. Over the past decade the scientific and medical community has had the opportunity to evaluate the safety record of research studies and clinical applications of TMS and repetitive TMS (rTMS). In these years the number of applications of conventional TMS has grown impressively, new paradigms of stimulation have been developed (e.g., patterned repetitive TMS) and technical advances have led to new device designs and to the real-time integration of TMS with electroencephalography (EEG), positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). Thousands of healthy subjects and patients with various neurological and psychiatric diseases have undergone TMS allowing a better assessment of relative risks. The occurrence of seizures (i.e., the most serious TMS-related acute adverse effect) has been extremely rare, with most of the few new cases receiving rTMS exceeding previous guidelines, often in patients under treatment with drugs which potentially lower the seizure threshold. The present updated guidelines review issues of risk and safety of conventional TMS protocols, address the undesired effects and risks of emerging TMS interventions, the applications of TMS in patients with implanted electrodes in the central nervous system, and safety aspects of TMS in neuroimaging environments. We cover recommended limits of stimulation parameters and other important precautions, monitoring of subjects, expertise of the rTMS team, and ethical issues. While all the recommendations here are expert based, they utilize published data to the extent possible.

Rossi, Simone; Hallett, Mark; Rossini, Paolo M.; Pascual-Leone, Alvaro

2011-01-01

407

The role of the right presupplementary motor area in stopping action: two studies with event-related transcranial magnetic stimulation  

PubMed Central

Rapidly stopping action engages a network in the brain including the right presupplementary motor area (preSMA), the right inferior frontal gyrus, and the basal ganglia. Yet the functional role of these different regions within the overall network still remains unclear. Here we focused on the role of the right preSMA in behavioral stopping. We hypothesized that the underlying neurocognitive function of this region is one or more of setting up a stopping rule in advance, modulating response tendencies (e.g., slowing down in anticipation of stopping), and implementing stopping when the stop signal occurs. We performed two experiments with magnetic resonance imaging (MRI)–guided, event-related, transcranial magnetic stimulation(TMS), during the performance of variants of the stop signal task. In experiment 1 we show that stimulation of the right preSMA versus vertex (control site) slowed the implementation of stopping (measured via stop signal reaction time) but had no influence on modulation of response tendencies. In experiment 2, we showed that stimulation of the right preSMA slowed implementation of stopping in a mechanistically selective form of stopping but had no influence on setting up stopping rules. The results go beyond the replication of prior findings by showing that TMS of the right preSMA impairs stopping behavior (including a behaviorally selective form of stopping) through a specific disruption of the implementation of stopping. Future studies are required to establish whether this was due to stimulation of the right preSMA itself or because of remote effects on the wider stopping network.

George, Jobi S.; Verbruggen, Frederick; Chambers, Christopher D.; Aron, Adam R.

2012-01-01

408

Examining Cortical Dynamics and Connectivity with Simultaneous Single-Pulse Transcranial Magnetic Stimulation and Fast Optical Imaging  

PubMed Central

Transcranial magnetic stimulation (TMS) is a widely used experimental and clinical technique that directly induces activity in human cortex using magnetic fields. However, the neural mechanisms of TMS-induced activity are not well understood. Here, we introduce a novel method of imaging TMS-evoked activity using a non-invasive fast optical imaging tool, the event-related optical signal (EROS). EROS measures changes in the scattering of near-infrared light that occur synchronously with electrical activity in cortical tissue. EROS has good temporal and spatial resolution, allowing the dynamics and spatial spread of a TMS pulse to be measured. We used EROS to monitor activity induced in primary motor cortex (M1) by a TMS pulse. Left- and right-hand representations were mapped using standard TMS procedures. Optical sources and detectors mounted on thin rubber patches were then centered on M1 hand representations. EROS was recorded bilaterally from motor cortex while unilateral TMS was simultaneously delivered. Robust ipsilateral EROS activations were apparent within 16 ms of a pulse for TMS delivered to both left and right hemispheres. Clear motor evoked potentials (MEPs) were also elicited by these TMS pulses. Movement artifacts could be excluded as a source of EROS, as no activation was present on short-distance optical channels. For left hemisphere TMS subsequent (40 ms) contralateral activity was also present, presumably due to trans-synaptic propagation of TMS-evoked activity. Results demonstrate that concurrent TMS/EROS is a viable and potentially powerful method for studying TMS-induced activity in the human brain. With further development, this technique may be applied more broadly in the study of the dynamics of causal cortico-cortical connectivity.

Parks, Nathan A.; Maclin, Edward L.; Low, Kathy A.; Beck, Diane M.; Fabiani, Monica; Gratton, Gabriele

2011-01-01

409

Application of high-frequency repetitive transcranial magnetic stimulation to the DLPFC alters human prefrontal-hippocampal functional interaction.  

PubMed

Neural plasticity is crucial for understanding the experience-dependent reorganization of brain regulatory circuits and the pathophysiology of schizophrenia. An important circuit-level feature derived from functional magnetic resonance imaging (fMRI) is prefrontal-hippocampal seeded connectivity during working memory, the best established intermediate connectivity phenotype of schizophrenia risk to date. The phenotype is a promising marker for the effects of plasticity-enhancing interventions, such as high-frequency repetitive transcranial magnetic stimulation (rTMS), and can be studied in healthy volunteers in the absence of illness-related confounds, but the relationship to brain plasticity is unexplored. We recruited 39 healthy volunteers to investigate the effects of 5 Hz rTMS on prefrontal-hippocampal coupling during working memory and rest. In a randomized and sham-controlled experiment, neuronavigation-guided rTMS was applied to the right dorsolateral prefrontal cortex (DLPFC), and fMRI and functional connectivity analyses [seeded connectivity and psychophysiological interaction (PPI)] were used as readouts. Moreover, the test-retest reliability of working-memory related connectivity markers was evaluated. rTMS provoked a significant decrease in seeded functional connectivity of the right DLPFC and left hippocampus during working memory that proved to be relatively time-invariant and robust. PPI analyses provided evidence for a nominal effect of rTMS and poor test-retest reliability. No effects on n-back-related activation and DLPFC-hippocampus resting-state connectivity were observed. These data provide the first in vivo evidence for the effects of plasticity induction on human prefrontal-hippocampal network dynamics, offer insights into the biological mechanisms of a well established intermediate phenotype linked to schizophrenia, and underscores the importance of the choice of outcome measures in test-retest designs. PMID:23595762

Bilek, Edda; Schäfer, Axel; Ochs, Elisabeth; Esslinger, Christine; Zangl, Maria; Plichta, Michael M; Braun, Urs; Kirsch, Peter; Schulze, Thomas G; Rietschel, Marcella; Meyer-Lindenberg, Andreas; Tost, Heike

2013-04-17

410

Coil positioning system for repetitive transcranial magnetic stimulation treatment by ToF camera ego-motion.  

PubMed

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive method for treating various neurological and psychiatric disorders. With the growing demands of neuropathic pain patients and their increasing numbers, rTMS treatment tools are becoming more necessary. rTMS uses electromagnetic induction to induce weak electric currents by rapidly changing the magnetic field. Targeting the electric current to a specific part of the brain is one treatment for pain relief. This paper focuses on treatment for neuropathic pain caused by a lesion or disease of the central or peripheral nervous system, including stroke, trauma, or surgery. However, the current style of rTMS treatment is still developing and is so technically specialized that only a limited number of hospitals and only a handful of specialists can provide this therapy. The existing rTMS systems use an optical markerbased 3D sensing technique that positions the stimulation coil to target the small region of interest in the brain through coregistration with pre-scanned MRI data. This system requires the patient to be immobilized on a bed. The optical markers for 3D sensing are placed on the patient's head to maintain accurate positioning. We propose a constraints-free, markerless rTMS system, which employs ego-motion, a computation technique to estimate relative 3D motion of a camera to what the camera sees. We use a ToF sensor as a camera, which is capble of capturing shape information from a single viewpoint instantly. The markerless target spot is based on the shape features of the patient's face. This paper shows the process of a prototype system and its potential for achieving an easy-to-handle system framework. PMID:24110505

Yasumuro, Yoshihiro; Ebisuwaki, Ryo; Fuyuki, Masahiko; Matsuzaki, Taiga; Saitoh, Youichi

2013-07-01

411

Transcranial magnetic stimulation with a half-sine wave pulse elicits direction-specific effects in human motor cortex  

PubMed Central

Background Transcranial magnetic stimulation (TMS) commonly uses so-called monophasic pulses where the initial rapidly changing current flow is followed by a critically dampened return current. It has been shown that a monophasic TMS pulse preferentially excites different cortical circuits in the human motor hand area (M1-HAND), if the induced tissue current has a posterior-to-anterior (PA) or anterior-to-posterior (AP) direction. Here we tested whether similar direction-specific effects could be elicited in M1-HAND using TMS pulses with a half-sine wave configuration. Results In 10 young participants, we applied half-sine pulses to the right M1-HAND which elicited PA or AP currents with respect to the orientation of the central sulcus. Measurements of the motor evoked potential (MEP) revealed that PA half-sine stimulation resulted in lower resting motor threshold (RMT) than AP stimulation. When stimulus intensity (SI) was gradually increased as percentage of maximal stimulator output, the stimulus–response curve (SRC) of MEP amplitude showed a leftward shift for PA as opposed to AP half-sine stimulation. Further, MEP latencies were approximately 1 ms shorter for PA relative to AP half-sine stimulation across the entire SI range tested. When adjusting SI to the respective RMT of PA and AP stimulation, the direction-specific differences in MEP latencies persisted, while the gain function of MEP amplitudes was comparable for PA and AP stimulation. Conclusions Using half-sine pulse configuration, single-pulse TMS elicits consistent direction-specific effects in M1-HAND that are similar to TMS with monophasic pulses. The longer MEP latency for AP half-sine stimulation suggests that PA and AP half-sine stimulation preferentially activates different sets of cortical neurons that are involved in the generation of different corticospinal descending volleys.

2012-01-01

412

Twelve-month, prospective, open-label study of repetitive transcranial magnetic stimulation for major depressive disorder in partial remission  

PubMed Central

Background The purpose of this study was to evaluate the long-term effect of repetitive transcranial magnetic stimulation (rTMS) as adjunctive treatment in patients with partial remission of major depressive disorder. Methods This was a 12-month, prospective, open-label study in patients meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for nonpsychotic major depressive disorder who responded to 8 weeks of medication treatment but did not reach remission. All patients were assigned to receive 10 sessions of rTMS applied at the left dorsolateral prefrontal cortex. During the course of rTMS, the patients were still taking their usual medication. Patients were followed up for 12 months to determine the long-term antidepressant effect. Results There were nine patients (seven women and two men) who met the inclusion criteria and agreed to receive rTMS. The mean Hamilton rating scale for depression (HAM-D) score prior to treatment with rTMS was 12.89 ± 2.15. At 12 months after treatment, the mean HAM-D score was 6.45 ± 1.67 using a Friedman test, and in patients with partial remission of major depressive disorder, the HAM-D score significantly decreased after treatment with rTMS at 12 months (P = 0.001). Seven patients (77.78%) had reached the stage of remission (HAM-D < 8) after treating with rTMS at 12 months. There were no serious adverse events. One patient had vertigo after the first session of treatment and one patient felt scalp contractions during treatment, and both fully recovered within half an hour with no medical intervention. Conclusion For patients with major depressive disorder in partial remission, high frequency rTMS at the left dorsolateral prefrontal cortex may provide benefits in adjunctive treatment with well tolerability. Also, follow-up findings show a long duration of benefit.

Charnsil, Chawanun; Suttajit, Sirijit; Boonyanaruthee, Vudhichai; Leelarphat, Samornsri

2012-01-01

413

Excitatory and inhibitory corticospinal responses to transcranial magnetic stimulation in patients with minor to moderate head injury  

PubMed Central

OBJECTIVES—The changes in excitatory and inhibitory responses to transcranial magnetic stimulation (TMS), as attested by motor evoked potential (MEP) and silent period (SP) parameters, were compared in patients who sustained minor to moderate head injury.?METHODS—A total of 38 patients with brain concussion, and diffuse, focal, and combined brain injury and 20 healthy volunteers were examined. The MEPs and SPs were recorded from the abductor pollicis brevis muscle after single pulse TMS 2 weeks after head trauma. The parameters assessed were the MEP resting threshold, the MEP/M wave amplitude ratio, the central motor conduction time (CMCT), the SP threshold, the interthreshold difference (ITD), and the SP duration (SPD).?RESULTS—The main finding was an increase in the ITD in patients with mild and moderate head injury due to the relatively greater augmentation of the MEP threshold. This was associated with a reduction of the MEP/M wave amplitude ratio. The degree of MEP and SP changes depended on severity of head injury and was not related to the type of brain lesions. The SPD did not differ significantly in brain concussion, or diffuse, focal and combined brain injury groups compared with the control group. The CMCT was prolonged in patients with diffuse and combined brain lesions. Among subjective complaints only fatigue was significantly related to ITD, MEP, and SP threshold abnormalities.?CONCLUSIONS—The results suggest that mechanisms involved in MEP and SP generation are differently affected in head injury, the first being impaired more severely. The increase of the ITD accompanied by reduction of the MEP/M wave amplitude ratio may reflect a dissociated impairment of inhibitory and excitatory components of central motor control in head trauma.??

Chistyakov, A; Soustiel, J; Hafner, H; Trubnik, M; Levy, G; Feinsod, M

2001-01-01

414

Carbonic Anhydrase I, II, and VI, Blood Plasma, Erythrocyte and Saliva Zinc and Copper Increase After Repetitive Transcranial Magnetic Stimulation  

PubMed Central

Introduction Repetitive transcranial magnetic stimulation (rTMS) has been used to treat symptoms from many disorders; biochemical changes occurred with this treatment. Preliminary studies with rTMS in patients with taste and smell dysfunction improved sensory function and increased salivary carbonic anhydrase (CA) VI and erythrocyte CA I, II. To obtain more information about these changes after rTMS, we measured changes in several CA enzymes, proteins, and trace metals in their blood plasma, erythrocytes, and saliva. Methods Ninety-three patients with taste and smell dysfunction were studied before and after rTMS in an open clinical trial. Before and after rTMS, we measured erythrocyte CA I, II and salivary CA VI, zinc and copper in parotid saliva, blood plasma, and erythrocytes, and appearance of novel salivary proteins by using mass spectrometry. Results After rTMS, CA I, II and CA VI activity and zinc and copper in saliva, plasma, and erythrocytes increased with significant sensory benefit. Novel salivary proteins were induced at an m/z value of 21.5K with a repetitive pattern at intervals of 5K m/z. Conclusions rTMS induced biochemical changes in specific enzymatic activities, trace metal concentrations, and induction of novel salivary proteins, with sensory improvement in patients with taste and smell dysfunction. Because patients with several neurologic disorders exhibit taste and smell dysfunction, including Parkinson disease, Alzheimer disease, and multiple sclerosis, and because rTMS improved their clinical symptoms, the biochemical changes we observed may be relevant not only in our patients with taste and smell dysfunction but also in patients with neurologic disorders with these sensory abnormalities.

Henkin, Robert I.; Potolicchio, Samuel J.; Levy, Lucien M.; Moharram, Ramy; Velicu, Irina; Martin, Brian M.

2010-01-01

415

Transcranial direct current stimulation (tDCS) produces localized and specific alterations in neurochemistry: a ¹H magnetic resonance spectroscopy study.  

PubMed

Transcranial direct current stimulation (tDCS) has been found to produce significant changes in behavior, including a large increase of learning and performance for a difficult visual perceptual task (Clark et al., NeuroImage 2010). The mechanisms by which tDCS produces these behavioral effects are currently uncertain. One hypothesis is that anodal tDCS leads to increased metabolic activity in the brain, which enhances cognitive and memory processes. Here we examined the neuronal mechanisms by which tDCS influences learning by measuring changes in brain metabolite concentrations using proton magnetic resonance spectroscopy (¹H MRS). As perception and learning can also influence neurochemistry, here we applied tDCS during rest. MRS data was obtained before and after 2.0 mA of anodal tDCS was applied for 30 min over electrode site P4, with the cathode placed on the contralateral arm. MRS data were acquired from the right parietal lobe beneath the anodal tDCS electrode, and from the homologous regions of the left hemisphere once before and once after tDCS. Significantly higher combined glutamate and glutamine levels were found in right parietal cortex, beneath the stimulating electrode, with non-significant increases in homologous regions of the opposite hemisphere. In addition, a significant interaction between hemispheres was found for tDCS effects on tNAA. These results suggest that changes in glutamatergic activity and tNAA may be related to the mechanisms by which tDCS influences learning and behavior. PMID:21683766

Clark, Vincent P; Coffman, Brian A; Trumbo, Michael C; Gasparovic, Charles

2011-06-12

416

The role of parietal cortex in awareness of self-generated movements: a transcranial magnetic stimulation study.  

PubMed

Awareness of self-generated movements arises from comparing motor plans, and the accompanying (hypothetical) efference copy, with the visual and proprioceptive consequences of movement. Here we used repetitive transcranial magnetic stimulation (rTMS) to investigate the role of a posterior region in the superior parietal lobule (SPL) in this process. Nine healthy volunteers performed a finger extension actively and passively while wearing a CyberGlove; the glove recorded these (actual) finger movements and used this information in real time to move a virtual hand displayed on a computer screen. To assess the participant's awareness of movement onset, we introduced a delay between the onset of the actual and virtual movement (60-270 ms, 30 ms increments); the task was to judge whether the virtual hand movements were delayed relative to the actual hand movements. Low-frequency rTMS (15 min, 0.6 Hz) was applied either over the left SPL or the left temporal cortex (control site) to decrease excitability of these regions and, in turn, test their role in the awareness of self-generated movement. Following the SPL stimulation, participants' assessments of asynchrony were impaired for active but not passive movements. No significant changes were observed after rTMS applied over the control site. We suggest that these findings are consistent with the role of the SPL in evaluating the temporal congruency of peripheral (visual) and central (efference copy) signals associated with self-generated movements. As such, this region may contribute to the sense of 'agency' and its disturbances in disorders such as apraxia and schizophrenia. PMID:12902395

MacDonald, Penny A; Paus, Tomás

2003-09-01

417

Repetitive Transcranial Magnetic Stimulation in the Treatment of depression: A Randomized, Double-blind, Placebo-controlled Trial  

PubMed Central

Background: The efficacy of repetitive transcranial magnetic stimulation (rTMS) in the treatment of depression has never been reported as yet in the Indian literature. Aims: To study the efficacy of rTMS in the treatment of depression and to evaluate its safety and tolerability. Settings and Design: A randomized, double-blind, sham-controlled trial was conducted at the Department of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore. Materials and Methods: 23 patients with depression were randomized to receive either active (n=9) or sham (n=14) treatment with rTMS. Treatment consisted of six sessions of rTMS for 2 weeks (10 trains of pulses, intensity equal to motor threshold, 10 Hz frequency, train duration of 5 seconds, 1 minute inter-train duration). Response was assessed using Hamilton Depression Rating Scale (HDRS), Montgomery Åsberg Depression Rating Scale (MADRS) and Clinical Global Index (CGI). The safety and tolerability was assessed with side-effect checklist for electroconvulsive therapy. 50% reduction in HDRS scores from baseline was defined as treatment response. Outcome measures were analyzed by repeated measures analysis of variance. Chi-square test was used to analyze the categorical variables. Results: No statistical significance was seen on the baseline socio-demographic and illness characteristics (Pearson's Chi-square=0.5). Although HDRS (sham 22.0-12.4; active 22.8-12.7) and MADRS (sham 30.7-17.3; active 31.8-16.7) scores reduced by the end of 2 weeks treatment, it was not statistically significant. One patient developed manic symptoms early in the treatment. Conclusions: Treatment with rTMS did not show improvement at the end of 2 weeks. More studies with larger sample size and with higher rTMS dosages need to be done.

Lingeswaran, Anand

2011-01-01

418

Meta-Review of Metanalytic Studies with Repetitive Transcranial Magnetic Stimulation (rTMS) for the Treatment of Major Depression  

PubMed Central

Background: Major Depression (MD) and treatment-resistant depression (TRD) are worldwide leading causes of disability and therapeutic strategies for these impairing and prevalent conditions include pharmacological augmentation strategies and brain stimulation techniques. In this perspective, repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique with a favorable profile of tolerability which, despite being recently approved by the Food and Drug Administration (FDA) for the treatment of patients with medication-refractory unipolar depression, still raises some doubts about most effective parameters of stimulation. Methods: A literature search was performed using PubMed for the years 2001 through February 2011 in order to review meta-analytic studies assessing efficacy and safety issues for rTMS in depressive disorders. Fifteen meta-analyses were identified and critically discussed in order to provide an updated and comprehensive overview of the topic with specific emphasis on potentially optimal parameters of stimulation. Results: First meta-analyses on the efficacy of rTMS for the treatment of MD and TRD have shown mixed results. On the other hand, more recent meta-analytic studies seem to support the antidepressant efficacy of the technique to a greater extent, also in light of longer periods of stimulation (e.g. > 2 weeks). Conclusion: rTMS seems to be an effective and safe brain stimulation technique for the treatment of medication refractory depression. Nevertheless, further studies are needed to better define specific stimulation-related issues, such as duration of treatment as well as durability of effects and predictors of response.

Dell'Osso, Bernardo; Camuri, Giulia; Castellano, Filippo; Vecchi, Vittoria; Benedetti, Matteo; Bortolussi, Sara; Altamura, A. Carlo

2011-01-01

419

The effects of transcranial magnetic stimulation on vibratory-induced presynaptic inhibition of the soleus H reflex.  

PubMed

A single-pulse transcranial magnetic stimulus (TMS) may induce contraction in many muscles of the body at the same time. This is specially the case when using the double-cone coil to obtain the motor evoked potentials in leg muscles. Even if intensity is kept below threshold for the soleus muscle, TMS induces facilitation of the soleus H reflex that is separated into two phases: the first, peaking at 10-20 ms and the second, peaking at 70-90 ms. We investigated the possibility that TMS-induced facilitation of the H reflex was related, at least in part, to the reafferentation volley reaching the alpha motoneuron after synchronized contraction of other muscles in the body. To test this hypothesis, we examined the effects of vibration on the TMS-induced facilitation of the soleus H reflex. As expected, vibration applied over the triceps tendon caused a significant reduction in H reflex amplitude: 42.4 ± 6.4 % of control values. When conditioned by TMS at intervals corresponding to the first phase, the H reflex was facilitated to the same extent in both conditions: with and without vibration. However, at intervals corresponding to the second facilitation phase, there was a significantly reduced facilitation with vibration. These differential effects of vibration on the two phases of the TMS-induced facilitation of the H reflex indicate a different mechanism for each facilitation phase. The first phase could result from direct corticospinal excitatory input, while the second phase might depend on inputs via Ia afferents from heteronymous muscles. PMID:22644238

Guzmán-López, Jessica; Costa, João; Selvi, Aikaterini; Barraza, Gonzalo; Casanova-Molla, Jordi; Valls-Solé, Josep

2012-05-29

420

Finding the Right Words: Transcranial Magnetic Stimulation Improves Discourse Productivity in Non-fluent Aphasia After Stroke.  

PubMed

BACKGROUND: Loss of fluency is a significant source of functional impairment in many individuals with aphasia. Repetitive transcranial magnetic stimulation (rTMS) administered to the right inferior frontal gyrus (IFG) has been shown to facilitate naming in persons with chronic left hemisphere stroke and non-fluent aphasia. However, changes in fluency in aphasic subjects receiving rTMS have not been adequately explored. AIMS: To determine whether rTMS improves fluency in individuals with chronic nonfluent aphasia, and to identify aspects of fluency that are modulated in persons who respond to rTMS. METHODS #ENTITYSTARTX00026; PROCEDURES: Ten individuals with left hemisphere MCA strokes and mild to moderate non-fluent aphasia participated in the study. Before treatment, subjects were asked to describe the Cookie Theft picture in three separate sessions. During treatment, all subjects received 1200 pulses of 1 Hz rTMS daily in 10 sessions over two weeks at a site that had previously been shown to improve naming. Subjects repeated the Cookie Theft description two months after treatment. Five subjects initially received sham stimulation instead of real TMS. Two months after sham treatment, these individuals received real rTMS. Performance both at baseline and after stimulation was coded using Quantitative Production Analysis (Saffran, Berndt & Schwartz, 1989) and Correct Information Unit (Nicholas & Brookshire, 1993) analysis. OUTCOMES #ENTITYSTARTX00026; RESULTS: Across all subjects (n=10), real rTMS treatment resulted in a significant increase in multiple measures of discourse productivity compared to baseline performance. There was no significant increase in measures of sentence productivity or grammatical accuracy. There was no significant increase from baseline in the sham condition (n=5) on any study measures. CONCLUSIONS: Stimulation of the right IFG in patients with chronic non-fluent aphasia facilitates discourse production. We posit that this effect may be attributable to improved lexical-semantic access. PMID:23280015

Medina, Jared; Norise, Catherine; Faseyitan, Olufunsho; Coslett, H Branch; Turkeltaub, Peter E; Hamilton, Roy H

2012-08-29

421

Motor and Gait Improvement in Patients With Incomplete Spinal Cord Injury Induced by High-Frequency Repetitive Transcranial Magnetic Stimulation  

PubMed Central

Objective: To assess the effect of high-frequency repetitive transcranial magnetic stimulation (rTMS) on lower extremities motor score (LEMS) and gait in patients with motor incomplete spinal cord injury (SCI). Method: The prospective longitudinal randomized, double-blind study assessed 17 SCI patients ASIA D. We assessed LEMS, modified Ashworth Scale (MAS), 10-m walking test (10MWT), Walking Index for SCI (WISCI II) scale, step length, cadence, and Timed Up and Go (TUG) test at baseline, after the last of 15 daily sessions of rTMS and 2 weeks later. Patients were randomized to active rTMS or sham stimulation. Three patients from the initial group of 10 randomized to sham stimulation entered the active rTMS group after a 3-week washout period. Therefore a total of 10 patients completed each study condition. Both groups were homogeneous for age, gender, time since injury, etiology, and ASIA scale. Active rTMS consisted of 15 days of daily sessions of 20 trains of 40 pulses at 20 Hz and an intensity of 90% of resting motor threshold. rTMS was applied with a double cone coil to the leg motor area. Results: There was a significant improvement in LEMS in the active group (28.4 at baseline and 33.2 after stimulation; P = .004) but not in the sham group (29.6 at baseline, and 30.9 after stimulation; P = .6). The active group also showed significant improvements in the MAS, 10MWT, cadence, step length, and TUG, and these improvements were maintained 2 weeks later. Following sham stimulation, significant improvement was found only for step length and TUG. No significant changes were observed in the WISCI II scale in either group. Conclusion: High-frequency rTMS over the leg motor area can improve LEMS, spasticity, and gait in patients with motor incomplete SCI.

Benito, J.; Kumru, H.; Murillo, N.; Costa, U.; Medina, J.; Tormos, J.M.; Pascual-Leone, Alvaro; Vidal, J.

2012-01-01

422

Safety and tolerability of repetitive transcranial magnetic stimulation in patients with pathologic positive sensory phenomena: a review of literature  

PubMed Central

BACKGROUND Repetitive transcranial magnetic stimulation (rTMS) is emerging as a valuable therapeutic and diagnostic tool. rTMS appears particularly promising for disorders characterized by positive sensory phenomena attributable to alterations in sensory cortex excitability. Among these are tinnitus, auditory and visual hallucinations, and pain syndromes. OBJECTIVE Despite studies addressing rTMS efficacy in suppression of positive sensory symptoms, the safety of stimulation of potentially hyperexcitable cortex has not been fully addressed. We performed a systematic literature review and metanalysis to describe the rTMS safety profile in these disorders. METHODS Using the PubMed database, we performed an English-language literature search from January 1985 to April 2011 to review all pertinent publications. Per study, we noted and listed pertinent details. From these data we also calculated a crude per-subject risk for each adverse event. RESULTS 106 publications (n = 1815 subjects) were identified with patients undergoing rTMS for pathologic positive sensory phenomena. Adverse events associated with rTMS were generally mild and occurred in 16.7% of subjects. Seizure was the most serious adverse event, and occurred in three patients with a 0.16% crude per-subject risk. The second most severe adverse event involved aggravation of sensory phenomena, occurring in 1.54%. CONCLUSIONS The published data suggest rTMS for the treatment or diagnosis of pathologic positive sensory phenomena appears to be a relatively safe and well-tolerated procedure. However, published data are lacking in systematic reporting of adverse events, and safety risks of rTMS in these patient populations will have to be addressed in future prospective trials.

Muller, Paul A; Pascual-Leone, Alvaro; Rotenberg, Alexander

2013-01-01

423

Parietal cortex involvement in the localization of tactile and noxious mechanical stimuli: a transcranial magnetic stimulation study.  

PubMed

The cortical system underlying perceptual ability to localize tactile and noxious cutaneous stimuli in humans is still incompletely understood. We used transcranial magnetic stimulation (TMS) to transiently interfere with the function of the parietal cortex, at different times after the beginning of noxious or non-noxious mechanical stimulation of the hairy skin overlying the dorsal surface of the first metacarpal of the contralateral hand. Peripheral stimuli consisted of rounded (1mm diameter) or sharp (0.2 mm) metal tips; skin contact lasted on average 242 ms (noxious) and 228 ms (non-noxious). Brief (80 ms, 25 Hz) TMS trains, given at 150 ms after the onset of cutaneous stimulation, significantly impaired subjects' ability in localizing non-nociceptive, tactile input, an effect which was not observed when TMS was applied at 300 ms after cutaneous stimulation. In contrast, brief TMS trains given at 300 ms after the onset of cutaneous stimulation significantly impaired subjects' ability in localizing nociceptive input, an effect which was not observed when TMS was applied at 150 ms after cutaneous stimulation. No impairment in stimulus detection was found in comparison with control sham TMS. The timing of parietal TMS interference with the ability to localize tactile and painful stimuli is compatible with known time differences in the arrival of non-noxious and noxious information in the postcentral gyrus. On these grounds, our findings support the existence of overlapping cortical populations in the contralateral parietal lobe, exerting a role in spatial discriminative aspects of touch and mechanically induced pain. PMID:17239452

Porro, Carlo A; Martinig, Michela; Facchin, Patrizia; Maieron, Marta; Jones, Anthony K P; Fadiga, Luciano

2007-01-17

424

The right planum temporale is involved in stimulus-driven, auditory attention--evidence from transcranial magnetic stimulation.  

PubMed

It is well known that the planum temporale (PT) area in the posterior temporal lobe carries out spectro-temporal analysis of auditory stimuli, which is crucial for speech, for example. There are suggestions that the PT is also involved in auditory attention, specifically in the discrimination and selection of stimuli from the left and right ear. However, direct evidence is missing so far. To examine the role of the PT in auditory attention we asked fourteen participants to complete the Bergen Dichotic Listening Test. In this test two different consonant-vowel syllables (e.g., "ba" and "da") are presented simultaneously, one to each ear, and participants are asked to verbally report the syllable they heard best or most clearly. Thus attentional selection of a syllable is stimulus-driven. Each participant completed the test three times: after their left and right PT (located with anatomical brain scans) had been stimulated with repetitive transcranial magnetic stimulation (rTMS), which transiently interferes with normal brain functioning in the stimulated sites, and after sham stimulation, where participants were led to believe they had been stimulated but no rTMS was applied (control). After sham stimulation the typical right ear advantage emerged, that is, participants reported relatively more right than left ear syllables, reflecting a left-hemispheric dominance for language. rTMS over the right but not left PT significantly reduced the right ear advantage. This was the result of participants reporting more left and fewer right ear syllables after right PT stimulation, suggesting there was a leftward shift in stimulus selection. Taken together, our findings point to a new function of the PT in addition to auditory perception: particularly the right PT is involved in stimulus selection and (stimulus-driven), auditory attention. PMID:23437367

Hirnstein, Marco; Westerhausen, René; Hugdahl, Kenneth

2013-02-20

425

Feasibility of automated analysis and inter-examiner variability of cortical silent period induced by transcranial magnetic stimulation.  

PubMed

Cortical silent period (cSP) is a short interruption in electromyography (EMG) during active muscle contraction induced with transcranial magnetic stimulation (TMS). The cSP is a measure of cortical inhibition and is believed to represent inhibitory interneuron effects on excited motor cortical areas. Several pathological conditions and pharmacological manipulations induce changes to cSP duration indicating alterations in intracortical inhibition. At present, it is common to manually analyse the cSP duration from measured EMG. However, to avoid inter-examiner effects on cSP interpretation and detection, as well as to allow for quick measurement online, automated routine would be preferable. In this study, we evaluate the feasibility of a straight-forward cSP detection routine based on analysing the rectified first derivative of the EMG signal following TMS. Previously measured cSPs of 54 healthy subjects were reanalysed manually by two of the authors and using the automated routine. Furthermore, we recruited one subject for whom the cSPs were induced with several stimulation intensities, and those cSPs were analysed manually by two of the authors as well as using the automated routine. We found that cSPs were detected correctly by the automated cSP detection routine, and agreement with manually analysed subject-specific mean cSPs was excellent (ICC=0.992, p<0.001). The inter-examiner variability was similar to the variability between manual and automated analysis. Hence, we believe the introduced cSP detection routine would be feasible for online cSP detection, in such a way that is presently used to detect the motor evoked potentials. PMID:23660523

Julkunen, Petro; Kallioniemi, Elisa; Könönen, Mervi; Säisänen, Laura

2013-05-06

426

Cognitive and anatomical underpinnings of the conceptual knowledge for common objects and familiar people: a repetitive transcranial magnetic stimulation study.  

PubMed

Several studies have addressed the issue of how knowledge of common objects is organized in the brain, whereas the cognitive and anatomical underpinnings of familiar people knowledge have been less explored. Here we applied repetitive transcranial magnetic stimulation (rTMS) over the left and right temporal poles before asking healthy individuals to perform a speeded word-to-picture matching task using familiar people and common objects as stimuli. We manipulated two widely used semantic variables, namely the semantic distance and the familiarity of stimuli, to assess whether the semantic organization of familiar people knowledge is similar to that of common objects. For both objects and faces we reliably found semantic distance and familiarity effects, with less accurate and slower responses for stimulus pairs that were more closely related and less familiar. However, the effects of semantic variables differed across categories, with semantic distance effects larger for objects and familiarity effects larger for faces, suggesting that objects and faces might share a partially comparable organization of their semantic representations. The application of rTMS to the left temporal pole modulated, for both categories, semantic distance, but not familiarity effects, revealing that accessing object and face concepts might rely on overlapping processes within left anterior temporal regions. Crucially, rTMS of the left temporal pole affected only the recognition of pairs of stimuli that could be discriminated at specific levels of categorization (e.g., two kitchen tools or two famous persons), with no effect for discriminations at either superordinate or individual levels. Conversely, rTMS of the right temporal pole induced an overall slowing of reaction times that positively correlated with the visual similarity of the stimuli, suggesting a more perceptual rather than semantic role of the right anterior temporal regions. Results are discussed in the light of current models of face and object semantic representations in the brain. PMID:23704999

Campanella, Fabio; Fabbro, Franco; Urgesi, Cosimo

2013-05-21

427

The role of the right cerebral hemisphere in processing novel metaphoric expressions: a transcranial magnetic stimulation study.  

PubMed

Abstract Previous research suggests that the right hemisphere (RH) may contribute uniquely to the processing of metaphoric language. However, causal relationships between local brain activity in the RH and metaphors comprehension were never established. In addition, most studies have focused on familiar metaphoric expressions which might be processed similarly to any conventional word combination. The present study was designed to overcome these two problems by employing repetitive transcranial magnetic stimulation (rTMS) to examine the role of the RH in processing novel metaphoric expressions taken from poetry. Right-handed participants were presented with four types of word pairs, literal, conventional metaphoric and novel metaphoric expressions, and unrelated word pairs, and were asked to perform a semantic judgment task. rTMS of the right posterior superior temporal sulcus disrupted processing of novel but not conventional metaphors, whereas rTMS over the left inferior frontal gyrus selectively impaired processing of literal word pairs and conventional but not novel metaphors (Experiment 1). In a further experiment, we showed that these effects were due to right-left asymmetries rather than posterior-anterior differences (Experiment 2). This is the first demonstration of TMS-induced impairment in processing novel metaphoric expressions, and as such, confirms the specialization of the RH in the activation of a broader range of related meanings than the left hemisphere, including novel, nonsalient meanings. The findings thus suggest that the RH may be critically involved in at least one important component of novel metaphor comprehension, the integration of the individual meanings of two seemingly unrelated concepts into a meaningful metaphoric expression. PMID:17919080

Pobric, Gorana; Mashal, Nira; Faust, Miriam; Lavidor, Michal

2008-01-01

428

Effects of Low Frequency Prefrontal Repetitive Transcranial Magnetic Stimulation on the N2 Amplitude in a GoNogo Task  

PubMed Central

During the last decade, repetitive transcranial magnetic stimulation (rTMS) of the prefrontal cortex has become established as a treatment for various mental diseases. The rational of prefrontal stimulation has been adapted from the mode of action known from rTMS using motor-evoked potentials though little is known about the precise effect of rTMS at prefrontal sites. The objective of the current study is to investigate the inhibitory effect of prefrontal 1 Hz rTMS by stimulating the generators of event-related potentials (ERP) which are located in the prefrontal cortex. Thus, 1 Hz rTMS was applied offline over the left dorsolateral prefrontal cortex (DLPFC) and the medial prefrontal cortex (MPFC) in 18 healthy subjects who subsequently underwent a GoNogo task. Both active conditions were compared to sham rTMS within a randomized and counterbalanced cross-over design in one day. ERPs were recorded during task performance and the N2 and the P3 were analysed. After 1 Hz rTMS of the left DLPFC (but not of the MPFC), an inhibitory effect on the N2 amplitude was observed, which was related to inhibitory control. In contrast, after 1 Hz rTMS of the MPFC (but not at the left DLPFC) a trend towards an increased P3 amplitude was found. There was no significant modulation of latencies and behavioural data. The results argue in favour of an inhibitory effect of 1 Hz rTMS on N2 amplitudes in a GoNogo task. Our findings suggest that rTMS may mildly modulate prefrontally generated ERP immediately after stimulation, even where behavioural effects are not measurable. Thus, combined rTMS-ERP approaches need to be further established in order to serve as paradigms in experimental neuroscience and clinical research.

Grossheinrich, Nicola; Reinl, Maren; Pogarell, Oliver; Karch, Susanne; Mulert, Christoph; Brueckl, Monika; Hennig-Fast, Kristina; Rau, Anne; Epple, Maria; Hornig, Ariane; Padberg, Frank

2013-01-01

429

Occurrence of Magnetic Reconnection in the Deep Magnetotail: ARTEMIS Results  

NASA Astrophysics Data System (ADS)

Using two-probe ARTEMIS magnetic field and plasma measurements we have accomplished a survey of the occurrence of magnetic reconnection signatures in the distant magnetotail between October 2010 and June 2011. We have considered highly accelerated electron and fast bulk plasma flow events during ARTEMIS tail crossings. Our findings suggest that the deep-tail region between -60{R}E < X({GSM}) < -40{R}E is rather active. Fourteen events have been found exhibiting signatures of magnetic reconnection occurrence during 29 days of plasma sheet crossings. Comparisons with mid-tail surveys of reconnection statistics indicate that the deep-tail region can play a significant role in global magnetosphere dynamics.

Vörös, Zoltán; Runov, Andrei; Kendl, Alexander

430

Repetitive Transcranial Magnetic Stimulation to the Primary Motor Cortex Interferes with Motor Learning by Observing  

Microsoft Academic Search

Neural representations of novel motor skills can be ac- quired through visual observation. We used repetitive trans- cranial magnetic stimulation (rTMS) to test the idea that this ''motor learning by observing'' is based on engagement of neural processes for learning in the primary motor cortex (M1). Human subjects who observed another person learning to reach in a novel force environment

Liana E. Brown; Elizabeth T. Wilson; Paul L. Gribble

2009-01-01

431

Topiramate modulates excitability of the occipital cortex when measured by transcranial magnetic stimulation  

Microsoft Academic Search

The aim of this study was to measure differences in occipital cortex excitability in migraineurs before and after administration of topiramate. We have previously demonstrated occipital cortex hyperexcitability in migraine using an objective technique of magnetic suppression of perceptual accuracy (MSPA). We hypothesized that a neuromodulator such as topiramate would demonstrate differences in MSPA in migraine compared with baseline. Ten

SK Aurora; PM Barrodale; AR Vermaas; CB Rudra

2010-01-01

432

Repetitive Transcranial Magnetic Stimulation of Broca's Area Affects Verbal Responses to Gesture Observation  

Microsoft Academic Search

The aim of the present study was to determine whether Broca's area is involved in translating some aspects of arm gesture representations into mouth articulation gestures. In Experiment 1, we applied low-frequency repetitive transcra- nial magnetic stimulation over Broca's area and over the sym- metrical loci of the right hemisphere of participants responding verbally to communicative spoken words, to gestures,

Maurizio Gentilucci; Paolo Bernardis; Girolamo Crisi; Riccardo Dalla Volta

2006-01-01

433

Magnetic petrology of deep crustal rocks-Ivrea Zone, Italy  

NASA Astrophysics Data System (ADS)

Magnetic petrology is an extension of petrology, integrating magnetic property studies with conventional petrology for the purpose of understanding the development and modification of the magnetization in rocks. The magnetic properties of a suite of samples from the Ivrea Zone, northern Italy, are described with the aim of developing a magnetic petrology for deep crustal rocks. Samples studied include a variety of metamorphosed mafic (granulites, granofelses, plagioklasfelse, amphibolite, pyriclasite) and pelitic/quartzo-feldspathic rocks (acid granulites, stronalite and kinzigite gneisses, schists), and representative ultramafic rocks (phlogopite peridotite, pyroxenite, hornblendite). Ilmenite is the chief oxide mineral in a majority of the samples, but in a few mafic rocks, magnetite is the principal oxide constituent. Cr,Al-spinel is common in ultramafic samples and rutile is present in some metapelites. Sulfides are generally subordinate in abundance to oxide minerals. The mafic rocks in the Ivrea section have the broadest range of magnetic properties and include the most strongly magnetic samples. The Ivrea ultramafic rocks are moderately magnetic-the magnetite present appears to be secondary and is associated with crustal alterations-while pelitic and quartzo-feldspathic lithologies are dominantly paramagnetic or only weakly magnetic. The main ferromagnetic mineral in all strongly magnetic samples is magnetite that is nearly pure Fe3O4 in composition. Consequently, Curie temperatures are 565-580°C for these rocks. Pyrrhotite contributes to the magnetism in several ultramafic and mafic rocks, and it is the sole ferromagnetic mineral in the pelitic and quartzo-feldspathic samples. The results of our study indicate that certain mafic rock types (amphibolites, mafic granulites, pyriclasites) are the most likely source of the Ivrea Zone's regional scale magnetic anomalies. If the Ivrea Zone represents a tectonically exposed cross section of continental crust, the geographic distribution of these rock types suggests the presence of multiple and variably thick, strongly magnetic layers, with magnetite Curie temperatures, in the deep crust. Petrographic evidence suggests, however, that the magnetic mineralogy of the sampled Ivrea rocks might have been changed subsequent to peak metamorphic conditions. Therefore, considerable care must be taken in evaluating the magnetic record in these crustal cross sections, particularly if they are to be used to model the magnetic characteristics of the lower crust.

Wasilewski, Peter; Warner, Richard D.

1988-02-01

434

Transcranial Magnetic Stimulation during Positron Emission Tomography: A New Method for Studying Connectivity of the Human Cerebral Cortex  

Microsoft Academic Search

We describe a new technique permitting the mapping of neural connections in the living human brain. The method combines two well established tools of brain research: transcranial mag- netic stimulation (TMS) and positron emission tomography (PET). We use TMS to stimulate directly a selected cortical area while simultaneously measuring changes in brain activity, in- dexed by cerebral blood flow (CBF),

Robert Jech; Christopher J. Thompson; Roch Comeau; Terry Peters; Alan C. Evans

1997-01-01

435

A mediating role of the auditory dorsal pathway in selective adaptation to speech: a state-dependent transcranial magnetic stimulation study.  

PubMed

In addition to sensory processing, recent neurobiological models of speech perception postulate the existence of a left auditory dorsal processing stream, linking auditory speech representations in the auditory cortex with articulatory representations in the motor system, through sensorimotor interaction interfaced in the supramarginal gyrus and/or the posterior part of the superior temporal gyrus. The present state-dependent transcranial magnetic stimulation study is aimed at determining whether speech recognition is indeed mediated by the auditory dorsal pathway, by examining the causal contribution of the left ventral premotor cortex, supramarginal gyrus and posterior part of the superior temporal gyrus during an auditory syllable identification/categorization task. To this aim, participants listened to a sequence of /ba/ syllables before undergoing a two forced-choice auditory syllable decision task on ambiguous syllables (ranging in the categorical boundary between /ba/ and /da/). Consistent with previous studies on selective adaptation to speech, following adaptation to /ba/, participants responses were biased towards /da/. In contrast, in a control condition without prior auditory adaptation no such bias was observed. Crucially, compared to the results observed without stimulation, single-pulse transcranial magnetic stimulation delivered at the onset of each target stimulus interacted with the initial state of each of the stimulated brain area by enhancing the adaptation effect. These results demonstrate that the auditory dorsal pathway contribute to auditory speech adaptation. PMID:23542585