Treatment of lithium induced tremor with atenolol.

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Davé, M

1989-03-01

This is the first report on the successful treatment of one patient with lithium induced tremor with hydrophilic atenolol, which is a relatively selective beta 1 adrenergic receptor blocker. Atenolol's advantages over lipophilic beta blockers in the treatment of lithium induced tremor are discussed.

Simulation of induced electric field distribution based on five-sphere model used in rTMS.

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Pu, Lina; Liu, Zhipeng; Yin, Tao; An, Hao; Li, Song

2010-01-01

Repetitive Transcranial magnetic stimulation (TMS) is a relatively new technique, which is non-invasive and painless used to stimulate the central and peripheral neural tissues. The principle is generating time-varying magnetic fields to stimulate the cerebral cortex neuron and inducing eddy current inside the tissues. Many researches study on the distributing of magnetic field and electric field induced inside the human brain, whereas the static electric field was neglected roughly in many studies. In this paper, a five-sphere model is established to simulate the human head used in rTMS. According to the different dielectric properties of the head tissues, the Laplace equation of static electric field is deduced by both of Gauss theorem and current's continuity principle. Boundary conditions used in different interface between two adjacent layers in the five-sphere model is proposed in this paper. Simulating study is conducted to calculate the distribution of the electric field in the model. Simulating results suggest that the model is useful to get the parameters of the most focus coil. Therefore this study could be potential to promote the development of rTMS stimulator.

Repetitive transcranial magnetic stimulation induces oscillatory power changes in chronic tinnitus

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Martin eSchecklmann

2015-10-01

Full Text Available Chronic tinnitus is associated with neuroplastic changes in auditory and non-auditory cortical areas. About ten years ago, repetitive transcranial magnetic stimulation (rTMS of auditory and prefrontal cortex was introduced as potential treatment for tinnitus. The resulting changes in tinnitus loudness are interpreted in the context of rTMS induced activity changes (neuroplasticity. Here, we investigate the effect of single rTMS sessions on oscillatory power to probe the capacity of rTMS to interfere with tinnitus-specific cortical plasticity. We measured 20 patients with bilateral chronic tinnitus and 20 healthy controls comparable for age, sex, handedness, and hearing level with a 63-channel EEG system. Educational level, intelligence, depressivity and hyperacusis were controlled for by analysis of covariance. Different rTMS protocols were tested: Left and right temporal and left and right prefrontal cortices were each stimulated with 200 pulses at 1Hz and with an intensity of 60% stimulator output. Stimulation of central parietal cortex with 6-fold reduced intensity (inverted passive-cooled coil served as sham condition. Before and after each rTMS protocol five minutes of resting state EEG were recorded. The order of rTMS protocols was randomized over two sessions with one week interval in between.Analyses on electrode level showed that people with and without tinnitus differed in their response to left temporal and right frontal stimulation. In tinnitus patients left temporal rTMS decreased frontal theta and delta and increased beta2 power, whereas right frontal rTMS decreased right temporal beta3 and gamma power. No changes or increases were observed in the control group. Only non-systematic changes in tinnitus loudness were induced by single sessions of rTMS.This is the first study to show tinnitus-related alterations of neuroplasticity that were specific to stimulation site and oscillatory frequency. The observed effects can be interpreted

Repetitive transcranial magnetic stimulation induces oscillatory power changes in chronic tinnitus

Science.gov (United States)

Schecklmann, Martin; Lehner, Astrid; Gollmitzer, Judith; Schmidt, Eldrid; Schlee, Winfried; Langguth, Berthold

2015-01-01

Chronic tinnitus is associated with neuroplastic changes in auditory and non-auditory cortical areas. About 10 years ago, repetitive transcranial magnetic stimulation (rTMS) of auditory and prefrontal cortex was introduced as potential treatment for tinnitus. The resulting changes in tinnitus loudness are interpreted in the context of rTMS induced activity changes (neuroplasticity). Here, we investigate the effect of single rTMS sessions on oscillatory power to probe the capacity of rTMS to interfere with tinnitus-specific cortical plasticity. We measured 20 patients with bilateral chronic tinnitus and 20 healthy controls comparable for age, sex, handedness, and hearing level with a 63-channel electroencephalography (EEG) system. Educational level, intelligence, depressivity and hyperacusis were controlled for by analysis of covariance. Different rTMS protocols were tested: Left and right temporal and left and right prefrontal cortices were each stimulated with 200 pulses at 1 Hz and with an intensity of 60% stimulator output. Stimulation of central parietal cortex with 6-fold reduced intensity (inverted passive-cooled coil) served as sham condition. Before and after each rTMS protocol 5 min of resting state EEG were recorded. The order of rTMS protocols was randomized over two sessions with 1 week interval in between. Analyses on electrode level showed that people with and without tinnitus differed in their response to left temporal and right frontal stimulation. In tinnitus patients left temporal rTMS decreased frontal theta and delta and increased beta2 power, whereas right frontal rTMS decreased right temporal beta3 and gamma power. No changes or increases were observed in the control group. Only non-systematic changes in tinnitus loudness were induced by single sessions of rTMS. This is the first study to show tinnitus-related alterations of neuroplasticity that were specific to stimulation site and oscillatory frequency. The observed effects can be

Impact of Repetitive Transcranial Magnetic Stimulation (rTMS on Brain Functional Marker of Auditory Hallucinations in Schizophrenia Patients

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Sonia Dollfus

2013-04-01

Full Text Available Several cross-sectional functional Magnetic Resonance Imaging (fMRI studies reported a negative correlation between auditory verbal hallucination (AVH severity and amplitude of the activations during language tasks. The present study assessed the time course of this correlation and its possible structural underpinnings by combining structural, functional MRI and repetitive Transcranial Magnetic Stimulation (rTMS. Methods: Nine schizophrenia patients with AVH (evaluated with the Auditory Hallucination Rating scale; AHRS and nine healthy participants underwent two sessions of an fMRI speech listening paradigm. Meanwhile, patients received high frequency (20 Hz rTMS. Results: Before rTMS, activations were negatively correlated with AHRS in a left posterior superior temporal sulcus (pSTS cluster, considered henceforward as a functional region of interest (fROI. After rTMS, activations in this fROI no longer correlated with AHRS. This decoupling was explained by a significant decrease of AHRS scores after rTMS that contrasted with a relative stability of cerebral activations. A voxel-based-morphometry analysis evidenced a cluster of the left pSTS where grey matter volume negatively correlated with AHRS before rTMS and positively correlated with activations in the fROI at both sessions. Conclusion: rTMS decreases the severity of AVH leading to modify the functional correlate of AVH underlain by grey matter abnormalities.

Insights into Pathophysiology from Medication-induced Tremor

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John C. Morgan

2017-10-01

Full Text Available Background: Medication-induced tremor (MIT is common in clinical practice and there are many medications/drugs that can cause or exacerbate tremors. MIT typically occurs by enhancement of physiological tremor (EPT, but not all drugs cause tremor in this way. In this manuscript, we review how some common examples of MIT have informed us about the pathophysiology of tremor.Methods: We performed a PubMed literature search for published articles dealing with MIT and attempted to identify articles that especially dealt with the medication’s mechanism of inducing tremor.Results: There is a paucity of literature that deals with the mechanisms of MIT, with most manuscripts only describing the frequency and clinical settings where MIT is observed. That being said, MIT emanates from multiple mechanisms depending on the drug and it often takes an individualized approach to manage MIT in a given patient.Discussion: MIT has provided some insight into the mechanisms of tremors we see in clinical practice. The exact mechanism of MIT is unknown for most medications that cause tremor, but it is assumed that in most cases physiological tremor is influenced by these medications. Some medications (epinephrine that cause EPT likely lead to tremor by peripheral mechanisms in the muscle (β-adrenergic agonists, but others may influence the central component (amitriptyline. Other drugs can cause tremor, presumably by blockade of dopamine receptors in the basal ganglia (dopamine-blocking agents, by secondary effects such as causing hyperthyroidism (amiodarone, or by other mechanisms. We will attempt to discuss what is known and unknown about the pathophysiology of the most common MITs.

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

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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

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…

Should We Expand the Toolbox of Psychiatric Treatment Methods to Include Repetitive Transcranial Magnetic Stimulation (rTMS)? A Meta-Analysis of the Efficacy of rTMS in Psychiatric Disorders

NARCIS (Netherlands)

Slotema, Christina W.; Blom, Jan Dirk; Hoek, Hans W.; Sommer, Iris E. C.

Objective: Repetitive transcranial magnetic stimulation (rTMS) is a safe treatment method with few side effects However, efficacy for various psychiatric disorders is currently not clear Data sources: A literature search was performed from 1966 through October 2008 using PubMed, Ovid Medline, Embase

What does low-intensity rTMS do to the cerebellum?

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Morellini, N; Grehl, S; Tang, A; Rodger, J; Mariani, J; Lohof, A M; Sherrard, R M

2015-02-01

Non-invasive stimulation of the human cerebellum, such as by transcranial magnetic stimulation (TMS), is increasingly used to investigate cerebellar function and identify potential treatment for cerebellar dysfunction. However, the effects of TMS on cerebellar neurons remain poorly defined. We applied low-intensity repetitive TMS (LI-rTMS) to the mouse cerebellum in vivo and in vitro and examined the cellular and molecular sequelae. In normal C57/Bl6 mice, 4 weeks of LI-rTMS using a complex biomimetic high-frequency stimulation (BHFS) alters Purkinje cell (PC) dendritic and spine morphology; the effects persist 4 weeks after the end of stimulation. We then evaluated whether LI-rTMS could induce climbing fibre (CF) reinnervation to denervated PCs. After unilateral pedunculotomy in adult mice and 2 weeks sham or BHFS stimulation, VGLUT2 immunohistochemistry was used to quantify CF reinnervation. In contrast to sham, LI-rTMS induced CF reinnervation to the denervated hemicerebellum. To examine potential mechanisms underlying the LI-rTMS effect, we verified that BHFS could induce CF reinnervation using our in vitro olivocerebellar explants in which denervated cerebellar tissue is co-cultured adjacent to intact cerebella and treated with brain-derived neurotrophic factor (BDNF) (as a positive control), sham or LI-rTMS for 2 weeks. Compared with sham, BDNF and BHFS LI-rTMS significantly increased CF reinnervation, without additive effect. To identify potential underlying mechanisms, we examined intracellular calcium flux during the 10-min stimulation. Complex high-frequency stimulation increased intracellular calcium by release from intracellular stores. Thus, even at low intensity, rTMS modifies PC structure and induces CF reinnervation.

Basic mechanisms of rTMS: Implications in Parkinson's disease

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Arias-Carrión Oscar

2008-04-01

Full Text Available Abstract Background Basic and clinical research suggests a potential role for repetitive transcranial magnetic stimulation (rTMS in the treatment of Parkinson's disease. However, compared to the growing number of clinical studies on its putative therapeutic properties, the studies on the basic mechanisms of rTMS are surprisingly scarce. Results Animal studies have broadened our understanding of how rTMS affects brain circuits and the causal chain in brain-behavior relationships. The observed changes are thought to be to neurotransmitter release, transsynaptic efficiency, signaling pathways and gene transcription. Furthermore, recent studies suggest that rTMS induces neurogenesis, neuronal viability and secretion of neuroprotective molecules. Conclusion The mechanisms underlying the disease-modifying effects of these and related rTMS in animals are the principle subject of the current review. The possible applications for treatment of Parkinson's disease are discussed.

Long-term effects of repetitive transcranial magnetic stimulation (rTMS) in patients with chronic tinnitus.

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Kleinjung, Tobias; Eichhammer, Peter; Langguth, Berthold; Jacob, Peter; Marienhagen, Joerg; Hajak, Goeran; Wolf, Stephan R; Strutz, Juergen

2005-04-01

The pathophysiologic mechanisms of idiopathic tinnitus remain unclear. Recent studies demonstrated focal brain activation in the auditory cortex of patients with chronic tinnitus. Low-frequency repetitive transcranial magnetic stimulation (rTMS) is able to reduce cortical hyperexcitability. Fusing of the individual PET-scan with the structural MRI-scan (T1, MPRAGE) allowed us to identify exactly the area of increased metabolic activity in the auditory cortex of patients with chronic tinnitus. With the use of a neuronavigational system, this target area was exactly stimulated by the figure 8-shaped magnetic coil. In a prospective study, rTMS (110% motor threshold; 1 Hz; 2000 stimuli/day over 5 days) was performed using a placebo controlled cross-over design. Patients were blinded regarding the stimulus condition. For the sham stimulation a specific sham-coil system was used. Fourteen patients were followed for 6 months. Treatment outcome was assessed with a specific tinnitus questionnaire (Goebel and Hiller). Tertiary referral medical center. Increased metabolic activation in the auditory cortex was verified in all patients. After 5 days of verum rTMS, a highly significant improvement of the tinnitus score was found whereas the sham treatment did not show any significant changes. The treatment outcome after 6 months still demonstrated significant reduction of tinnitus score. These preliminary results demonstrate that neuronavigated rTMS offers new possibilities in the understanding and treatment of chronic tinnitus.

Neurocognitive Effects of Repetitive Transcranial Magnetic Stimulation (rTMS in Adolescents with Major Depressive Disorder (MDD

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Christopher A Wall

2013-12-01

Full Text Available Objectives: It is estimated that 30% to 40% of adolescents with major depressive disorder (MDD do not receive full benefit from current antidepressant therapies. Repetitive transcranial magnetic stimulation (rTMS is a novel therapy approved by the US FDA to treat adults with MDD. Research suggests rTMS is not associated with adverse neurocognitive effects in adult populations; however, there is no documentation of its neurocognitive effects in adolescents. This is a secondary post hoc analysis of neurocognitive outcome in adolescents who were treated with open label rTMS in two separate studies. Methods: Eighteen patients (mean age, 16.2 ± 1.1 years; 11 females, 7 males with MDD who failed to adequately respond to at least 1 antidepressant agent were enrolled in the studies. Fourteen patients completed all 30 rTMS treatments (5 days/week, 120% of motor threshold, 10 Hz, 3,000 stimulations per session applied to the left dorsolateral prefrontal cortex (L-DLPFC. Depression was rated using the Children’s Depression Rating Scale-Revised (CDRS-R. Neurocognitive evaluation was performed at baseline and after completion of 30 rTMS treatments with the Children’s Auditory Verbal Learning Test (CAVLT and Delis-Kaplan Executive Function System (DKEFS Trail Making Test. Results: Over the course of 30 rTMS treatments, adolescents showed a substantial decrease in depression severity and a statistically significant improvement in memory and delayed verbal recall. Other learning and memory indices and executive function remained intact. Neither participants nor their family members reported clinically meaningful changes in neurocognitive function. Conclusion: These preliminary findings suggest rTMS does not adversely impact neurocognitive functioning in adolescents and may provide subtle enhancement of verbal memory as measured by the CAVLT. Further controlled investigations are warranted to confirm and extend these findings.

Differential effects of alpha-adrenoceptor blockade on essential, physiological and isoprenaline-induced tremor: evidence for a central origin of essential tremor.

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Abila, B; Wilson, J F; Marshall, R W; Richens, A

1985-01-01

Intravenous thymoxamine reduced the power of essential tremor but increased that of physiological and isoprenaline-induced tremor. These findings indicate that essential and physiological tremor have dissimilar pathophysiological mechanisms. They also suggest that central adrenergic mechanisms are involved in the pathophysiology of essential tremor and that isoprenaline-induced tremor is not a good model of essential tremor. Furthermore, alpha-adrenoceptor blockers may be a useful therapy for...

Striatal dopamine release induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex: effect of aging

International Nuclear Information System (INIS)

Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Kim, Ji Sun; Lee, Byung Chul; Kim, Yu Kyeong; Kim, Sang Eun

2007-01-01

We previously demonstrated dopamine (DA) release in the bilateral striatal regions following prefrontal repetitive transcranial magnetic stimulation (rTMS) in young subjects. Several lines of evidence support substantial age-related changes in human dopaminergic neurotransmission. One possible explanation is alteration of cortico striatal neural connection with aging. Therefore, we investigated how frontal activation by rTMS influences striatal DA release in the elderly with SPECT measurements of striatal binding of [123I]iodobenzamide (lBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy elderly male subjects (age, 64 3 y) were studied with brain [123I]IBZM SPECT under three conditions (resting, sham stimulation, and active rTMS over left dorsolateral prefrontal cortex (DLPFC)), while receiving a bolus plus constant infusion of [123I]IBZM. rTMS session consisted of three blocks. In each block, 15 trains of 2 sec duration were delivered with 10 Hz stimulation frequency and 100% motor threshold. Striatal V3', calculated as (striatal - occipital)/occipital radioactivity, was measured under equilibrium condition at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over left DLPFC induced no significant change in V3' in the right striatum compared with baseline condition (0.91 0.25 vs. 0.96 0.25, P = NS). Interestingly, left striatal V3' showed a significant increase after rTMS over left DLPFC compared with sham condition (1.09 0.33 vs. 0.93 0.27, P < 0.05; 17.0 11.1% increase). These results are discrepant from previous ones from young subjects, who showed frontal rTMS-induced reduction of striatal V3', indicating rTMS-induced striatal DA release. We found no significant striatal DA release induced by rTMS over DLPFC in healthy elderly subjects using in vivo binding competition techniques. These results may support an altered cortico striatal circuit in normal aging

Striatal dopamine release induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex: effect of aging

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Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Kim, Ji Sun; Lee, Byung Chul; Kim, Yu Kyeong; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

2007-07-01

We previously demonstrated dopamine (DA) release in the bilateral striatal regions following prefrontal repetitive transcranial magnetic stimulation (rTMS) in young subjects. Several lines of evidence support substantial age-related changes in human dopaminergic neurotransmission. One possible explanation is alteration of cortico striatal neural connection with aging. Therefore, we investigated how frontal activation by rTMS influences striatal DA release in the elderly with SPECT measurements of striatal binding of [123I]iodobenzamide (lBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy elderly male subjects (age, 64 3 y) were studied with brain [123I]IBZM SPECT under three conditions (resting, sham stimulation, and active rTMS over left dorsolateral prefrontal cortex (DLPFC)), while receiving a bolus plus constant infusion of [123I]IBZM. rTMS session consisted of three blocks. In each block, 15 trains of 2 sec duration were delivered with 10 Hz stimulation frequency and 100% motor threshold. Striatal V3', calculated as (striatal - occipital)/occipital radioactivity, was measured under equilibrium condition at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over left DLPFC induced no significant change in V3' in the right striatum compared with baseline condition (0.91 0.25 vs. 0.96 0.25, P = NS). Interestingly, left striatal V3' showed a significant increase after rTMS over left DLPFC compared with sham condition (1.09 0.33 vs. 0.93 0.27, P < 0.05; 17.0 11.1% increase). These results are discrepant from previous ones from young subjects, who showed frontal rTMS-induced reduction of striatal V3', indicating rTMS-induced striatal DA release. We found no significant striatal DA release induced by rTMS over DLPFC in healthy elderly subjects using in vivo binding competition techniques. These results may support an altered cortico striatal circuit in normal aging.

Low-Frequency rTMS Ameliorates Autistic-Like Behaviors in Rats Induced by Neonatal Isolation Through Regulating the Synaptic GABA Transmission

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Tao Tan

2018-02-01

Full Text Available Patients with autism spectrum disorder (ASD display abnormalities in neuronal development, synaptic function and neural circuits. The imbalance of excitatory and inhibitory (E/I synaptic transmission has been proposed to cause the main behavioral characteristics of ASD. Repetitive transcranial magnetic stimulation (rTMS can directly or indirectly induce excitability and synaptic plasticity changes in the brain noninvasively. However, whether rTMS can ameliorate autistic-like behaviors in animal model via regulating the balance of E/I synaptic transmission is unknown. By using our recent reported animal model with autistic-like behaviors induced by neonatal isolation (postnatal days 1–9, we found that low-frequency rTMS (LF-rTMS, 1 Hz treatment for 2 weeks effectively alleviated the acquired autistic-like symptoms, as reflected by an increase in social interaction and decrease in self-grooming, anxiety- and depressive-like behaviors in young adult rats compared to those in untreated animals. Furthermore, the amelioration in autistic-like behavior was accompanied by a restoration of the balance between E/I activity, especially at the level of synaptic transmission and receptors in synaptosomes. These findings indicated that LF-rTMS may alleviate the symptoms of ASD-like behaviors caused by neonatal isolation through regulating the synaptic GABA transmission, suggesting that LF-rTMS may be a potential therapeutic technique to treat ASD.

Unraveling the cellular and molecular mechanisms of repetitive magnetic stimulation

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Florian eMüller-Dahlhaus

2013-12-01

Full Text Available Despite numerous clinical studies, which have investigated the therapeutic potential of repetitive transcranial magnetic stimulation (rTMS in various brain diseases, our knowledge of the cellular and molecular mechanisms underlying rTMS-based therapies remains limited. Thus, a deeper understanding of rTMS-induced neural plasticity is required to optimize current treatment protocols. Studies in small animals or appropriate in vitro preparations (including models of brain diseases provide highly useful experimental approaches in this context. State-of-the-art electrophysiological and live-cell imaging techniques that are well established in basic neuroscience can help answering some of the major questions in the field, such as (i which neural structures are activated during TMS, (ii how does rTMS induce Hebbian plasticity, and (iii are other forms of plasticity (e.g., metaplasticity, structural plasticity induced by rTMS? We argue that data gained from these studies will support the development of more effective and specific applications of rTMS in clinical practice.

Preliminary Evidence of the Effects of High-frequency Repetitive Transcranial Magnetic Stimulation (rTMS) on Swallowing Functions in Post-Stroke Individuals with Chronic Dysphagia

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Cheng, Ivy K. Y.; Chan, Karen M. K.; Wong, C. S.; Cheung, Raymond T. F.

2015-01-01

Background: There is growing evidence of potential benefits of repetitive transcranial magnetic stimulation (rTMS) in the rehabilitation of dysphagia. However, the site and frequency of stimulation for optimal effects are not clear. Aims: The aim of this pilot study is to investigate the short-term effects of high-frequency 5 Hz rTMS applied to…

Improvement of auditory hallucinations and reduction of primary auditory area's activation following TMS

International Nuclear Information System (INIS)

Giesel, Frederik L.; Mehndiratta, Amit; Hempel, Albrecht; Hempel, Eckhard; Kress, Kai R.; Essig, Marco; Schröder, Johannes

2012-01-01

Background: In the present case study, improvement of auditory hallucinations following transcranial magnetic stimulation (TMS) therapy was investigated with respect to activation changes of the auditory cortices. Methods: Using functional magnetic resonance imaging (fMRI), activation of the auditory cortices was assessed prior to and after a 4-week TMS series of the left superior temporal gyrus in a schizophrenic patient with medication-resistant auditory hallucinations. Results: Hallucinations decreased slightly after the third and profoundly after the fourth week of TMS. Activation in the primary auditory area decreased, whereas activation in the operculum and insula remained stable. Conclusions: Combination of TMS and repetitive fMRI is promising to elucidate the physiological changes induced by TMS.

Serotonergic modulation of nicotine-induced kinetic tremor in mice

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Naofumi Kunisawa

2017-06-01

Full Text Available We previously demonstrated that nicotine elicited kinetic tremor by elevating the neural activity of the inferior olive via α7 nicotinic acetylcholine (nACh receptors. Since α7 nACh receptors reportedly facilitate synaptic monoamine release, we explored the role of 5-HT receptors in induction and/or modulation of nicotine tremor. Treatment of mice with nicotine induced kinetic tremor that normally appeared during movement. The 5-HT1A agonist, 8-hydroxydipropylaminotetraline (8-OH-DPAT, significantly enhanced nicotine-induced tremor and the action of 8-OH-DPAT was antagonized by WAY-100135 (5-HT1A antagonist. In addition, the cerebral 5-HT depletion by repeated treatment with p-chlorophenylalanine did not reduce, but rather potentiated the facilitatory effects of 8-OH-DPAT. In contrast, the 5-HT2 agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI, significantly attenuated nicotine tremor, which was antagonized by ritanserin (5-HT2 antagonist. The 5-HT3 agonist SR-57227 did not affect nicotine-induced tremor. Furthermore, when testing the direct actions of 5-HT antagonists, nicotine tremor was inhibited by WAY-100135, but was unaffected by ritanserin, ondansetron (5-HT3 antagonist or SB-258585 (5-HT6 antagonist. These results suggest that postsynaptic 5-HT1A receptors are involved in induction of nicotine tremor mediated by α7 nACh receptors. In addition, 5-HT2 receptors have an inhibitory modulatory role in induction of nicotine tremor.

A double-blind, randomized trial of deep repetitive transcranial magnetic stimulation (rTMS) for autism spectrum disorder.

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Enticott, Peter G; Fitzgibbon, Bernadette M; Kennedy, Hayley A; Arnold, Sara L; Elliot, David; Peachey, Amy; Zangen, Abraham; Fitzgerald, Paul B

2014-01-01

Biomedical treatment options for autism spectrum disorder (ASD) are extremely limited. Repetitive transcranial magnetic stimulation (rTMS) is a safe and efficacious technique when targeting specific areas of cortical dysfunction in major depressive disorder, and a similar approach could yield therapeutic benefits in ASD, if applied to relevant cortical regions. The aim of this study was to examine whether deep rTMS to bilateral dorsomedial prefrontal cortex improves social relating in ASD. 28 adults diagnosed with either autistic disorder (high-functioning) or Asperger's disorder completed a prospective, double-blind, randomized, placebo-controlled design with 2 weeks of daily weekday treatment. This involved deep rTMS to bilateral dorsomedial prefrontal cortex (5 Hz, 10-s train duration, 20-s inter-train interval) for 15 min (1500 pulses per session) using a HAUT-Coil. The sham rTMS coil was encased in the same helmet of the active deep rTMS coil, but no effective field was delivered into the brain. Assessments were conducted before, after, and one month following treatment. Participants in the active condition showed a near significant reduction in self-reported social relating symptoms from pre-treatment to one month follow-up, and a significant reduction in social relating symptoms (relative to sham participants) for both post-treatment assessments. Those in the active condition also showed a reduction in self-oriented anxiety during difficult and emotional social situations from pre-treatment to one month follow-up. There were no changes for those in the sham condition. Deep rTMS to bilateral dorsomedial prefrontal cortex yielded a reduction in social relating impairment and socially-related anxiety. Further research in this area should employ extended rTMS protocols that approximate those used in depression in an attempt to replicate and amplify the clinical response. Copyright © 2014 Elsevier Inc. All rights reserved.

Serotonergic modulation of nicotine-induced kinetic tremor in mice.

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Kunisawa, Naofumi; Iha, Higor A; Nomura, Yuji; Onishi, Misaki; Matsubara, Nami; Shimizu, Saki; Ohno, Yukihiro

2017-06-01

We previously demonstrated that nicotine elicited kinetic tremor by elevating the neural activity of the inferior olive via α7 nicotinic acetylcholine (nACh) receptors. Since α7 nACh receptors reportedly facilitate synaptic monoamine release, we explored the role of 5-HT receptors in induction and/or modulation of nicotine tremor. Treatment of mice with nicotine induced kinetic tremor that normally appeared during movement. The 5-HT 1A agonist, 8-hydroxydipropylaminotetraline (8-OH-DPAT), significantly enhanced nicotine-induced tremor and the action of 8-OH-DPAT was antagonized by WAY-100135 (5-HT 1A antagonist). In addition, the cerebral 5-HT depletion by repeated treatment with p-chlorophenylalanine did not reduce, but rather potentiated the facilitatory effects of 8-OH-DPAT. In contrast, the 5-HT 2 agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI), significantly attenuated nicotine tremor, which was antagonized by ritanserin (5-HT 2 antagonist). The 5-HT 3 agonist SR-57227 did not affect nicotine-induced tremor. Furthermore, when testing the direct actions of 5-HT antagonists, nicotine tremor was inhibited by WAY-100135, but was unaffected by ritanserin, ondansetron (5-HT 3 antagonist) or SB-258585 (5-HT 6 antagonist). These results suggest that postsynaptic 5-HT 1A receptors are involved in induction of nicotine tremor mediated by α7 nACh receptors. In addition, 5-HT 2 receptors have an inhibitory modulatory role in induction of nicotine tremor. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Improvements in symptoms following neuronavigated repetitive transcranial magnetic stimulation (rTMS) in severe and enduring anorexia nervosa: findings from two case studies.

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McClelland, Jessica; Bozhilova, Natali; Nestler, Steffen; Campbell, Iain C; Jacob, Shirabdi; Johnson-Sabine, Eric; Schmidt, Ulrike

2013-11-01

Advances in the treatment of anorexia nervosa (AN) are most likely to arise from targeted, brain-directed treatments, such as repetitive transcranial magnetic stimulation (rTMS). We describe findings from two individuals with treatment-resistant AN who received 19-20 sessions of neuronavigated, high frequency rTMS, applied to the left dorsolateral prefrontal cortex. Within-session measures assessed changes pre-rTMS, post-rTMS in subjective eating disorder (ED) experiences. Weight, ED symptoms and mood were assessed pre-treatment, post-treatment and at 1 month follow-up. In both cases, there was improvement in ED symptomatology and mood after 19-20 sessions of neuronavigated rTMS, and these changes persisted or continued to improve at follow-up. Within sessions, Patient A demonstrated a consistent reduction in subjective ED experiences, and Patient B a reduction in some ED related experiences. These findings suggest that rTMS has potential as an adjunct to the treatment of AN and deserves further study. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.

A real electro-magnetic placebo (REMP) device for sham transcranial magnetic stimulation (TMS).

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Rossi, Simone; Ferro, Marisa; Cincotta, Massimo; Ulivelli, Monica; Bartalini, Sabina; Miniussi, Carlo; Giovannelli, Fabio; Passero, Stefano

2007-03-01

There is growing interest in neuropsychiatry for repetitive transcranial magnetic stimulation (rTMS) as a neuromodulatory treatment. However, there are limitations in interpreting rTMS effects as a real consequence of physiological brain changes or as placebo-mediated unspecific effects, which may be particularly strong in psychiatric patients. This is due to the fact that existing sham rTMS procedures are less than optimal. A new placebo tool is introduced here, called real electro-magnetic placebo (REMP) device, which can simulate the scalp sensation induced by the real TMS, while leaving both the visual impact and acoustic sensation of real TMS unaltered. Physical, neurophysiological and behavioural variables of monophasic and biphasic single-pulse TMS and biphasic 1Hz and 20Hz rTMS procedures (at different intensities) were tested in subjects who were expert or naïve of TMS. Results of the real TMS were compared with those induced by the REMP device and with two other currently used sham procedures, namely the commercially available Magstim sham coil and tilting the real coil by 90 degrees . The REMP device, besides producing scalp sensations similar to the real TMS, attenuated the TMS-induced electric field (as measured by a dipole probe) to a biologically inactive level. Behaviourally, neither expert nor naïve TMS subjects identified the "coil at 90 degrees " or the "Magstim sham coil" as a real TMS intervention, whilst naïve subjects were significantly more likely to identify the REMP-attenuated TMS as real. The "goodness of sham" of the REMP device is demonstrated by physical, neurophysiological, and behavioural results. Such placebo TMS is superior to the available sham procedures when applied on subjects naïve to TMS, as in case of patients undergoing a clinical rTMS trial.

[Hospital production cost of repetitive transcranial magnetic stimulation (rTMS) in the treatment of depression].

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Etcheverrigaray, F; Bulteau, S; Machon, L O; Riche, V P; Mauduit, N; Tricot, R; Sellal, O; Sauvaget, A

2015-08-01

Repetitive transcranial magnetic stimulation (rTMS) is an effective and well-tolerated treatment in resistant depression with mild to moderate intensity. This indication has not yet been approved in France. The cost and medico-economic value of rTMS in psychiatry remains unknown. The aim of this preliminary study was to assess rTMS cost production analysis as an in-hospital treatment for depression. The methodology, derived from analytical accounts, was validated by a multidisciplinary task force (clinicians, public health doctors, pharmacists, administrative officials and health economist). It was pragmatic, based on official and institutional documentary sources and from field practice. It included equipment, staff, and structure costs, to get an estimate as close to reality as possible. First, we estimated the production cost of rTMS session, based on our annual activity. We then estimated the cost of a cure, which includes 15 sessions. A sensitivity analysis was also performed. The hospital production cost of a cure for treating depression was estimated at € 1932.94 (€ 503.55 for equipment, € 1082.75 for the staff, and € 346.65 for structural expenses). This cost-estimate has resulted from an innovative, pragmatic, and cooperative approach. It is slightly higher but more comprehensive than the costs estimated by the few international studies. However, it is limited due to structure-specific problems and activity. This work could be repeated in other circumstances in order to obtain a more general estimate, potentially helpful for determining an official price for the French health care system. Moreover, budgetary constraints and public health choices should be taken into consideration. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Low-frequency repetitive transcranial magnetic stimulation (rTMS) affects event-related potential measures of novelty processing in autism.

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Sokhadze, Estate; Baruth, Joshua; Tasman, Allan; Mansoor, Mehreen; Ramaswamy, Rajesh; Sears, Lonnie; Mathai, Grace; El-Baz, Ayman; Casanova, Manuel F

2010-06-01

In our previous study on individuals with autism spectrum disorder (ASD) (Sokhadze et al., Appl Psychophysiol Biofeedback 34:37-51, 2009a) we reported abnormalities in the attention-orienting frontal event-related potentials (ERP) and the sustained-attention centro-parietal ERPs in a visual oddball experiment. These results suggest that individuals with autism over-process information needed for the successful differentiation of target and novel stimuli. In the present study we examine the effects of low-frequency, repetitive Transcranial Magnetic Stimulation (rTMS) on novelty processing as well as behavior and social functioning in 13 individuals with ASD. Our hypothesis was that low-frequency rTMS application to dorsolateral prefrontal cortex (DLFPC) would result in an alteration of the cortical excitatory/inhibitory balance through the activation of inhibitory GABAergic double bouquet interneurons. We expected to find post-TMS differences in amplitude and latency of early and late ERP components. The results of our current study validate the use of low-frequency rTMS as a modulatory tool that altered the disrupted ratio of cortical excitation to inhibition in autism. After rTMS the parieto-occipital P50 amplitude decreased to novel distracters but not to targets; also the amplitude and latency to targets increased for the frontal P50 while decreasing to non-target stimuli. Low-frequency rTMS minimized early cortical responses to irrelevant stimuli and increased responses to relevant stimuli. Improved selectivity in early cortical responses lead to better stimulus differentiation at later-stage responses as was made evident by our P3b and P3a component findings. These results indicate a significant change in early, middle-latency and late ERP components at the frontal, centro-parietal, and parieto-occipital regions of interest in response to target and distracter stimuli as a result of rTMS treatment. Overall, our preliminary results show that rTMS may prove to

Effect of mental fatigue on induced tremor in human knee extensors.

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Budini, Francesco; Lowery, Madeleine; Durbaba, Rade; De Vito, Giuseppe

2014-06-01

In this study, the effects of mental fatigue on mechanically induced tremor at both a low (3-6Hz) and high (8-12Hz) frequency were investigated. The two distinct tremor frequencies were evoked using two springs of different stiffness, during 20s sustained contractions of the knee extensor muscles at 30% maximum voluntary contraction (MVC) before and after 100min of a mental fatigue task, in 12 healthy (29±3.7years) participants. Mental fatigue resulted in a 6.9% decrease in MVC and in a 9.4% decrease in the amplitude of the agonist muscle EMG during sustained 30% MVC contractions in the induced high frequency only. Following the mental fatigue task, the coefficient of variation and standard deviation of the force signal decreased at 8-12Hz induced tremor by 31.7% and 35.2% respectively, but not at 3-6Hz induced tremor. Similarly, the maximum value and area underneath the peak in the power spectrum of the force signal decreased by 55.5% and 53.1% respectively in the 8-12Hz range only. In conclusion, mental fatigue decreased mechanically induced 8-12Hz tremor and had no effect on induced 3-6Hz tremor. We suggest that the reduction could be attributed to the decreased activation of the agonist muscles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Repetitive activation of the corticospinal tract by means of rTMS may reduce the efficiency of corticomotoneuronal synapses

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Taube, Wolfgang; Leukel, Christian; Schubert, Martin

Repetitive transcranial magnetic stimulation (rTMS) is extensively used to study cognitive and motor function in humans and might be of value in the treatment of various disorders. For a better understanding of the effects of rTMS and its more efficient application it is crucial to identify......-conditioning by testing interstimulus intervals (ISIs) from -9 to 0 ms (for instance “ISI -3 ms” indicated that the H-reflex was elicited 3 ms before the supraspinal stimulus). The amplitude of the short-latency facilitation was expressed as percentage of the unconditioned control H-reflex and compared before and after...... is the synapses of the corticomotoneuronal neurones on the spinal motoneurones. Perez et al. (2005). Exp Brain Res 162, 202-212. Speer et al. (2003). Biol Psychiatry 54, 818-825....

Effects of beta-blockers and nicardipine on oxotremorine-induced tremor in common marmosets.

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Mitsuda, M; Nomoto, M; Iwata, S

1999-10-01

Effects of beta-blockers (propranolol, arotinolol and nipradilol) and a Ca2+ channel blocker (nicardipine) on oxotremorine-induced tremor were studied in common marmosets. Generalized tremor was elicited by an intraperitoneal administration of 0.25 mg/kg oxotremorine. Intensity of the tremor was classified into 7 degrees, and it was evaluated every 10 min. The total intensity of oxotremorine-induced tremor for each drug was expressed as "points", which were the sum of tremor intensity scores evaluated every 10 min up to 190 min following the administration of oxotremorine. Beta-blockers significantly suppressed the tremor. On the other hand, the Ca2+ channel blocker exacerbated the tremor.

Repetitive transcranial magnetic stimulation once a week induces sustainable long-term relief of central poststroke pain.

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Kobayashi, Masahito; Fujimaki, Takamitsu; Mihara, Ban; Ohira, Takayuki

2015-06-01

Central poststroke pain is a serious problem for some patients after stroke. Repetitive transcranial magnetic stimulation (rTMS) has been reported to relieve poststroke pain but its efficacy is still controversial. We tested the possibility that rTMS, when applied once a week, would induce sustainable relief of poststroke pain. Eighteen patients with central poststroke pain were included in this study. rTMS (10 trains of 10-sec 5 Hz-rTMS) was delivered over the primary motor cortex on the affected side. The rTMS session was repeated once a week for 12 weeks, and for six patients the intervention was continued for one year. The degree of the pain was assessed before each weekly rTMS session to evaluate sustainable effects. The effects of the rTMS reached a plateau at the eighth week. At the 12th week, the rTMS was effective in 61.1% of the patients; 5 of the 18 patients showed more than 70% reduction based on a visual analog scale, 6 patients showed 40-69% reduction, and 7 remained at a pain reduction level of less than 40%. When patients were divided into two groups with or without severe dysesthesia, it was found that eight patients with severe dysesthesia showed less pain relief than those without. In the six patients who continued rTMS for one year, the pain relief effects also were sustained. Although this was an open-label study without a control group, our findings suggest that rTMS of the primary motor cortex, when maintained once a week, could help to relieve poststroke pain. © 2015 International Neuromodulation Society.

Repetitive transcranial magnetic stimulator with controllable pulse parameters

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

2011-06-01

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.

High-Frequency Repetitive Transcranial Magnetic Stimulation (rTMS Improves Functional Recovery by Enhancing Neurogenesis and Activating BDNF/TrkB Signaling in Ischemic Rats

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Jing Luo

2017-02-01

Full Text Available Repetitive transcranial magnetic stimulation (rTMS has rapidly become an attractive therapeutic approach for stroke. However, the mechanisms underlying this remain elusive. This study aimed to investigate whether high-frequency rTMS improves functional recovery mediated by enhanced neurogenesis and activation of brain-derived neurotrophic factor (BDNF/tropomyosin-related kinase B (TrkB pathway and to compare the effect of conventional 20 Hz rTMS and intermittent theta burst stimulation (iTBS on ischemic rats. Rats after rTMS were sacrificed seven and 14 days after middle cerebral artery occlusion (MCAO, following evaluation of neurological function. Neurogenesis was measured using specific markers: Ki67, Nestin, doublecortin (DCX, NeuN and glial fibrillary acidic protein (GFAP, and the expression levels of BDNF were visualized by Western blotting and RT-PCR analysis. Both high-frequency rTMS methods significantly improved neurological function and reduced infarct volume. Moreover, 20 Hz rTMS and iTBS significantly promoted neurogenesis, shown by an increase of Ki67/DCX, Ki67/Nestin, and Ki67/NeuN-positive cells in the peri-infarct striatum. These beneficial effects were accompanied by elevated protein levels of BDNF and phosphorylated-TrkB. In conclusion, high-frequency rTMS improves functional recovery possibly by enhancing neurogenesis and activating BDNF/TrkB signaling pathway and conventional 20 Hz rTMS is better than iTBS at enhancing neurogenesis in ischemic rats.

Dopamine release in human striatum induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex

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Cho, Sang Soo; Yoon, Eun Jin; Kim, Yu Kyeong; Lee, Won Woo; Kim, Sang Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2005-07-01

Animal study suggests that prefrontal cortex plays an important Animal studies suggest that prefrontal cortex plays an important role in the modulation of dopamine (DA) release in subcortical areas. However, little is known about the relationship between DA release and prefrontal activation in human. We investigated whether repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex (DLPFC) influences DA release in human striatum with SPECT measurements of striatal binding of [123I)iodobenzamide (IBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy male volunteers (age, 25{+-}2 yr) were studied with brain [123I]IBZM SPECT under three conditions (resting, Sham stimulation, and active rTMS over left DLPFC), while receiving a bolus plus constant infusion of [123I]IBZM DLPFC was defined as a 6 cm anterior and 1cm lateral from the primary motor cortex. rTMS session consisted of three blocks, in each block, 15 trains of 2 see duration were delivered with 10 Hz stimulation frequency, 100% motor threshold, and between-train intervals of 10 sec. Striatal V3', calculated as (striatal - occipital) / occipital activity ratio, was measured under equilibrium condition, at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over DLPFC induced reduction of V3' in the ipsilateral and contralateral striatum by 9.7% {+-} 1.3% and 10.6% {+-} 3.2%, respectively, compared with sham procedures (P < 0.01 and P < 0.01, respectively), indicating striatal DA release elicited by rTMS over DLPFC. V3' reduction in the ipsilateral caudate nucleus was greater than that in the contralateral caudate nucleus (9.9% {+-} 4.5% vs. 6.6% {+-} 3.1%, P < 0.05). These data demonstrate DA release in human striatum induced by rTMS over DLPFC, supporting that cortico-striatal fibers originating in prefrontal cortex are involved in local DA release.

Dopamine release in human striatum induced by repetitive transcranial magnetic stimulation over dorsolateral prefrontal cortex

International Nuclear Information System (INIS)

Cho, Sang Soo; Yoon, Eun Jin; Kim, Yu Kyeong; Lee, Won Woo; Kim, Sang Eun

2005-01-01

Animal study suggests that prefrontal cortex plays an important Animal studies suggest that prefrontal cortex plays an important role in the modulation of dopamine (DA) release in subcortical areas. However, little is known about the relationship between DA release and prefrontal activation in human. We investigated whether repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex (DLPFC) influences DA release in human striatum with SPECT measurements of striatal binding of [123I)iodobenzamide (IBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy male volunteers (age, 25±2 yr) were studied with brain [123I]IBZM SPECT under three conditions (resting, Sham stimulation, and active rTMS over left DLPFC), while receiving a bolus plus constant infusion of [123I]IBZM DLPFC was defined as a 6 cm anterior and 1cm lateral from the primary motor cortex. rTMS session consisted of three blocks, in each block, 15 trains of 2 see duration were delivered with 10 Hz stimulation frequency, 100% motor threshold, and between-train intervals of 10 sec. Striatal V3', calculated as (striatal - occipital) / occipital activity ratio, was measured under equilibrium condition, at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over DLPFC induced reduction of V3' in the ipsilateral and contralateral striatum by 9.7% ± 1.3% and 10.6% ± 3.2%, respectively, compared with sham procedures (P < 0.01 and P < 0.01, respectively), indicating striatal DA release elicited by rTMS over DLPFC. V3' reduction in the ipsilateral caudate nucleus was greater than that in the contralateral caudate nucleus (9.9% ± 4.5% vs. 6.6% ± 3.1%, P < 0.05). These data demonstrate DA release in human striatum induced by rTMS over DLPFC, supporting that cortico-striatal fibers originating in prefrontal cortex are involved in local DA release

Low-dose acute vanillin is beneficial against harmaline-induced tremors in rats.

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Abdulrahman, Al Asmari; Faisal, Kunnathodi; Meshref, Ali Al Amri; Arshaduddin, Mohammed

2017-03-01

To study the effect of pretreatment with low doses of vanillin, a flavoring agent used as a food additive, on harmaline-induced tremor in rats. Sprague Dawley rats (110 ± 5 g) were divided into groups of six animals each. Vanillin (6.25 mg, 12.5 mg, and 25 mg/kg) was administered by gavage to different groups of rats, 30 minutes before the induction of tremor. Harmaline (10 mg/kg, i.p.) was used for the induction of tremor. The latency of onset, duration, tremor intensity, tremor index, and spontaneous locomotor activity were recorded. A separate batch of animals was used for the determination of serotonin (5HT) and 5 hydroxyindole acetic acid (5HIAA) levels in the brain. Harmaline treatment resulted in characteristic tremor that lasted for more than 2 hours and decreased the locomotor activity of rats. Pre-treatment with vanillin significantly reduced the duration, intensity, and tremor index of harmaline-treated animals. Vanillin treatment also significantly attenuated harmaline-induced decrease in the locomotor activity. An increase in 5HT levels and the changes in 5HIAA/5HT ratio observed in harmaline treated rats were significantly corrected in vanillin pretreated animals. Vanillin in low doses reduces harmaline-induced tremor in rats, probably through its modulating effect on serotonin levels in the brain. These findings suggest a beneficial effect of vanillin in essential tremor.

Short-term adaptations in spinal cord circuits evoked by repetitive transcranial magnetic stimulation: possible underlying mechanisms

DEFF Research Database (Denmark)

Perez, Monica A.; Lungholt, Bjarke K.S.; Nielsen, Jens Bo

2005-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been shown to induce adaptations in cortical neuronal circuitries. In the present study we investigated whether rTMS, through its effect on corticospinal pathways, also produces adaptations at the spinal level, and what the neuronal mechanisms...... that the depression of the H-reflex by rTMS can be explained, at least partly, by an increased presynaptic inhibition of soleus Ia afferents. In contrast, rTMS had no effect on disynaptic reciprocal Ia inhibition from ankle dorsiflexors to plantarflexors. We conclude that a train of rTMS may modulate transmission...

A Meta-Analysis of the Effectiveness of Different Cortical Targets Used in Repetitive Transcranial Magnetic Stimulation (rTMS) for the Treatment of Obsessive-Compulsive Disorder (OCD).

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Rehn, Simone; Eslick, Guy D; Brakoulias, Vlasios

2018-02-09

Randomised and sham-controlled trials (RCTs) of repetitive transcranial magnetic stimulation (rTMS) in the treatment of obsessive-compulsive disorder (OCD) have yielded conflicting results, which may be due to the variability in rTMS parameters used. We performed an updated systematic review and meta-analysis on the effectiveness of rTMS for the treatment of OCD and aimed to determine whether certain rTMS parameters, such as cortical target, may be associated with higher treatment effectiveness. After conducting a systematic literature review for RCTs on rTMS for OCD through to 1 December 2016 using MEDLINE, PubMed, Web of Science, PsycINFO, Google, and Google Scholar, we performed a random-effects meta-analysis with the outcome measure as pre-post changes in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores. To determine whether rTMS parameters may have influenced treatment effectiveness, studies were further analysed according to cortical target, stimulation frequency, and length of follow-up. Data were obtained from 18 RCTs on rTMS in the treatment of OCD. Overall, rTMS yielded a modest effect in reducing Y-BOCS scores with Hedge's g of 0.79 (95% CI = 0.43-1.15, p OCD. The therapeutic effects of rTMS also appear to persist post-treatment and may offer beneficial long-term effectiveness. With our findings, it is suggested that future large-scale studies focus on the supplementary motor area and include follow-up periods of 12 weeks or more.

Water diffusion reveals networks that modulate multiregional morphological plasticity after repetitive brain stimulation.

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Abe, Mitsunari; Fukuyama, Hidenao; Mima, Tatsuya

2014-03-25

Repetitive brain stimulation protocols induce plasticity in the stimulated site in brain slice models. Recent evidence from network models has indicated that additional plasticity-related changes occur in nonstimulated remote regions. Despite increasing use of brain stimulation protocols in experimental and clinical settings, the neural substrates underlying the additional effects in remote regions are unknown. Diffusion-weighted MRI (DWI) probes water diffusion and can be used to estimate morphological changes in cortical tissue that occur with the induction of plasticity. Using DWI techniques, we estimated morphological changes induced by application of repetitive transcranial magnetic stimulation (rTMS) over the left primary motor cortex (M1). We found that rTMS altered water diffusion in multiple regions including the left M1. Notably, the change in water diffusion was retained longest in the left M1 and remote regions that had a correlation of baseline fluctuations in water diffusion before rTMS. We conclude that synchronization of water diffusion at rest between stimulated and remote regions ensures retention of rTMS-induced changes in water diffusion in remote regions. Synchronized fluctuations in the morphology of cortical microstructures between stimulated and remote regions might identify networks that allow retention of plasticity-related morphological changes in multiple regions after brain stimulation protocols. These results increase our understanding of the effects of brain stimulation-induced plasticity on multiregional brain networks. DWI techniques could provide a tool to evaluate treatment effects of brain stimulation protocols in patients with brain disorders.

Harmaline Tremor: Underlying Mechanisms in a Potential Animal Model of Essential Tremor

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Adrian Handforth

2012-09-01

Full Text Available Background: Harmaline and harmine are tremorigenic β-carbolines that, on administration to experimental animals, induce an acute postural and kinetic tremor of axial and truncal musculature. This drug-induced action tremor has been proposed as a model of essential tremor. Here we review what is known about harmaline tremor.Methods: Using the terms harmaline and harmine on PubMed, we searched for papers describing the effects of these β-carbolines on mammalian tissue, animals, or humans.Results: Investigations over four decades have shown that harmaline induces rhythmic burst-firing activity in the medial and dorsal accessory inferior olivary nuclei that is transmitted via climbing fibers to Purkinje cells and to the deep cerebellar nuclei, then to brainstem and spinal cord motoneurons. The critical structures required for tremor expression are the inferior olive, climbing fibers, and the deep cerebellar nuclei; Purkinje cells are not required. Enhanced synaptic norepinephrine or blockade of ionic glutamate receptors suppresses tremor, whereas enhanced synaptic serotonin exacerbates tremor. Benzodiazepines and muscimol suppress tremor. Alcohol suppresses harmaline tremor but exacerbates harmaline-associated neural damage. Recent investigations on the mechanism of harmaline tremor have focused on the T-type calcium channel.Discussion: Like essential tremor, harmaline tremor involves the cerebellum, and classic medications for essential tremor have been found to suppress harmaline tremor, leading to utilization of the harmaline model for preclinical testing of antitremor drugs. Limitations are that the model is acute, unlike essential tremor, and only approximately half of the drugs reported to suppress harmaline tremor are subsequently found to suppress tremor in clinical trials.

TMS-induced cortical potentiation during wakefulness locally increases slow wave activity during sleep.

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Reto Huber

2007-03-01

Full Text Available Sleep slow wave activity (SWA is thought to reflect sleep need, increasing in proportion to the length of prior wakefulness and decreasing during sleep. However, the process responsible for SWA regulation is not known. We showed recently that SWA increases locally after a learning task involving a circumscribed brain region, suggesting that SWA may reflect plastic changes triggered by learning.To test this hypothesis directly, we used transcranial magnetic stimulation (TMS in conjunction with high-density EEG in humans. We show that 5-Hz TMS applied to motor cortex induces a localized potentiation of TMS-evoked cortical EEG responses. We then show that, in the sleep episode following 5-Hz TMS, SWA increases markedly (+39.1+/-17.4%, p<0.01, n = 10. Electrode coregistration with magnetic resonance images localized the increase in SWA to the same premotor site as the maximum TMS-induced potentiation during wakefulness. Moreover, the magnitude of potentiation during wakefulness predicts the local increase in SWA during sleep.These results provide direct evidence for a link between plastic changes and the local regulation of sleep need.

Examining frontotemporal connectivity and rTMS in healthy controls: implications for auditory hallucinations in schizophrenia.

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Gromann, Paula M; Tracy, Derek K; Giampietro, Vincent; Brammer, Michael J; Krabbendam, Lydia; Shergill, Sukhwinder S

2012-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been shown to have clinically beneficial effects in altering the perception of auditory hallucinations (AH) in patients with schizophrenia. However, the mode of action is not clear. Recent neuroimaging findings indicate that rTMS has the potential to induce not only local effects but also changes in remote, functionally connected brain regions. Frontotemporal dysconnectivity has been proposed as a mechanism leading to psychotic symptoms in schizophrenia. The current study examines functional connectivity between temporal and frontal brain regions after rTMS and the implications for AH in schizophrenia. A connectivity analysis was conducted on the fMRI data of 11 healthy controls receiving rTMS, compared with 11 matched subjects receiving sham TMS, to the temporoparietal junction, before engaging in a task associated with robust frontotemporal activation. Compared to the control group, the rTMS group showed an altered frontotemporal connectivity with stronger connectivity between the right temporoparietal cortex and the dorsolateral prefrontal cortex and the angular gyrus. This finding provides preliminary evidence for the hypothesis that normalizing the functional connectivity between the temporoparietal and frontal brain regions may underlie the therapeutic effect of rTMS on AH in schizophrenia.

Contribution of TMS and rTMS in the Understanding of the Pathophysiology and in the Treatment of Dystonia.

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Lozeron, Pierre; Poujois, Aurélia; Richard, Alexandra; Masmoudi, Sana; Meppiel, Elodie; Woimant, France; Kubis, Nathalie

2016-01-01

Dystonias represent a heterogeneous group of movement disorders responsible for sustained muscle contraction, abnormal postures, and muscle twists. It can affect focal or segmental body parts or be generalized. Primary dystonia is the most common form of dystonia but it can also be secondary to metabolic or structural dysfunction, the consequence of a drug's side-effect or of genetic origin. The pathophysiology is still not elucidated. Based on lesion studies, dystonia has been regarded as a pure motor dysfunction of the basal ganglia loop. However, basal ganglia lesions do not consistently produce dystonia and lesions outside basal ganglia can lead to dystonia; mild sensory abnormalities have been reported in the dystonic limb and imaging studies have shown involvement of multiple other brain regions including the cerebellum and the cerebral motor, premotor and sensorimotor cortices. Transcranial magnetic stimulation (TMS) is a non-invasive technique of brain stimulation with a magnetic field applied over the cortex allowing investigation of cortical excitability. Hyperexcitability of contralateral motor cortex has been suggested to be the trigger of focal dystonia. High or low frequency repetitive TMS (rTMS) can induce excitatory or inhibitory lasting effects beyond the time of stimulation and protocols have been developed having either a positive or a negative effect on cortical excitability and associated with prevention of cell death, γ-aminobutyric acid (GABA) interneurons mediated inhibition and brain-derived neurotrophic factor modulation. rTMS studies as a therapeutic strategy of dystonia have been conducted to modulate the cerebral areas involved in the disease. Especially, when applied on the contralateral (pre)-motor cortex or supplementary motor area of brains of small cohorts of dystonic patients, rTMS has shown a beneficial transient clinical effect in association with restrained motor cortex excitability. TMS is currently a valuable tool to improve

Contribution of TMS and rTMS in the understanding of the pathophysiology and in the treatment of dystonia.

Directory of Open Access Journals (Sweden)

Pierre Lozeron

2016-11-01

Full Text Available Dystonias represent a heterogeneous group of movement disorders responsible for sustained muscle contraction, abnormal postures and muscle twists. It can affect focal or segmental body parts or be generalized. Primary dystonia is the most common form of dystonia but it can also be secondary to metabolic or structural dysfunction, the consequence of a drug’s side-effect or of genetic origin. The pathophysiology is still not elucidated. Based on lesion studies, dystonia has been regarded as a pure motor dysfunction of the basal ganglia loop. However, basal ganglia lesions do not consistently produce dystonia and lesions outside basal ganglia can lead to dystonia; mild sensory abnormalities have been reported in the dystonic limb and imaging studies have shown involvement of multiple other brain regions including the cerebellum and the cerebral motor, premotor and sensorimotor cortices. Transcranial magnetic stimulation (TMS is a non-invasive technique of brain stimulation with a magnetic field applied over the cortex allowing investigation of cortical excitability. Hyperexcitability of contralateral motor cortex has been suggested to be the trigger of focal dystonia. High or low frequency repetitive TMS (rTMS can induce excitatory or inhibitory lasting effects beyond the time of stimulation and protocols have been developed having either a positive or a negative effect on cortical excitability and associated with prevention of cell death, γ-aminobutyric acid (GABA interneurons mediated inhibition and brain-derived neurotrophic factor (BDNF modulation. rTMS studies as a therapeutic strategy of dystonia have been conducted to modulate the cerebral areas involved in the disease. Especially, when applied on the contralateral (pre-motor cortex or supplementary motor area of brains of small cohorts of dystonic patients, rTMS has shown a beneficial transient clinical effect in association with restrained motor cortex excitability. TMS is currently a

rTMS Induced Tinnitus Relief Is Related to an Increase in Auditory Cortical Alpha Activity

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Müller, Nadia; Lorenz, Isabel; Langguth, Berthold; Weisz, Nathan

2013-01-01

Chronic tinnitus, the continuous perception of a phantom sound, is a highly prevalent audiological symptom. A promising approach for the treatment of tinnitus is repetitive transcranial magnetic stimulation (rTMS) as this directly affects tinnitus-related brain activity. Several studies indeed show tinnitus relief after rTMS, however effects are moderate and vary strongly across patients. This may be due to a lack of knowledge regarding how rTMS affects oscillatory activity in tinnitus sufferers and which modulations are associated with tinnitus relief. In the present study we examined the effects of five different stimulation protocols (including sham) by measuring tinnitus loudness and tinnitus-related brain activity with Magnetoencephalography before and after rTMS. Changes in oscillatory activity were analysed for the stimulated auditory cortex as well as for the entire brain regarding certain frequency bands of interest (delta, theta, alpha, gamma). In line with the literature the effects of rTMS on tinnitus loudness varied strongly across patients. This variability was also reflected in the rTMS effects on oscillatory activity. Importantly, strong reductions in tinnitus loudness were associated with increases in alpha power in the stimulated auditory cortex, while an unspecific decrease in gamma and alpha power, particularly in left frontal regions, was linked to an increase in tinnitus loudness. The identification of alpha power increase as main correlate for tinnitus reduction sheds further light on the pathophysiology of tinnitus. This will hopefully stimulate the development of more effective therapy approaches. PMID:23390539

Insights on the neural basis of motor plasticity induced by theta burst stimulation from TMS-EEG

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VERNET, Marine; BASHIR, Shahid; YOO, Woo-Kyoung; PEREZ, Jennifer M.; NAJIB, Umer; PASCUAL-LEONE, Alvaro

2014-01-01

Transcranial magnetic stimulation (TMS) is a useful tool to induce and measure plasticity in the human brain. However, the cortical effects are generally indirectly evaluated with motor-evoked potentials (MEPs) reflective of modulation of cortico-spinal excitability. In this study, we aim to provide direct measures of cortical plasticity by combining TMS with electroencephalography (EEG). Continuous theta-burst stimulation (cTBS) was applied over the primary motor cortex (M1) of young healthy adults; and we measured modulation of (i) motor evoked-potentials (MEPs), (ii) TMS-induced EEG evoked potentials (TEPs), (iii) TMS-induced EEG synchronization and (iv) eyes-closed resting EEG. Our results show the expected cTBS-induced decrease in MEPs size, which we found to be paralleled by a modulation of a combination of TEPs. Furthermore, we found that cTBS increased the power in the theta band of eyes-closed resting EEG, whereas it decreased single-pulse TMS-induced power in the theta and alpha bands. In addition, cTBS decreased the power in the beta band of eyes-closed resting EEG, whereas it increased single-pulse TMS-induced power in the beta band. We suggest that cTBS acts by modulating the phase alignment between already active oscillators; it synchronizes low frequency (theta and/or alpha) oscillators and desynchronizes high frequency (beta) oscillators. These results provide novel insights into the cortical effects of cTBS and could be useful for exploring cTBS-induced plasticity outside of the motor cortex. PMID:23190020

Electrical and magnetic repetitive transcranial stimulation of the primary motor cortex in healthy subjects.

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Gilio, Francesca; Iacovelli, Elisa; Frasca, Vittorio; Gabriele, Maria; Giacomelli, Elena; De Lena, Carlo; Cipriani, Anna Maria; Inghilleri, Maurizio

2009-05-08

Repetitive transcranial magnetic stimulation (rTMS) delivered in short trains at 5Hz frequency and suprathreshold intensity over the primary motor cortex (M1) in healthy subjects facilitates the motor-evoked potential (MEP) amplitude by increasing cortical excitability through mechanisms resembling short-term synaptic plasticity. In this study, to investigate whether rTES acts through similar mechanisms we compared the effects of rTMS and repetitive transcranial electrical stimulation (rTES) (10 stimuli-trains, 5Hz frequency, suprathreshold intensity) delivered over the M1 on the MEP amplitude. Four healthy subjects were studied in two separate sessions in a relaxed condition. rTMS and anodal rTES were delivered in trains to the left M1 over the motor area for evoking a MEP in the right first dorsal interosseous muscle. Changes in MEP size and latency during the course of the rTMS and rTES trains were compared. The possible effects of muscle activation on MEP amplitude were evaluated, and the possible effects of cutaneous trigeminal fibre activation on corticospinal excitability were excluded in a control experiment testing the MEP amplitude before and after supraorbital nerve repetitive electrical stimulation. Repeated measures analysis of variance (ANOVA) showed that rTES and rTMS trains elicited similar amplitude first MEPs and a similar magnitude MEP amplitude facilitation during the trains. rTES elicited a first MEP with a shorter latency than rTMS, without significant changes during the course of the train of stimuli. The MEP elicited by single-pulse TES delivered during muscle contraction had a smaller amplitude than the last MEP in the rTES trains. Repetitive supraorbital nerve stimulation left the conditioned MEP unchanged. Our results suggest that 5 Hz-rTES delivered in short trains increases cortical excitability and does so by acting on the excitatory interneurones probably through mechanisms similar to those underlying the rTMS-induced MEP facilitation.

Repetitive activation of the corticospinal pathway by means of rTMS may reduce the efficiency of corticomotoneuronal synapses

DEFF Research Database (Denmark)

Taube, Wolfgang; Leukel, Christian; Nielsen, Jens Bo

2015-01-01

Low-frequency rTMS applied to the primary motor cortex (M1) may produce depression of motor-evoked potentials (MEPs). This depression is commonly assumed to reflect changes in cortical circuits. However, little is known about rTMS-induced effects on subcortical circuits. Therefore, the present st......-either at M1 and/or the CM synapse. As the early facilitation reflects activation of direct CM projections, the most likely site of action is the synapse of the CM neurons onto spinal motoneurons....

Effect of nipradilol, a beta-adrenergic blocker with vasodilating activity, on oxotremorine-induced tremor in mice.

Science.gov (United States)

Iwata, S; Nomoto, M; Fukuda, T

1996-10-01

The effect of nipradilol, a nonselective beta-adrenergic receptor blocker with nitroglycerin-like vasodilating activity, on oxotremorine-induced tremor was studied in mice. General tremor in mice was elicited by 0.5 mg/kg oxotremorine. The tremor was quantified using a capacitance transducer, then analyzed by a signal processor. The strength of the tremor was expressed in "points". The point values of the tremor (mean +/- SE) in control mice for 5 mg/kg (+/-)-propranolol, 2.5 mg/kg arotinolol, 0.5 mg/kg nipradilol, 1.0 mg/kg nipradilol and 2.5 mg/kg nipradilol were 87 +/- 16, 42 +/- 6, 38 +/- 6, 99 +/- 28, 28 +/- 6 and 31 +/- 7, respectively. The strength of the tremor was reduced by all beta-blockers. Although 1.0 mg/kg nipradilol significantly reduced the tremor, further inhibition of the tremor was not obtained with dosages up to 2.5 mg/kg of the drug. In conclusion, nipradilol was effective for suppressing oxotremorine-induced tremor, as were other beta-blockers.

Contribution of the pre-SMA to the production of words and non-speech oral motor gestures, as revealed by repetitive transcranial magnetic stimulation (rTMS).

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Tremblay, Pascale; Gracco, Vincent L

2009-05-01

An emerging theoretical perspective, largely based on neuroimaging studies, suggests that the pre-SMA is involved in planning cognitive aspects of motor behavior and language, such as linguistic and non-linguistic response selection. Neuroimaging studies, however, cannot indicate whether a brain region is equally important to all tasks in which it is activated. In the present study, we tested the hypothesis that the pre-SMA is an important component of response selection, using an interference technique. High frequency repetitive TMS (10 Hz) was used to interfere with the functioning of the pre-SMA during tasks requiring selection of words and oral gestures under different selection modes (forced, volitional) and attention levels (high attention, low attention). Results show that TMS applied to the pre-SMA interferes selectively with the volitional selection condition, resulting in longer RTs. The low- and high-attention forced selection conditions were unaffected by TMS, demonstrating that the pre-SMA is sensitive to selection mode but not attentional demands. TMS similarly affected the volitional selection of words and oral gestures, reflecting the response-independent nature of the pre-SMA contribution to response selection. The implications of these results are discussed.

Tremor: Tremor:

OpenAIRE

Georgiev, Dejan; Kragelj, Veronika; Pirtošek, Zvezdan; Ribarič, Samo

2012-01-01

Tremor is one of the most common disorders in the population of patients diagnosed with movement disorders. In the literature we find several classifications and different types of tremors. Each tremor type has its own characteristics. The most frequently used and widely accepted tremor classification divides tremors according to clinical appearance. First, they are roughly divided into resting tremor and action tremor. Action tremor is then subdivided into postural, kinetic, intention, task ...

Improved language in a chronic nonfluent aphasia patient after treatment with CPAP and TMS.

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Naeser, Margaret A; Martin, Paula I; Lundgren, Kristine; Klein, Reva; Kaplan, Jerome; Treglia, Ethan; Ho, Michael; Nicholas, Marjorie; Alonso, Miguel; Pascual-Leone, Alvaro

2010-03-01

To present pretreatment and post-treatment language data for a nonfluent aphasia patient who received 2 treatment modalities: (1) continuous positive airway pressure (CPAP) for his sleep apnea, starting 1-year poststroke; and (2) repetitive transcranial magnetic brain stimulation (TMS), starting 2 years poststroke. Language data were acquired beyond the spontaneous recovery period of 3 to 6 months poststroke onset. CPAP restores adequate oxygen flow throughout all stages of sleep, and may improve cognition. A series of slow, 1 Hz repetitive TMS treatments to suppress a posterior portion of right pars triangularis has been shown to improve phrase length and naming in chronic nonfluent aphasia. The Boston Diagnostic Aphasia Examination and Boston Naming Test were administered pre-CPAP, and after 2 to 5 months of CPAP. These same tests were administered pre-TMS, and at 3 and 6 months post-TMS, and again 2.4 years later. Post-CPAP testing showed increased Phrase Length, Auditory Comprehension, and naming Animals and Tools/Implements (Boston Diagnostic Aphasia Examination). Testing at 3 and 6 months post-TMS showed significant increase in Phrase Length, Auditory Comprehension, and Boston Naming Test compared with pre-TMS. These gains were retained at 2.4 years post-TMS. CPAP use continued throughout. Physiologic treatment interventions may promote language recovery in chronic aphasia.

Neuromodulation integrating rTMS and neurofeedback for the treatment of autism spectrum disorder: An exploratory study

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Sokhadze, Estate M.; El-Baz, Ayman S.; Tasman, Allan; Sears, Lonnie L.; Wang, Yao; Lamina, Eva V.; Casanova, Manuel F.

2014-01-01

Autism spectrum disorder (ASD) is a pervasive developmental disorder characterized by deficits in social interaction, language, stereotyped behaviors, and restricted range of interests. In previous studies low frequency repetitive transcranial magnetic stimulation (rTMS) has been used, with positive behavioral and electrophysiological results, for the experimental treatment in ASD. In this study we combined prefrontal rTMS sessions with electroencephalographic (EEG) neurofeedback (NFB) to prolong and reinforce TMS-induced EEG changes. The pilot trial recruited 42 children with ASD (~14.5 yrs). Outcome measures included behavioral evaluations and reaction time test with event-related potential (ERP) recording. For the main goal of this exploratory study we used rTMS-neurofeedback combination (TMS-NFB, N=20) and waitlist (WTL, N=22) groups to examine effects of 18 sessions of integrated rTMS-NFB treatment or wait period) on behavioral responses, stimulus and response-locked ERPs, and other functional and clinical outcomes. The underlying hypothesis was that combined TMS-NFB will improve executive functions in autistic patients as compared to the waitlist group. Behavioral and ERP outcomes were collected in pre- and post-treatment tests in both groups. Results of the study supported our hypothesis by demonstration of positive effects of combined TMS-NFB neurotherapy in active treatment group as compared to control waitlist group, as the TMS-NFB group showed significant improvements in behavioral and functional outcomes as compared to the waitlist group. PMID:25267414

Understanding of action-related and abstract verbs in comparison: a behavioral and TMS study.

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Innocenti, Alessandro; De Stefani, Elisa; Sestito, Mariateresa; Gentilucci, Maurizio

2014-02-01

Does the comprehension of both action-related and abstract verbs rely on motor simulation? In a behavioral experiment, in which a semantic task was used, response times to hand-action-related verbs were briefer than those to abstract verbs and both decreased with repetition of presentation. In a transcranial magnetic stimulation (TMS) experiment, single-pulse stimulation was randomly delivered over hand motor area of the left primary motor cortex to measure cortical-spinal excitability at 300 or 500 ms after verb presentation. Two blocks of trials were run. In each block, the same verbs were randomly presented. In the first block, stimulation induced an increase in motor evoked potentials only when TMS was applied 300 ms after action-related verb presentation. In the second block, no modulation of motor cortex was found according to type of verb and stimulation-delay. These results confirm that motor simulation can be used to understand action rather than abstract verbs. Moreover, they suggest that with repetition, the semantic processing for action verbs does not require activation of primary motor cortex anymore.

Subcortical substrates of TMS induced modulation of the cortico-cortical connectivity

DEFF Research Database (Denmark)

Groppa, Sergiu; Muthuraman, Muthuraman; Otto, Birte

2013-01-01

pulse TMS to the primary motor cortex (M1) of healthy subjects to interfere the cortical oscillatory activity recorded by simultaneous EEG and calculated the cortico-cortical coherence and power in the alpha and beta band. To study the structural substrate of the functional connectivity we performed...... diffusion tensor imaging and fractional anisotropy analysis (FA). To capture the pathways involved we applied probabilistic tractography to reconstruct the entire network. RESULTS: Suprathreshold TMS of M1 induced a consistent enhancement of interhemispheric cortico-cortical alpha band coherence that lasted...... ca. 175 ms. after the pulse has been applied. The changes were confined to the interhemispheric central EEG electrodes (i.e. C3-C4). There were no consistent changes in the beta band. Power analysis revealed a longer lasting increase in the beta band after TMS pulses. A cluster in the contralateral...

Challenges in comparing the acute cognitive outcomes of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) vs. electroconvulsive therapy (ECT) in major depression: A systematic review.

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Kedzior, Karina Karolina; Schuchinsky, Maria; Gerkensmeier, Imke; Loo, Colleen

2017-08-01

The present study aimed to systematically compare the cognitive outcomes of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) and electroconvulsive therapy (ECT) in head-to-head studies with major depression (MDD) patients. A systematic literature search identified six studies with 219 MDD patients that were too heterogeneous to reliably detect meaningful differences in acute cognitive outcomes after ECT vs. HF-rTMS. Cognitive effects of brain stimulation vary depending on the timeframe and methods of assessment, stimulation parameters, and maintenance treatment. Thus, acute and longer-term differences in cognitive outcomes both need to be investigated at precisely defined timeframes and with similar instruments assessing comparable functions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Accelerated high-frequency repetitive transcranial magnetic stimulation enhances motor activity in rats

NARCIS (Netherlands)

El Arfani, Anissa; Parthoens, Joke; Demuyser, Thomas; Servaes, Stijn; De Coninck, Mattias; De Deyn, Peter Paul; Van Dam, Debby; Wyckhuys, Tine; Baeken, Chris; Smolders, Ilse; Staelens, Steven

2017-01-01

High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) is currently accepted as an evidence-based treatment option for treatment-resistant depression (TRD). Additionally, HF-rTMS showed beneficial effects on psychomotor retardation in patients. The classical HF-rTMS paradigms however

Network-wise cerebral blood flow redistribution after 20 Hz rTMS on left dorso-lateral prefrontal cortex.

Science.gov (United States)

Shang, Yuan-Qi; Xie, Jun; Peng, Wei; Zhang, Jian; Chang, Da; Wang, Ze

2018-04-01

The repetitive application of transcranial magnetic stimulation (rTMS) on left dorsolateral prefrontal cortex (DLPFC) has been consistently shown to be beneficial for treating various neuropsychiatric or neuropsychological disorders, but its neural mechanisms still remain unclear. The purpose of this study was to measure the effects of high-frequency left DLPFC rTMS using cerebral blood flow (CBF) collected from 40 young healthy subjects before and after applying 20 Hz left DLPFC rTMS or SHAM stimulations. Relative CBF (rCBF) changes before and after 20 Hz rTMS or SHAM were assessed with paired-t test. The results show that 20 Hz DLPFC rTMS induced CBF redistribution in the default mode network, including increased rCBF in left medial temporal cortex (MTC)/hippocampus, but reduced rCBF in precuneus and cerebellum. Meanwhile, SHAM stimulation didn't produce any rCBF changes. After controlling SHAM effects, only the rCBF increase in MTC/hippocampus remained. Those data suggest that the beneficial effects of high-frequency rTMS may be through a within-network rCBF redistribution. Copyright © 2018 Elsevier B.V. All rights reserved.

Combining near-infrared spectroscopy with electroencephalography and repetitive transcranial magnetic stimulation

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Näsi, Tiina; Kotilahti, Kalle; Mäki, Hanna; Nissilä, Ilkka; Meriläinen, Pekka

2009-07-01

The objective of the study was to assess the usability of a near-infrared spectroscopy (NIRS) device in multimodal measurements. We combined NIRS with electroencephalography (EEG) to record hemodynamic responses and evoked potentials simultaneously, and with transcranial magnetic stimulation (TMS) to investigate hemodynamic responses to repetitive TMS (rTMS). Hemodynamic responses and visual evoked potentials (VEPs) to 3, 6, and 12 s stimuli consisting of pattern-reversing checkerboards were successfully recorded in the NIRS/EEG measurement, and ipsi- and contralateral hemodynamic responses to 0.5, 1, and 2 Hz rTMS in the NIRS/TMS measurement. In the NIRS/EEG measurements, the amplitudes of the hemodynamic responses increased from 3- to 6-s stimulus, but not from 6- to 12-s stimulus, and the VEPs showed peaks N75, P100, and N135. In the NIRS/TMS measurements, the 2-Hz stimulus produced the strongest hemodynamic responses compared to the 0.5- and 1-Hz stimuli. In two subjects oxyhemoglobin concentration decreased and in one increased as a consequence of the 2-Hz rTMS. To locate the origin of the measured NIRS responses, methods have to be developed to investigate TMS-induced scalp muscle contractions. In the future, multimodal measurements may prove useful in monitoring or treating diseases such as stroke or Alzheimer's disease.

Therapeutic effects of arotinolol, a beta-adrenergic blocker, on tremor in MPTP-induced parkinsonian monkeys.

Science.gov (United States)

Kuno, S; Mizuta, E; Nishida, J; Takechi, M

1992-10-01

The effect of arotinolol, a peripherally acting beta-adrenergic-blocking agent, on postural or kinetic tremor was studied in monkeys with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism. Male cynomolgus monkeys (Macaca fascicularis) were treated with three injections of MPTP hydrochloride (0.3 mg/kg, i.v.) at an interval of 3-4 days, followed by several injections of the same dose every 7 days. Four monkeys with persistent parkinsonian symptoms manifested for greater than 1 year were used. The animals developed mild to moderate degrees of postural or kinetic tremor, and their motor activity was reduced. Arotinolol (20-30 mg/kg, s.c.) significantly suppressed postural tremor in a dose-dependent manner. Propranolol (20-30 mg/kg) was also effective in suppressing the tremor. However, the application of propranolol induced emesis, whereas arotinolol had no adverse effects. These results suggest that arotinolol is a useful adjunct to dopaminergic therapy for tremor in Parkinson's disease.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS)

DEFF Research Database (Denmark)

Lefaucheur, Jean-Pascal; André-Obadia, Nathalie; Antal, Andrea

2014-01-01

, consciousness disorders, tinnitus, depression, anxiety disorders, obsessive-compulsive disorder, schizophrenia, craving/addiction, and conversion. Despite unavoidable inhomogeneities, there is a sufficient body of evidence to accept with level A (definite efficacy) the analgesic effect of high-frequency (HF) r...... for the negative symptoms of schizophrenia, and LF-rTMS of contralesional M1 in chronic motor stroke. The effects of rTMS in a number of indications reach level C (possible efficacy), including LF-rTMS of the left temporoparietal cortex in tinnitus and auditory hallucinations. It remains to determine how...

Use of repetitive transcranial magnetic stimulation for treatment in psychiatry.

Science.gov (United States)

Aleman, André

2013-08-01

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.

Safety of primed repetitive transcranial magnetic stimulation and modified constraint-induced movement therapy in a randomized controlled trial in pediatric hemiparesis.

Science.gov (United States)

Gillick, Bernadette T; Krach, Linda E; Feyma, Tim; Rich, Tonya L; Moberg, Kelli; Menk, Jeremiah; Cassidy, Jessica; Kimberley, Teresa; Carey, James R

2015-04-01

To investigate the safety of combining a 6-Hz primed low-frequency repetitive transcranial magnetic stimulation (rTMS) intervention in the contralesional hemisphere with a modified constraint-induced movement therapy (mCIMT) program in children with congenital hemiparesis. Phase 1 randomized, double-blinded, placebo-controlled pretest/posttest trial. University academic facility and pediatric specialty hospital. Subjects (N = 19; age range, 8-17 y) with congenital hemiparesis caused by ischemic stroke or periventricular leukomalacia. No subject withdrew because of adverse events. All subjects included completed the study. Subjects were randomized to 1 of 2 groups: either real rTMS plus mCIMT (n = 10) or sham rTMS plus mCIMT (n = 9). Adverse events, physician assessment, ipsilateral hand function, stereognosis, cognitive function, subject report of symptoms assessment, and subject questionnaire. No major adverse events occurred. Minor adverse events were found in both groups. The most common events were headaches (real: 50%, sham: 89%; P = .14) and cast irritation (real: 30%, sham: 44%; P = .65). No differences between groups in secondary cognitive and unaffected hand motor measures were found. Primed rTMS can be used safely with mCIMT in congenital hemiparesis. We provide new information on the use of rTMS in combination with mCIMT in children. These findings could be useful in research and future clinical applications in advancing function in congenital hemiparesis. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Transcranial magnetic stimulation (TMS) in stroke: Ready for clinical practice?

Science.gov (United States)

Smith, Marie-Claire; Stinear, Cathy M

2016-09-01

The use of transcranial magnetic stimulation (TMS) in stroke research has increased dramatically over the last decade with two emerging and potentially useful functions identified. Firstly, the use of single pulse TMS as a tool for predicting recovery of motor function after stroke, and secondly, the use of repetitive TMS (rTMS) as a treatment adjunct aimed at modifying the excitability of the motor cortex in preparation for rehabilitation. This review discusses recent advances in the use of TMS in both prediction and treatment after stroke. Prediction of recovery after stroke is a complex process and the use of TMS alone is not sufficient to provide accurate prediction for an individual after stroke. However, when applied in conjunction with other tools such as clinical assessment and MRI, accuracy of prediction using TMS is increased. rTMS temporarily modulates cortical excitability after stroke. Very few rTMS studies are completed in the acute or sub-acute stages after stroke and the translation of altered cortical excitability into gains in motor function are modest, with little evidence of long term effects. Although gains have been made in both of these areas, further investigation is needed before these techniques can be applied in routine clinical care. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Case of Action-Induced Clonus that Mimicked Action Tremors and was Associated with Cervical Schwannoma

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Young-Hee Sung

2010-10-01

Full Text Available Clonus is the rhythmic muscle contraction which usually occurs in patients with lesions involving descending motor pathways. Sometimes, rhythmic oscillation of action induced clonus could be confused to action tremor. We report a case of action induced clonus associated with cervical schwannoma which was misdiagnosed as essential tremor. The patient had spasticity in all limbs with exaggerated tendon reflexes, and passive stretch-induced clonus. Imaging and histological examinations revealed a schwannoma extending from C2 to C7. The lesion was partially removed by surgery. Even though essential tremor is a common disease, clinician have to do sufficient neurologic examination considering differential diagnosis.

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

Science.gov (United States)

Jalinous, Reza; Lisanby, Sarah H.

2013-01-01

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 μs to over 100 μs. 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 μs, 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

Primed low-frequency repetitive transcranial magnetic stimulation and constraint-induced movement therapy in pediatric hemiparesis: a randomized controlled trial.

Science.gov (United States)

Gillick, Bernadette T; Krach, Linda E; Feyma, Tim; Rich, Tonya L; Moberg, Kelli; Thomas, William; Cassidy, Jessica M; Menk, Jeremiah; Carey, James R

2014-01-01

The aim of this study was to determine the feasibility and efficacy of five treatments of 6 Hz primed, low-frequency, repetitive transcranial magnetic stimulation (rTMS) combined with constraint-induced movement therapy (CIMT) to promote recovery of the paretic hand in children with congenital hemiparesis. Nineteen children with congenital hemiparesis aged between 8 and 17 years (10 males, nine females; mean age 10 years 10 months, SD 2 years 10 months; Manual Ability Classification Scale levels I-III) underwent five sessions of either real rTMS (n=10) or sham rTMS (n=9) alternated daily with CIMT. CIMT consisted of 13 days of continuous long-arm casting with five skin-check sessions. Each child received a total of 10 hours of one-to-one therapy. The primary outcome measure was the Assisting Hand Assessment (AHA) and the secondary outcome variables were the Canadian Occupational Performance Measure (COPM) and stereognosis. A Wilcoxon signed-rank sum test was used to analyze differences between pre- and post-test scores within the groups. Analysis of covariance was used to compute mean differences between groups adjusting for baseline. Fisher's exact test was used to compare individual change in AHA raw scores with the smallest detectable difference (SDD) of 4 points. All participants receiving treatment finished the study. Improvement in AHA differed significantly between groups (p=0.007). No significant differences in the secondary outcome measures were found. Eight out of 10 participants in the rTMS/CIMT group showed improvement greater than the SDD, but only two out of nine in the sham rTMS/CIMT group showed such improvement (p=0.023). No serious adverse events occurred. Primed, low-frequency rTMS combined with CIMT appears to be safe, feasible, and efficacious in pediatric hemiparesis. Larger clinical trials are now indicated. © 2013 Mac Keith Press.

Low-intensity repetitive magnetic stimulation lowers action potential threshold and increases spike firing in layer 5 pyramidal neurons in vitro.

Science.gov (United States)

Tang, Alexander D; Hong, Ivan; Boddington, Laura J; Garrett, Andrew R; Etherington, Sarah; Reynolds, John N J; Rodger, Jennifer

2016-10-29

Repetitive transcranial magnetic stimulation (rTMS) has become a popular method of modulating neural plasticity in humans. Clinically, rTMS is delivered at high intensities to modulate neuronal excitability. While the high-intensity magnetic field can be targeted to stimulate specific cortical regions, areas adjacent to the targeted area receive stimulation at a lower intensity and may contribute to the overall plasticity induced by rTMS. We have previously shown that low-intensity rTMS induces molecular and structural plasticity in vivo, but the effects on membrane properties and neural excitability have not been investigated. Here we investigated the acute effect of low-intensity repetitive magnetic stimulation (LI-rMS) on neuronal excitability and potential changes on the passive and active electrophysiological properties of layer 5 pyramidal neurons in vitro. Whole-cell current clamp recordings were made at baseline prior to subthreshold LI-rMS (600 pulses of iTBS, n=9 cells from 7 animals) or sham (n=10 cells from 9 animals), immediately after stimulation, as well as 10 and 20min post-stimulation. Our results show that LI-rMS does not alter passive membrane properties (resting membrane potential and input resistance) but hyperpolarises action potential threshold and increases evoked spike-firing frequency. Increases in spike firing frequency were present throughout the 20min post-stimulation whereas action potential (AP) threshold hyperpolarization was present immediately after stimulation and at 20min post-stimulation. These results provide evidence that LI-rMS alters neuronal excitability of excitatory neurons. We suggest that regions outside the targeted region of high-intensity rTMS are susceptible to neuromodulation and may contribute to rTMS-induced plasticity. Copyright © 2016 IBRO. All rights reserved.

On the Mechanisms of Transcranial Magnetic Stimulation (TMS: How Brain State and Baseline Performance Level Determine Behavioral Effects of TMS

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Juha Silvanto

2018-05-01

Full Text Available The behavioral effects of Transcranial Magnetic Stimulation (TMS can change qualitatively when stimulation is preceded by initial state manipulations such as priming or adaptation. In addition, baseline performance level of the participant has been shown to play a role in modulating the impact of TMS. Here we examined the link between these two factors. This was done using data from a previous study using a TMS-priming paradigm, in which, at group level, TMS selectively facilitated targets incongruent with the prime while having no statistically significant effects on other prime-target congruencies. Correlation and linear mixed-effects analyses indicated that, for all prime-target congruencies, a significant linear relationship between baseline performance and the magnitude of the induced TMS effect was present: low levels of baseline performance were associated with TMS-induced facilitations and high baseline performance with impairments. Thus as performance level increased, TMS effects turned from facilitation to impairment. The key finding was that priming shifted the transition from facilitatory to disruptive effects for targets incongruent with the prime, such that TMS-induced facilitations were obtained until a higher level of performance than for other prime-target congruencies. Given that brain state manipulations such as priming operate via modulations of neural excitability, this result is consistent with the view that neural excitability, coupled with non-linear neural effects, underlie behavioral effects of TMS.

Repetitive Transcranial Magnetic Stimulation: a Novel Approach for Treating Oropharyngeal Dysphagia

OpenAIRE

Michou, Emilia; Raginis-Zborowska, Alicja; Watanabe, Masahiro; Lodhi, Taha; Hamdy, Shaheen

2016-01-01

In recent years, repetitive transcranial magnetic stimulation, a technique used to produce human central neurostimulation, has attracted increased interest and been applied experimentally in the treatment of dysphagia. This review presents a synopsis of the current research for the application of repetitive transcranial magnetic stimulation (rTMS) on dysphagia. Here, we review the mechanisms underlying the effects of rTMS and the results from studies on both healthy volunteers and dysphagic p...

Muscle-Cooling Intervention to Reduce Fatigue and Fatigue-Induced Tremor in Novice and Experienced Surgeons: A Preliminary Investigation

OpenAIRE

Jensen, Lauren; Dancisak, Michael; Korndorffer, James

2016-01-01

A localized, intermittent muscle-cooling protocol was implemented to determine cooling garment efficacy in reducing upper extremity muscular fatigue and tremor in novice ( n  = 10) and experienced surgeons ( n  = 9). Subjects wore a muscle-cooling garment while performing multiple trials of a forearm exercise and paired suturing task to induce muscular fatigue and exercise-induced tremor. A reduction in tremor amplitude and an extension in time to fatigue were expected with muscle...

A Review of Repetitive Transcranial Magnetic Stimulation Use in Psychiatry

Directory of Open Access Journals (Sweden)

Onur Durmaz

2013-08-01

Full Text Available Repetitive transcranial magnetic stimulation (rTMS is a non-invasive brain stimulation technique first introduced by Barker et al. in 1985. The principle of rTMS is based on a cortical neuronal transmembrane potential stimulated by a pulsative magnetic field. This magnetic field is induced by a direct electrical current sent through a circular coil. rTMS is an effective and widely used therapeutic stimulation method for psychiatric disorders, primarily for unipolar depression. Cost-effectiveness, minor side effects and well-tolerated profile of rTMS with no need to hospitalization for administation are the prominent features of this method. Beside the information for depression, rTMS has been reported to have some remarkable impacts in alleviating symptoms of anxiety disorders. Although data regarding efficacy of rTMS in anxiety disorders is conflicting, there are positive outcomes about generalized anxiety disorder, post-traumatic stress disorder and panic disorder whereas results of rTMS treatment in obsessive-compulsive disorder are generally not favorable. Since low frequency stimulation techniques have been found to be effective in treatment of auditory hallucinations, methodological similarity in concerned studies could be accepted as a supportive aspect of efficacy. Additionally, high frequency stimulation techniques applied to prefrontal area have a potential to impact negative symptoms of schizophrenia. With improving novel techniques of this stimulation method, rTMS is being used increasingly in psychiatric disorders. However, some issues concerning rTMS treatment such as maintenance or prophilactic therapy procedures, duration of effect are remain unclear. Hence, we conclude that multicenter sham controlled studies including similar designs, sociodemographic and clinical variables, methodological protocols with larger sample sizes and studies guieded by imaging methods are warranted to determinate efficacy and side effects of rTMS use

Test-retest assessment of cortical activation induced by repetitive transcranial magnetic stimulation with brain atlas-guided optical topography

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Tian, Fenghua; Kozel, F. Andrew; Yennu, Amarnath; Croarkin, Paul E.; McClintock, Shawn M.; Mapes, Kimberly S.; Husain, Mustafa M.; Liu, Hanli

2012-11-01

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 (Δ[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 Δ[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.

The tremorolytic action of beta-adrenoceptor blockers in essential, physiological and isoprenaline-induced tremor is mediated by beta-adrenoceptors located in a deep peripheral compartment.

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Abila, B; Wilson, J F; Marshall, R W; Richens, A

1985-10-01

The effects of intravenous propranolol 100 micrograms kg-1, sotalol 500 micrograms kg-1, timolol 7.8 micrograms kg-1, atenolol 125 micrograms kg-1 and placebo on essential, physiological and isoprenaline-induced tremor were studied. These beta-adrenoceptor blocker doses produced equal reduction of standing-induced tachycardia in essential tremor patients. Atenolol produced significantly less reduction of essential and isoprenaline-induced tremor than the non-selective drugs, confirming the importance of beta 2-adrenoceptor blockade in these effects. Propranolol and sotalol produced equal maximal inhibition of isoprenaline-induced tremor but propranolol was significantly more effective in reducing essential tremor. The rate of development of the tremorolytic effect was similar in essential, physiological and isoprenaline-induced tremors but all tremor responses developed significantly more slowly than the heart rate responses. It is proposed that these results indicate that the tremorolytic activity of beta-adrenoceptor blockers in essential, physiological and isoprenaline-induced tremor is exerted via the same beta 2-adrenoceptors located in a deep peripheral compartment which is thought to be in the muscle spindles.

Tectonic tremor and LFEs on a reverse fault in Taiwan

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Aguiar, Ana C.; Chao, Kevin; Beroza, Gregory C.

2017-07-01

We compare low-frequency earthquakes (LFEs) from triggered and ambient tremor under the southern Central Range, Taiwan. We apply the PageRank algorithm used by Aguiar and Beroza (2014) that exploits the repetitive nature of the LFEs to find repeating LFEs in both ambient and triggered tremor. We use these repeaters to create LFE templates and find that the templates created from both tremor types are very similar. To test their similarity, we use both interchangeably and find that most of both the ambient and triggered tremor match the LFE templates created from either data set, suggesting that LFEs for both events have a common origin. We locate the LFEs by using local earthquake P wave and S wave information and find that LFEs from triggered and ambient tremor locate to between 20 and 35 km on what we interpret as the deep extension of the Chaochou-Lishan Fault.

Effects of prefrontal rTMS on autonomic reactions to affective pictures.

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Berger, Christoph; Domes, Gregor; Balschat, Johannes; Thome, Johannes; Höppner, Jacqueline

2017-02-01

Repetitive transcranial magnetic stimulation (rTMS) can modulate the excitability of stimulated cortical areas, such as prefrontal areas involved in emotion regulation. Low frequency (LF) rTMS is expected to have inhibitory effects on prefrontal regions, and thereby should disinhibit limbic activity, resulting in enhanced emotional and autonomic reactions. For high frequency (HF) rTMS, the opposite pattern might be assumed. The objective of this study was to determine the effects of different rTMS frequencies applied to the right dlPFC on autonomic functions and on emotional perception. In a crossover design, two groups of 20 healthy young women were either stimulated with one session of LF rTMS (1 Hz) or one session of HF rTMS (10 Hz), compared to sham stimulation. We assessed phasic cardiac responses (PCR), skin conductance reactions (SCR), and emotional appraisal of emotional pictures as well as recognition memory after each rTMS application. After LF rTMS, PCR (heart rate deceleration) during presentation of pictures with negative and neutral valence was significantly increased compared to the presentation of positive pictures. In contrast, the modulatory effect of picture valence and arousal on the cardiac orienting response was absent after HF rTMS. Our results suggest that frontal LF rTMS indirectly activates the ANS via inhibition of the right dlPFC activity, likely by enhancing the sensory processing or attention to aversive and neutral stimuli.

Acute rCBF changes in depressed patients receiving repetitive transcranial magnetic stimulation (rTMS)

International Nuclear Information System (INIS)

Haindl, W.; Loo, C.; Mitchell, P.; Sachdev, P.; Zheng, X.; Som, S.; Walker, B.

1999-01-01

Full text: Electroconvulsant therapy (ECT) is very effective in treatment resistant severe depression with response rates of 70-90%. However, ECT has major limitations including the need for anaesthesia, memory difficulties and public apprehension about its use. Transcranial magnetic stimulation (rTMS) has been used as a diagnostic technique in neurology with recent reports of potential benefit in depressed patients. In this study, 5 patients (3 females, 2 males aged 36-66 years, mean 48.6 years) with major depression underwent SPET brain scanning using a Picker 3000 triple-headed camera. Each patient had a baseline rCBF scan with 500 MBq of 99 Tc m HMPAO injected intravenously during sham rTMS. On the following day, each patient received another 500 MBq of 99 Tc m HMPAo during rTMS to the left dorsolateral prefrontal cortex using a Magstim Super Rapid magnetic stimulator with a 70-mm figure eight coil. The stimulator parameters were 15 Hz, 90% of resting motor threshold, 1 s on 3 s off for 30 trains prior to injection and 15-30 trains following injection. Each patient continued to receive their usual medication during this period. The reconstructed SPET data sets were normalized to the global mean, registered to the Talairach template and analysed using statistical parametric mapping (SPM). Compared with the baseline group, the rTMS group showed a significant perfusion increase in the pre-frontal cortices, especially on the left, and also in the anterior left temporal lobe (P < 0.05). Frontal lobe perfusion reduction is a common finding in depression. This study demonstrates the ability of rTMS to acutely increase frontal lobe perfusion, and therefore a possible mechanism for its therapeutic use as an adjunct to pharmacological therapy or as an alternative to ECT in depression

A Single Session of rTMS Enhances Small-Worldness in Writer’s Cramp: Evidence from Simultaneous EEG-fMRI Multi-Modal Brain Graph

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Rose D. Bharath

2017-09-01

Full Text Available Background and Purpose: Repetitive transcranial magnetic stimulation (rTMS induces widespread changes in brain connectivity. As the network topology differences induced by a single session of rTMS are less known we undertook this study to ascertain whether the network alterations had a small-world morphology using multi-modal graph theory analysis of simultaneous EEG-fMRI.Method: Simultaneous EEG-fMRI was acquired in duplicate before (R1 and after (R2 a single session of rTMS in 14 patients with Writer’s Cramp (WC. Whole brain neuronal and hemodynamic network connectivity were explored using the graph theory measures and clustering coefficient, path length and small-world index were calculated for EEG and resting state fMRI (rsfMRI. Multi-modal graph theory analysis was used to evaluate the correlation of EEG and fMRI clustering coefficients.Result: A single session of rTMS was found to increase the clustering coefficient and small-worldness significantly in both EEG and fMRI (p < 0.05. Multi-modal graph theory analysis revealed significant modulations in the fronto-parietal regions immediately after rTMS. The rsfMRI revealed additional modulations in several deep brain regions including cerebellum, insula and medial frontal lobe.Conclusion: Multi-modal graph theory analysis of simultaneous EEG-fMRI can supplement motor physiology methods in understanding the neurobiology of rTMS in vivo. Coinciding evidence from EEG and rsfMRI reports small-world morphology for the acute phase network hyper-connectivity indicating changes ensuing low-frequency rTMS is probably not “noise”.

What saccadic eye movements tell us about TMS-induced neuromodulation of the DLPFC and mood changes: a pilot study in bipolar disorders

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Lysianne eBeynel

2014-08-01

Full Text Available The study assumed that the antisaccade (AS task is a relevant psychophysical tool to assess (i short-term neuromodulation of the dorsolateral prefrontal cortex (DLPFC induced by intermittent theta burst stimulation (iTBS and (ii mood change occurring during the course of the treatment. Saccadic inhibition is known to strongly involve the DLPFC, whose neuromodulation with iTBS requires less stimulation time and lower stimulation intensity, as well as results in longer aftereffects than the conventional repetitive transcranial magnetic stimulation (rTMS. Active or sham iTBS was applied every day for three weeks over the left DLPFC of 12 drug-resistant bipolar depressed patients. To assess the iTBS-induced short-term neuromodulation, the saccadic task was performed just before (S1 and just after (S2 the iTBS session, the first day of each week. Mood was evaluated through MADRS scores and the difference in scores between the beginning and the end of treatment was correlated with AS performance change between these two periods. As expected, only patients from the active group improved their performance from S1 to S2 and mood improvement was significantly correlated with AS performance improvement. In addition, the AS task also discriminated depressive bipolar patients from healthy control subjects. Therefore, the AS task could be a relevant and useful tool for clinicians to assess if the TMS-induced short-term neuromodulation of the DLPFC occurs as well as a ‘trait vs. state’ objective marker of depressive mood disorder.

What saccadic eye movements tell us about TMS-induced neuromodulation of the DLPFC and mood changes: a pilot study in bipolar disorders.

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Beynel, Lysianne; Chauvin, Alan; Guyader, Nathalie; Harquel, Sylvain; Szekely, David; Bougerol, Thierry; Marendaz, Christian

2014-01-01

The study assumed that the antisaccade (AS) task is a relevant psychophysical tool to assess (i) short-term neuromodulation of the dorsolateral prefrontal cortex (DLPFC) induced by intermittent theta burst stimulation (iTBS); and (ii) mood change occurring during the course of the treatment. Saccadic inhibition is known to strongly involve the DLPFC, whose neuromodulation with iTBS requires less stimulation time and lower stimulation intensity, as well as results in longer aftereffects than the conventional repetitive transcranial magnetic stimulation (rTMS). Active or sham iTBS was applied every day for 3 weeks over the left DLPFC of 12 drug-resistant bipolar depressed patients. To assess the iTBS-induced short-term neuromodulation, the saccadic task was performed just before (S1) and just after (S2) the iTBS session, the first day of each week. Mood was evaluated through Montgomery and Asberg Depression Rating Scale (MADRS) scores and the difference in scores between the beginning and the end of treatment was correlated with AS performance change between these two periods. As expected, only patients from the active group improved their performance from S1 to S2 and mood improvement was significantly correlated with AS performance improvement. In addition, the AS task also discriminated depressive bipolar patients from healthy control subjects. Therefore, the AS task could be a relevant and useful tool for clinicians to assess if the Transcranial magnetic stimulation (TMS)-induced short-term neuromodulation of the DLPFC occurs as well as a "trait vs. state" objective marker of depressive mood disorder.

Repetitive transcranial magnetic stimulation affects behavior by biasing endogenous cortical oscillations

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Massihullah Hamidi

2009-06-01

Full Text Available A governing assumption about repetitive transcranial magnetic stimulation (rTMS has been that it interferes with task-related neuronal activity – in effect, by “injecting noise” into the brain – and thereby disrupts behavior. Recent reports of rTMS-produced behavioral enhancement, however, call this assumption into question. We investigated the neurophysiological effects of rTMS delivered during the delay period of a visual working memory task by simultaneously recording brain activity with electroencephalography (EEG. Subjects performed visual working memory for locations or for shapes, and in half the trials a 10-Hz train of rTMS was delivered to the superior parietal lobule or a control brain area. The wide range of individual differences in the effects of rTMS on task accuracy, from improvement to impairment, was predicted by individual differences in the effect of rTMS on power in the alpha-band of the EEG (~ 10 Hz: a decrease in alpha-band power corresponded to improved performance, whereas an increase in alpha-band power corresponded to the opposite. The EEG effect was localized to cortical sources encompassing the frontal eye fields and the intraparietal sulcus, and was specific to task (location, but not object memory and to rTMS target (superior parietal lobule, not control area. Furthermore, for the same task condition, rTMS-induced changes in cross-frequency phase synchrony between alpha- and gamma-band (> 40 Hz oscillations predicted changes in behavior. These results suggest that alpha-band oscillations play an active role cognitive processes and do not simply reflect absence of processing. Furthermore, this study shows that the complex effects of rTMS on behavior can result from biasing endogenous patterns of network-level oscillations.

Diagnosis and Treatment of Common Forms of Tremor

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Puschmann, Andreas; Wszolek, Zbigniew K.

2014-01-01

Tremor is the most common movement disorder presenting to an outpatient neurology practice and is defined as a rhythmical, involuntary oscillatory movement of a body part. The authors review the clinical examination, classification, and diagnosis of tremor. The pathophysiology of the more common forms of tremor is outlined, and treatment options are discussed. Essential tremor is characterized primarily by postural and action tremors, may be a neurodegenerative disorder with pathologic changes in the cerebellum, and can be treated with a wide range of pharmacologic and nonpharmacologic methods. Tremor at rest is typical for Parkinson’s disease, but may arise independently of a dopaminergic deficit. Enhanced physiologic tremor, intention tremor, and dystonic tremor are discussed. Further differential diagnoses described in this review include drug- or toxin-induced tremor, neuropathic tremor, psychogenic tremor, orthostatic tremor, palatal tremor, tremor in Wilson’s disease, and tremor secondary to cerebral lesions, such as Holmes’ tremor (midbrain tremor). An individualized approach to treatment of tremor patients is important, taking into account the degree of disability, including social embarrassment, which the tremor causes in the patient’s life. PMID:21321834

Effects of parietal TMS on visual and auditory processing at the primary cortical level -- a concurrent TMS-fMRI study

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Leitão, Joana; Thielscher, Axel; Werner, Sebastian

2013-01-01

cortices under 3 sensory contexts: visual, auditory, and no stimulation. IPS-TMS increased activations in auditory cortices irrespective of sensory context as a result of direct and nonspecific auditory TMS side effects. In contrast, IPS-TMS modulated activations in the visual cortex in a state...... deactivations induced by auditory activity to TMS sounds. TMS to IPS may increase the responses in visual (or auditory) cortices to visual (or auditory) stimulation via a gain control mechanism or crossmodal interactions. Collectively, our results demonstrate that understanding TMS effects on (uni......Accumulating evidence suggests that multisensory interactions emerge already at the primary cortical level. Specifically, auditory inputs were shown to suppress activations in visual cortices when presented alone but amplify the blood oxygen level-dependent (BOLD) responses to concurrent visual...

Muscle-Cooling Intervention to Reduce Fatigue and Fatigue-Induced Tremor in Novice and Experienced Surgeons: A Preliminary Investigation.

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Jensen, Lauren; Dancisak, Michael; Korndorffer, James

2016-10-01

A localized, intermittent muscle-cooling protocol was implemented to determine cooling garment efficacy in reducing upper extremity muscular fatigue and tremor in novice ( n  = 10) and experienced surgeons ( n  = 9). Subjects wore a muscle-cooling garment while performing multiple trials of a forearm exercise and paired suturing task to induce muscular fatigue and exercise-induced tremor. A reduction in tremor amplitude and an extension in time to fatigue were expected with muscle cooling as compared with control trials. Each subject completed an intervention session (5°C cooling condition) and a control session (32°C or thermal neutral condition). A paired samples t test indicated that tremor amplitude was significantly reduced ( t [8] = 1.89458; p  effect was not significant. Time to fatigue and suture time improved in both cohorts with muscle cooling, but the effect did not reach significance. Results from the pilot work suggest muscle cooling as an intervention for reduction of fatigue and tremor is very promising, warranting further investigation. Surgical specialties that require prolonged procedures might benefit more from this intervention.

Unusual Wrist Tremor: Unilateral Isometric Tremor?

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Theresa A. Zesiewicz

2014-01-01

Full Text Available Background: Tremors may be difficult to classify.Case Report: An 83‐year‐old male presented with an unusual left wrist tremor. The tremor could be reproducibly elicited by making a fist or carrying a weighted object (e.g., a shopping bag, bottle of water of approximately 1 lb or more, and it intensified with heavier weights. The tremor was difficult to classify, although it shared features with isometric tremor.Discussion: This specific presentation of tremor has not been reported previously. We hope that the detailed description we provide will aid other neurologists who encounter this or similar tremors in their clinics.

Concurrent TMS to the primary motor cortex augments slow motor learning

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Narayana, Shalini; Zhang, Wei; Rogers, William; Strickland, Casey; Franklin, Crystal; Lancaster, Jack L.; Fox, Peter T.

2013-01-01

Transcranial magnetic stimulation (TMS) has shown promise as a treatment tool, with one FDA approved use. While TMS alone is able to up- (or down-) regulate a targeted neural system, we argue that TMS applied as an adjuvant is more effective for repetitive physical, behavioral and cognitive therapies, that is, therapies which are designed to alter the network properties of neural systems through Hebbian learning. We tested this hypothesis in the context of a slow motor learning paradigm. Healthy right-handed individuals were assigned to receive 5 Hz TMS (TMS group) or sham TMS (sham group) to the right primary motor cortex (M1) as they performed daily motor practice of a digit sequence task with their non-dominant hand for 4 weeks. Resting cerebral blood flow (CBF) was measured by H215O PET at baseline and after 4 weeks of practice. Sequence performance was measured daily as the number of correct sequences performed, and modeled using a hyperbolic function. Sequence performance increased significantly at 4 weeks relative to baseline in both groups. The TMS group had a significant additional improvement in performance, specifically, in the rate of skill acquisition. In both groups, an improvement in sequence timing and transfer of skills to non-trained motor domains was also found. Compared to the sham group, the TMS group demonstrated increases in resting CBF specifically in regions known to mediate skill learning namely, the M1, cingulate cortex, putamen, hippocampus, and cerebellum. These results indicate that TMS applied concomitantly augments behavioral effects of motor practice, with corresponding neural plasticity in motor sequence learning network. These findings are the first demonstration of the behavioral and neural enhancing effects of TMS on slow motor practice and have direct application in neurorehabilitation where TMS could be applied in conjunction with physical therapy. PMID:23867557

Treating Clinical Depression with Repetitive Deep Transcranial Magnetic Stimulation Using the Brainsway H1-coil

OpenAIRE

Feifel, David; Pappas, Katherine

2016-01-01

Repetitive transcranial magnetic stimulation (rTMS) is an emerging non-pharmacological approach to treating many brain-based disorders. rTMS uses electromagnetic coils to stimulate areas of the brain non-invasively. Deep transcranial magnetic stimulation (dTMS) with the Brainsway H1-coil system specifically is a type of rTMS indicated for treating patients with major depressive disorder (MDD) who are resistant to medication. The unique H1-coil design of this device is able to stimulate neuron...

Unusual Forehead Tremor in Four Patients with Essential Tremor

OpenAIRE

Gascón-Bayarri, Jordi; Campdelacreu, Jaume; Calopa, Màtil; Jaumà, Serge; Bau, Laura; Povedano, Mònica; Montero, Jordi

2012-01-01

Forehead tremor has only been reported in two patients with essential tremor, one with rhythmic tremor and the other with dystonic tremor. We report 4 new patients with essential tremor who present a 4–6 Hz frontal tremor registered by electromyography and unusual features like frontal tremor preceding limb tremor or unilateral involvement. Frontal tremor is present in some patients with essential tremor, sometimes preceding limb tremor. Treatment with botulinum toxin may be useful.

Unusual Forehead Tremor in Four Patients with Essential Tremor

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Jordi Gascón-Bayarri

2012-01-01

Full Text Available Forehead tremor has only been reported in two patients with essential tremor, one with rhythmic tremor and the other with dystonic tremor. We report 4 new patients with essential tremor who present a 4–6 Hz frontal tremor registered by electromyography and unusual features like frontal tremor preceding limb tremor or unilateral involvement. Frontal tremor is present in some patients with essential tremor, sometimes preceding limb tremor. Treatment with botulinum toxin may be useful.

Dystonia and Tremor: The Clinical Syndromes with Isolated Tremor

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Alberto Albanese

2016-04-01

Full Text Available Background: Dystonia and tremor share many commonalities. Isolated tremor is part of the phenomenological spectrum of isolated dystonia and of essential tremor. The occurrence of subtle features of dystonia may allow one to differentiate dystonic tremor from essential tremor. Diagnostic uncertainty is enhanced when no features of dystonia are found in patients with a tremor syndrome, raising the question whether the observed phenomenology is an incomplete form of dystonia. Methods: Known forms of syndromes with isolated tremor are reviewed. Diagnostic uncertainties between tremor and dystonia are put into perspective. Results: The following isolated tremor syndromes are reviewed: essential tremor, head tremor, voice tremor, jaw tremor, and upper-limb tremor. Their varied phenomenology is analyzed and appraised in the light of a possible relationship with dystonia. Discussion: Clinicians making a diagnosis of isolated tremor should remain vigilant for the detection of features of dystonia. This is in keeping with the recent view that isolated tremor may be an incomplete phenomenology of dystonia.

Dystonia and Tremor: The Clinical Syndromes with Isolated Tremor

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Albanese, Alberto; Sorbo, Francesca Del

2016-01-01

Background Dystonia and tremor share many commonalities. Isolated tremor is part of the phenomenological spectrum of isolated dystonia and of essential tremor. The occurrence of subtle features of dystonia may allow one to differentiate dystonic tremor from essential tremor. Diagnostic uncertainty is enhanced when no features of dystonia are found in patients with a tremor syndrome, raising the question whether the observed phenomenology is an incomplete form of dystonia. Methods Known forms of syndromes with isolated tremor are reviewed. Diagnostic uncertainties between tremor and dystonia are put into perspective. Results The following isolated tremor syndromes are reviewed: essential tremor, head tremor, voice tremor, jaw tremor, and upper-limb tremor. Their varied phenomenology is analyzed and appraised in the light of a possible relationship with dystonia. Discussion Clinicians making a diagnosis of isolated tremor should remain vigilant for the detection of features of dystonia. This is in keeping with the recent view that isolated tremor may be an incomplete phenomenology of dystonia. PMID:27152246

rTMS of the prefrontal cortex has analgesic effects on neuropathic pain in subjects with spinal cord injury.

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Nardone, R; Höller, Y; Langthaler, P B; Lochner, P; Golaszewski, S; Schwenker, K; Brigo, F; Trinka, E

2017-01-01

Repetitive transcranial magnetic stimulation study. The analgesic effects of repetitive transcranial magnetic stimulation (rTMS) in chronic pain have been the focus of several studies. In particular, rTMS of the premotor cortex/dorsolateral prefrontal cortex (PMC/DLPFC) changes pain perception in healthy subjects and has analgesic effects in acute postoperative pain, as well as in fibromyalgia patients. However, its effect on neuropathic pain in patients with traumatic spinal cord injury (SCI) has not been assessed. Merano (Italy) and Salzburg (Austria). In this study, we performed PMC/DLPFC rTMS in subjects with SCI and neuropathic pain. Twelve subjects with chronic cervical or thoracic SCI were randomized to receive 1250 pulses at 10 Hz rTMS (n=6) or sham rTMS (n=6) treatment for 10 sessions over 2 weeks. The visual analog scale, the sensory and affective pain rating indices of the McGill Pain Questionnaire (MPQ), the Hamilton Depression Rating Scale and the Hamilton Anxiety Rating Scale were used to assed pain and mood at baseline (T0), 1 day after the first week of treatment (T1), 1 day (T2), 1 week (T3) and 1 month (T4) after the last intervention. Subjects who received active rTMS had a statistically significant reduction in pain symptoms in comparison with their baseline pain, whereas sham rTMS participants had a non-significant change in daily pain from their baseline pain. The findings of this preliminary study in a small patient sample suggest that rTMS of the PMC/DLPFC may be effective in relieving neuropathic pain in SCI patients.

Event-related rTMS at encoding affects differently deep and shallow memory traces.

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Innocenti, Iglis; Giovannelli, Fabio; Cincotta, Massimo; Feurra, Matteo; Polizzotto, Nicola R; Bianco, Giovanni; Cappa, Stefano F; Rossi, Simone

2010-10-15

The "level of processing" effect is a classical finding of the experimental psychology of memory. Actually, the depth of information processing at encoding predicts the accuracy of the subsequent episodic memory performance. When the incoming stimuli are analyzed in terms of their meaning (semantic, or deep, encoding), the memory performance is superior with respect to the case in which the same stimuli are analyzed in terms of their perceptual features (shallow encoding). As suggested by previous neuroimaging studies and by some preliminary findings with transcranial magnetic stimulation (TMS), the left prefrontal cortex may play a role in semantic processing requiring the allocation of working memory resources. However, it still remains unclear whether deep and shallow encoding share or not the same cortical networks, as well as how these networks contribute to the "level of processing" effect. To investigate the brain areas casually involved in this phenomenon, we applied event-related repetitive TMS (rTMS) during deep (semantic) and shallow (perceptual) encoding of words. Retrieval was subsequently tested without rTMS interference. RTMS applied to the left dorsolateral prefrontal cortex (DLPFC) abolished the beneficial effect of deep encoding on memory performance, both in terms of accuracy (decrease) and reaction times (increase). Neither accuracy nor reaction times were instead affected by rTMS to the right DLPFC or to an additional control site excluded by the memory process (vertex). The fact that online measures of semantic processing at encoding were unaffected suggests that the detrimental effect on memory performance for semantically encoded items took place in the subsequent consolidation phase. These results highlight the specific causal role of the left DLPFC among the wide left-lateralized cortical network engaged by long-term memory, suggesting that it probably represents a crucial node responsible for the improved memory performance induced by

Optimal timing of pulse onset for language mapping with navigated repetitive transcranial magnetic stimulation.

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Krieg, Sandro M; Tarapore, Phiroz E; Picht, Thomas; Tanigawa, Noriko; Houde, John; Sollmann, Nico; Meyer, Bernhard; Vajkoczy, Peter; Berger, Mitchel S; Ringel, Florian; Nagarajan, Srikantan

2014-10-15

Within the primary motor cortex, navigated transcranial magnetic stimulation (nTMS) has been shown to yield maps strongly correlated with those generated by direct cortical stimulation (DCS). However, the stimulation parameters for repetitive nTMS (rTMS)-based language mapping are still being refined. For this purpose, the present study compares two rTMS protocols, which differ in the timing of pulse train onset relative to picture presentation onset during object naming. Results were the correlated with DCS language mapping during awake surgery. Thirty-two patients with left-sided perisylvian tumors were examined by rTMS prior to awake surgery. Twenty patients underwent rTMS pulse trains starting at 300 ms after picture presentation onset (delayed TMS), whereas another 12 patients received rTMS pulse trains starting at the picture presentation onset (ONSET TMS). These rTMS results were then evaluated for correlation with intraoperative DCS results as gold standard in terms of differential consistencies in receiver operating characteristics (ROC) statistics. Logistic regression analysis by protocols and brain regions were conducted. Within and around Broca's area, there was no difference in sensitivity (onset TMS: 100%, delayed TMS: 100%), negative predictive value (NPV) (onset TMS: 100%, delayed TMS: 100%), and positive predictive value (PPV) (onset TMS: 55%, delayed TMS: 54%) between the two protocols compared to DCS. However, specificity differed significantly (onset TMS: 67%, delayed TMS: 28%). In contrast, for posterior language regions, such as supramarginal gyrus, angular gyrus, and posterior superior temporal gyrus, early pulse train onset stimulation showed greater specificity (onset TMS: 92%, delayed TMS: 20%), NPV (onset TMS: 92%, delayed TMS: 57%) and PPV (onset TMS: 75%, delayed TMS: 30%) with comparable sensitivity (onset TMS: 75%, delayed TMS: 70%). Logistic regression analysis also confirmed the greater fit of the predictions by rTMS that had the

Non-invasive mapping of calculation function by repetitive navigated transcranial magnetic stimulation.

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Maurer, Stefanie; Tanigawa, Noriko; Sollmann, Nico; Hauck, Theresa; Ille, Sebastian; Boeckh-Behrens, Tobias; Meyer, Bernhard; Krieg, Sandro M

2016-11-01

Concerning calculation function, studies have already reported on localizing computational function in patients and volunteers by functional magnetic resonance imaging and transcranial magnetic stimulation. However, the development of accurate repetitive navigated TMS (rTMS) with a considerably higher spatial resolution opens a new field in cognitive neuroscience. This study was therefore designed to evaluate the feasibility of rTMS for locating cortical calculation function in healthy volunteers, and to establish this technique for future scientific applications as well as preoperative mapping in brain tumor patients. Twenty healthy subjects underwent rTMS calculation mapping using 5 Hz/10 pulses. Fifty-two previously determined cortical spots of the whole hemispheres were stimulated on both sides. The subjects were instructed to perform the calculation task composed of 80 simple arithmetic operations while rTMS pulses were applied. The highest error rate (80 %) for all errors of all subjects was observed in the right ventral precentral gyrus. Concerning division task, a 45 % error rate was achieved in the left middle frontal gyrus. The subtraction task showed its highest error rate (40 %) in the right angular gyrus (anG). In the addition task a 35 % error rate was observed in the left anterior superior temporal gyrus. Lastly, the multiplication task induced a maximum error rate of 30 % in the left anG. rTMS seems feasible as a way to locate cortical calculation function. Besides language function, the cortical localizations are well in accordance with the current literature for other modalities or lesion studies.

Tremor

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Tremors are unintentional trembling or shaking movements in one or more parts of your body. Most tremors occur in the hands. You can also have arm, head, face, vocal cord, trunk, and leg tremors. Tremors are most common in middle-aged and ...

Safety of repetitive transcranial magnetic stimulation in patients with epilepsy: A systematic review.

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Pereira, Luisa Santos; Müller, Vanessa Teixeira; da Mota Gomes, Marleide; Rotenberg, Alexander; Fregni, Felipe

2016-04-01

Approximately one-third of patients with epilepsy remain with pharmacologically intractable seizures. An emerging therapeutic modality for seizure suppression is repetitive transcranial magnetic stimulation (rTMS). Despite being considered a safe technique, rTMS carries the risk of inducing seizures, among other milder adverse events, and thus, its safety in the population with epilepsy should be continuously assessed. We performed an updated systematic review on the safety and tolerability of rTMS in patients with epilepsy, similar to a previous report published in 2007 (Bae EH, Schrader LM, Machii K, Alonso-Alonso M, Riviello JJ, Pascual-Leone A, Rotenberg A. Safety and tolerability of repetitive transcranial magnetic stimulation in patients with epilepsy: a review of the literature. Epilepsy Behav. 2007; 10 (4): 521-8), and estimated the risk of seizures and other adverse events during or shortly after rTMS application. We searched the literature for reports of rTMS being applied on patients with epilepsy, with no time or language restrictions, and obtained studies published from January 1990 to August 2015. A total of 46 publications were identified, of which 16 were new studies published after the previous safety review of 2007. We noted the total number of subjects with epilepsy undergoing rTMS, medication usage, incidence of adverse events, and rTMS protocol parameters: frequency, intensity, total number of stimuli, train duration, intertrain intervals, coil type, and stimulation site. Our main data analysis included separate calculations for crude per subject risk of seizure and other adverse events, as well as risk per 1000 stimuli. We also performed an exploratory, secondary analysis on the risk of seizure and other adverse events according to the type of coil used (figure-of-8 or circular), stimulation frequency (≤ 1 Hz or > 1 Hz), pulse intensity in terms of motor threshold (stimulator output for speech arrest, clinically arising from the region of

Cortical modulation of short-latency TMS-evoked potentials

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Domenica eVeniero

2013-01-01

Full Text Available Transcranial magnetic stimulation - electroencephalogram (TMS-EEG co-registration offers the opportunity to test reactivity of brain areas across distinct conditions through TMS-evoked potentials (TEPs. Several TEPs have been described, their functional meaning being largely unknown. In particular, short-latency potentials peaking at 5 (P5 and 8 (N8 ms after the TMS pulse have been recently described, but because of their huge amplitude, the problem of whether their origin is cortical or not has been opened. To gain information about these components, we employed a protocol that modulates primary motor cortex excitability (MI through an exclusively cortical phenomena: low frequency stimulation of premotor area (PMC. TMS was applied simultaneously with EEG recording from 70 electrodes. Amplitude of TEPs evoked by 200 single-pulses TMS delivered over MI at 110% of resting motor threshold was measured before and after applying 900 TMS conditioning stimuli to left premotor cortex with 1 Hz repetition rate. Single subject analyses showed reduction in TEPs amplitude after PMC conditioning in a sample of participants and increase in TEPs amplitude in two subjects. No effects were found on corticospinal excitability as recorded by motor evoked potentials (MEPs. Furthermore, correlation analysis showed an inverse relation between the effects of the conditioning protocol on P5-N8 complex amplitude and MEPs amplitude. Because the effects of the used protocol have been ascribed to a cortical interaction between premotor area and MI, we suggest that despite the sign of P5-N8 amplitude modulation is not consistent across participant, this modulation could indicate, at least in part, their cortical origin. We conclude that with an accurate experimental procedure early-latency components can be used to evaluate the reactivity of the stimulated cortex.

Ambient Tremor, But No Triggered Tremor at the Northern Costa Rica Subduction Zone

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Swiecki, Z.; Schwartz, S. Y.

2010-12-01

Non-volcanic tremor (NVT) has been found to be triggered during the passage of surface waves from various teleseismic events in locations around the world including Cascadia, Southwest Japan, Taiwan, and California. In this study we examine the northern Costa Rica subduction zone for evidence of triggered tremor. The Nicoya Peninsula segment of the northern Costa Rica margin experiences both slow-slip and tremor and is thus a prime candidate for triggered tremor observations. Eleven teleseismic events with magnitudes (Mw) greater than 8 occurring between 2006 and 2010 were examined using data from both broadband and short period sensors deployed on the Nicoya Peninsula, Costa Rica. Waveforms from several large regional events were also considered. The largest teleseismic and regional events (27 February 2010 Chile, Mw 8.8 and 28 May 2009 Honduras, Mw 7.3) induced peak ground velocities (PGV) at the NIcoya stations of ~2 and 6 mm/s, respectively; larger than PGVs in other locations that have triggered tremor. Many of the earthquakes examined occurred during small episodes of background ambient tremor. In spite of this, no triggered tremor was observed during the passage of seismic waves from any event. This is significant because other studies have demonstrated that NVT is not triggered everywhere by all events above some threshold magnitude, indicating that unique conditions are required for its occurrence. The lack of triggered tremor at the Costa Rica margin can help to better quantify the requisite conditions and triggering mechanisms. An inherent difference between the Costa Rica margin and the other subduction zones where triggered tremor exists is its erosional rather than accretionary nature. Its relatively low sediment supply likely results in a drier, lower pore fluid pressure, stronger and less compliant thrust interface that is less receptive to triggering tremor from external stresses generated by teleseismic or strong local earthquakes. Another

Predictive value of brain perfusion SPECT for rTMS response in pharmacoresistant depression

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Richieri, Raphaelle; Lancon, Christophe; Boyer, Laurent; Farisse, Jean; Colavolpe, Cecile; Mundler, Olivier; Guedj, Eric

2011-01-01

The aim of this study was to determine the predictive value of whole-brain voxel-based regional cerebral blood flow (rCBF) for repetitive transcranial magnetic stimulation (rTMS) response in patients with pharmacoresistant depression. Thirty-three right-handed patients who met DSM-IV criteria for major depressive disorder (unipolar or bipolar depression) were included before rTMS. rTMS response was defined as at least 50% reduction in the baseline Beck Depression Inventory scores. The predictive value of 99m Tc-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) for rTMS response was studied before treatment by comparing rTMS responders to non-responders at voxel level using Statistical Parametric Mapping (SPM) (p 0.10). In comparison to responders, non-responders showed significant hypoperfusions (p < 0.001, uncorrected) in the left medial and bilateral superior frontal cortices (BA10), the left uncus/parahippocampal cortex (BA20/BA35) and the right thalamus. The area under the curve for the combination of SPECT clusters to predict rTMS response was 0.89 (p < 0.001). Sensitivity, specificity, positive predictive value and negative predictive value for the combination of clusters were: 94, 73, 81 and 92%, respectively. This study shows that, in pharmacoresistant depression, pretreatment rCBF of specific brain regions is a strong predictor for response to rTMS in patients with homogeneous demographic/clinical features. (orig.)

[A Case of Psychogenic Tremor during Awake Craniotomy].

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Kujirai, Kazumasa; Kamata, Kotoe; Uno, Toshihiro; Hamada, Keiko; Ozaki, Makoto

2016-01-01

A 31-year-old woman with a left frontal and parietal brain tumor underwent awake craniotomy. Propofol/remifentanil general anesthesia was induced. Following craniotomy, anesthetic administrations ceased. The level of consciousness was sufficient and she was not agitated. However, the patient complained of nausea 70 minutes into the awake phase. Considering the adverse effects of antiemetics and the upcoming surgical strategy, we did not give any medications. Nausea disappeared spontaneously while the operation was suspended. When surgical intervention extended to the left caudate nucleus, involuntary movement, classified as a tremor, with 5-6 Hz frequency, abruptly occurred on her left forearm. The patient showed emotional distress. Tremor appeared on her right forearm and subsequently spread to her lower extremities. Intravenous midazolam and fentanyl could not reduce her psychological stress. Since the tremor disturbed microscopic observation, general anesthesia was induced. Consequently, the tremor disappeared and did not recur. Based on the anatomical ground and the medication status, her involuntary movement was diagnosed as psychogenic tremor. Various factors can induce involuntary movements. In fact, intraoperative management of nausea and vomiting takes priority during awake craniotomy, but we should be reminded that some antiemetics potentially induce involuntary movement that could be caused by surgery around basal ganglia.

The nature of tremor circuits in parkinsonian and essential tremor

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Cagnan, Hayriye; Little, Simon; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Hariz, Marwan; Cheeran, Binith; Fitzgerald, James; Green, Alexander L.; Aziz, Tipu

2014-01-01

Tremor is a cardinal feature of Parkinson’s disease and essential tremor, the two most common movement disorders. Yet, the mechanisms underlying tremor generation remain largely unknown. We hypothesized that driving deep brain stimulation electrodes at a frequency closely matching the patient’s own tremor frequency should interact with neural activity responsible for tremor, and that the effect of stimulation on tremor should reveal the role of different deep brain stimulation targets in tremor generation. Moreover, tremor responses to stimulation might reveal pathophysiological differences between parkinsonian and essential tremor circuits. Accordingly, we stimulated 15 patients with Parkinson’s disease with either thalamic or subthalamic electrodes (13 male and two female patients, age: 50–77 years) and 10 patients with essential tremor with thalamic electrodes (nine male and one female patients, age: 34–74 years). Stimulation at near-to tremor frequency entrained tremor in all three patient groups (ventrolateral thalamic stimulation in Parkinson’s disease, P = 0.0078, subthalamic stimulation in Parkinson’s disease, P = 0.0312; ventrolateral thalamic stimulation in essential tremor, P = 0.0137; two-tailed paired Wilcoxon signed-rank tests). However, only ventrolateral thalamic stimulation in essential tremor modulated postural tremor amplitude according to the timing of stimulation pulses with respect to the tremor cycle (e.g. P = 0.0002 for tremor amplification, two-tailed Wilcoxon rank sum test). Parkinsonian rest and essential postural tremor severity (i.e. tremor amplitude) differed in their relative tolerance to spontaneous changes in tremor frequency when stimulation was not applied. Specifically, the amplitude of parkinsonian rest tremor remained unchanged despite spontaneous changes in tremor frequency, whereas that of essential postural tremor reduced when tremor frequency departed from median values. Based on these results we conclude that

Repetitive Transcranial Magnetic Stimulation in Patients with Hereditary Spastic Paraplegia

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Mehmet Ağırman

2011-06-01

Full Text Available Hereditary spastic paraplegia (HSPP is a heterogeneous genetic disease characterized by progressive spasticity of lower extremities. Spasticity is a major cause of long-term disability in HSPP and significantly affects the functional life of patients. Repetitive transcranial magnetic stimulation (rTMS is widely used in diagnosis and treatment of many neurological and psychiatric diseases. Although the positive impacts of rTMS for spasticity have been reported, no study has been found on HSPP. We present two HSPP patients treated with low frequency rTMS (20 minutes at a frequency of 1 Hz (1200 pulses, for a period of 10 treatment sessions.

Repetitive Transcranial Magnetic Stimulation in Patients with Hereditary Spastic Paraplegia

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Mehmet Ağırman

2011-06-01

Full Text Available Hereditary spastic paraplegia (HSPP is a heterogeneous genetic disease characterized by progressive spasticity of lower extremities. Spasticity is a major cause of long-term disability in HSPP and significantly affects the functional life of patients. Repetitive transcranial magnetic stimulation (rTMS is widely used in diagnosis and treatment of many neurological and psychiatric diseases. Although the positive impacts of rTMS for spasticity have been reported, no study has been found on HSPP. We present two HSPP patients treated with low frequency rTMS (20 minutes at a frequency of 1 Hz (1200 pulses, for a period of 10 treatment sessions

Contribution of the primary motor cortex to motor imagery: a subthreshold TMS study.

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Pelgrims, Barbara; Michaux, Nicolas; Olivier, Etienne; Andres, Michael

2011-09-01

Motor imagery (MI) mostly activates the same brain regions as movement execution (ME) including the primary motor cortex (Brodmann area 4, BA4). However, whether BA4 is functionally relevant for MI remains controversial. The finding that MI tasks are impaired by BA4 virtual lesions induced by transcranial magnetic stimulation (TMS) supports this view, though previous studies do not permit to exclude that BA4 is also involved in other processes such as hand recognition. Additionally, previous works largely underestimated the possible negative consequences of TMS-induced muscle twitches on MI task performance. Here we investigated the role of BA4 in MI by interfering with the function of the left or right BA4 in healthy subjects performing a MI task in which they had to make laterality judgements on rotated hand drawings. We used a subthreshold repetitive TMS protocol and monitored electromyographic activity to exclude undesirable effects of hand muscle twitches. We found that BA4 virtual lesions selectively increased reaction times in laterality judgments on hand drawings, leaving unaffected a task of equal difficulty, involving judgments on letters. Interestingly, the effects of virtual lesions of left and right BA4 on MI task performance were the same irrespective of the laterality (left/right) of hand drawings. A second experiment allowed us to rule out the possibility that BA4 lesions affect visual or semantic processing of hand drawings. Altogether, these results indicate that BA4 contribution to MI tasks is specifically related to the mental simulation process and further emphasize the functional coupling between ME and MI. Copyright © 2010 Wiley-Liss, Inc.

Imaging the neural mechanisms of TMS neglect-like bias in healthy volunteers with the interleaved TMS/fMRI technique: preliminary evidence

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Raffaella eRicci

2012-12-01

Full Text Available Applying a precisely timed pulse of Transcranial Magnetic Stimulation (TMS over the right posterior parietal cortex (PPC can produce temporary visuo-spatial neglect-like effects. Although the TMS is applied over PPC, it is not clear what other brain regions are involved. We applied TMS within a functional Magnetic Resonance Imaging (fMRI scanner to investigate brain activity during TMS induction of neglect-like bias in three healthy volunteers, while they performed a line bisection judgment task (i.e. the landmark task. Single-pulse TMS at 115% of motor threshold was applied 150 ms after the visual stimulus onset. Participants completed two different TMS/fMRI sessions while performing this task: one session while single-pulse TMS was intermittently and time-locked applied to the right PPC and a control session with TMS positioned over the vertex. Perceptual rightward bias was observed when TMS was delivered over the right PPC. During neglect-like behavior, the fMRI maps showed decreased neural activity within parieto-frontal areas which are often lesioned or dysfunctional in patients with left neglect. Vertex TMS induced behavioral effects compatible with leftward response bias and increased BOLD signal in the left caudate (a site which has been linked to response bias. These results are discussed in relation to recent findings on neural networks subserving attention in space.

Effect of low-frequency rTMS on aphasia in stroke patients: a meta-analysis of randomized controlled trials.

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Cai-Li Ren

Full Text Available Small clinical trials have reported that low-frequency repetitive transcranial magnetic stimulation (rTMS might improve language recovery in patients with aphasia after stroke. However, no systematic reviews or meta-analyses studies have investigated the effect of rTMS on aphasia. The objective of this study was to perform a meta-analysis of studies that explored the effects of low-frequency rTMS on aphasia in stroke patients.We searched PubMed, CENTRAL, Embase, CINAHL, ScienceDirect, and Journals@Ovid for randomized controlled trials published between January 1965 and October 2013 using the keywords "aphasia OR language disorders OR anomia OR linguistic disorders AND repetitive transcranial magnetic stimulation OR rTMS". We used fixed- and random-effects models to estimate the standardized mean difference (SMD and a 95% CI for the language outcomes.Seven eligible studies involving 160 stroke patients were identified in this meta-analysis. A significant effect size of 1.26 was found for the language outcome severity of impairment (95% CI = 0.80 to 1.71 without heterogeneity (I2 = 0%, P = 0.44. Further analyses demonstrated prominent effects for the naming subtest (SMD = 0.52, 95% CI = 0.18 to 0.87, repetition (SMD = 0.54, 95% CI = 0.16 to 0.92, writing (SMD = 0.70, 95% CI = 0.19 to 1.22, and comprehension (the Token test: SMD = 0.58, 95% CI = 0.07 to 1.09 without heterogeneity (I2 = 0%. The SMD of AAT and BDAE comprehension subtests was 0.32 (95% CI = -0.08 to 0.72 with moderate heterogeneity (I2 = 32%,P = 0.22. The effect size did not change significantly even when any one trial was eliminated. None of the patients from the 7 included articles reported adverse effects from rTMS.Low-frequency rTMS with a 90% resting motor threshold that targets the triangular part of the right inferior frontal gyrus (IFG has a positive effect on language recovery in patients with aphasia following

A case of cerebral reversible vasoconstriction syndrome triggered by repetition transcranial magnetic stimulation.

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Sato, Mamiko; Yamate, Koji; Hayashi, Hiromi; Miura, Toyoaki; Kobayashi, Yasutaka

2017-08-31

A 75-year-old man was admitted for combined low-frequency repetitive transcranial magnetic stimulation (rTMS) and intensive occupational therapy. Five days after the initiation of rTMS, he developed hypotension and temporary exacerbation of the right hemiplegia with thunderclap headache. MRA showed segmental stenosis of the left middle cerebral artery, which findings were improved at 9 days after the onset of the headache. He was diagnosed as having the reversible cerebral vasoconstriction syndrome (RCVS). The rTMS was recognized as safe rehabilitation treatment. However, it is necessary to recognize that RCVS can become one of the precipitants. This is the first report of RCVS triggered by rTMS.

Accelerometer-based automatic voice onset detection in speech mapping with navigated repetitive transcranial magnetic stimulation.

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Vitikainen, Anne-Mari; Mäkelä, Elina; Lioumis, Pantelis; Jousmäki, Veikko; Mäkelä, Jyrki P

2015-09-30

The use of navigated repetitive transcranial magnetic stimulation (rTMS) in mapping of speech-related brain areas has recently shown to be useful in preoperative workflow of epilepsy and tumor patients. However, substantial inter- and intraobserver variability and non-optimal replicability of the rTMS results have been reported, and a need for additional development of the methodology is recognized. In TMS motor cortex mappings the evoked responses can be quantitatively monitored by electromyographic recordings; however, no such easily available setup exists for speech mappings. We present an accelerometer-based setup for detection of vocalization-related larynx vibrations combined with an automatic routine for voice onset detection for rTMS speech mapping applying naming. The results produced by the automatic routine were compared with the manually reviewed video-recordings. The new method was applied in the routine navigated rTMS speech mapping for 12 consecutive patients during preoperative workup for epilepsy or tumor surgery. The automatic routine correctly detected 96% of the voice onsets, resulting in 96% sensitivity and 71% specificity. Majority (63%) of the misdetections were related to visible throat movements, extra voices before the response, or delayed naming of the previous stimuli. The no-response errors were correctly detected in 88% of events. The proposed setup for automatic detection of voice onsets provides quantitative additional data for analysis of the rTMS-induced speech response modifications. The objectively defined speech response latencies increase the repeatability, reliability and stratification of the rTMS results. Copyright © 2015 Elsevier B.V. All rights reserved.

A Pilot Study of EEG Source Analysis Based Repetitive Transcranial Magnetic Stimulation for the Treatment of Tinnitus.

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Hui Wang

Full Text Available Repetitive Transcranial Magnetic Stimulation (rTMS is a novel therapeutic tool to induce a suppression of tinnitus. However, the optimal target sites are unknown. We aimed to determine whether low-frequency rTMS induced lasting suppression of tinnitus by decreasing neural activity in the cortex, navigated by high-density electroencephalogram (EEG source analysis, and the utility of EEG for targeting treatment.In this controlled three-armed trial, seven normal hearing patients with tonal tinnitus received a 10-day course of 1-Hz rTMS to the cortex, navigated by high-density EEG source analysis, to the left temporoparietal cortex region, and to the left temporoparietal with sham stimulation. The Tinnitus handicap inventory (THI and a visual analog scale (VAS were used to assess tinnitus severity and loudness. Measurements were taken before, and immediately, 2 weeks, and 4 weeks after the end of the interventions.Low-frequency rTMS decreased tinnitus significantly after active, but not sham, treatment. Responders in the EEG source analysis-based rTMS group, 71.4% (5/7 patients, experienced a significant reduction in tinnitus loudness, as evidenced by VAS scores. The target site of neuronal generators most consistently associated with a positive response was the frontal lobe in the right hemisphere, sourced using high-density EEG equipment, in the tinnitus patients. After left temporoparietal rTMS stimulation, 42.8% (3/7 patients experienced a decrease in tinnitus loudness.Active EEG source analysis based rTMS resulted in significant suppression in tinnitus loudness, showing the superiority of neuronavigation-guided coil positioning in dealing with tinnitus. Non-auditory areas should be considered in the pathophysiology of tinnitus. This knowledge in turn can contribute to investigate the pathophysiology of tinnitus.

Using a Double-Coil TMS Protocol to Assess Preparatory Inhibition Bilaterally.

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Vassiliadis, Pierre; Grandjean, Julien; Derosiere, Gerard; de Wilde, Ysaline; Quemener, Louise; Duque, Julie

2018-01-01

Transcranial magnetic stimulation (TMS) applied over the primary motor cortex (M1), elicits motor-evoked potentials (MEPs) in contralateral limb muscles which are valuable indicators of corticospinal excitability (CSE) at the time of stimulation. So far, most studies have used single-coil TMS over one M1, yielding MEPs in muscles of a single limb-usually the hand. However, tracking CSE in the two hands simultaneously would be useful in many contexts. We recently showed that, in the resting state, double-coil stimulation of the two M1 with a 1 ms inter-pulse interval (double-coil 1 ms TMS) elicits MEPs in both hands that are comparable to MEPs obtained using single-coil TMS. To further evaluate this new technique, we considered the MEPs elicited by double-coil 1 ms TMS in an instructed-delay choice reaction time task where a prepared response has to be withheld until an imperative signal is displayed. Single-coil TMS studies have repetitively shown that in this type of task, the motor system is transiently inhibited during the delay period, as evident from the broad suppression of MEP amplitudes. Here, we aimed at investigating whether a comparable inhibitory effect can be observed with MEPs elicited using double-coil 1 ms TMS. To do so, we compared the amplitude as well as the coefficient of variation (CV) of MEPs produced by double-coil 1 ms or single-coil TMS during action preparation. We observed that MEPs were suppressed (smaller amplitude) and often less variable (smaller CV) during the delay period compared to baseline. Importantly, these effects were equivalent whether single-coil or double-coil 1 ms TMS was used. This suggests that double-coil 1 ms TMS is a reliable tool to assess CSE, not only when subjects are at rest, but also when they are involved in a task, opening new research horizons for scientists interested in the corticospinal correlates of human behavior.

Alpha band cortico-muscular coherence occurs in healthy individuals during mechanically-induced tremor.

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Francesco Budini

Full Text Available The present work aimed at investigating the effects of mechanically amplified tremor on cortico-muscular coherence (CMC in the alpha band. The study of CMC in this specific band is of particular interest because this coherence is usually absent in healthy individuals and it is an aberrant feature in patients affected by pathological tremors; understanding its mechanisms is therefore important. Thirteen healthy volunteers (23±4 years performed elbow flexor sustained contractions both against a spring load and in isometric conditions at 20% of maximal voluntary isometric contraction (MVC. Spring stiffness was selected to induce instability in the stretch reflex servo loop. 64 EEG channels, surface EMG from the biceps brachii muscle and force were simultaneously recorded. Contractions against the spring resulted in greater fluctuations of the force signal and EMG amplitude compared to isometric conditions (p<.05. During isometric contractions CMC was systematically found in the beta band and sporadically observed in the alpha band. However, during the contractions against the spring load, CMC in the alpha band was observed in 12 out of 13 volunteers. Partial directed coherence (PDC revealed an increased information flow in the EMG to EEG direction in the alpha band (p<.05. Therefore, coherence in the alpha band between the sensory-motor cortex and the biceps brachii muscle can be systematically induced in healthy individuals by mechanically amplifying tremor. The increased information flow in the EMG to EEG direction may reflect enhanced afferent activity from the muscle spindles. These results may contribute to the understanding of the presence of alpha band CMC in tremor related pathologies by suggesting that the origin of this phenomenon may not only be at cortical level but may also be affected by spinal circuit loops.

Effects of DBS, premotor rTMS, and levodopa on motor function and silent period in advanced Parkinson's disease

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Bäumer, Tobias; Hidding, Ute; Hamel, Wolfgang

2009-01-01

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a widely used and highly effective treatment for patients with advanced Parkinson's disease (PD). Repetitive TMS (rTMS) applied to motor cortical areas has also been shown to improve symptoms in PD and modulate motor cortical...... excitability. Here, we compared clinical and neurophysiological effects of STN stimulation with those of 1 Hz rTMS given to the dorsal premotor cortex (PMd) and those following intake of levodopa in a group of PD patients with advanced disease. Ten PD patients were studied on 2 consecutive days before...... and after surgery. Clinical effects were determined using the UPDRS motor score. Motor thresholds, motor-evoked potential (MEP) amplitudes during slight voluntary contraction, and the cortical silent periods (SP) were measured using TMS. Before surgery effects of levodopa and 1 Hz PMd rTMS and after surgery...

Transcranial magnetic stimulation (TMS) in Attention Deficit Hyperactivity Disorder (ADHD).

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Zaman, Rashid

2015-09-01

Attention Deficit Hyperactivity Disorder (ADHD) is a common neuropsychiatric disorder, which affects children as well as adults and leads to significant impairment in educational, social and occupational functioning and has associated personal and societal costs. Whilst there are effective medications (mostly stimulants) as well as some psychobehavioural treatments that help alleviate symptoms of ADHD, there is still need to improve our understanding of its neurobiology as well as explore other treatment options. Transcranial Magnetic Stimulation (TMS) and repetitive transcranial magnetic stimulation (rTMS) are safe and non-invasive investigative and therapeutic tools respectively. In this short article, I will explore their potential for improving our understanding of the neurobiology of ADHD as well consider its as a possible treatment option.

Defining Dystonic Tremor

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Elble, Rodger J

2013-01-01

A strong association between dystonia and tremor has been known for more than a century. Two forms of tremor in dystonia are currently recognized: 1) dystonic tremor, which is tremor produced by dystonic muscle contraction and 2) tremor associated with dystonia, which is tremor in a body part that is not dystonic, but there is dystonia elsewhere. Both forms of tremor in dystonia frequently resemble essential tremor or another pure tremor syndrome (e.g., isolated head and voice tremors and tas...

Efficacy of intermittent Theta Burst Stimulation (iTBS) and 10-Hz high-frequency repetitive transcranial magnetic stimulation (rTMS) in treatment-resistant unipolar depression: study protocol for a randomised controlled trial.

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Bulteau, Samuel; Sébille, Veronique; Fayet, Guillemette; Thomas-Ollivier, Veronique; Deschamps, Thibault; Bonnin-Rivalland, Annabelle; Laforgue, Edouard; Pichot, Anne; Valrivière, Pierre; Auffray-Calvier, Elisabeth; Fortin, June; Péréon, Yann; Vanelle, Jean-Marie; Sauvaget, Anne

2017-01-13

The treatment of depression remains a challenge since at least 40% of patients do not respond to initial antidepressant therapy and 20% present chronic symptoms (more than 2 years despite standard treatment administered correctly). Repetitive transcranial magnetic stimulation (rTMS) is an effective adjuvant therapy but still not ideal. Intermittent Theta Burst Stimulation (iTBS), which has only been used recently in clinical practice, could have a faster and more intense effect compared to conventional protocols, including 10-Hz high-frequency rTMS (HF-rTMS). However, no controlled study has so far highlighted the superiority of iTBS in resistant unipolar depression. This paper focuses on the design of a randomised, controlled, double-blind, single-centre study with two parallel arms, carried out in France, in an attempt to assess the efficacy of an iTBS protocol versus a standard HF- rTMS protocol. Sixty patients aged between 18 and 75 years of age will be enrolled. They must be diagnosed with major depressive disorder persisting despite treatment with two antidepressants at an effective dose over a period of 6 weeks during the current episode. The study will consist of two phases: a treatment phase comprising 20 sessions of rTMS to the left dorsolateral prefrontal cortex, localised via a neuronavigation system and a 6-month longitudinal follow-up. The primary endpoint will be the number of responders per group, defined by a decrease of at least 50% in the initial score on the Montgomery and Asberg Rating Scale (MADRS) at the end of rTMS sessions. The secondary endpoints will be: response rate 1 month after rTMS sessions; number of remissions defined by a MADRS score of iTBS superiority in the management of unipolar depression and we will discuss its effect over time. In case of a significant increase in the number of therapeutic responses with a prolonged effect, the iTBS protocol could be considered a first-line protocol in resistant unipolar depression

TMS suppression of right pars triangularis, but not pars opercularis, improves naming in aphasia

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Naeser, Margaret A.; Martin, Paula I.; Theoret, Hugo; Kobayashi, Masahito; Fregni, Felipe; Nicholas, Marjorie; Tormos, Jose M.; Steven, Megan S.; Baker, Errol H.; Pascual-Leone, Alvaro

2011-01-01

This study sought to discover if an optimum 1 cm2 area in the non-damaged right hemisphere (RH) was present, which could temporarily improve naming in chronic, nonfluent aphasia patients when suppressed with repetitive transcranial magnetic stimulation (rTMS). Ten minutes of slow, 1 Hz rTMS was applied to suppress different RH ROIs in eight aphasia cases. Picture naming and response time (RT) were examined before, and immediately after rTMS. In aphasia patients, suppression of right pars triangularis (PTr) led to significant increase in pictures named, and significant decrease in RT. Suppression of right pars opercularis (POp), however, led to significant increase in RT, but no change in number of pictures named. Eight normals named all pictures correctly; similar to aphasia patients, RT significantly decreased following rTMS to suppress right PTr, versus right POp. Differential effects following suppression of right PTr versus right POp suggest different functional roles for these regions. PMID:21864891

Essential Tremor Is More Than a Tremor

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... Giving Options Donate Prev Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens ... Click to print (Opens in new window) Essential Tremor is More Than a Tremor Providing a voice ...

Abnormal short-latency synaptic plasticity in the motor cortex of subjects with Becker muscular dystrophy: a rTMS study.

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Golaszewski, Stefan; Schwenker, Kerstin; Bergmann, Jürgen; Brigo, Francesco; Christova, Monica; Trinka, Eugen; Nardone, Raffaele

2016-01-01

We used repetitive transcranial magnetic stimulation (rTMS) to further investigate motor cortex excitability in 13 patients with Becker muscular dystrophy (BMD), six of them with slight mental retardation. RTMS delivered at 5Hz frequency and suprathreshold intensity progressively increases the size of motor evoked potentials (MEPs) in healthy subjects; the rTMS-induced facilitation of MEPs was significantly reduced in the BMD patients mentally retarded or classified as borderline when compared with age-matched control subjects and the BMD patients with normal intelligence. The increase in the duration of the cortical silent period was similar in both patient groups and controls. These findings suggest an altered cortical short-term synaptic plasticity in glutamate-dependent excitatory circuits within the motor cortex in BMD patients with intellectual disabilities. RTMS studies may shed new light on the physiological mechanisms of cortical involvement in dystrophinopathies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Dystonia and Tremor: The Clinical Syndromes with Isolated Tremor

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Albanese, Alberto; Sorbo, Francesca Del

2016-01-01

Background: Dystonia and tremor share many commonalities. Isolated tremor is part of the phenomenological spectrum of isolated dystonia and of essential tremor. The occurrence of subtle features of dystonia may allow one to differentiate dystonic tremor from essential tremor. Diagnostic uncertainty is enhanced when no features of dystonia are found in patients with a tremor syndrome, raising the question whether the observed phenomenology is an incomplete form of dystonia. Methods: Known form...

Benefits of Repetitive Transcranial Magnetic Stimulation (rTMS for Spastic Subjects: Clinical, Functional, and Biomechanical Parameters for Lower Limb and Walking in Five Hemiparetic Patients

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Luc Terreaux

2014-01-01

Full Text Available Introduction. Spasticity is a disabling symptom resulting from reorganization of spinal reflexes no longer inhibited by supraspinal control. Several studies have demonstrated interest in repetitive transcranial magnetic stimulation in spastic patients. We conducted a prospective, randomized, double-blind crossover study on five spastic hemiparetic patients to determine whether this type of stimulation of the premotor cortex can provide a clinical benefit. Material and Methods. Two stimulation frequencies (1 Hz and 10 Hz were tested versus placebo. Patients were assessed clinically, by quantitative analysis of walking and measurement of neuromechanical parameters (H and T reflexes, musculoarticular stiffness of the ankle. Results. No change was observed after placebo and 10 Hz protocols. Clinical parameters were not significantly modified after 1 Hz stimulation, apart from a tendency towards improved recruitment of antagonist muscles on the Fügl-Meyer scale. Only cadence and recurvatum were significantly modified on quantitative analysis of walking. Neuromechanical parameters were modified with significant decreases in Hmax⁡ /Mmax⁡ and T/Mmax⁡ ratios and stiffness indices 9 days or 31 days after initiation of TMS. Conclusion. This preliminary study supports the efficacy of low-frequency TMS to reduce reflex excitability and stiffness of ankle plantar flexors, while clinical signs of spasticity were not significantly modified.

Benefits of repetitive transcranial magnetic stimulation (rTMS) for spastic subjects: clinical, functional, and biomechanical parameters for lower limb and walking in five hemiparetic patients.

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Terreaux, Luc; Gross, Raphael; Leboeuf, Fabien; Desal, Hubert; Hamel, Olivier; Nguyen, Jean Paul; Pérot, Chantal; Buffenoir, Kévin

2014-01-01

Introduction. Spasticity is a disabling symptom resulting from reorganization of spinal reflexes no longer inhibited by supraspinal control. Several studies have demonstrated interest in repetitive transcranial magnetic stimulation in spastic patients. We conducted a prospective, randomized, double-blind crossover study on five spastic hemiparetic patients to determine whether this type of stimulation of the premotor cortex can provide a clinical benefit. Material and Methods. Two stimulation frequencies (1 Hz and 10 Hz) were tested versus placebo. Patients were assessed clinically, by quantitative analysis of walking and measurement of neuromechanical parameters (H and T reflexes, musculoarticular stiffness of the ankle). Results. No change was observed after placebo and 10 Hz protocols. Clinical parameters were not significantly modified after 1 Hz stimulation, apart from a tendency towards improved recruitment of antagonist muscles on the Fügl-Meyer scale. Only cadence and recurvatum were significantly modified on quantitative analysis of walking. Neuromechanical parameters were modified with significant decreases in H max⁡ /M max⁡ and T/M max⁡ ratios and stiffness indices 9 days or 31 days after initiation of TMS. Conclusion. This preliminary study supports the efficacy of low-frequency TMS to reduce reflex excitability and stiffness of ankle plantar flexors, while clinical signs of spasticity were not significantly modified.

Quantitative assessment of rest and action tremor and the effect of cueing in Parkinson’s disease patients treated with deep brain stimulation

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Heida, Tjitske; Wentink, E.C.; Marani, Enrico

2011-01-01

Introduction: In Parkinson’s disease rest and action tremor may occur. High frequency deep brain stimulation in basal ganglia nuclei has proved to be effective in the suppression of tremor. In addition, rhythmic auditory cues have shown to result in improved performance of repetitive movements,

rTMS in fibromyalgia: a randomized trial evaluating QoL and its brain metabolic substrate

NARCIS (Netherlands)

Boyer, L.; Dousset, A.; Roussel, P.; Dossetto, N.; Cammilleri, S.; Piano, V.M.M.; Khalfa, S.; Mundler, O.; Donnet, A.; Guedj, E.

2014-01-01

OBJECTIVE: This double-blind, randomized, placebo-controlled study investigated the impact of repetitive transcranial magnetic stimulation (rTMS) on quality of life (QoL) of patients with fibromyalgia, and its possible brain metabolic substrate. METHODS: Thirty-eight patients were randomly assigned

Left prefrontal repetitive transcranial magnetic stimulation in schizophrenia.

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Holi, Matti M; Eronen, Markku; Toivonen, Kari; Toivonen, Päivi; Marttunen, Mauri; Naukkarinen, Hannu

2004-01-01

In a double-blind, controlled study, we examined the therapeutic effects of high-frequency left prefrontal repetitive transcranial magnetic stimulation (rTMS) on schizophrenia symptoms. A total of 22 chronic hospitalized schizophrenia patients were randomly assigned to 2 weeks (10 sessions) of real or sham rTMS. rTMS was given with the following parameters: 20 trains of 5-second 10-Hz stimulation at 100 percent motor threshold, 30 seconds apart. Effects on positive and negative symptoms, self-reported symptoms, rough neuropsychological functioning, and hormones were assessed. Although there was a significant improvement in both groups in most of the symptom measures, no real differences were found between the groups. A decrease of more than 20 percent in the total PANSS score was found in 7 control subjects but only 1 subject from the real rTMS group. There was no change in hormone levels or neuropsychological functioning, measured by the MMSE, in either group. Left prefrontal rTMS (with the used parameters) seems to produce a significant nonspecific effect of the treatment procedure but no therapeutic effect in the most chronic and severely ill schizophrenia patients.

Essential Tremor Is More Than a Tremor

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Full Text Available ... Giving Options Donate Prev Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens ... Click to print (Opens in new window) Essential Tremor is More Than a Tremor Providing a voice ...

Involvement of adrenergic and serotonergic nervous mechanisms in allethrin-induced tremors in mice.

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Nishimura, M; Obana, N; Yagasaki, O; Yanagiya, I

1984-05-01

Oral or intravenous administration of allethrin, a synthetic derivative of the pirethrin-based insecticides, produces neurotoxic symptoms consisting of mild salivation, hyperexcitability, tremors and convulsions which result in death. Intracerebroventricular injection of allethrin to mouse at about one-nineth the dose of intravenous administration, produced qualitatively identical but less prominent symptoms, indicating that at least some of the symptoms may be originated in the central nervous system. To investigate the mechanism of action of the compound, we studied the ability of agents which alter neurotransmission to prevent or potentiate the effect of convulsive doses of technical grade (15.5% cis, 84.5% trans) allethrin. Intraperitoneal pretreatment with drugs which block noradrenergic receptors or norepinephrine synthesis, such as pentobarbital, chlorpromazine, phentolamine, phenoxybenzamine and reserpine, depressed the tremor induced by allethrin. The inhibitory effect of reserpine was reversed by phenylephrine. Both the serotonergic blocker, methysergide, and the serotonin depletor, rho-chlorphenylalanine, potentiated the effect of allethrin. The potentiating effect of methysergide was antagonized by 5-hydroxytryptamine. However, intracerebroventricular administration of methysergide was ineffective in potentiating the effect of allethrin. alpha 2- and beta-adrenoceptor blockers, muscarinic antagonists, GABA mimenergics and morphine had no effect. These results suggest that allethrin produces its neurotoxic responses in mice by acting on the brain and spinal levels. Furthermore, adrenergic excitatory and serotonergic inhibitory mechanisms may be involved in the neural pathway through which the allethrin-induced tremor is evoked.

Parkinsonian Rest Tremor Is Associated With Modulations of Subthalamic High-Frequency Oscillations.

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Hirschmann, Jan; Butz, Markus; Hartmann, Christian J; Hoogenboom, Nienke; Özkurt, Tolga E; Vesper, Jan; Wojtecki, Lars; Schnitzler, Alfons

2016-10-01

High frequency oscillations (>200 Hz) have been observed in the basal ganglia of PD patients and were shown to be modulated by the administration of levodopa and voluntary movement. The objective of this study was to test whether the power of high-frequency oscillations in the STN is associated with spontaneous manifestation of parkinsonian rest tremor. The electromyogram of both forearms and local field potentials from the STN were recorded in 11 PD patients (10 men, age 58 [9.4] years, disease duration 9.2 [6.3] years). Patients were recorded at rest and while performing repetitive hand movements before and after levodopa intake. High-frequency oscillation power was compared across epochs containing rest tremor, tremor-free rest, or voluntary movement and related to the tremor cycle. We observed prominent slow (200-300 Hz) and fast (300-400 Hz) high-frequency oscillations. The ratio between slow and fast high-frequency oscillation power increased when tremor became manifest. This increase was consistent across nuclei (94%) and occurred in medication ON and OFF. The ratio outperformed other potential markers of tremor, such as power at individual tremor frequency, beta power, or low gamma power. For voluntary movement, we did not observe a significant difference when compared with rest or rest tremor. Finally, rhythmic modulations of high-frequency oscillation power occurred within the tremor cycle. Subthalamic high-frequency oscillation power is closely linked to the occurrence of parkinsonian rest tremor. The balance between slow and fast high-frequency oscillation power combines information on motor and medication state. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

Teleseismically-induced tremor near Parkfield, CA - a cacophony or a symphony?

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Vidale, J. E.; Peng, Z.; Creager, K. C.; Bodin, P.

2007-12-01

The tremor triggered near Parkfield, CA by the 2002 Denali and 2004 Sumatra earthquakes was strong and well recorded by the dense regional CISN and the borehole HRSN networks. Peng et al. (this meeting) survey tremors triggered by a larger set of 12 regional and teleseismic events, providing a broader context. In the case of both the 2002 M7.9 Denali and 2004 M9.1 Sumatra earthquakes, the tremor emanates from at least two source regions deep within the SAF. The first source region is 40 km NW of the SAFOD in the creeping section of the SAF, and the second region is 40 km SE of the SAFOD near Cholame, close to the location where most of the non-triggered tremor has been found previously (Nadeau and Dolenc, Science, 2005). The Denali earthquake triggered tremor is in phase with the surface waves for about 400s. The northern region started tremoring first by about 100s, and both regions quieted before the end of the surface waves. The wavetrain for the 2004 M9.1 Sumatra earthquake was long enough that tremors were also excited by the weak diffracted P waves, and tremor turned up the volume for an hour upon the arrival of the surface waves, underwent a sudden and curious hiatus for 500s before the end of the surface waves, then re-started and continued for at least an hour after the passage of the surface waves. It is easy to suggest that the tremor was accompanied by deep slip on the SAF, but creep and strain data indicate any slip was too small to generate a detectable surface deformation. These observations suggest a component of driven, instantaneous, perhaps Coulomb-friction response with an added dose of self-sustaining, dribbling activity more suggestive of the oozing of fluids.

An evoked auditory response fMRI study of the effects of rTMS on putative AVH pathways in healthy volunteers.

LENUS (Irish Health Repository)

Tracy, D K

2010-01-01

Auditory verbal hallucinations (AVH) are the most prevalent symptom in schizophrenia. They are associated with increased activation within the temporoparietal cortices and are refractory to pharmacological and psychological treatment in approximately 25% of patients. Low frequency repetitive transcranial magnetic stimulation (rTMS) over the temporoparietal cortex has been demonstrated to be effective in reducing AVH in some patients, although results have varied. The cortical mechanism by which rTMS exerts its effects remain unknown, although data from the motor system is suggestive of a local cortical inhibitory effect. We explored neuroimaging differences in healthy volunteers between application of a clinically utilized rTMS protocol and a sham rTMS equivalent when undertaking a prosodic auditory task.

Functional anatomy of top-down visuospatial processing in the human brain : evidence from rTMS

NARCIS (Netherlands)

Aleman, A; Schutter, DJLG; Ramsey, NF; van Honk, J; Kessels, RPC; Hoogduin, JM; Postma, A; Kahn, RS; de Haan, EHF

The hypothesis was tested that visuospatial mental imagery relies on processing in the posterior parietal lobe. Using repetitive transcranial magnetic stimulation (rTMS) in a cross-over, sham-controlled design, we compared involvement of right posterior parietal cortex with primary visual cortex.

Improved discrimination of visual stimuli following repetitive transcranial magnetic stimulation.

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Michael L Waterston

Full Text Available BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS at certain frequencies increases thresholds for motor-evoked potentials and phosphenes following stimulation of cortex. Consequently rTMS is often assumed to introduce a "virtual lesion" in stimulated brain regions, with correspondingly diminished behavioral performance. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the effects of rTMS to visual cortex on subjects' ability to perform visual psychophysical tasks. Contrary to expectations of a visual deficit, we find that rTMS often improves the discrimination of visual features. For coarse orientation tasks, discrimination of a static stimulus improved consistently following theta-burst stimulation of the occipital lobe. Using a reaction-time task, we found that these improvements occurred throughout the visual field and lasted beyond one hour post-rTMS. Low-frequency (1 Hz stimulation yielded similar improvements. In contrast, we did not find consistent effects of rTMS on performance in a fine orientation discrimination task. CONCLUSIONS/SIGNIFICANCE: Overall our results suggest that rTMS generally improves or has no effect on visual acuity, with the nature of the effect depending on the type of stimulation and the task. We interpret our results in the context of an ideal-observer model of visual perception.

Tremor in dystonia.

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Pandey, Sanjay; Sarma, Neelav

2016-08-01

Tremor has been recognized as an important clinical feature in dystonia. Tremor in dystonia may occur in the body part affected by dystonia known as dystonic tremor or unaffected body regions known as tremor associated with dystonia. The most common type of tremor seen in dystonia patients is postural and kinetic which may be mistaken for familial essential tremor. Similarly familial essential tremor patients may have associated dystonia leading to diagnostic uncertainties. The pathogenesis of tremor in dystonia remains speculative, but its neurophysiological features are similar to dystonia which helps in differentiating it from essential tremor patients. Treatment of tremor in dystonia depends upon the site of involvement. Dystonic hand tremor is treated with oral pharmacological therapy and dystonic head, jaw and voice tremor is treated with injection botulinum toxin. Neurosurgical interventions such as deep brain stimulation and lesion surgery should be an option in patients not responding to the pharmacological treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigative and therapeutic uses of Transcranial magnetic stimulation (TMS) in Attention Deficit Hyperactivity Disorder (ADHD).

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Zaman, Rashid

2016-09-01

Attention Deficit Hyperactivity Disorder (ADHD) is a common neuropsychiatric disorder that affects children and young adults. It results in significant impairment of their educational, social and occupational functioning and is associated economic societal burden. Whilst there are effective medications (such as methylphenidate) as well as some psychobehavioural therapies that can help with management of symptoms of ADHD, the former can have significant cardiac side effects, which limit their use. For number of patients these treatment options lack efficacy or are not acceptable. There is need to improve our understanding of neurobiology of ADHD as well as explore other treatment options. Transcranial magnetic stimulation (TMS) and repetitive transcranial magnetic stimulation (rTMS) are safe and non-invasive investigative and therapeutic tools respectively. In this short paper, I will explore the potential role of TMS and rTMS in further improving our understanding of the neurobiology of ADHD as well as possible treatment option.

A randomized controlled comparison of electroconvulsive therapy and repetitive transcranial magnetic stimulation in severe and resistant nonpsychotic major depression.

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Grunhaus, Leon; Schreiber, Shaul; Dolberg, Ornah T; Polak, Dana; Dannon, Pinhas N

2003-02-15

Studies published over the past few years suggest that transcranial magnetic stimulation (TMS) may have significant antidepressant actions. In a previous report, we compared electroconvulsive therapy (ECT) and repetitive TMS (rTMS) and found ECT to be superior for psychotic major depression (MD); however, ECT and rTMS had similar results in nonpsychotic MD. We now report on a controlled randomized comparison of ECT and rTMS in patients with nonpsychotic MD. Forty patients with nonpsychotic MD referred for ECT were included. Electroconvulsive therapy was performed according to established protocols. Repetitive TMS was performed over the left dorsolateral prefrontal cortex at 90% motor threshold. Patients were treated with 20 sessions (five times per week for 4 weeks) of 10-Hz treatments (1200 pulses per treatment-day) at 90% motor threshold. Response to treatment was defined as a decrease of at least 50% in the Hamilton Rating Scale for Depression (HRSD) score, with a final HRSD equal or less than 10 points and a final Global Assessment of Function Scale rating of 60 or more points. The overall response rate was 58% (23 out of 40 patients responded to treatment). In the ECT group, 12 responded and eight did not; in the rTMS group, 11 responded and nine did not (chi2 =.10, ns). Thus, patients responded as well to either ECT or rTMS. This study adds to the growing literature supporting an antidepressant effect for rTMS. This study is particularly relevant because it suggests that rTMS and ECT reach similar results in nonpsychotic major depressive disorder.

Effects of Weekly Low-Frequency rTMS on Autonomic Measures in Children with Autism Spectrum Disorder

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Manuel Fernando Casanova

2014-10-01

Full Text Available The term autism spectrum disorder (ASD describes a range of conditions characterized by impairments in social interactions, communication, and by restricted and repetitive behaviors. ASD may also present with symptoms suggestive of autonomic nervous system (ANS dysfunction. The objective of this study was to determine the effect of 18 sessions of low frequency repetitive transcranial magnetic stimulation (rTMS on autonomic function in children with ASD by recording electrocardiogram (EKG and electrodermal activity pre-, post- and during each rTMS session. The autonomic measures of interest in this study were R-R cardiointervals in EKG (R-R, time and frequency domain measures of heart rate variability (HRV and skin conductance level (SCL. HRV measures such as R-R intervals, standard deviation of cardiac intervals, pNN50 (percentage of cardiointervals>50 ms different from preceding interval, power of high frequency (HF and low frequency (LF components of HRV spectrum, LF/HF ratio, were then derived from the recorded EKG. We expected that the course of 18 weekly inhibitory low-frequency rTMS applied to the dorsolateral prefrontal cortex (DLPFC would enhance autonomic balance by facilitating frontal inhibition of limbic activity thus resulting in decreased overall heart rate, increased HRV (in a form of increased HF power, decreased LF power (resulting in decreased LF/HF ratio, and decreased SCL. Behavioral evaluations post-18 TMS showed decreased irritability, hyperactivity, stereotype behavior and compulsive behavior ratings while autonomic measures indicated a significant increase in cardiac interval variability and a decrease of tonic SCL. The results suggest that 18 sessions of low frequency rTMS in ASD results in increased cardiac vagal control and reduced sympathetic arousal.

Long-latency TMS-evoked potentials during motor execution and inhibition

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Kentaro eYamanaka

2013-11-01

Full Text Available Transcranial magnetic stimulation (TMS has often been used in conjunction with electroencephalography (EEG, which is effective for the direct demonstration of cortical reactivity and corticocortical connectivity during cognitive tasks through the spatio-temporal pattern of long-latency TMS-evoked potentials (TEPs. However, it remains unclear what pattern is associated with the inhibition of a planned motor response. Therefore, we performed TMS-EEG recording during a go/stop task, in which participants were instructed to click a computer mouse with a right index finger when an indicator that was moving with a constant velocity reached a target (go trial or to avoid the click when the indicator randomly stopped just before it reached the target (stop trial. Single-pulse TMS to the left (contralateral or right (ipsilateral motor cortex was applied 500 ms before or just at the target time. TEPs related to motor execution and inhibition were obtained by subtractions between averaged EEG waveforms with and without TMS. As a result, in TEPs induced by both contralateral and ipsilateral TMS, small oscillations were followed by a prominent negative deflection around the TMS site peaking at approximately 100 ms post-TMS (N100, and a less pronounced later positive component (LPC over the broad areas that was centered at the midline-central site in both go and stop trials. However, compared to the pattern in go and stop trials with TMS at 500 ms before the target time, N100 and LPC were differently modulated in the go and stop trials with TMS just at the target time. The amplitudes of both N100 and LPC decreased in go trials, while the amplitude of LPC decreased and the latency of LPC was delayed in both go and stop trials. These results suggested that TMS-induced neuronal reactions in the motor cortex and subsequent their propagation to surrounding cortical areas might change functionally according to task demand when executing and inhibiting a motor

Predictive value of brain perfusion SPECT for rTMS response in pharmacoresistant depression

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Richieri, Raphaelle; Lancon, Christophe [Sainte-Marguerite University Hospital, Department of Psychiatry, Marseille (France); La Timone University, EA 3279 - Self-perceived Health Assessment Research Unit, School of Medicine, Marseille (France); Boyer, Laurent [La Timone University, EA 3279 - Self-perceived Health Assessment Research Unit, School of Medicine, Marseille (France); La Timone University Hospital, Assistance Publique - Hopitaux de Marseille, Department of Public Health, Marseille (France); Farisse, Jean [Sainte-Marguerite University Hospital, Department of Psychiatry, Marseille (France); Colavolpe, Cecile; Mundler, Olivier [La Timone University Hospital, Assistance Publique - Hopitaux de Marseille, Service Central de Biophysique et Medecine Nucleaire, Marseille (France); Universite de la Mediterranee, Centre Europeen de Recherche en Imagerie Medicale (CERIMED), Marseille (France); Guedj, Eric [La Timone University Hospital, Assistance Publique - Hopitaux de Marseille, Service Central de Biophysique et Medecine Nucleaire, Marseille (France); Universite de la Mediterranee, Centre Europeen de Recherche en Imagerie Medicale (CERIMED), Marseille (France); Hopital de la Timone, Service Central de Biophysique et de Medecine Nucleaire, Marseille Cedex 5 (France)

2011-09-15

The aim of this study was to determine the predictive value of whole-brain voxel-based regional cerebral blood flow (rCBF) for repetitive transcranial magnetic stimulation (rTMS) response in patients with pharmacoresistant depression. Thirty-three right-handed patients who met DSM-IV criteria for major depressive disorder (unipolar or bipolar depression) were included before rTMS. rTMS response was defined as at least 50% reduction in the baseline Beck Depression Inventory scores. The predictive value of {sup 99m}Tc-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) for rTMS response was studied before treatment by comparing rTMS responders to non-responders at voxel level using Statistical Parametric Mapping (SPM) (p < 0.001, uncorrected). Of the patients, 18 (54.5%) were responders to rTMS and 15 were non-responders (45.5%). There were no statistically significant differences in demographic and clinical characteristics (p > 0.10). In comparison to responders, non-responders showed significant hypoperfusions (p < 0.001, uncorrected) in the left medial and bilateral superior frontal cortices (BA10), the left uncus/parahippocampal cortex (BA20/BA35) and the right thalamus. The area under the curve for the combination of SPECT clusters to predict rTMS response was 0.89 (p < 0.001). Sensitivity, specificity, positive predictive value and negative predictive value for the combination of clusters were: 94, 73, 81 and 92%, respectively. This study shows that, in pharmacoresistant depression, pretreatment rCBF of specific brain regions is a strong predictor for response to rTMS in patients with homogeneous demographic/clinical features. (orig.)

[Speech-related tremor of lips: a focal task-specific tremor].

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Morita, Shuhei; Takagi, Rieko; Miwa, Hideto; Kondo, Tomoyoshi

2002-04-01

We report a 66-year-old Japanese woman in whom tremor of lips appeared during speech. Her past and family histories were unremarkable. On neurological examination, there was no abnormal finding except the lip tremor. Results of laboratory findings were all within normal levels. Her MRI and EEG were normal. Surface EMG studies revealed that regular grouped discharges at a frequency of about 4-5 Hz appeared in the orbicularis oris muscle only during voluntary speaking. The tremor was not observed under conditions of a purposeless phonation or a vocalization of a simple word, suggesting that the tremor was not a vocal tremor but a task-specific tremor related to speaking. Administration of a beta-blocker and consumption of small amount of alcohol could effectively improve the tremor, possibly suggesting that this type of tremor might be a clinical variant of essential tremor.

Use of Repetitive Transcranial Magnetic Stimulation for Treatment in Psychiatry

NARCIS (Netherlands)

Aleman, Andre

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.

Treating Clinical Depression with Repetitive Deep Transcranial Magnetic Stimulation Using the Brainsway H1-coil.

Science.gov (United States)

Feifel, David; Pappas, Katherine

2016-10-04

Repetitive transcranial magnetic stimulation (rTMS) is an emerging non-pharmacological approach to treating many brain-based disorders. rTMS uses electromagnetic coils to stimulate areas of the brain non-invasively. Deep transcranial magnetic stimulation (dTMS) with the Brainsway H1-coil system specifically is a type of rTMS indicated for treating patients with major depressive disorder (MDD) who are resistant to medication. The unique H1-coil design of this device is able to stimulate neuronal pathways that lie deeper in the targeted brain areas than those reached by conventional rTMS coils. dTMS is considered to be low-risk and well tolerated, making it a viable treatment option for people who have not responded to medication or psychotherapy trials for their depression. Randomized, sham-control studies have demonstrated that dTMS produces significantly greater improvement in depressive symptoms than sham dTMS treatment in patients with major depression that has not responded to antidepressant medication. In this paper, we will review the methodology for treating major depression with dTMS using an H1-coil.

Time of Day Does Not Modulate Improvements in Motor Performance following a Repetitive Ballistic Motor Training Task

Science.gov (United States)

Sale, Martin V.; Ridding, Michael C.; Nordstrom, Michael A.

2013-01-01

Repetitive performance of a task can result in learning. The neural mechanisms underpinning such use-dependent plasticity are influenced by several neuromodulators. Variations in neuromodulator levels may contribute to the variability in performance outcomes following training. Circulating levels of the neuromodulator cortisol change throughout the day. High cortisol levels inhibit neuroplasticity induced with a transcranial magnetic stimulation (TMS) paradigm that has similarities to use-dependent plasticity. The present study investigated whether performance changes following a motor training task are modulated by time of day and/or changes in endogenous cortisol levels. Motor training involving 30 minutes of repeated maximum left thumb abduction was undertaken by twenty-two participants twice, once in the morning (8 AM) and once in the evening (8 PM) on separate occasions. Saliva was assayed for cortisol concentration. Motor performance, quantified by measuring maximum left thumb abduction acceleration, significantly increased by 28% following training. Neuroplastic changes in corticomotor excitability of abductor pollicis brevis, quantified with TMS, increased significantly by 23% following training. Training-related motor performance improvements and neuroplasticity were unaffected by time of day and salivary cortisol concentration. Although similar neural elements and processes contribute to motor learning, training-induced neuroplasticity, and TMS-induced neuroplasticity, our findings suggest that the influence of time of day and cortisol differs for these three interventions. PMID:23577271

Time of Day Does Not Modulate Improvements in Motor Performance following a Repetitive Ballistic Motor Training Task

Directory of Open Access Journals (Sweden)

Martin V. Sale

2013-01-01

Full Text Available Repetitive performance of a task can result in learning. The neural mechanisms underpinning such use-dependent plasticity are influenced by several neuromodulators. Variations in neuromodulator levels may contribute to the variability in performance outcomes following training. Circulating levels of the neuromodulator cortisol change throughout the day. High cortisol levels inhibit neuroplasticity induced with a transcranial magnetic stimulation (TMS paradigm that has similarities to use-dependent plasticity. The present study investigated whether performance changes following a motor training task are modulated by time of day and/or changes in endogenous cortisol levels. Motor training involving 30 minutes of repeated maximum left thumb abduction was undertaken by twenty-two participants twice, once in the morning (8 AM and once in the evening (8 PM on separate occasions. Saliva was assayed for cortisol concentration. Motor performance, quantified by measuring maximum left thumb abduction acceleration, significantly increased by 28% following training. Neuroplastic changes in corticomotor excitability of abductor pollicis brevis, quantified with TMS, increased significantly by 23% following training. Training-related motor performance improvements and neuroplasticity were unaffected by time of day and salivary cortisol concentration. Although similar neural elements and processes contribute to motor learning, training-induced neuroplasticity, and TMS-induced neuroplasticity, our findings suggest that the influence of time of day and cortisol differs for these three interventions.

Re-Emergent Tremor of Parkinson's Disease Masquerading as Essential Tremor

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Sarah Morgan

2016-03-01

Full Text Available Background: The re-emergent tremor of Parkinson’s disease (PD is generally recognized as a postural tremor. Phenomenology Shown: A PD patient with a re-emergent tremor occurring during a task (spiral drawing, which on the surface produced a tremor that resembled that of essential tremor (ET. Educational Value: Researchers and clinicians should be aware of features of this re-emergent tremor to help distinguish it from that of ET.

Effects of coil orientation on the electric field induced by TMS over the hand motor area

International Nuclear Information System (INIS)

Laakso, Ilkka; Hirata, Akimasa; Ugawa, Yoshikazu

2014-01-01

Responses elicited by transcranial magnetic stimulation (TMS) over the hand motor area depend on the position and orientation of the stimulating coil. In this work, we computationally investigate the induced electric field for multiple coil orientations and locations in order to determine which parts of the brain are affected and how the sensitivity of motor cortical activation depends on the direction of the electric field. The finite element method is used for calculating the electric field induced by TMS in two individual anatomical models of the head and brain. The orientation of the coil affects both the strength and depth of penetration of the electric field, and the field strongly depends on the direction of the sulcus, where the target neurons are located. The coil position that gives the strongest electric field in the target cortical region may deviate from the closest scalp location by a distance on the order of 1 cm. Together with previous experimental data, the results support the hypothesis that the cortex is most sensitive to fields oriented perpendicular to the cortical layers, while it is relatively insensitive to fields parallel to them. This has important implications for targeting of TMS. To determine the most effective coil position and orientation, it is essential to consider both biological (the direction of the targeted axons) and physical factors (the strength and direction of the electric field). (paper)

Lasting modulation effects of rTMS on neural activity and connectivity as revealed by resting-state EEG.

Science.gov (United States)

Ding, Lei; Shou, Guofa; Yuan, Han; Urbano, Diamond; Cha, Yoon-Hee

2014-07-01

The long-lasting neuromodulatory effects of repetitive transcranial magnetic stimulation (rTMS) are of great interest for therapeutic applications in various neurological and psychiatric disorders, due to which functional connectivity among brain regions is profoundly disturbed. Classic TMS studies selectively alter neural activity in specific brain regions and observe neural activity changes on nonperturbed areas to infer underlying connectivity and its changes. Less has been indicated in direct measures of functional connectivity and/or neural network and on how connectivity/network alterations occur. Here, we developed a novel analysis framework to directly investigate both neural activity and connectivity changes induced by rTMS from resting-state EEG (rsEEG) acquired in a group of subjects with a chronic disorder of imbalance, known as the mal de debarquement syndrome (MdDS). Resting-state activity in multiple functional brain areas was identified through a data-driven blind source separation analysis on rsEEG data, and the connectivity among them was characterized using a phase synchronization measure. Our study revealed that there were significant long-lasting changes in resting-state neural activity, in theta, low alpha, and high alpha bands and neural networks in theta, low alpha, high alpha and beta bands, over broad cortical areas 4 to 5 h after the last application of rTMS in a consecutive five-day protocol. Our results of rsEEG connectivity further indicated that the changes, mainly in the alpha band, over the parietal and occipital cortices from pre- to post-TMS sessions were significantly correlated, in both magnitude and direction, to symptom changes in this group of subjects with MdDS. This connectivity measure not only suggested that rTMS can generate positive treatment effects in MdDS patients, but also revealed new potential targets for future therapeutic trials to improve treatment effects. It is promising that the new connectivity measure

Local Immediate versus Long-Range Delayed Changes in Functional Connectivity Following rTMS on the Visual Attention Network.

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Battelli, Lorella; Grossman, Emily D; Plow, Ela B

The interhemispheric competition hypothesis attributes the distribution of selective attention to a balance of mutual inhibition between homotopic, interhemispheric connections in parietal cortex (Kinsbourne 1977; Battelli et al., 2009). In support of this hypothesis, repetitive inhibitory TMS over right parietal cortex in healthy individuals rapidly induces interhemispheric imbalance in cortical activity that spreads beyond the site of stimulation (Plow et al., 2014). Behaviorally, the impacts of inhibitory rTMS may be long delayed from the onset of stimulation, as much as 30 minutes (Agosta et al., 2014; Hubl et al., 2008). In this study, we examine the temporal dynamics of inhibitory rTMS on cortical network integrity that supports sustained visual attention. Healthy individuals received 15 min of 1 Hz offline, inhibitory rTMS (or sham) over left parietal cortex, and then immediately engaged in a bilateral visual tracking task while we recorded brain activity with fMRI. We computed functional connectivity (FC) between three nodes of the attention network engaged by visual tracking: the intraparietal sulcus (IPS), frontal eye fields (FEF) and human MT+ (hMT+). FC immediately and significantly decreased between the stimulation site (left IPS) and all other regions, then recovered to normal levels within 30 minutes. rTMS increased FC between left and right FEF at approximately 36 min following stimulation, and between sites in the unstimulated hemisphere approximately 48 min after stimulation. These findings demonstrate large-scale changes in cortical organization following inhibitory rTMS. The immediate impact of rTMS on connectivity to the stimulation site dovetails with the putative role of interhemispheric balance for bilateral visual sustained attention. The delayed, compensatory increases in functional connectivity have implications for models of dynamic reorganization in networks supporting spatial and nonspatial selective attention, and

Thalamic Deep Brain Stimulation for Essential Tremor Also Reduces Voice Tremor.

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Kundu, Bornali; Schrock, Lauren; Davis, Tyler; House, Paul A

2017-12-12

Voice tremor is a common feature of essential tremor (ET) that is difficult to treat medically and significantly affects quality of life. Deep brain stimulation (DBS) of the ventral intermediate nucleus (Vim) of the thalamus is effective in improving contralateral distal limb tremor and has been shown in limited studies to affect voice tremor. Our objective was to retrospectively evaluate whether Vim-DBS used to treat patients with essential motor tremor also effectively treated underlying concurrent voice tremor and assess whether particular lead locations were favorable for treating vocal tremor. In this retrospective cohort study, patients had unilateral or bilateral lead placement and were monitored for up to 12 months. We used the Fahn-Tolosa-Marin (FTM) subscore to assess vocal tremor. Changes in vocal tremor before and after stimulation and over several sessions were assessed. Of the 77 patients who met the inclusion criteria and were treated for essential tremor, 20 (26%) patients had vocal tremor prior to stimulation. Active Vim-DBS decreased the amplitude of voice tremor by 80% (p centroid of stimulation showed that Vim thalamic stimulation that is more anterior on average yielded better voice tremor control, significantly so on the left side (p < 0.05). Additionally, there was improvement in head, tongue, and face tremor scores (p < 0.05). Unilateral and bilateral Vim-DBS targeted to treat the motor component of essential tremor also dramatically decreased the amplitude of voice tremor in this group of patients, suggesting a potential benefit of this treatment for affected patients. © 2017 International Neuromodulation Society.

The Effects of rTMS Combined with Motor Training on Functional Connectivity in Alpha Frequency Band.

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Jin, Jing-Na; Wang, Xin; Li, Ying; Jin, Fang; Liu, Zhi-Peng; Yin, Tao

2017-01-01

It has recently been reported that repetitive transcranial magnetic stimulation combined with motor training (rTMS-MT) could improve motor function in post-stroke patients. However, the effects of rTMS-MT on cortical function using functional connectivity and graph theoretical analysis remain unclear. Ten healthy subjects were recruited to receive rTMS immediately before application of MT. Low frequency rTMS was delivered to the dominant hemisphere and non-dominant hand performed MT over 14 days. The reaction time of Nine-Hole Peg Test and electroencephalography (EEG) in resting condition with eyes closed were recorded before and after rTMS-MT. Functional connectivity was assessed by phase synchronization index (PSI), and subsequently thresholded to construct undirected graphs in alpha frequency band (8-13 Hz). We found a significant decrease in reaction time after rTMS-MT. The functional connectivity between the parietal and frontal cortex, and the graph theory statistics of node degree and efficiency in the parietal cortex increased. Besides the functional connectivity between premotor and frontal cortex, the degree and efficiency of premotor cortex showed opposite results. In addition, the number of connections significantly increased within inter-hemispheres and inter-regions. In conclusion, this study could be helpful in our understanding of how rTMS-MT modulates brain activity. The methods and results in this study could be taken as reference in future studies of the effects of rTMS-MT in stroke patients.

rTMS in the treatment of drug addiction: an update about human studies.

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Bellamoli, Elisa; Manganotti, Paolo; Schwartz, Robert P; Rimondo, Claudia; Gomma, Maurizio; Serpelloni, Giovanni

2014-01-01

Drug addiction can be a devastating and chronic relapsing disorder with social, psychological, and physical consequences, and more effective treatment options are needed. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation technique that has been assessed in a growing number of studies for its therapeutic potential in treating addiction. This review paper offers an overview on the current state of clinical research in treating drug addiction with rTMS. Because of the limited research in this area, all studies (including case reports) that evaluated the therapeutic use of rTMS in nicotine, alcohol, or illicit drug addiction were included in this review. Papers published prior to December 2012 were found through an NCBI PubMed search. A total of eleven studies were identified that met review criteria. There is nascent evidence that rTMS could be effective in reducing cocaine craving and nicotine and alcohol craving and consumption and might represent a potential therapeutic tool for treating addiction. Further studies are needed to identify the optimal parameters of stimulation for the most effective treatment of drug addiction, to improve our comprehension of the treatment neurophysiological effects, and to conduct rigorous, controlled efficacy studies with adequate power.

Determination of stimulation focality in heterogeneous head models during transcranial magnetic stimulation (TMS)

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Lee, Erik; Hadimani, Ravi; Jiles, David

2015-03-01

Transcranial Magnetic Stimulation (TMS) is an increasingly popular tool used by both the scientific and medical community to understand and treat the brain. TMS has the potential to help people with a wide range of diseases such as Parkinson's, Alzheimer's, and PTSD, while currently being used to treat people with chronic, drug-resistant depression. Through computer simulations, we are able to see the electric field that TMS induces in anatomical human models, but there is no measure to quantify this electric field in a way that relates to a specific patient undergoing TMS therapy. We propose a way to quantify the focality of the induced electric field in a heterogeneous head model during TMS by relating the surface area of the brain being stimulated to the total volume of the brain being stimulated. This figure would be obtained by conducting finite element analysis (FEA) simulations of TMS therapy on a patient specific head model. Using this figure to assist in TMS therapy will allow clinicians and researchers to more accurately stimulate the desired region of a patient's brain and be more equipped to do comparative studies on the effects of TMS across different patients. This work was funded by the Carver Charitable Trust.

Linking Essential Tremor to the Cerebellum-Animal Model Evidence.

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Handforth, Adrian

2016-06-01

In this review, we hope to stimulate interest in animal models as opportunities to understand tremor mechanisms within the cerebellar system. We begin by considering the harmaline model of essential tremor (ET), which has ET-like anatomy and pharmacology. Harmaline induces the inferior olive (IO) to burst fire rhythmically, recruiting rhythmic activity in Purkinje cells (PCs) and deep cerebellar nuclei (DCN). This model has fostered the IO hypothesis of ET, which postulates that factors that promote excess IO, and hence PC complex spike synchrony, also promote tremor. In contrast, the PC hypothesis postulates that partial PC cell loss underlies tremor of ET. We describe models in which chronic partial PC loss is associated with tremor, such as the Weaver mouse, and others with PC loss that do not show tremor, such as the Purkinje cell degeneration mouse. We postulate that partial PC loss with tremor is associated with terminal axonal sprouting. We then discuss tremor that occurs with large lesions of the cerebellum in primates. This tremor has variable frequency and is an ataxic tremor not related to ET. Another tremor type that is not likely related to ET is tremor in mice with mutations that cause prolonged synaptic GABA action. This tremor is probably due to mistiming within cerebellar circuitry. In the final section, we catalog tremor models involving neurotransmitter and ion channel perturbations. Some appear to be related to the IO hypothesis of ET, while in others tremor may be ataxic or due to mistiming. In summary, we offer a tentative framework for classifying animal action tremor, such that various models may be considered potentially relevant to ET, subscribing to IO or PC hypotheses, or not likely relevant, as with mistiming or ataxic tremor. Considerable further research is needed to elucidate the mechanisms of tremor in animal models.

Differential Diagnosis of Parkinson Disease, Essential Tremor, and Enhanced Physiological Tremor with the Tremor Analysis of EMG

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Jie Zhang

2017-01-01

Full Text Available We investigate the differential diagnostic value of tremor analysis of EMG on Parkinson’s disease (PD, essential tremor (ET, and enhanced physiological tremor (EPT. Clinical data from 25 patients with PD, 20 patients with ET, and 20 patients with EPT were collected. The tremor frequency and muscle contraction pattern of the resting, posture, and 500 g and 1000 g overload were recorded. The frequency of PD tremor was 4–6 Hz, and the frequency of ET was also in this range; the frequency of EPT is 6–12 hz having some overlap with PD. The muscle contraction patterns of the ET and EPT group were mainly synchronous contraction, and the muscle contraction mode of the PD group was mainly alternating contraction. Having tremor latency from rest to postural position and having changes in tremor amplitude after mental concentration in PD might distinguish ET. Tremor analysis of EMG was able to distinguish PD from ET and EPT by varying the tremor frequency and muscle contraction pattern. It can also differentiate between PD and ET by the latency and concentration effect and ET and EPT by weight load effect.

Chronic treatment with repetitive transcranial magnetic stimulation inhibits seizure induction by electroconvulsive shock in rats.

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Fleischmann, A; Hirschmann, S; Dolberg, O T; Dannon, P N; Grunhaus, L

1999-03-15

Studies in laboratory animals suggest that repetitive transcranial magnetic stimulation (rTMS) and electroconvulsive shock (ECS) increase seizure inhibition acutely. This study was designed to explore whether chronic rTMS would also have seizure inhibition properties. To this purpose we administered rTMS (Magstim Rapid) and sham rTMS twice daily (2.5 T, 4-sec train duration, 20 Hz) to two groups of 10 rats for 16 days. The rTMS coil was a 50-mm figure-8 coil held directly over the rat's head. Raters were blind to experimental groups. On days 11, 17, and 21 (5 days after the last rTMS) ECS was administered with a Siemens convulsator using three electrical charge levels. Variables examined were the presence or absence of seizures and seizure length (measured from the initiation of the tonic contraction until the end of the limb movement). At day 11 rTMS had no effect on seizures, and both rTMS and sham rTMS animals convulsed equally. At day 17, however, rTMS-treated animals convulsed significantly less (both at presence/absence of seizures, and at seizure length) than sham rTMS animals. At day 21 the effects of rTMS had disappeared. These findings suggest that rTMS administered chronically leads to changes in seizure threshold similar to those reported for ECS and ECT; however, these effects were short-lived.

Functional tremor.

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Schwingenschuh, P; Deuschl, G

2016-01-01

Functional tremor is the commonest reported functional movement disorder. A confident clinical diagnosis of functional tremor is often possible based on the following "positive" criteria: a sudden tremor onset, unusual disease course, often with fluctuations or remissions, distractibility of the tremor if attention is removed from the affected body part, tremor entrainment, tremor variability, and a coactivation sign. Many patients show excessive exhaustion during examination. Other somatizations may be revealed in the medical history and patients may show additional functional neurologic symptoms and signs. In cases where the clinical diagnosis remains challenging, providing a "laboratory-supported" level of certainty aids an early positive diagnosis. In rare cases, in which the distinction from Parkinson's disease is difficult, dopamine transporter single-photon emission computed tomography (DAT-SPECT) can be indicated. © 2016 Elsevier B.V. All rights reserved.

Deep TMS in a resistant major depressive disorder: a brief report.

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Rosenberg, O; Shoenfeld, N; Zangen, A; Kotler, M; Dannon, P N

2010-05-01

Repetitive transcranial magnetic stimulation (rTMS) has proven effective. Recently, a greater intracranial penetration coil has been developed. We tested the efficacy of the coil in the treatment of resistant major depression. Our sample included seven patients suffering from major depression who were treated using Brainsway's H1-coil connected to a Magstim rapid 2 stimulator. Deep TMS treatment was given to each patient in five sessions per week over a period of 4 weeks. Patients were treated with 120% intensity of the motor threshold and a frequency of 20 HZ with a total of 1,680 pulses per session. Five patients completed 20 sessions: one attained remission (Hamilton Depression Rating Scale (HDRS)=9); three patients reached a reduction of more than 50% in their pre-treatment HDRS; and one patient achieved a partial response (i.e., the HDRS score dropped from 21 to 12). Average HDRS score dropped to 12.6 and average Hamilton Anxiety Rating Scale score dropped to 9.Two patients dropped out: one due to insomnia and the second due to a lack of response. Compared to the pooled response and remission rates when treating major depression with rTMS, deep TMS as used in this study is at least similarly effective. Still, a severe limitation of this study is its small sample size, which makes the comparison of the two methods in terms of their effectiveness or side effects impossible. Greater numbers of subjects should be studied to achieve this aim. An H1 deep TMS coil could be used as an alternative treatment for major depressive disorder.

Electrophysiologic characteristics of tremor in Parkinson?s disease and essential tremor

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Ederson Cichaczewski

2014-04-01

Full Text Available Tremor in essential tremor (ET and Parkinson’s disease (PD usually present specific electrophysiologic profiles, however amplitude and frequency may have wide variations. Objective: To present the electrophysiologic findings in PD and ET. Method: Patients were assessed at rest, with posture and action. Seventeen patients with ET and 62 with PD were included. PD cases were clustered into three groups: predominant rest tremor; tremor with similar intensity at rest, posture and during kinetic task; and predominant kinetic tremor. Results: Patients with PD presented tremors with average frequency of 5.29±1.18 Hz at rest, 5.79±1.39 Hz with posture and 6.48±1.34 Hz with the kinetic task. Tremor in ET presented with an average frequency of 5.97±1.1 Hz at rest, 6.18±1 Hz with posture and 6.53±1.2 Hz with kinetic task. Seven (41.2% also showed rest tremor. Conclusion: The tremor analysis alone using the methodology described here, is not sufficient to differentiate tremor in ET and PD.

Can repetitive transcranial magnetic stimulation increase muscle strength in functional neurological paresis? A proof-of-principle study.

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Broersma, M; Koops, E A; Vroomen, P C; Van der Hoeven, J H; Aleman, A; Leenders, K L; Maurits, N M; van Beilen, M

2015-05-01

Therapeutic options are limited in functional neurological paresis disorder. Earlier intervention studies did not control for a placebo effect, hampering assessment of effectivity. A proof-of-principle investigation was conducted into the therapeutic potential of repetitive transcranial magnetic stimulation (rTMS), using a single-blind two-period placebo-controlled cross-over design. Eleven patients received active 15 Hz rTMS over the contralateral motor cortex (hand area), in two periods of 5 days, for 30 min once a day at 80% of resting motor threshold, with a train length of 2 s and an intertrain interval of 4 s. Eight of these eleven patients were also included in the placebo treatment condition. Primary outcome measure was change in muscle strength as measured by dynamometry after treatment. Secondary outcome measure was the subjective change in muscle strength after treatment. In patients who received both treatments, active rTMS induced a significantly larger median increase in objectively measured muscle strength (24%) compared to placebo rTMS (6%; P difference due to treatment, i.e. patients did not perceive these objectively measured motor improvements (P = 0.40). Our findings suggest that rTMS by itself can potentially improve muscle weakness in functional neurological paresis disorder. Whereas patients' muscle strength increased as measured with dynamometry, patients did not report increased functioning of the affected hand, subjectively. The results may indicate that decreased muscle strength is not the core symptom and that rTMS should be added to behavioral approaches in functional neurological paresis. © 2015 EAN.

Repetitive Transcranial Magnetic Stimulation for Wernicke-Korsakoff Syndrome: A Case Report.

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Chung, So Won; Park, Shin Who; Seo, Young Jae; Kim, Jae-Hyung; Lee, Chan Ho; Lim, Jong Youb

2017-02-01

A 57-year-old man who was diagnosed with Wernicke-Korsakoff syndrome showed severe impairment of cognitive function and a craving for alcohol, even after sufficient supplementation with thiamine. After completing 10 sessions of 10 Hz repetitive transcranial magnetic stimulation (rTMS) at 100% of the resting motor threshold over the left dorsolateral prefrontal cortex, dramatic improvement in cognitive function and a reduction in craving for alcohol were noted. This is the first case report of the efficacy of a high-frequency rTMS in the treatment of Wernicke-Korsakoff syndrome.

Real-time measurement of cerebral blood flow during and after repetitive transcranial magnetic stimulation: A near-infrared spectroscopy study.

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Park, Eunhee; Kang, Min Jae; Lee, Ahee; Chang, Won Hyuk; Shin, Yong-Il; Kim, Yun-Hee

2017-07-13

To confirm the interhemispheric modulation induced by low-frequency repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex, real-time regional cerebral blood flow (rCBF) was assessed using functional near-infrared spectroscopy (fNIRS) in the contralateral primary motor cortex (M1) and premotor cortex (PM). Ten right-handed healthy subjects completed two experimental sessions that were randomly arranged for real or sham rTMS session. In the real rTMS session, fNIRS data were acquired from the right M1 and PM area, while the motor hot spot of the left M1 was stimulated with 1Hz rTMS for 1200 pulses with two boosters. In the sham stimulation session, stimulation was delivered with a disconnected coil. During the real rTMS session, the concentration of oxyhemoglobin ([oxy-Hb]) in the right M1 increased continuously until the end of the stimulation. These changes lasted for 20min, while the right PM did not show a change in [oxy-Hb] concentration. On the other hand, the concentration of deoxy-hemoglobin ([deoxy-Hb]) decreased continuously in the right M1 and PM during the real rTMS stimulation, and this change lasted for 20min after the stimulation. The sham stimulation did not exhibit any significant change in both [oxy-Hb] and [deoxy-Hb] concentration during or after the stimulation. Application of 1Hz rTMS over M1 resulted in changes of rCBF in contralateral M1 and PM, which seemed to constitute a function of interhemispheric modulation of rTMS. The fNIRS data was able to detect this physiological change of neuromodulatory action of rTMS in real-time. Copyright © 2017. Published by Elsevier B.V.

Inhibitory rTMS applied on somatosensory cortex in Wilson's disease patients with hand dystonia.

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Lozeron, Pierre; Poujois, Aurélia; Meppiel, Elodie; Masmoudi, Sana; Magnan, Thierry Peron; Vicaut, Eric; Houdart, Emmanuel; Guichard, Jean-Pierre; Trocello, Jean-Marc; Woimant, France; Kubis, Nathalie

2017-10-01

Hand dystonia is a common complication of Wilson's disease (WD), responsible for handwriting difficulties and disability. Alteration of sensorimotor integration and overactivity of the somatosensory cortex have been demonstrated in dystonia. This study investigated the immediate after effect of an inhibitory repetitive transcranial magnetic stimulation (rTMS) applied over the somatosensory cortex on the writing function in WD patients with hand dystonia. We performed a pilot prospective randomized double-blind sham-controlled crossover rTMS study. A 20-min 1-Hz rTMS session, stereotaxically guided, was applied over the left somatosensory cortex in 13 WD patients with right dystonic writer's cramp. After 3 days, each patient was crossed-over to the alternative treatment. Patients were clinically evaluated before and immediately after each rTMS session with the Unified Wilson's Disease rating scale (UWDRS), the Writers' Cramp Rating Scale (WCRS), a specifically designed scale for handwriting difficulties in Wilson's disease patients (FAR, flow, accuracy, and rhythmicity evaluation), and a visual analog scale (VAS) for handwriting discomfort. No significant change in UWDRS, WCRS, VAS, or FAR scores was observed in patients treated with somatosensory inhibitory rTMS compared to the sham protocol. The FAR negatively correlated with UWDRS (r = -0.6; P = 0.02), but not with the WCRS score, disease duration, MRI diffusion lesions, or with atrophy scores. In our experimental conditions, a single inhibitory rTMS session applied over somatosensory cortex did not improve dystonic writer cramp in WD patients.

Tremor in the Elderly: Essential and Aging-Related Tremor

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Deuschl, Günthe; Petersen, Inge; Lorenz, Delia; Christensen, Kaare

2016-01-01

Isolated tremor in the elderly is commonly diagnosed as essential tremor (ET). The prevalence of tremor increases steeply with increasing age, whereas hereditary tremor is becoming less common. Moreover, late-manifesting tremor seems to be associated with dementia and earlier mortality. We hypothesize that different entities underlie tremor in the elderly. Two thousand four hundred forty-eight subjects from the Longitudinal Study of Aging Danish Twins older than 70 y answered screening questions for ET in 2001. Two thousan fifty-six (84%) participants drew Archimedes spirals to measure their tremor severity, and classical aging phenotypes were assessed. A subgroup of 276 individuals fulfilling either screening criteria for ET or being controls were personally assessed. Medications and mortality data are available. The spiral score increased with age. The spiral score correlated with tremor severity. For the whole cohort, mortality was significantly correlated with the spiral score, and higher spiral scores were associated with lower physical and cognitive functioning. Multivariate analysis identified higher spiral scores as an independent risk factor for mortality. In contrast, the ET patients did not show an increased but rather a lower mortality rate although it was not statistically significant. Consistent with a slower than normal aging, they were also physically and cognitively better functioning than controls. Because incident tremors beyond 70 y of age show worse aging parameters and mortality than controls and ET, we propose to label it ‘aging-related tremor’ (ART). This tremor starts later in life and is accompanied by subtle signs of aging both cognitively and physically. More detailed clinical features and pathogenesis warrant further assessment. PMID:26095699

Research with rTMS in the treatment of aphasia

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Naeser, Margaret A.; Martin, Paula I; Treglia, Ethan; Ho, Michael; Kaplan, Elina; Bashir, Shahid; Hamilton, Roy; Coslett, H. Branch; Pascual-Leone, Alvaro

2013-01-01

This review of our research with rTMS to treat aphasia contains four parts: Part 1 reviews functional brain imaging studies related to recovery of language in aphasia with emphasis on nonfluent aphasia. Part 2 presents the rationale for using rTMS to treat nonfluent aphasia patients (based on results from functional imaging studies). Part 2 also reviews our current rTMS treatment protocol used with nonfluent aphasia patients, and our functional imaging results from overt naming fMRI scans, obtained pre- and post- a series of rTMS treatments. Part 3 presents results from a pilot study where rTMS treatments were followed immediately by constraint-induced language therapy (CILT). Part 4 reviews our diffusion tensor imaging (DTI) study that examined white matter connections between the horizontal, midportion of the arcuate fasciculus (hAF) to different parts within Broca’s area (pars triangularis, PTr; pars opercularis, POp), and the ventral premotor cortex (vPMC) in the RH and in the LH. Part 4 also addresses some of the possible mechanisms involved with improved naming and speech, following rTMS with nonfluent aphasia patients. PMID:20714075

Clinical and electrophysiological impact of repetitive low-frequency transcranial magnetic stimulation on the sensory–motor network in patients with restless legs syndrome

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Cantone, Mariagiovanna; Aricò, Debora; Lanuzza, Bartolo; Cosentino, Filomena Irene Ilaria; Paci, Domenico; Papotto, Maurizio; Pennisi, Manuela; Bella, Rita; Pennisi, Giovanni; Paulus, Walter; Ferri, Raffaele

2018-01-01

Background: Based on the hyperexcitability and disinhibition observed in patients with restless legs syndrome (RLS) following transcranial magnetic stimulation (TMS), we conducted a study with low-frequency repetitive TMS (rTMS) over the primary motor (M1) and somatosensory cortical areas (S1) in patients with RLS. Methods: A total of 13 right-handed patients and 10 age-matched controls were studied using clinical scales and TMS. Measurements included resting motor threshold (rMT), motor-evoked potentials (MEPs), cortical silent period (CSP), and central motor conduction time (CMCT). A single evening session of rTMS (1 Hz, 20 trains, 50 stimuli each) was administered over the left M1, left S1, and sham stimulation over M1 in a random order. Clinical and TMS measures were repeated after each stimulation modality. Results: Baseline CSP was shorter in patients than in controls and remained shorter in patients for both motor and somatosensory stimulation. The patients reported a subjective improvement of both initiating and maintaining sleep the night after the rTMS over S1. Patients exhibited a decrease in rMT after rTMS of S1 only, although the effect was smaller than in controls. MEP latency and CMCT changed only in controls after stimulation. Sham stimulation was without effect on the observed variables. Conclusions: rTMS on S1-M1 connectivity alleviated the sensory–motor complaints of RLS patients. The TMS indexes of excitation and inhibition indicate an intracortical and corticospinal imbalance, mainly involving gamma-aminobutyric acid (GABA)ergic and glutamatergic circuitries, as well as an impairment of the short-term mechanisms of cortical plasticity. The rTMS-induced activation of the dorsal striatum with the consequent increase of dopamine release may have contributed to the clinical and neurophysiological outcome. PMID:29511386

Clinical and electrophysiological impact of repetitive low-frequency transcranial magnetic stimulation on the sensory-motor network in patients with restless legs syndrome.

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Lanza, Giuseppe; Cantone, Mariagiovanna; Aricò, Debora; Lanuzza, Bartolo; Cosentino, Filomena Irene Ilaria; Paci, Domenico; Papotto, Maurizio; Pennisi, Manuela; Bella, Rita; Pennisi, Giovanni; Paulus, Walter; Ferri, Raffaele

2018-01-01

Based on the hyperexcitability and disinhibition observed in patients with restless legs syndrome (RLS) following transcranial magnetic stimulation (TMS), we conducted a study with low-frequency repetitive TMS (rTMS) over the primary motor (M1) and somatosensory cortical areas (S1) in patients with RLS. A total of 13 right-handed patients and 10 age-matched controls were studied using clinical scales and TMS. Measurements included resting motor threshold (rMT), motor-evoked potentials (MEPs), cortical silent period (CSP), and central motor conduction time (CMCT). A single evening session of rTMS (1 Hz, 20 trains, 50 stimuli each) was administered over the left M1, left S1, and sham stimulation over M1 in a random order. Clinical and TMS measures were repeated after each stimulation modality. Baseline CSP was shorter in patients than in controls and remained shorter in patients for both motor and somatosensory stimulation. The patients reported a subjective improvement of both initiating and maintaining sleep the night after the rTMS over S1. Patients exhibited a decrease in rMT after rTMS of S1 only, although the effect was smaller than in controls. MEP latency and CMCT changed only in controls after stimulation. Sham stimulation was without effect on the observed variables. rTMS on S1-M1 connectivity alleviated the sensory-motor complaints of RLS patients. The TMS indexes of excitation and inhibition indicate an intracortical and corticospinal imbalance, mainly involving gamma-aminobutyric acid (GABA)ergic and glutamatergic circuitries, as well as an impairment of the short-term mechanisms of cortical plasticity. The rTMS-induced activation of the dorsal striatum with the consequent increase of dopamine release may have contributed to the clinical and neurophysiological outcome.

Optimal digital filtering for tremor suppression.

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Gonzalez, J G; Heredia, E A; Rahman, T; Barner, K E; Arce, G R

2000-05-01

Remote manually operated tasks such as those found in teleoperation, virtual reality, or joystick-based computer access, require the generation of an intermediate electrical signal which is transmitted to the controlled subsystem (robot arm, virtual environment, or a cursor in a computer screen). When human movements are distorted, for instance, by tremor, performance can be improved by digitally filtering the intermediate signal before it reaches the controlled device. This paper introduces a novel tremor filtering framework in which digital equalizers are optimally designed through pursuit tracking task experiments. Due to inherent properties of the man-machine system, the design of tremor suppression equalizers presents two serious problems: 1) performance criteria leading to optimizations that minimize mean-squared error are not efficient for tremor elimination and 2) movement signals show ill-conditioned autocorrelation matrices, which often result in useless or unstable solutions. To address these problems, a new performance indicator in the context of tremor is introduced, and the optimal equalizer according to this new criterion is developed. Ill-conditioning of the autocorrelation matrix is overcome using a novel method which we call pulled-optimization. Experiments performed with artificially induced vibrations and a subject with Parkinson's disease show significant improvement in performance. Additional results, along with MATLAB source code of the algorithms, and a customizable demo for PC joysticks, are available on the Internet at http:¿tremor-suppression.com.

Metabolic changes of cerebrum by repetitive transcranial magnetic stimulation over lateral cerebellum: a study with FDG PET.

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Cho, Sang Soo; Yoon, Eun Jin; Bang, Sung Ae; Park, Hyun Soo; Kim, Yu Kyeong; Strafella, Antonio P; Kim, Sang Eun

2012-09-01

To better understand the functional role of cerebellum within the large-scale cerebellocerebral neural network, we investigated the changes of neuronal activity elicited by cerebellar repetitive transcranial magnetic stimulation (rTMS) using (18)F-fluorodeoxyglucose (FDG) and positron emission tomography (PET). Twelve right-handed healthy volunteers were studied with brain FDG PET under two conditions: active rTMS of 1 Hz frequency over the left lateral cerebellum and sham stimulation. Compared to the sham condition, active rTMS induced decreased glucose metabolism in the stimulated left lateral cerebellum, the areas known to be involved in voluntary motor movement (supplementary motor area and posterior parietal cortex) in the right cerebral hemisphere, and the areas known to be involved in cognition and emotion (orbitofrontal, medial frontal, and anterior cingulate gyri) in the left cerebral hemisphere. Increased metabolism was found in cognition- and language-related brain regions such as the left inferior frontal gyrus including Broca's area, bilateral superior temporal gyri including Wernicke's area, and bilateral middle temporal gyri. Left cerebellar rTMS also led to increased metabolism in the left cerebellar dentate nucleus and pons. These results demonstrate that rTMS over the left lateral cerebellum modulates not only the target region excitability but also excitability of remote, but interconnected, motor-, language-, cognition-, and emotion-related cerebral regions. They provide further evidence that the cerebellum is involved not only in motor-related functions but also in higher cognitive abilities and emotion through the large-scale cerebellocereberal neural network.

Partial clinical response to 2 weeks of 2 Hz repetitive transcranial magnetic stimulation to the right parietal cortex in depression

NARCIS (Netherlands)

Schutter, D.J.L.G.; Laman, D.M.; Honk, E.J. van; Vergouwen, A.C.M.; Koerselman, F.

2009-01-01

The aim of this treatment study was to evaluate the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) over the right parietal cortex in depression. In a double-blind, sham-controlled design ten consecutive sessions of 2 Hz rTMS (inter-pulse interval 0.5 s) at 90% motor

Triple Halo Coil: Development and Comparison with Other TMS Coils

Science.gov (United States)

Rastogi, Priyam; Hadimani, Ravi; Jiles, David

Transcranial Magnetic Stimulation (TMS) is a non-invasive stimulation technique that can be used for the treatment of various neurological disorders such as Parkinson's Disease, PTSD, TBI and anxiety by regulating synaptic activity. TMS is FDA approved for the treatment of major depressive disorder. There is a critical need to develop deep TMS coils that can stimulate deeper regions of the brain without excessively stimulating the cortex in order to provide an alternative to surgical methods. We have developed a novel multi-coil configuration called ``Triple Halo Coil'' (THC) that can stimulate deep brain regions. Investigation of induced electric and magnetic field in these regions have been achieved by computer modelling. Comparison of the results due to THC configuration have been conducted with other TMS coils such as ``Halo Coil'', circular coil and ``Figure of Eight'' coil. There was an improvement of more than 15 times in the strength of magnetic field, induced by THC configuration at 10 cm below the vertex of the head when compared with the ``Figure of Eight'' coil alone. Carver Charitable Trust.

1-Hz rTMS in the treatment of tinnitus: A sham-controlled, randomized multicenter trial.

Science.gov (United States)

Landgrebe, Michael; Hajak, Göran; Wolf, Stefan; Padberg, Frank; Klupp, Philipp; Fallgatter, Andreas J; Polak, Thomas; Höppner, Jacqueline; Haker, Rene; Cordes, Joachim; Klenzner, Thomas; Schönfeldt-Lecuona, Carlos; Kammer, Thomas; Graf, Erika; Koller, Michael; Kleinjung, Tobias; Lehner, Astrid; Schecklmann, Martin; Pöppl, Timm B; Kreuzer, Peter; Frank, Elmar; Langguth, Berthold

Chronic tinnitus is a frequent, difficult to treat disease with high morbidity. This multicenter randomized, sham-controlled trial investigated the efficacy and safety of 1-Hz repetitive transcranial magnetic stimulation (rTMS) applied to the left temporal cortex in patients with chronic tinnitus. Tinnitus patients were randomized to receive 10 sessions of either real or sham 1-Hz-rTMS (2000 stimuli, 110% motor threshold) to the left temporal cortex. The primary outcome was the change in the sum score of the tinnitus questionnaire (TQ) of Goebel and Hiller from baseline to end of treatment. A total of 163 patients were enrolled in the study (real rTMS: 75; sham rTMS: 78). At day 12, the baseline mean of 43.1 TQ points in 71 patients assigned to real rTMS changed by -0.5 points; it changed by 0.5 points from a baseline of 42.1 in 75 patients randomized to sham rTMS (adjusted mean difference between groups: -1.0; 95.19% confidence interval: -3.2 to 1.2; p = 0.36). All secondary outcome measures including measures of depression and quality of life showed no significant differences either (p > 0.11). The number of participants with side-effects or adverse events did not differ between groups. Real 1-Hz-rTMS over the left temporal cortex was well tolerated but not superior compared with sham rTMS in improving tinnitus severity. These findings are in contrast to results from studies with smaller sample sizes and put the efficacy of this rTMS protocol for treatment of chronic tinnitus into question. Controlled Trials: http://www.isrctn.com/ISRCTN89848288. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of rTMS over the inferior parietal lobule on EEG sensorimotor reactivity differs according to self-reported traits of autism in typically developing individuals.

Science.gov (United States)

Puzzo, Ignazio; Cooper, Nicholas R; Cantarella, Simona; Fitzgerald, Paul B; Russo, Riccardo

2013-12-06

Previous research suggested that EEG markers of mirror neuron system activation may differ, in the normal population as a function of different levels of the autistic spectrum quotient; (AQ). The present study aimed at modulating the EEG sensorimotor reactivity induced by hand movement observation by means of repetitive transcranial magnetic stimulation (rTMS) applied to the inferior parietal lobule. We examined how the resulting rTMS modulation differed in relation to the self-reported autistic traits in the typically developing population. Results showed that during sham stimulation, all participants had significantly greater sensorimotor alpha reactivity (motor cortex-C electrodes) when observing hand movements compared to static hands. This sensorimotor alpha reactivity difference was reduced during active rTMS stimulation. Results also revealed that in the average AQ group at sham there was a significant increase in low beta during hand movement than static hand observation (pre-motor areas-FC electrodes) and that (like alpha over the C electrodes) this difference is abolished when active rTMS is delivered. Participants with high AQ scores showed no significant difference in low beta sensorimotor reactivity between active and sham rTMS during static hand or hand movement observation. These findings suggest that unlike sham, active rTMS over the IPL modulates the oscillatory activity of the low beta frequency of a distal area, namely the anterior sector of the sensorimotor cortex, when participants observe videos of static hand. Importantly, this modulation differs according to the degree of self-reported traits of autism in a typically developing population. © 2013 Elsevier B.V. All rights reserved.

The phenomenology of parkinsonian tremor.

Science.gov (United States)

Deuschl, Günther; Papengut, Frank; Hellriegel, Helge

2012-01-01

The definition of Parkinsonian tremor covers all different forms occurring in Parkinson's disease. The most common form is rest tremor, labelled as typical Parkinsonian tremor. Other variants cover also postural and action tremors. Data support the notion that suppression of rest tremor may be more specific for PD tremors. Several differential diagnoses like rest tremor in ET, dystonic tremor, psychogenic tremor and Holmes' tremor may be misinterpreted as PD-tremor. Tests and clinical clues to separate them are presented. Copyright © 2011 Elsevier Ltd. All rights reserved.

Low-Frequency Repetitive Transcranial Magnetic Stimulation Ameliorates Cognitive Function and Synaptic Plasticity in APP23/PS45 Mouse Model of Alzheimer’s Disease

Directory of Open Access Journals (Sweden)

Zhilin Huang

2017-09-01

Full Text Available Alzheimer’s disease (AD is a chronic neurodegenerative disease leading to dementia, which is characterized by progressive memory loss and other cognitive dysfunctions. Recent studies have attested that noninvasive repetitive transcranial magnetic stimulation (rTMS may help improve cognitive function in patients with AD. However, the majority of these studies have focused on the effects of high-frequency rTMS on cognitive function, and little is known about low-frequency rTMS in AD treatment. Furthermore, the potential mechanisms of rTMS on the improvement of learning and memory also remain poorly understood. In the present study, we reported that severe deficits in spatial learning and memory were observed in APP23/PS45 double transgenic mice, a well known mouse model of AD. Furthermore, these behavioral changes were accompanied by the impairment of long-term potentiation (LTP in the CA1 region of hippocampus, a brain region vital to spatial learning and memory. More importantly, 2-week low-frequency rTMS treatment markedly reversed the impairment of spatial learning and memory as well as hippocampal CA1 LTP. In addition, low-frequency rTMS dramatically reduced amyloid-β precursor protein (APP and its C-terminal fragments (CTFs including C99 and C89, as well as β-site APP-cleaving enzyme 1 (BACE1 in the hippocampus. These results indicate that low-frequency rTMS noninvasively and effectively ameliorates cognitive and synaptic functions in a mouse model of AD, and the potential mechanisms may be attributed to rTMS-induced reduction in Aβ neuropathology.

Low-frequency rTMS in the superior parietal cortex affects the working memory in horizontal axis during the spatial task performance.

Science.gov (United States)

Ribeiro, Jéssica Alves; Marinho, Francisco Victor Costa; Rocha, Kaline; Magalhães, Francisco; Baptista, Abrahão Fontes; Velasques, Bruna; Ribeiro, Pedro; Cagy, Mauricio; Bastos, Victor Hugo; Gupta, Daya; Teixeira, Silmar

2018-03-01

Spatial working memory has been extensively investigated with different tasks, treatments, and analysis tools. Several studies suggest that low frequency of the repetitive transcranial magnetic stimulation (rTMS) applied to the parietal cortex may influence spatial working memory (SWM). However, it is not yet known if after low-frequency rTMS applied to the superior parietal cortex, according to Pz electroencephalography (EEG) electrode, would change the orientation interpretation about the vertical and horizontal axes coordinates in an SWM task. The current study aims at filling this gap and obtains a better understanding of the low-frequency rTMS effect in SWM. In this crossover study, we select 20 healthy subjects in two conditions (control and 1-Hz rTMS). The subjects performed an SWM task with two random coordinates. Our results presented that low-frequency rTMS applied over the superior parietal cortex may influence the SWM to lead to a larger distance of axes interception point (p low-frequency rTMS over the superior parietal cortex (SPC) changes the SWM performance, and it has more predominance in horizontal axis.

10 Hz rTMS over right parietal cortex alters sense of agency during self-controlled movements

DEFF Research Database (Denmark)

Ritterband-Rosenbaum, Anina; Karabanov, Anke N; Christensen, Mark Schram

2014-01-01

A large body of fMRI and lesion-literature has provided evidence that the Inferior Parietal Cortex (IPC) is important for sensorimotor integration and sense of agency (SoA). We used repetitive transcranial magnetic stimulation (rTMS) to explore the role of the IPC during a validated SoA detection...

Autosomal dominant cortical tremor, myoclonus and epilepsy.

Science.gov (United States)

Striano, Pasquale; Zara, Federico

2016-09-01

The term 'cortical tremor' was first introduced by Ikeda and colleagues to indicate a postural and action-induced shivering movement of the hands which mimics essential tremor, but presents with the electrophysiological findings of cortical reflex myoclonus. The association between autosomal dominant cortical tremor, myoclonus and epilepsy (ADCME) was first recognized in Japanese families and is now increasingly reported worldwide, although it is described using different acronyms (BAFME, FAME, FEME, FCTE and others). The disease usually takes a benign course, although drug-resistant focal seizures or slight intellectual disability occur in some cases. Moreover, a worsening of cortical tremor and myoclonus is common in advanced age. Although not yet recognized by the International League Against Epilepsy (ILAE), this is a well-delineated epilepsy syndrome with remarkable features that clearly distinguishes it from other myoclonus epilepsies. Moreover, genetic studies of these families show heterogeneity and different susceptible chromosomal loci have been identified.

Repetitive transcranial magnetic stimulation modulates the impact of a negative mood induction

NARCIS (Netherlands)

Möbius, M.; Lacomblé, L.M.T.; Meyer, T.; Schutter, D.J.L.G.; Gielkens, T.; Becker, E.S.; Tendolkar, I.; Eijndhoven, P.F.P. van

2017-01-01

High frequency repetitive Transcranial Magnetic Stimulation (rTMS) over the left dorsolateral prefrontal cortex (DLPFC) has been found to alleviate depressive symptoms. However, the mechanisms driving these effects are still poorly understood. In the current study, we tested the idea that this

76 FR 44489 - Medical Devices; Neurological Devices; Classification of Repetitive Transcranial Magnetic...

Science.gov (United States)

2011-07-26

... is an external device that delivers transcranial repetitive pulsed magnetic fields of sufficient... premarket notification, prior to marketing the device, which contains information about the rTMS system they... significant effect on the human environment. Thus, neither an environmental assessment nor an environmental...

Understanding hypnosis metacognitively: rTMS applied to left DLPFC increases hypnotic suggestibility.

Science.gov (United States)

Dienes, Zoltan; Hutton, Sam

2013-02-01

According to the cold control theory of hypnosis (Dienes and Perner, 2007), hypnotic response occurs because of inaccurate higher order thoughts of intending. The dorsolateral prefrontal cortex (DLPFC) is a region likely involved in constructing accurate higher order thoughts. Thus, disrupting DLPFC with low frequency repetitive transcranial magnetic stimulation (rTMS) should make it harder to be aware of intending to perform an action. That is, it should be easier to respond to a hypnotic suggestion. Twenty-four medium hypnotisable subjects received low frequency rTMS to the left DLPFC and to a control site, the vertex, in counterbalanced order. The hypnotist was blind to which site had been stimulated. Subjects rated how strongly they expected to respond to each suggestion, and gave ratings on a 0-5 scale of the extent to which they experienced the response, for four suggestions (magnetic hands, arm levitation, rigid arm and taste hallucination). The experimenter also rated behavioural response. Low frequency rTMS to the DLPFC rather than vertex increased the degree of combined behavioural and subjective response. Further, subjects did not differ in their expectancy that they would respond in the two conditions, so the rTMS had an effect on hypnotic response above and beyond expectancies. The results support theories, including cold control theory, postulating a component of hypofrontality in hypnotic response. Copyright © 2012 Elsevier Ltd. All rights reserved.

Chronic treatment with rivastigmine in patients with Alzheimer's disease: a study on primary motor cortex excitability tested by 5 Hz-repetitive transcranial magnetic stimulation.

Science.gov (United States)

Trebbastoni, A; Gilio, F; D'Antonio, F; Cambieri, C; Ceccanti, M; de Lena, C; Inghilleri, M

2012-05-01

To investigate changes in cortical excitability and short-term synaptic plasticity we delivered 5 Hz repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex in 11 patients with mild-to-moderate Alzheimer's disease (AD) before and after chronic therapy with rivastigmine. Resting motor threshold (RMT), motor evoked potential (MEP), cortical silent period (CSP) after single stimulus and MEP facilitation during rTMS trains were tested three times during treatment. All patients underwent neuropsychological tests before and after receiving rivastigmine. rTMS data in patients were compared with those from age-matched healthy controls. At baseline, RMT was significantly lower in patients than in controls whereas CSP duration and single MEP amplitude were similar in both groups. In patients, rTMS failed to induce the normal MEP facilitation during the trains. Chronic rivastigmine intake significantly increased MEP amplitude after a single stimulus, whereas it left the other neurophysiological variables studied unchanged. No significant correlation was found between patients' neuropsychological test scores and TMS measures. Chronic treatment with rivastigmine has no influence on altered cortical excitability and short-term synaptic plasticity as tested by 5 Hz-rTMS. The limited clinical benefits related to cholinesterase inhibitor therapy in patients with AD depend on factors other than improved plasticity within the cortical glutamatergic circuits. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Essential Tremor Is More Than a Tremor

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Full Text Available Home About the IETF Volunteer For Healthcare Providers Giving Options Donate Prev Next IETF > About Essential Tremor > ... Mild Hereditary Tremor No Big Deal Raving Fan Home About the IETF Volunteer For Healthcare Providers Giving ...

Essential Tremor Is More Than a Tremor

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Full Text Available ... More Than a Tremor Providing a voice for people with essential tremor means also reaching out to ... six-minute video tells the stories of six people living with ET. It goes beyond diagnosis and ...

Essential Tremor Is More Than a Tremor

Medline Plus

Full Text Available Home About the IETF Volunteer For Healthcare Providers Giving Options Donate Prev Next IETF > About Essential Tremor > ... for Grants Relevant to Essential Tremor IETF Champion Home About the IETF Volunteer For Healthcare Providers Giving ...

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

International Nuclear Information System (INIS)

Aizawa, Yuuichi; Morishita, Joe; Kano, Michiko; Mori, Takayuki; Izumi, Shin-ichi; Kanazawa, Motoyori; Fukudo, Shin; Tsutsui, Kenichiro; Iijima, Toshio

2011-01-01

A previous brain imaging study demonstrated activation of the right dorsolateral prefrontal cortex (DLPFC) during visceral nociception, and this activation was associated with anxiety. We hypothesized that functional modulation of the right DLPFC by repetitive transcranial magnetic stimulation (rTMS) can reveal the actual role of right DLPFC in brain-gut interactions in humans. Subjects were 11 healthy males aged 23.5±1.4 (mean±spin echo (SE)) years. Viscerosensory evoked potential (VEP) with sham (0 mA) or actual (30 mA) electrical stimulation (ES) of the rectum was taken after sham, low frequency rTMS at 0.1 Hz, and high frequency rTMS at 10 Hz to the right DLPFC. Rectal tone was measured with a rectal barostat. Visceral perception and emotion were analyzed using an ordinate scale, rectal barostat, and VEP. Low frequency rTMS significantly reduced anxiety evoked by ES at 30 mA (p<0.05). High frequency rTMS-30 mA ES significantly produced more phasic volume events than sham rTMS-30 mA ES (p<0.05). We successfully modulated the gastrointestinal function of healthy individuals through rTMS to the right DLPFC. Thus, rTMS to the DLPFC appears to modulate the affective, but not direct, component of visceral perception and motility of the rectum. (author)

Acute Frontal Lobe Dysfunction Following Prefrontal Low-Frequency Repetitive Transcranial Magnetic Stimulation in a Patient with Treatment-Resistant Depression

Directory of Open Access Journals (Sweden)

Guilhem Carle

2017-05-01

Full Text Available The potential of repetitive transcranial magnetic stimulation (rTMS to treat numerous neurological and psychiatric disorders has been thoroughly studied for the last two decades. Here, we report for the first time, the case of a 65-year-old woman suffering from treatment-resistant depression who developed an acute frontal lobe syndrome following eight sessions of low-frequency rTMS (LF-rTMS to the right dorsolateral prefrontal cortex while also treated with sertraline and mianserin. The pathophysiological mechanisms underlying such an unexpected acute frontal lobe dysfunction are discussed in relation to the therapeutic use of LF-rTMS in combination with pharmacotherapy in depressed patients.

rTMS on left prefrontal cortex contributes to memories for positive emotional cues: a comparison between pictures and words.

Science.gov (United States)

Balconi, M; Cobelli, C

2015-02-26

The present research explored the cortical correlates of emotional memories in response to words and pictures. Subjects' performance (Accuracy Index, AI; response times, RTs; RTs/AI) was considered when a repetitive Transcranial Magnetic Stimulation (rTMS) was applied on the left dorsolateral prefrontal cortex (LDLPFC). Specifically, the role of LDLPFC was tested by performing a memory task, in which old (previously encoded targets) and new (previously not encoded distractors) emotional pictures/words had to be recognized. Valence (positive vs. negative) and arousing power (high vs. low) of stimuli were also modulated. Moreover, subjective evaluation of emotional stimuli in terms of valence/arousal was explored. We found significant performance improving (higher AI, reduced RTs, improved general performance) in response to rTMS. This "better recognition effect" was only related to specific emotional features, that is positive high arousal pictures or words. Moreover no significant differences were found between stimulus categories. A direct relationship was also observed between subjective evaluation of emotional cues and memory performance when rTMS was applied to LDLPFC. Supported by valence and approach model of emotions, we supposed that a left lateralized prefrontal system may induce a better recognition of positive high arousal words, and that evaluation of emotional cue is related to prefrontal activation, affecting the recognition memories of emotions. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

10 Hz rTMS over right parietal cortex alters sense of agency during self-generated movements

Directory of Open Access Journals (Sweden)

Anina eRitterband-Rosenbaum

2014-06-01

Full Text Available A large body of fMRI and lesion-literature has provided evidence that the Inferior Parietal Cortex (IPC is important for sensorimotor integration and sense of agency (SoA. We used repetitive transcranial magnetic stimulation (rTMS to explore the role of the IPC during a validated SoA detection task. 12 healthy, right-handed adults were included. The effects of rTMS on subjects’ SoA during self-generated movements were explored. The experiment consisted of 1/3 self-generated movements and 2/3 computer manipulated movements that introduced uncertainty as to whether the subjects were agents of an observed movement. Subjects completed three sessions, in which subjects received online rTMS over the right IPC (active condition, over the vertex (CZ (sham condition or no TMS but a sound-matched control. We found that rTMS over right IPC significantly altered SoA of the non-perturbed movements. Following IPC stimulation subjects were more likely to experience self-generated movements as being externally perturbed compared to the control site (P=0.002 and the stimulation-free control (P=0.042. The data support the importance of IPC activation during sensorimotor comparison in order to correctly determine the agent of movements.

rTMS in fibromyalgia: a randomized trial evaluating QoL and its brain metabolic substrate.

Science.gov (United States)

Boyer, Laurent; Dousset, Alix; Roussel, Philippe; Dossetto, Nathalie; Cammilleri, Serge; Piano, Virginie; Khalfa, Stéphanie; Mundler, Olivier; Donnet, Anne; Guedj, Eric

2014-04-08

This double-blind, randomized, placebo-controlled study investigated the impact of repetitive transcranial magnetic stimulation (rTMS) on quality of life (QoL) of patients with fibromyalgia, and its possible brain metabolic substrate. Thirty-eight patients were randomly assigned to receive high-frequency rTMS (n = 19) or sham stimulation (n = 19), applied to left primary motor cortex in 14 sessions over 10 weeks. Primary clinical outcomes were QoL changes at the end of week 11, measured using the Fibromyalgia Impact Questionnaire (FIQ). Secondary clinical outcomes were mental and physical QoL component measured using the 36-Item Short Form Health Survey (SF-36), but also pain, mood, and anxiety. Resting-state [(18)F]-fluorodeoxyglucose-PET metabolism was assessed at baseline, week 2, and week 11. Whole-brain voxel-based analysis was performed to study between-group metabolic changes over time. At week 11, patients of the active rTMS group had greater QoL improvement in the FIQ (p = 0.032) and in the mental component of the SF-36 (p = 0.019) than the sham stimulation group. No significant impact was found for other clinical outcomes. Compared with the sham stimulation group, patients of the active rTMS group presented an increase in right medial temporal metabolism between baseline and week 11 (p FIQ and mental component SF-36 concomitant changes (r = -0.38, p = 0.043; r = 0.51, p = 0.009, respectively). QoL improvement involved mainly affective, emotional, and social dimensions. Our study shows that rTMS improves QoL of patients with fibromyalgia. This improvement is associated with a concomitant increase in right limbic metabolism, arguing for a neural substrate to the impact of rTMS on emotional dimensions involved in QoL. This study provides Class II evidence that rTMS compared with sham rTMS improves QoL in patients with fibromyalgia.

Effect of repetitive transcranial magnetic stimulation in drug resistant depressed patients

International Nuclear Information System (INIS)

Chung, Yong An; Yoo, Ie Ryung; Kang, Bong Joo; Chae, Jeong Ho; Lee, Hye Won; Moon, Hyun Jin; Kim, Sung Hoon; Sohn, Hyung Sun; Chung, Soo Kyo

2007-01-01

Repetitive transcranial magnetic stimulation (rTMS) has recently been clinically applied in the treatment of drug resistant depressed patients. There are mixed findings about the efficacy of rTMS on depression. Furthermore, the influence of rTMS on the physiology of the brain is not clear. We prospectively evaluated changes of regional cerebral blood flow (rCBF) between pre- and post-rTMS treatment in patients with drug resistant depression. Twelve patients with drug-resistant depression (7 male, 5 female; age range; 19∼ 52 years; mean age: 29.3 ± 9.3 years) were given rTMS on right prefrontal lobe with low frequency (1 Hz) and on left prefrontal lobe with high frequency (20 Hz), with 20-minute-duration each day for 3 weeks. Tc-99m ECD brain perfusion SPECT was obtained before and after rTMS treatment. The changes of cerebral perfusion were analyzed using statistical parametric mapping (SPM; t=3.14, uncorrected ρ < 0.01, voxel = 100). Following areas showed significant increase in rCBF after 3 weeks rTMS treatment: the cingulate gyrus, fusiform gyrus of right temporal lobe, precuneus, and left lateral globus pallidus. Significant decrement was noted in the precental and middle frontal gyrus of right frontal lobe, and fusiform gyrus of left occipital lobe. Low-frequency rTMS on the right prefrontal cortex and high-frequency rTMS on the left prefrontal cortex for 3 weeks as an add-on regimen have increased and decreased rCBF in the specific brain regions in drug-resistant depressed patients. Further analyses correlating clinical characteristics and treatment paradigm with functional imaging data may be helpful in clarifying the pathophysiology of drug-resistant patients

Effect of repetitive transcranial magnetic stimulation in drug resistant depressed patients

Energy Technology Data Exchange (ETDEWEB)

Chung, Yong An; Yoo, Ie Ryung; Kang, Bong Joo; Chae, Jeong Ho; Lee, Hye Won; Moon, Hyun Jin; Kim, Sung Hoon; Sohn, Hyung Sun; Chung, Soo Kyo [The Catholic University of Korea, Seoul (Korea, Republic of)

2007-02-15

Repetitive transcranial magnetic stimulation (rTMS) has recently been clinically applied in the treatment of drug resistant depressed patients. There are mixed findings about the efficacy of rTMS on depression. Furthermore, the influence of rTMS on the physiology of the brain is not clear. We prospectively evaluated changes of regional cerebral blood flow (rCBF) between pre- and post-rTMS treatment in patients with drug resistant depression. Twelve patients with drug-resistant depression (7 male, 5 female; age range; 19{approx} 52 years; mean age: 29.3 {+-} 9.3 years) were given rTMS on right prefrontal lobe with low frequency (1 Hz) and on left prefrontal lobe with high frequency (20 Hz), with 20-minute-duration each day for 3 weeks. Tc-99m ECD brain perfusion SPECT was obtained before and after rTMS treatment. The changes of cerebral perfusion were analyzed using statistical parametric mapping (SPM; t=3.14, uncorrected {rho} < 0.01, voxel = 100). Following areas showed significant increase in rCBF after 3 weeks rTMS treatment: the cingulate gyrus, fusiform gyrus of right temporal lobe, precuneus, and left lateral globus pallidus. Significant decrement was noted in the precental and middle frontal gyrus of right frontal lobe, and fusiform gyrus of left occipital lobe. Low-frequency rTMS on the right prefrontal cortex and high-frequency rTMS on the left prefrontal cortex for 3 weeks as an add-on regimen have increased and decreased rCBF in the specific brain regions in drug-resistant depressed patients. Further analyses correlating clinical characteristics and treatment paradigm with functional imaging data may be helpful in clarifying the pathophysiology of drug-resistant patients.

Coherence analysis differentiates between cortical myoclonic tremor and essential tremor

NARCIS (Netherlands)

van Rootselaar, AF; Maurits, NM; Koelman, JHTM; van der Hoeven, JH; Bour, LJ; Leenders, KL; Brown, P; Tijssen, MAJ

Familial cortical myoclonic tremor with epilepsy (FCMTE) is characterized by a distal kinetic tremor, infrequent epileptic attacks, and autosomal dominant inheritance. The tremor is thought to originate from the motor cortex. In our patient group, a premovement cortical spike Could not be

Repetitive transcranial magnetic stimulation to improve mood and motor function in Parkinson's disease.

NARCIS (Netherlands)

Helmich, R.C.G.; Siebner, H.R.; Bakker, M.; Munchau, A.; Bloem, B.R.

2006-01-01

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that can produce lasting changes in excitability and activity in cortical regions underneath the stimulation coil (local effect), but also within functionally connected cortical or subcortical regions

Fentanyl bolus induces muscle tremors in sevoflurane-anaesthetized piglets.

Science.gov (United States)

Ringer, S K; Spielmann, N; Weiss, M; Mauch, J Y

2016-08-01

Intravenous fentanyl (10 mcg/kg) or saline (control) was randomly administered to 10 healthy sevoflurane-mono-anaesthetized piglets. Trembling was assessed by two blinded observers using a visual analogue scale (VAS) and a simple ordinal scale at baseline and 5 min (T5) after drug administration. If no trembling was observed at that time point, the opposite treatment was administered and piglets were re-evaluated after another 5 min (T10). Four out of five piglets showed trembling after fentanyl (T5), while none given saline showed any trembling. With fentanyl the VAS scores were significantly higher at T5 compared either with baseline or with the control treatment. Control animals received fentanyl after the 5 min evaluation and all piglets showed clear trembling afterwards. The median time after fentanyl administration until first muscle tremors was 51 (20-840) s. In summary, nine out of 10 sevoflurane-anaesthetized piglets showed muscle tremors after intravenous fentanyl. Tremors subsided over time and no specific treatment was necessary. © The Author(s) 2015.

Long-lasting repetitive transcranial magnetic stimulation modulates electroencephalography oscillation in patients with disorders of consciousness.

Science.gov (United States)

Xia, Xiaoyu; Liu, Yang; Bai, Yang; Liu, Ziyuan; Yang, Yi; Guo, Yongkun; Xu, Ruxiang; Gao, Xiaorong; Li, Xiaoli; He, Jianghong

2017-10-18

Repetitive transcranial magnetic stimulation (rTMS) has been applied for the treatment of patients with disorders of consciousness (DOC). Timely and accurate assessments of its modulation effects are very useful. This study evaluated rTMS modulation effects on electroencephalography (EEG) oscillation in patients with chronic DOC. Eighteen patients with a diagnosis of DOC lasting more than 3 months were recruited. All patients received one session of 10-Hz rTMS at the left dorsolateral prefrontal cortex and then 12 of them received consecutive rTMS treatment everyday for 20 consecutive days. Resting-state EEGs were recorded before the experiment (T0) after one session of rTMS (T1) and after the entire treatment (T2). The JFK Coma Recovery Scale-Revised scale scores were also recorded at the time points. Our data showed that application of 10-Hz rTMS to the left dorsolateral prefrontal cortex decreased low-frequency band power and increased high-frequency band power in DOC patients, especially in minimal conscious state patients. Considering the correlation of the EEG spectrum with the consciousness level of patients with DOC, quantitative EEG might be useful for assessment of the effect of rTMS in DOC patients.

Thalamic physiology of intentional essential tremor is more like cerebellar tremor than postural essential tremor

OpenAIRE

Zakaria, R; Lenz, FA; Hua, S; Avin, BH; Liu, CC; Mari, Z

2013-01-01

The neuronal physiological correlates of clinical heterogeneity in human essential tremor are unknown. We now test the hypothesis that thalamic neuronal and EMG activities during intention essential tremor are similar to those of the intention tremor which is characteristic of cerebellar lesions. Thalamic neuronal firing was studied in a cerebellar relay nucleus (ventral intermediate, Vim) and in a pallidal relay nucleus (ventral oral posterior, Vop) during stereotactic surgery for the treatm...

Approach to a tremor patient

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Sharma, Soumya; Pandey, Sanjay

2016-01-01

Tremors are commonly encountered in clinical practice and are the most common movement disorders seen. It is defined as a rhythmic, involuntary oscillatory movement of a body part around one or more joints. In the majority of the population, tremor tends to be mild. They have varying etiology; hence, classifying them appropriately helps in identifying the underlying cause. Clinically, tremor is classified as occurring at rest or action. They can also be classified based on their frequency, amplitude, and body part involved. Parkinsonian tremor is the most common cause of rest tremor. Essential tremor (ET) and enhanced physiological tremor are the most common causes of action tremor. Isolated head tremor is more likely to be dystonic rather than ET. Isolated voice tremor could be considered to be a spectrum of ET. Psychogenic tremor is not a diagnosis of exclusion; rather, demonstration of various clinical signs is needed to establish the diagnosis. Severity of tremor and response to treatment can be assessed using clinical rating scales as well as using electrophysiological measurements. The treatment of tremor is symptomatic. Medications are effective in half the cases of essential hand tremor and in refractory patients; deep brain stimulation is an alternative therapy. Midline tremors benefit from botulinum toxin injections. It is also the treatment of choice in dystonic tremor and primary writing tremor. PMID:27994349

Short-latency afferent inhibition is a poor predictor of individual susceptibility to rTMS-induced plasticity in the motor cortex of young and older adults.

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Marielle eYoung-Bernier

2014-08-01

Full Text Available Cortical plasticity, including long-term potentiation (LTP-like plasticity, can be assessed non-invasively with repetitive transcranial magnetic stimulation (rTMS protocols. In this study, we examined age differences in responses to intermittent theta burst stimulation (iTBS in a group of 20 young and 18 healthy older adults. Because the cholinergic system plays a role in the neural processes underlying learning and memory, including LTP, we also investigated whether short latency afferent inhibition (SAI, a neurophysiological marker of central cholinergic activity, would be associated with age-related differences in LTP-like plasticity induced by iTBS. Methods: SAI was first assessed by examining the modulation of motor evoked potentials (MEPs in response to median nerve conditioning 20 ms prior to TMS. Participants then underwent iTBS (3 pulses at 50 HZ every 200 ms for 2 s with 8 s between trains, repeated 20 times. MEP responses (120% RMT were assessed immediately after iTBS and 5, 10, and 20 min post-application. Results: Responses to iTBS were quite variable in both age groups, with only approximately 60% of the participants (n=13 young and 10 older adults showing the expected facilitation of MEP responses. There were no significant age group differences in MEP facilitation following iTBS. Although older adults exhibited reduced SAI, individual variations were not associated with susceptibility to express LTP-like induced plasticity after iTBS. Conclusion: Overall, these results are consistent with reports of high inter-individual variability in responses to iTBS. Although SAI was reduced in older adults, consistent with a deterioration of the cholinergic system with age, SAI levels were not associated with LTP-like plasticity as assessed with iTBS.

Short-latency afferent inhibition is a poor predictor of individual susceptibility to rTMS-induced plasticity in the motor cortex of young and older adults.

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Young-Bernier, Marielle; Tanguay, Annick N; Davidson, Patrick S R; Tremblay, François

2014-01-01

Cortical plasticity, including long-term potentiation (LTP)-like plasticity, can be assessed non-invasively with repetitive transcranial magnetic stimulation (rTMS) protocols. In this study, we examined age differences in responses to intermittent theta burst stimulation (iTBS) in a group of 20 young and 18 healthy older adults. Because the cholinergic system plays a role in the neural processes underlying learning and memory, including LTP, we also investigated whether short latency afferent inhibition (SAI), a neurophysiological marker of central cholinergic activity, would be associated with age-related differences in LTP-like plasticity induced by iTBS. SAI was first assessed by examining the modulation of motor evoked potentials (MEPs) in response to median nerve conditioning 20 ms prior to TMS. Participants then underwent iTBS (3 pulses at 50 Hz every 200 ms for 2 s with 8 s between trains, repeated 20 times). MEP responses (120% resting motor threshold (RMT)) were assessed immediately after iTBS and 5, 10, and 20 min post-application. Responses to iTBS were quite variable in both age groups, with only approximately 60% of the participants (n = 13 young and 10 older adults) showing the expected facilitation of MEP responses. There were no significant age group differences in MEP facilitation following iTBS. Although older adults exhibited reduced SAI, individual variations were not associated with susceptibility to express LTP-like induced plasticity after iTBS. Overall, these results are consistent with reports of high inter-individual variability in responses to iTBS. Although SAI was reduced in older adults, consistent with a deterioration of the cholinergic system with age, SAI levels were not associated with LTP-like plasticity as assessed with iTBS.

Enhancing memory performance with rTMS in healthy and neurological subjects: the role of the right dorsolateral prefrontal cortex

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Patrizia eTurriziani

2012-04-01

Full Text Available A debated question in the literature is the degree of anatomical and functional lateralization of the executive control processes subserved by the dorsolateral prefrontal cortex (DLPFC during recognition memory retrieval.We investigated if transient inhibition and excitation of the left and right DLPFC at retrieval by means of repetitive transcranial magnetic stimulation (rTMS modulate recognition memory performance in 100 healthy controls (HCs and in 8 patients with Mild Cognitive Impairment (MCI. Recognition memory tasks of faces, buildings and words were used in different experiments.rTMS-inhibition of the right DLPFC enhanced recognition memory of verbal and non verbal material in both HCs and MCIs. rTMS-excitation of the same region in HCs deteriorated memory performance.Bilateral recruitment of the DLPFC could represent a dysfunctional use of brain resources in recognition memory. Inhibitory rTMS of the right DLPFC may modulate the activity in this dysfunctional network enhancing function in HCs or restoring an adaptive equilibrium in MCI.

TMS Affects Moral Judgment, Showing the Role of DLPFC and TPJ in Cognitive and Emotional Processing

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Danique eJeurissen

2014-02-01

Full Text Available Decision-making involves a complex interplay of emotional responses and reasoning processes. In this study, we use TMS to explore the neurobiological substrates of moral decisions in humans. To examining the effects of TMS on the outcome of a moral-decision, we compare the decision outcome of moral-personal and moral-impersonal dilemmas to each other and examine the differential effects of applying TMS over the right DLPFC or right TPJ. In this comparison, we find that the TMS-induced disruption of the DLPFC during the decision process, affects the outcome of the moral-personal judgment, while TMS-induced disruption of TPJ affects only moral-impersonal conditions. In other words, we find a double-dissociation between DLPFC and TPJ in the outcome of a moral decision. Furthermore, we find that TMS-induced disruption of the DLPFC during non-moral, moral-impersonal, and moral-personal decisions lead to lower ratings of regret about the decision. Our results are in line with the dual-process theory and suggest a role for both the emotional response and cognitive reasoning process in moral judgment. Both the emotional and cognitive processes were shown to be involved in the decision outcome.

TMS affects moral judgment, showing the role of DLPFC and TPJ in cognitive and emotional processing.

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Jeurissen, Danique; Sack, Alexander T; Roebroeck, Alard; Russ, Brian E; Pascual-Leone, Alvaro

2014-01-01

Decision-making involves a complex interplay of emotional responses and reasoning processes. In this study, we use TMS to explore the neurobiological substrates of moral decisions in humans. To examining the effects of TMS on the outcome of a moral-decision, we compare the decision outcome of moral-personal and moral-impersonal dilemmas to each other and examine the differential effects of applying TMS over the right DLPFC or right TPJ. In this comparison, we find that the TMS-induced disruption of the DLPFC during the decision process, affects the outcome of the moral-personal judgment, while TMS-induced disruption of TPJ affects only moral-impersonal conditions. In other words, we find a double-dissociation between DLPFC and TPJ in the outcome of a moral decision. Furthermore, we find that TMS-induced disruption of the DLPFC during non-moral, moral-impersonal, and moral-personal decisions lead to lower ratings of regret about the decision. Our results are in line with the dual-process theory and suggest a role for both the emotional response and cognitive reasoning process in moral judgment. Both the emotional and cognitive processes were shown to be involved in the decision outcome.

Predictive value of dorso-lateral prefrontal connectivity for rTMS response in treatment-resistant depression: A brain perfusion SPECT study.

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Richieri, Raphaëlle; Verger, Antoine; Boyer, Laurent; Boucekine, Mohamed; David, Anthony; Lançon, Christophe; Cermolacce, Michel; Guedj, Eric

2018-05-18

Previous clinical trials have suggested that repetitive transcranial magnetic stimulation (rTMS) has a significant antidepressant effect in patients with treatment resistant depression (TRD). However, results remain heterogeneous with many patients without effective response. The aim of this SPECT study was to determine before treatment the predictive value of the connectivity of the stimulated area on further rTMS response in patients with TRD. Fifty-eight TRD patients performed a brain perfusion SPECT before high frequency rTMS of the left dorsolateral prefrontal cortex (DLPFC). A voxel based-analysis was achieved to compare connectivity of the left DLPFC in responders and non-responders using inter-regional correlations (p left DLPFC and the right cerebellum in comparison to non-responders, independently of age, gender, severity of depression, and severity of treatment resistance. The area under the curve for the combination of these two SPECT clusters to predict rTMS response was 0.756 (p left DLPFC predicts rTMS response before treatment. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

Lessons from (triggered) tremor

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Gomberg, Joan

2010-01-01

I test a “clock-advance” model that implies triggered tremor is ambient tremor that occurs at a sped-up rate as a result of loading from passing seismic waves. This proposed model predicts that triggering probability is proportional to the product of the ambient tremor rate and a function describing the efficacy of the triggering wave to initiate a tremor event. Using data mostly from Cascadia, I have compared qualitatively a suite of teleseismic waves that did and did not trigger tremor with ambient tremor rates. Many of the observations are consistent with the model if the efficacy of the triggering wave depends on wave amplitude. One triggered tremor observation clearly violates the clock-advance model. The model prediction that larger triggering waves result in larger triggered tremor signals also appears inconsistent with the measurements. I conclude that the tremor source process is a more complex system than that described by the clock-advance model predictions tested. Results of this and previous studies also demonstrate that (1) conditions suitable for tremor generation exist in many tectonic environments, but, within each, only occur at particular spots whose locations change with time; (2) any fluid flow must be restricted to less than a meter; (3) the degree to which delayed failure and secondary triggering occurs is likely insignificant; and 4) both shear and dilatational deformations may trigger tremor. Triggered and ambient tremor rates correlate more strongly with stress than stressing rate, suggesting tremor sources result from time-dependent weakening processes rather than simple Coulomb failure.

Right prefrontal TMS disrupts interregional anticipatory EEG alpha activity during shifting of visuospatial attention

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Paul eSauseng

2011-10-01

Full Text Available Visual attention can be shifted in space without moving the eyes. Amplitude decrease of rhythmical brain activity around 10 Hz (so called alpha activity at contralateral posterior sites has been reported during covert shifts of visuospatial attention to one visual hemifield. Alpha amplitude increase, on the other hand, can be found at ipsilateral visual cortex. There is some evidence suggesting an involvement of prefrontal brain areas during the control of attention-related anticipatory alpha amplitude asymmetry. However, the exact neural mechanism by which prefrontal cortex influences visual processing has not been completely clear yet. This open question has been studied in detail using a multimodal approach combining transcranial magnetic stimulation (TMS and multichannel electroencephalography (EEG in healthy humans. Slow (1 Hz repetitive TMS inducing an inhibitory effect at the stimulation site was delivered either to right frontal eye field or a control site (vertex. Subsequently, participants had to perform a spatial cueing task in which covert shifts of attention were required to either the left or the right visual hemi-field. After stimulation at the vertex (control condition a pattern of anticipatory, attention-related ipsilateral alpha increase / contralateral alpha decrease over posterior recording sites could be obtained. Additionally, there was pronounced coupling between (in particular right FEF and posterior brain sites. When, however, the right prefrontal cortex had been virtually lesioned preceding the task, these EEG correlates of visuospatial attention were attenuated. Notably, the effect of TMS at the right FEF on interregional fronto-parietal alpha coupling predicted the effect on response times. This suggests that visual attention processes associated with posterior EEG alpha activity are at least partly top-down controlled by the prefrontal cortex.

Repetitive transcranial magnetic stimulation is effective following repeated courses in the treatment of major depressive disorder--a case report.

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Dannon, Pinhas N; Grunhaus, Leon

2003-06-01

Repetitive transcranial magnetic stimulation (rTMS) is a relatively new treatment modality for psychiatric patients. rTMS was demonstrated to be effective in the treatment of depression. However, longitudinal outcome studies have not yet been published. Relapse rates are higher in depressed patients and most of them do not respond to the same treatment with similar success. In this report we present a patient, who experienced relapse with the various conventional drug treatments, but responded well to rTMS at three different points in time. Copyright 2003 John Wiley & Sons, Ltd.

Suppression of motor cortical excitability in anesthetized rats by low frequency repetitive transcranial magnetic stimulation.

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Paul A Muller

Full Text Available Repetitive transcranial magnetic stimulation (rTMS is a widely-used method for modulating cortical excitability in humans, by mechanisms thought to involve use-dependent synaptic plasticity. For example, when low frequency rTMS (LF rTMS is applied over the motor cortex, in humans, it predictably leads to a suppression of the motor evoked potential (MEP, presumably reflecting long-term depression (LTD -like mechanisms. Yet how closely such rTMS effects actually match LTD is unknown. We therefore sought to (1 reproduce cortico-spinal depression by LF rTMS in rats, (2 establish a reliable animal model for rTMS effects that may enable mechanistic studies, and (3 test whether LTD-like properties are evident in the rat LF rTMS setup. Lateralized MEPs were obtained from anesthetized Long-Evans rats. To test frequency-dependence of LF rTMS, rats underwent rTMS at one of three frequencies, 0.25, 0.5, or 1 Hz. We next tested the dependence of rTMS effects on N-methyl-D-aspartate glutamate receptor (NMDAR, by application of two NMDAR antagonists. We find that 1 Hz rTMS preferentially depresses unilateral MEP in rats, and that this LTD-like effect is blocked by NMDAR antagonists. These are the first electrophysiological data showing depression of cortical excitability following LF rTMS in rats, and the first to demonstrate dependence of this form of cortical plasticity on the NMDAR. We also note that our report is the first to show that the capacity for LTD-type cortical suppression by rTMS is present under barbiturate anesthesia, suggesting that future neuromodulatory rTMS applications under anesthesia may be considered.

Tremor in the elderly

DEFF Research Database (Denmark)

Deuschl, Günther; Petersen, Inge; Lorenz, Delia

2015-01-01

Isolated tremor in the elderly is commonly diagnosed as essential tremor (ET). The prevalence of tremor increases steeply with increasing age, whereas hereditary tremor is becoming less common. Moreover, late-manifesting tremor seems to be associated with dementia and earlier mortality. We...... hypothesize that different entities underlie tremor in the elderly. Two thousand four hundred forty-eight subjects from the Longitudinal Study of Aging Danish Twins older than 70 y answered screening questions for ET in 2001. Two thousan fifty-six (84%) participants drew Archimedes spirals to measure...

Exploratory Study of rTMS Neuromodulation Effects on Electrocortical Functional Measures of Performance in an Oddball Test and Behavioral Symptoms in Autism

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Estate M. Sokhadze

2018-05-01

Full Text Available There is no accepted pathology to autism spectrum disorders (ASD but research suggests the presence of an altered excitatory/inhibitory (E/I bias in the cerebral cortex. Repetitive transcranial magnetic stimulation (rTMS offers a non-invasive means of modulating the E/I cortical bias with little in terms of side effects. In this study, 124 high functioning ASD children (IQ > 80, <18 years of age were recruited and assigned using randomization to either a waitlist group or one of three different number of weekly rTMS sessions (i.e., 6, 12, and 18. TMS consisted of trains of 1.0 Hz frequency pulses applied over the dorsolateral prefrontal cortex (DLPFC. The experimental task was a visual oddball with illusory Kanizsa figures. Behavioral response variables included reaction time and error rate along with such neurophysiological indices such as stimulus and response-locked event-related potentials (ERP. One hundred and twelve patients completed the assigned number of TMS sessions. Results showed significant changes from baseline to posttest period in the following measures: motor responses accuracy [lower percentage of committed errors, slower latency of commission errors and restored normative post-error reaction time slowing in both early and later-stage ERP indices, enhanced magnitude of error-related negativity (ERN, improved error monitoring and post-error correction functions]. In addition, screening surveys showed significant reductions in aberrant behavior ratings and in both repetitive and stereotypic behaviors. These differences increased with the total number of treatment sessions. Our results suggest that rTMS, particularly after 18 sessions, facilitates cognitive control, attention and target stimuli recognition by improving discrimination between task-relevant and task-irrelevant illusory figures in an oddball test. The noted improvement in executive functions of behavioral performance monitoring further suggests that TMS has the

Essential Tremor

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... Treatment There is no definitive cure for essential tremor. Symptomatic drug therapy may include propranolol or other beta blockers and primidone, an anticonvulsant drug. Eliminating tremor "triggers" ...

Daily left prefrontal repetitive transcranial magnetic stimulation for medication-resistant burning mouth syndrome.

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Umezaki, Y; Badran, B W; Gonzales, T S; George, M S

2015-08-01

Burning mouth syndrome (BMS) is a persistent and chronic burning sensation in the mouth in the absence of any abnormal organic findings. The pathophysiology of BMS is unclear and its treatment is not fully established. Although antidepressant medication is commonly used for treatment, there are some medication-resistant patients, and a new treatment for medication-resistant BMS is needed. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technology approved by the US Food and Drug Administration (FDA) for the treatment of depression. Recent studies have found beneficial effects of TMS for the treatment of pain. A case of BMS treated successfully with daily left prefrontal rTMS over a 2-week period is reported here. Based on this patient's clinical course and a recent pain study, the mechanism by which TMS may act to decrease the burning pain is discussed. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Effective treatment of narcolepsy-like symptoms with high-frequency repetitive transcranial magnetic stimulation

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Lai, Jian-bo; Han, Mao-mao; Xu, Yi; Hu, Shao-hua

2017-01-01

Abstract Rationale: Narcolepsy is a rare sleep disorder with disrupted sleep-architecture. Clinical management of narcolepsy lies dominantly on symptom-driven pharmacotherapy. The treatment role of repetitive transcranial magnetic stimulation (rTMS) for narcolepsy remains unexplored. Patient concerns: In this paper, we present a case of a 14-year-old young girl with excessive daytime sleepiness (EDS), cataplexy and hypnagogic hallucinations. Diagnoses: After excluding other possible medical conditions, this patient was primarily diagnosed with narcolepsy. Interventions: The patient received 25 sessions of high-frequency rTMS over the left dorsolateral prefrontal cortex (DLPFC). Outcomes: The symptoms of EDS and cataplexy significantly improved after rTMS treatment. Meanwhile, her score in the Epworth sleep scale (ESS) also remarkably decreased. Lessons: This case indicates that rTMS may be selected as a safe and effective alternative strategy for treating narcolepsy-like symptoms. Well-designed researches are warranted in future investigations on this topic. PMID:29145290

How typical are 'typical' tremor characteristics? : Sensitivity and specificity of five tremor phenomena

NARCIS (Netherlands)

van der Stouwe, A. M. M.; Elting, J. W.; van der Hoeven, J. H.; van Laar, T.; Leenders, K. L.; Maurits, N. M.; Tijssen, M. Aj.

Introduction: Distinguishing between different tremor disorders can be challenging. Some tremor disorders are thought to have typical tremor characteristics: the current study aims to provide sensitivity and specificity for five 'typical' tremor phenomena. Methods: Retrospectively, we examined 210

Intermittent cortical involvement in the preservation of tremor in essential tremor

NARCIS (Netherlands)

Sharifi, Sarvi; Luft, Frauke; Verhagen, Rens; Heida, Tjitske; Speelman, Johannes D.; Bour, Lo J.; van Rootselaar, Anne-Fleur

2017-01-01

Cortical involvement in essential tremor, an involuntary action tremor supposedly of subcortical origin, is uncertain. Conflicting results of corticomuscular coherence studies in essential tremor suggest an intermittent corticomuscular coupling. On the basis of the literature, we hypothesized that

Effect of low frequency rTMS stimulation over lateral cerebellum: a FDG PET study

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Yoon, Eun Jin; Cho, Sang Soo; Bang, Soong Ae; Park, Hyun Soo; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

2007-07-01

Several lines of evidence suggested the involvement of cerebellum in cognitive function as well as motor function. Because of the measurement difficulty of functional connectivity, little is known about the underlying mechanism involvement of cerebellum in motor and cognitive function in living human brain. To understand the role of cerebellum within the neural network, we investigated the changes of neuronal activity elicited by the cerebellar repetitive transcranial magnetic stimulation (rTMS). 11 right-handed normal volunteers (age: 23.4{+-}2.5 y;6 males) were studied with FDG PET under two conditions; sham and 1Hz rTMS over left lateral cerebellum. With 10 min inter-block interval, three blocks of rTMS were started with the intravenous injection of [18F]FDG. In each block, 5min rTMS were delivered with an intensity of 90% of the resting motor threshold (RMT). Sham rTMS was delivered with same protocol but the coil was positioned perpendicular to the target area with 50% RMT. PET scans were acquired immediately after the rTMS stimulation. Sham and 1Hz rTMS images compared using paired t-test with SPM2. Inhibited neuronal activity compare to the sham condition were revealed in the stimulated left lateral cerebellum and orbitofrontal gyrus and right motor related areas (S1, SMA and posterior parietal cortex). While enhanced neuronal activity compare to the sham condition were revealed in the bilateral inferior frontal gyri including Broca's area and superior temporal gyrus including primary auditory cortex. Bilateral middle temporal, left precentral and right middle occipital gyri were also showed enhanced neuronal activity. This result showed that rTMS over left lateral cerebellum modulate direct vicinity of the targeted region and a large network of remote interconnected contralateral motor and ipsilateral language related brain regions. Present result provide evidence that cerebellum may contribute to language related cognitive function as well as motor

Effect of low frequency rTMS stimulation over lateral cerebellum: a FDG PET study

International Nuclear Information System (INIS)

Yoon, Eun Jin; Cho, Sang Soo; Bang, Soong Ae; Park, Hyun Soo; Kim, Sang Eun

2007-01-01

Several lines of evidence suggested the involvement of cerebellum in cognitive function as well as motor function. Because of the measurement difficulty of functional connectivity, little is known about the underlying mechanism involvement of cerebellum in motor and cognitive function in living human brain. To understand the role of cerebellum within the neural network, we investigated the changes of neuronal activity elicited by the cerebellar repetitive transcranial magnetic stimulation (rTMS). 11 right-handed normal volunteers (age: 23.4±2.5 y;6 males) were studied with FDG PET under two conditions; sham and 1Hz rTMS over left lateral cerebellum. With 10 min inter-block interval, three blocks of rTMS were started with the intravenous injection of [18F]FDG. In each block, 5min rTMS were delivered with an intensity of 90% of the resting motor threshold (RMT). Sham rTMS was delivered with same protocol but the coil was positioned perpendicular to the target area with 50% RMT. PET scans were acquired immediately after the rTMS stimulation. Sham and 1Hz rTMS images compared using paired t-test with SPM2. Inhibited neuronal activity compare to the sham condition were revealed in the stimulated left lateral cerebellum and orbitofrontal gyrus and right motor related areas (S1, SMA and posterior parietal cortex). While enhanced neuronal activity compare to the sham condition were revealed in the bilateral inferior frontal gyri including Broca's area and superior temporal gyrus including primary auditory cortex. Bilateral middle temporal, left precentral and right middle occipital gyri were also showed enhanced neuronal activity. This result showed that rTMS over left lateral cerebellum modulate direct vicinity of the targeted region and a large network of remote interconnected contralateral motor and ipsilateral language related brain regions. Present result provide evidence that cerebellum may contribute to language related cognitive function as well as motor control

[Clinical subtypes of essential tremor and their electrophysiological and pharmacological differences].

Science.gov (United States)

Koguchi, Y; Nakajima, M; Kawamura, M; Hirayama, K

1995-02-01

We divided 19 patients with essential tremor into two subtypes according to clinical characteristics of the tremor. Ten patients had pure postural tremor distributed in the hand(s), head, and face (group A). Nine patients had tremor extending to the voice or leg(s), associated with resting tremor and/or hyperkinesie volitionnelle of the hand(s) (group B). Their ages, the age of onset, and the duration of illness were not different between the two groups. Electrophysiologically, the tremor of group A patients had higher frequencies than that of group B patients, and had synchronized activities for antagonistic muscles. Four of group B patients had reciprocal antagonistic activities of the tremor. Inactive phase of tremor induced by an electrically-evoked muscle twitch was invariably within the range of the physiological silent period for group A patients, and prolonged beyond the range for four of group B patients. Pharmacologically, 78% of group A patients responded well to beta-blocker, which was effective for 25% of group B patients. Sixty per cent of beta-blocker-resistant group B patients responded well to phenobarbital. In conclusion, a peripheral mechanism, presumably beta-adrenergic drive, is important for the tremor in group A patients, while central pathogenic mechanisms are more important for the tremor of group B patients.

Modulation of motor control in saccadic behaviors by TMS over the posterior parietal cortex.

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Liang, Wei-Kuang; Juan, Chi-Hung

2012-08-01

The right posterior parietal cortex (rPPC) has been found to be critical in shaping visual selection and distractor-induced saccade curvature in the context of predictive as well as nonpredictive visual cues by means of transcranial magnetic stimulation (TMS) interference. However, the dynamic details of how distractor-induced saccade curvatures are affected by rPPC TMS have not yet been investigated. This study aimed to elucidate the key dynamic properties that cause saccades to curve away from distractors with different degrees of curvature in various TMS and target predictability conditions. Stochastic optimal feedback control theory was used to model the dynamics of the TMS saccade data. This allowed estimation of torques, which was used to identify the critical dynamic mechanisms producing saccade curvature. The critical mechanisms of distractor-induced saccade curvatures were found to be the motor commands and torques in the transverse direction. When an unpredictable saccade target occurred with rPPC TMS, there was an initial period of greater distractor-induced torque toward the side opposite the distractor in the transverse direction, immediately followed by a relatively long period of recovery torque that brought the deviated trace back toward the target. The results imply that the mechanisms of distractor-induced saccade curvature may be comprised of two mechanisms: the first causing the initial deviation and the second bringing the deviated trace back toward the target. The pattern of the initial torque in the transverse direction revealed the former mechanism. Conversely, the later mechanism could be well explained as a consequence of the control policy in this model. To summarize, rPPC TMS increased the initial torque away from the distractor as well as the recovery torque toward the target.

The compensatory dynamic of inter-hemispheric interactions in visuospatial attention revealed using rTMS and fMRI

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Ela B Plow

2014-04-01

Full Text Available A balance of mutual tonic inhibition between bi-hemispheric posterior parietal cortices is believed to play an important role in bilateral visual attention. However, experimental support for this notion has been mainly drawn from clinical models of unilateral damage. We have previously shown that low-frequency repetitive TMS (rTMS over the intraparietal sulcus (IPS generates a contralateral attentional deficit in bilateral visual tracking. Here, we used functional Magnetic Resonance Imaging (fMRI to study whether rTMS temporarily disrupts the inter-hemispheric balance between bilateral IPS in visual attention. Following application of 1 Hz rTMS over the left IPS, subjects performed a bilateral visual tracking task while their brain activity was recorded using fMRI. Behaviorally, tracking accuracy was reduced immediately following rTMS. Areas ventro-lateral to left IPS, including inferior parietal lobule (IPL, lateral IPS (LIPS, and middle occipital gyrus (MoG, showed decreased activity following rTMS, while dorsomedial areas, such as Superior Parietal Lobule (SPL, Superior occipital gyrus (SoG, and lingual gyrus, as well as middle temporal areas (MT+, showed higher activity. The brain activity of the homologues of these regions in the un-stimulated, right hemisphere was reversed. Interestingly, the evolution of network-wide activation related to attentional behavior following rTMS showed that activation of most occipital synergists adaptively compensated for contralateral and ipsilateral decrement after rTMS, but that of parietal synergists, and SoG remained competing. This pattern of ipsilateral and contralateral activations empirically supports the hypothesized loss of inter-hemispheric balance that underlies clinical manifestation of visual attentional extinction.

Resection of highly language-eloquent brain lesions based purely on rTMS language mapping without awake surgery.

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Ille, Sebastian; Sollmann, Nico; Butenschoen, Vicki M; Meyer, Bernhard; Ringel, Florian; Krieg, Sandro M

2016-12-01

The resection of left-sided perisylvian brain lesions harbours the risk of postoperative language impairment. Therefore the individual patient's language distribution is investigated by intraoperative direct cortical stimulation (DCS) during awake surgery. Yet, not all patients qualify for awake surgery. Non-invasive language mapping by repetitive navigated transcranial magnetic stimulation (rTMS) has frequently shown a high correlation in comparison with the results of DCS language mapping in terms of language-negative brain regions. The present study analyses the extent of resection (EOR) and functional outcome of patients who underwent left-sided perisylvian resection of brain lesions based purely on rTMS language mapping. Four patients with left-sided perisylvian brain lesions (two gliomas WHO III, one glioblastoma, one cavernous angioma) underwent rTMS language mapping prior to surgery. Data from rTMS language mapping and rTMS-based diffusion tensor imaging fibre tracking (DTI-FT) were transferred to the intraoperative neuronavigation system. Preoperatively, 5 days after surgery (POD5), and 3 months after surgery (POM3) clinical follow-up examinations were performed. No patient suffered from a new surgery-related aphasia at POM3. Three patients underwent complete resection immediately, while one patient required a second rTMS-based resection some days later to achieve the final, complete resection. The present study shows for the first time the feasibility of successfully resecting language-eloquent brain lesions based purely on the results of negative language maps provided by rTMS language mapping and rTMS-based DTI-FT. In very select cases, this technique can provide a rescue strategy with an optimal functional outcome and EOR when awake surgery is not feasible.

Repetitive transcranial magnetic stimulation and transcranial direct-current stimulation in neuropathic pain due to radiculopathy: a randomized sham-controlled comparative study.

Science.gov (United States)

Attal, Nadine; Ayache, Samar S; Ciampi De Andrade, Daniel; Mhalla, Alaa; Baudic, Sophie; Jazat, Frédérique; Ahdab, Rechdi; Neves, Danusa O; Sorel, Marc; Lefaucheur, Jean-Pascal; Bouhassira, Didier

2016-06-01

No study has directly compared the effectiveness of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS) in neuropathic pain (NP). In this 2-centre randomised double-blind sham-controlled study, we compared the efficacy of 10-Hz rTMS and anodal 2-mA tDCS of the motor cortex and sham stimulation contralateral to the painful area (3 daily sessions) in patients with NP due to lumbosacral radiculopathy. Average pain intensity (primary outcome) was evaluated after each session and 5 days later. Secondary outcomes included neuropathic symptoms and thermal pain thresholds for the upper limbs. We used an innovative design that minimised bias by randomly assigning patients to 1 of 2 groups: active rTMS and tDCS or sham rTMS and tDCS. For each treatment group (active or sham), the order of the sessions was again randomised according to a crossover design. In total, 51 patients were screened and 35 (51% women) were randomized. Active rTMS was superior to tDCS and sham in pain intensity (F = 2.89 and P = 0.023). Transcranial direct-current stimulation was not superior to sham, but its analgesic effects were correlated to that of rTMS (P = 0.046), suggesting common mechanisms of action. Repetitive transcranial magnetic stimulation lowered cold pain thresholds (P = 0.04) and its effect on cold pain was correlated with its analgesic efficacy (P = 0.006). However, rTMS had no impact on individual neuropathic symptoms. Thus, rTMS is more effective than tDCS and sham in patients with NP due to lumbosacral radiculopathy and may modulate the sensory and affective dimensions of pain.

[Repetitive transcranial magnetic stimulation: A potential therapy for cognitive disorders?

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Nouhaud, C; Sherrard, R M; Belmin, J

2017-03-01

Considering the limited effectiveness of drugs treatments in cognitive disorders, the emergence of noninvasive techniques to modify brain function is very interesting. Among these techniques, repetitive transcranial magnetic stimulation (rTMS) can modulate cortical excitability and have potential therapeutic effects on cognition and behaviour. These effects are due to physiological modifications in the stimulated cortical tissue and their associated circuits, which depend on the parameters of stimulation. The objective of this article is to specify current knowledge and efficacy of rTMS in cognitive disorders. Previous studies found very encouraging results with significant improvement of higher brain functions. Nevertheless, these few studies have limits: a few patients were enrolled, the lack of control of the mechanisms of action by brain imaging, insufficiently formalized technique and variability of cognitive tests. It is therefore necessary to perform more studies, which identify statistical significant improvement and to specify underlying mechanisms of action and the parameters of use of the rTMS to offer rTMS as a routine therapy for cognitive dysfunction. Copyright © 2016 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Differences in striatal dopamine transporter density between tremor dominant and non-tremor Parkinson's disease

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Kaasinen, Valtteri; Kinos, Maija; Joutsa, Juho; Seppaenen, Marko; Noponen, Tommi

2014-01-01

Parkinson's disease (PD) can manifest with a tremor-dominant or a non-tremor (akinetic-rigid) phenotype. Although the tremor-dominant subtype may show a better prognosis, there is limited information on the phenotypic differences regarding the level of striatal dopamine transmission. The present study investigated striatal dopamine transporter (DAT) binding characteristics in a large sample of patients with and without tremor. [ 123 I]FP-CIT SPECT scans of 231 patients with a clinical diagnosis of PD and abnormal FP-CIT binding (157 with tremor, 74 without tremor) and 230 control patients with normal FP-CIT binding (148 with tremor, 82 without tremor) were analysed using an automated region-of-interest analysis of the scans (BRASS). Specific striatal binding ratios were compared between phenotypes and groups using age, sex, and symptom duration, predominant side of symptoms, dopaminergic medications and scanner as covariates. Patients with PD had 28.1 - 65.0 % lower binding in all striatal regions compared to controls (p < 0.001). The mean FP-CIT caudate nucleus uptake and the left caudate nucleus uptake were higher in PD patients with tremor than in PD patients without tremor (mean 9.0 % higher, left 10.5 % higher; p < 0.05), whereas there were no differences between tremor and non-tremor control patients. No significant effects of tremor on DAT binding were observed in the anterior or posterior putamen. The motor phenotype is associated with the extent of caudate dopamine terminal loss in PD, as dopamine function is relatively more preserved in tremor patients. Symptom type is related to caudate dopamine function only in association with Parkinsonian dopaminergic degeneration, not in intact dopamine systems in patients with non-PD tremor. (orig.)

Effect of Intermediate-Frequency Repetitive Transcranial Magnetic Stimulation on Recovery following Traumatic Brain Injury in Rats

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Leticia Verdugo-Diaz

2017-01-01

Full Text Available Traumatic brain injury (TBI represents a significant public health concern and has been associated with high rates of morbidity and mortality. Although several research groups have proposed the use of repetitive transcranial magnetic stimulation (rTMS to enhance neuroprotection and recovery in patients with TBI, few studies have obtained sufficient evidence regarding its effects in this population. Therefore, we aimed to analyze the effect of intermediate-frequency rTMS (2 Hz on behavioral and histological recovery following TBI in rats. Male Wistar rats were divided into six groups: three groups without TBI (no manipulation, movement restriction plus sham rTMS, and movement restriction plus rTMS and three groups subjected to TBI (TBI only, TBI plus movement restriction and sham rTMS, and TBI plus movement restriction and rTMS. The movement restriction groups were included so that rTMS could be applied without anesthesia. Our results indicate that the restriction of movement and sham rTMS per se promotes recovery, as measured using a neurobehavioral scale, although rTMS was associated with faster and superior recovery. We also observed that TBI caused alterations in the CA1 and CA3 subregions of the hippocampus, which are partly restored by movement restriction and rTMS. Our findings indicated that movement restriction prevents damage caused by TBI and that intermediate-frequency rTMS promotes behavioral and histologic recovery after TBI.

TMS-induced neural noise in sensory cortex interferes with short-term memory storage in prefrontal cortex.

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Bancroft, Tyler D; Hogeveen, Jeremy; Hockley, William E; Servos, Philip

2014-01-01

In a previous study, Harris et al. (2002) found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation (TMS) to primary somatosensory cortex (SI) early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence from human EEG and single-cell recording in primates that instead points to prefrontal cortex as the storage substrate for vibrotactile memory. In the present study, we use computational methods to demonstrate how Harris et al.'s results can be reproduced by TMS-induced activity in sensory cortex and subsequent feedforward interference with memory traces stored in prefrontal cortex, thereby reconciling discordant findings in the tactile memory literature.

Waveform analysis of tremor may help to differentiate Parkinson's disease from drug-induced parkinsonism

International Nuclear Information System (INIS)

Jang, W; Han, J; Kim, I Y; Park, J; Kim, J-S; Cho, J W; Koh, S-B; Chung, S J; Kim, H-T

2013-01-01

In this study, we analyzed the waveform characteristics of resting tremor by accelerometer recordings in patients with drug-induced parkinsonism (DIP) and Parkinson's disease (PD). We prospectively recruited 12 patients with tremulous PD and 12 patients with DIP presenting with resting tremor. Tremor was recorded from the more affected side and was recorded twice for a 60 s period in each patient. Peak frequency, amplitude and all harmonic peaks were obtained, and the asymmetry of the decay of the autocorrelation function, third momentum and time-reversal invariance were also computed using a mathematical algorithm. Among the parameters used in the waveform analysis, the harmonic ratio, time-reversal invariance and asymmetric decay of the autocorrelation function were different between PD and DIP at a statistically significant level (all p < 0.01). The total harmonic peak power and third momentum in the time series were not significantly different. The clinical characteristics of DIP patients may be similar to those of PD patients in some cases, which makes the clinical differentiation between DIP and PD challenging. Our study shows that the identification of parameters reflecting waveform asymmetry might be helpful in differentiating between DIP and PD. (note)

TMS field modelling-status and next steps

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Thielscher, Axel

2013-01-01

In the recent years, an increasing number of studies used geometrically accurate head models and finite element (FEM) or finite difference methods (FDM) to estimate the electric field induced by non-invasive neurostimulation techniques such as transcranial magnetic stimulation (TMS) or transcranial...

Tremors and Klinefelter's Syndrome

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Marcie L. Rabin

2015-06-01

Full Text Available Background: Klinefelter’s syndrome (KS has been associated with tremor, but reports on tremor phenomenology and treatment are limited. Case Reports: Patient 1 is a 17‐year‐old male with a dystonic tremor treated with deep brain stimulation (DBS. Patient 2 is a 57‐year‐old male with a predominant left hand resting tremor and dystonic features. Discussion: Our cases suggest that the tremor in patients with KS may be dystonic in nature. Patient 1 is also the third reported case of successful treatment with DBS. These cases have implications for elucidating the underlying neurobiological mechanism of tremor and identifying treatment options.

Essential tremor

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... such as: Smoking and smokeless tobacco Overactive thyroid ( hyperthyroidism ) Suddenly stopping alcohol after drinking a lot for ... from the medicines used to treat your tremor Prevention Alcoholic beverages in small quantities may decrease tremors. ...

The effectiveness of non-invasive brain stimulation in improving clinical signs of hyperkinetic movement disorders

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Ignacio eObeso

2016-01-01

Full Text Available Repetitive transcranial magnetic stimulation (rTMS is a safe and non-invasive method for stimulating cortical neurons. In neurological realm, rTMS has prevalently been applied to understand pathophysiological mechanisms underlying movement disorders. However, this tool has also the potential to be translated into a clinically applicable therapeutic use. Several available studies supported this hypothesis, but differences in protocols, clinical enrollment and variability of rTMS effects across individuals complicate better understanding of efficient clinical protocols.The aim of this present review is to discuss to what extent the evidence provided by the therapeutic use of rTMS may be generalized. In particular, we attempted to define optimal cortical regions and stimulation protocols that have been demonstrated to maximize the effectiveness seen in the actual literature for the three most prevalent hyperkinetic movement disorders: Parkinson´s disease with levodopa-induced dyskinesias, essential tremor and dystonia. A total of 28 rTMS studies met our search criteria. Despite clinical and methodological differences, overall these studies demonstrated that therapeutic applications of rTMS to normalize pathologically decreased or increased levels of cortical activity have given moderate progress in patient´s quality of life. Moreover, the present literature suggests that altered pathophysiology in hyperkinetic movement disorders establishes motor, premotor or cerebellar structures as candidate regions to reset cortico-subcortical pathways back to normal. Although rTMS has the potential to become a powerful tool for ameliorating the clinical outcome of hyperkinetic neurological patients, until now there is not a clear consensus on optimal protocols for these motor disorders. Well-controlled multicenter randomized clinical trials with high numbers of patients are urgently required.

Effective treatment of narcolepsy-like symptoms with high-frequency repetitive transcranial magnetic stimulation: A case report.

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Lai, Jian-Bo; Han, Mao-Mao; Xu, Yi; Hu, Shao-Hua

2017-11-01

Narcolepsy is a rare sleep disorder with disrupted sleep-architecture. Clinical management of narcolepsy lies dominantly on symptom-driven pharmacotherapy. The treatment role of repetitive transcranial magnetic stimulation (rTMS) for narcolepsy remains unexplored. In this paper, we present a case of a 14-year-old young girl with excessive daytime sleepiness (EDS), cataplexy and hypnagogic hallucinations. After excluding other possible medical conditions, this patient was primarily diagnosed with narcolepsy. The patient received 25 sessions of high-frequency rTMS over the left dorsolateral prefrontal cortex (DLPFC). The symptoms of EDS and cataplexy significantly improved after rTMS treatment. Meanwhile, her score in the Epworth sleep scale (ESS) also remarkably decreased. This case indicates that rTMS may be selected as a safe and effective alternative strategy for treating narcolepsy-like symptoms. Well-designed researches are warranted in future investigations on this topic.

Repetitive transcranial magnetic stimulation as a neuropsychiatric tool: present status and future potential.

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Post, R M; Kimbrell, T A; McCann, U D; Dunn, R T; Osuch, E A; Speer, A M; Weiss, S R

1999-03-01

Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising therapeutic intervention in the treatment of affective disorders. The differences in the type of electrical stimulation required for therapeutic efficacy by rTMS and electroconvulsive therapy (ECT) are discussed. In contrast to ECT, rTMS would not appear to require the generation of a major motor seizure to achieve therapeutic efficacy. Accordingly, it carries the potentially important clinical advantages of not requiring anesthesia and of avoiding side effects such as transient memory loss. Preclinical studies on long-term potentiation (LTP) and long-term depression (LTD) in hippocampal and amygdala slices, as well as clinical data from neuroimaging studies, have provided encouraging clues for potential frequency-dependent effects of rTMS. Preliminary evidence from position emission tomography (PET) scans suggests that higher frequency (20 Hz) stimulation may increase brain glucose metabolism in a transsynaptic fashion, whereas lower frequency (1 Hz) stimulation may decrease it. Therefore, the ability of rTMS to control the frequency as well as the location of stimulation, in addition to its other advantages, has opened up new possibilities for clinical explorations and treatments of neuropsychiatric conditions.

Effects of low-frequency repetitive transcranial magnetic stimulation on event-related potential P300

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Torii, Tetsuya; Sato, Aya; Iwahashi, Masakuni; Iramina, Keiji

2012-04-01

The present study analyzed the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. P300 latency of event-related potential (ERP) was used to evaluate the effects of low-frequency and short-term rTMS by stimulating the supramarginal gyrus (SMG), which is considered to be the related area of P300 origin. In addition, the prolonged stimulation effects on P300 latency were analyzed after applying rTMS. A figure-eight coil was used to stimulate left-right SMG, and intensity of magnetic stimulation was 80% of motor threshold. A total of 100 magnetic pulses were applied for rTMS. The effects of stimulus frequency at 0.5 or 1 Hz were determined. Following rTMS, an odd-ball task was performed and P300 latency of ERP was measured. The odd-ball task was performed at 5, 10, and 15 min post-rTMS. ERP was measured prior to magnetic stimulation as a control. Electroencephalograph (EEG) was measured at Fz, Cz, and Pz that were indicated by the international 10-20 electrode system. Results demonstrated that different effects on P300 latency occurred between 0.5-1 Hz rTMS. With 1 Hz low-frequency magnetic stimulation to the left SMG, P300 latency decreased. Compared to the control, the latency time difference was approximately 15 ms at Cz. This decrease continued for approximately 10 min post-rTMS. In contrast, 0.5 Hz rTMS resulted in delayed P300 latency. Compared to the control, the latency time difference was approximately 20 ms at Fz, and this delayed effect continued for approximately 15 min post-rTMS. Results demonstrated that P300 latency varied according to rTMS frequency. Furthermore, the duration of the effect was not similar for stimulus frequency of low-frequency rTMS.

A TMS coil positioning/holding system for MR image-guided TMS interleaved with fMRI.

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Bohning, Daryl E; Denslow, S; Bohning, P A; Walker, J A; George, M S

2003-11-01

Transcranial magnetic stimulation (TMS) can be interleaved with fMRI to visualize regional brain activity in response to direct, non-invasive, cortical stimulation, making it a promising tool for studying brain function. A major practical difficulty is accurately positioning the TMS coil within the MRI scanner for stimulating a particular area of brain cortex. The objective of this work was to design and build a self-contained hardware/software system for MR-guided TMS coil positioning in interleaved TMS/fMRI studies. A compact, manually operated, articulated TMS coil positioner/holder with 6 calibrated degrees of freedom was developed for use inside a cylindrical RF head coil, along with a software package for transforming between MR image coordinates, MR scanner space coordinates, and positioner/holder settings. Phantom calibration studies gave an accuracy for positioning within setups of dx=+/-1.9 mm, dy=+/-1.4 mm, dz=+/-0.8 mm and a precision for multiple setups of dx=+/-0.8 mm, dy=+/-0.1 mm, dz=+/-0.1 mm. This self-contained, integrated MR-guided TMS system for interleaved TMS/fMRI studies provides fast, accurate location of motor cortex stimulation sites traditionally located functionally, and a means of consistent, anatomy-based TMS coil positioning for stimulation of brain areas without overt response.

Prefrontal rTMS for treating depression: location and intensity results from the OPT-TMS multi-site clinical trial.

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Johnson, Kevin A; Baig, Mirza; Ramsey, Dave; Lisanby, Sarah H; Avery, David; McDonald, William M; Li, Xingbao; Bernhardt, Elisabeth R; Haynor, David R; Holtzheimer, Paul E; Sackeim, Harold A; George, Mark S; Nahas, Ziad

2013-03-01

Motor cortex localization and motor threshold determination often guide Transcranial Magnetic Stimulation (TMS) placement and intensity settings for non-motor brain stimulation. However, anatomic variability results in variability of placement and effective intensity. Post-study analysis of the OPT-TMS Study reviewed both the final positioning and the effective intensity of stimulation (accounting for relative prefrontal scalp-cortex distances). We acquired MRI scans of 185 patients in a multi-site trial of left prefrontal TMS for depression. Scans had marked motor sites (localized with TMS) and marked prefrontal sites (5 cm anterior of motor cortex by the "5 cm rule"). Based on a visual determination made before the first treatment, TMS therapy occurred either at the 5 cm location or was adjusted 1 cm forward. Stimulation intensity was 120% of resting motor threshold. The "5 cm rule" would have placed stimulation in premotor cortex for 9% of patients, which was reduced to 4% with adjustments. We did not find a statistically significant effect of positioning on remission, but no patients with premotor stimulation achieved remission (0/7). Effective stimulation ranged from 93 to 156% of motor threshold, and no seizures were induced across this range. Patients experienced remission with effective stimulation intensity ranging from 93 to 146% of motor threshold, and we did not find a significant effect of effective intensity on remission. Our data indicates that individualized positioning methods are useful to reduce variability in placement. Stimulation at 120% of motor threshold, unadjusted for scalp-cortex distances, appears safe for a broad range of patients. Copyright © 2013 Elsevier Inc. All rights reserved.

Three and six-month outcome following courses of either ECT or rTMS in a population of severely depressed individuals--preliminary report.

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Dannon, Pinhas N; Dolberg, Ornah T; Schreiber, Shaul; Grunhaus, Leon

2002-04-15

Recent studies have strengthened the claim that repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for major depression. The longitudinal outcome of TMS-treated patients, however, has not been described. We report on the 3- and 6-month outcomes of a group of patients treated with either electroconvulsive therapy (ECT) (n = 20) or (rTMS) (n = 21). Patients diagnosed with major depressive disorder with or without psychotic features referred for ECT were randomly assigned to receive either ECT or rTMS. Forty-one patients who responded to either treatment constituted the sample. Patients were followed on a monthly basis and outcomes were determined with the Hamilton Rating Scale for Depression-17 items (HRSD) and the Global Assessment of Functioning (GAF) scales. Medications were routinely prescribed. There were no differences in the 6-month relapse rate between the groups. Overall, 20% of the patients relapsed (four from the ECT group and four from the rTMS group). Patients reported equally low and not significantly different scores in the HRSD (ECT group 8.4 +/- 5.6 and TMS group 7.9 +/- 7.1) and the GAF (ECT group 72.8 +/- 12 and TMS group 77.8 +/- 17.1) at the 6-month follow up. Patients treated with rTMS do as well as those treated with ECT at the 3- and 6-month follow-up points. These data suggest that the clinical gains obtained with rTMS last at least as long as those obtained with ECT.

Static field influences on transcranial magnetic stimulation: considerations for TMS in the scanner environment.

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Yau, Jeffrey M; Jalinous, Reza; Cantarero, Gabriela L; Desmond, John E

2014-01-01

Transcranial magnetic stimulation (TMS) can be combined with functional magnetic resonance imaging (fMRI) to simultaneously manipulate and monitor human cortical responses. Although tremendous efforts have been directed at characterizing the impact of TMS on image acquisition, the influence of the scanner's static field on the TMS coil has received limited attention. The aim of this study was to characterize the influence of the scanner's static field on TMS. We hypothesized that spatial variations in the static field could account for TMS field variations in the scanner environment. Using an MRI-compatible TMS coil, we estimated TMS field strengths based on TMS-induced voltage changes measured in a search coil. We compared peak field strengths obtained with the TMS coil positioned at different locations (B0 field vs fringe field) and orientations in the static field. We also measured the scanner's static field to derive a field map to account for TMS field variations. TMS field strength scaled depending on coil location and orientation with respect to the static field. Larger TMS field variations were observed in fringe field regions near the gantry as compared to regions inside the bore or further removed from the bore. The scanner's static field also exhibited the greatest spatial variations in fringe field regions near the gantry. The scanner's static field influences TMS fields and spatial variations in the static field correlate with TMS field variations. Coil orientation changes in the B0 field did not result in substantial TMS field variations. TMS field variations can be minimized by delivering TMS in the bore or outside of the 0-70 cm region from the bore entrance. Copyright © 2014 Elsevier Inc. All rights reserved.

Palatal tremor after lithium and carbamazepine use: a case report

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Kuruvilla Anju

2010-06-01

Full Text Available Abstract Introduction Palatal tremor, characterized by rhythmic contractions of the soft palate, can occur secondary to pathology in the dentato-rubro-olivary pathway, or in the absence of such structural lesions. Its pathogenesis is only partially understood. We describe a case of probable drug-induced palatal tremor. Case presentation A 27-year-old Indian man had taken carbamazepine and lithium for 7 years for the treatment of a manic episode. He presented with a one-year history of bilateral rhythmic oscillations of his soft palate and tremors of his tongue. There were no other abnormalities detected from his examination or after detailed investigation. Conclusion Palatal tremors may result from medication used in the treatment of psychiatric disorders.

Nadolol for lithium tremor in the presence of liver damage.

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Dave, M; Langbart, M M

1994-03-01

Lithium-induced tremor classically responds to treatment with propranolol. Since it is metabolized in the liver, propranolol may not be the drug of choice in those patients who have compromised liver function or who are recovering from prior liver diseases. Another nonselective beta-adrenergic blocker, nadolol, has no hepatic biotransformation. We present here the first case report of successful treatment of lithium-induced tremor with nadolol, which was selected because the patient had compromised liver function. The patient's liver function tests remained stable with the therapy.

Proprioceptive drift in the rubber hand illusion is intensified following 1 Hz TMS of the left EBA

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Andrew eWold

2014-06-01

Full Text Available The rubber hand illusion (RHI is a paradigm used to induce an illusory feeling of owning a dummy hand through congruent multisensory stimulation. Thus, it can grant insights into how our brain represents our body as our own. Recent research has demonstrated an involvement of the extrastriate body area (EBA, an area of the brain that is typically implicated in the perception of non-face body parts, in illusory body ownership. In this experiment we sought causal evidence for the involvement of the EBA in the RHI. 16 participants took part in a sham controlled, 1 Hz repetitive TMS (1200 pulse experiment where they received synchronous (RHI condition or asynchronous (control stroking and were asked to report the perceived location of their real hand as well as the intensity and the temporal onset of experienced ownership of the dummy hand. Following TMS of the left EBA, participants misjudged their real hand's location significantly more towards the rubber hand during synchronous stroking than after sham stimulation. This difference in proprioceptive drift provides the first causal evidence that the EBA is involved in the RHI and subsequently in body representation and further supports the view that the EBA is necessary for multimodal integration.

TMS modeling toolbox for realistic simulation.

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Cho, Young Sun; Suh, Hyun Sang; Lee, Won Hee; Kim, Tae-Seong

2010-01-01

Transcranial magnetic stimulation (TMS) is a technique for brain stimulation using rapidly changing magnetic fields generated by coils. It has been established as an effective stimulation technique to treat patients suffering from damaged brain functions. Although TMS is known to be painless and noninvasive, it can also be harmful to the brain by incorrect focusing and excessive stimulation which might result in seizure. Therefore there is ongoing research effort to elucidate and better understand the effect and mechanism of TMS. Lately Boundary element method (BEM) and Finite element method (FEM) have been used to simulate the electromagnetic phenomenon of TMS. However, there is a lack of general tools to generate the models of TMS due to some difficulties in realistic modeling of the human head and TMS coils. In this study, we have developed a toolbox through which one can generate high-resolution FE TMS models. The toolbox allows creating FE models of the head with isotropic and anisotropic electrical conductivities in five different tissues of the head and the coils in 3D. The generated TMS model is importable to FE software packages such as ANSYS for further and efficient electromagnetic analysis. We present a set of demonstrative results of realistic simulation of TMS with our toolbox.

Effects of Bilateral Repetitive Transcranial Magnetic Stimulation on Post-Stroke Dysphagia.

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Park, Eunhee; Kim, Min Su; Chang, Won Hyuk; Oh, Su Mi; Kim, Yun Kwan; Lee, Ahee; Kim, Yun-Hee

Optimal protocol of repetitive transcranial magnetic stimulation (rTMS) on post-stroke dysphagia remains uncertain with regard to its clinical efficacy. The aim of the present study is to investigate the effects of high-frequency rTMS at the bilateral motor cortices over the cortical representation of the mylohyoid muscles in the patients with post-stroke dysphagia. This study was a single-blind, randomized controlled study with a blinded observer. Thirty-five stroke patients were randomly divided into three intervention groups: the bilateral stimulation group, the unilateral stimulation group, and the sham stimulation group. For the bilateral stimulation group, 500 pulses of 10 Hz rTMS over the ipsilesional and 500 pulses of 10 Hz rTMS over the contralesional motor cortices over the cortical areas that project to the mylohyoid muscles were administered daily for 2 consecutive weeks. For the unilateral stimulation group, 500 pulses of 10 Hz rTMS over the ipsilesional motor cortex over the cortical representation of the mylohyoid muscle and the same amount of sham rTMS over the contralesional hemisphere were applied. For the sham stimulation group, sham rTMS was applied at the bilateral motor cortices. Clinical swallowing function and videofluoroscopic swallowing studies were assessed before the intervention (T0), immediately after the intervention (T1) and 3 weeks after the intervention (T2) using Clinical Dysphagia Scale (CDS), Dysphagia Outcome and Severity Scale (DOSS), Penetration Aspiration Scale (PAS), and Videofluoroscopic Dysphagia Scale (VDS). There were significant time and intervention interaction effects in the CDS, DOSS, PAS, and VDS scores (p dysphagia therapies. Copyright © 2016. Published by Elsevier Inc.

Effects of low frequency rTMS treatment on brain networks for inner speech in patients with schizophrenia and auditory verbal hallucinations.

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Bais, Leonie; Liemburg, Edith; Vercammen, Ans; Bruggeman, Richard; Knegtering, Henderikus; Aleman, André

2017-08-01

Efficacy of repetitive Transcranial Magnetic Stimulation (rTMS) targeting the temporo-parietal junction (TPJ) for the treatment of auditory verbal hallucinations (AVH) remains under debate. We assessed the influence of a 1Hz rTMS treatment on neural networks involved in a cognitive mechanism proposed to subserve AVH. Patients with schizophrenia (N=24) experiencing medication-resistant AVH completed a 10-day 1Hz rTMS treatment. Participants were randomized to active stimulation of the left or bilateral TPJ, or sham stimulation. The effects of rTMS on neural networks were investigated with an inner speech task during fMRI. Changes within and between neural networks were analyzed using Independent Component Analysis. rTMS of the left and bilateral TPJ areas resulted in a weaker network contribution of the left supramarginal gyrus to the bilateral fronto-temporal network. Left-sided rTMS resulted in stronger network contributions of the right superior temporal gyrus to the auditory-sensorimotor network, right inferior gyrus to the left fronto-parietal network, and left middle frontal gyrus to the default mode network. Bilateral rTMS was associated with a predominant inhibitory effect on network contribution. Sham stimulation showed different patterns of change compared to active rTMS. rTMS of the left temporo-parietal region decreased the contribution of the left supramarginal gyrus to the bilateral fronto-temporal network, which may reduce the likelihood of speech intrusions. On the other hand, left rTMS appeared to increase the contribution of functionally connected regions involved in perception, cognitive control and self-referential processing. These findings hint to potential neural mechanisms underlying rTMS for hallucinations but need corroboration in larger samples. Copyright © 2017 Elsevier Inc. All rights reserved.

Low- vs high- frequency Repetitive Transcranial Magnetic Stimulation as an add-on treatment for refractory depression

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julien eeche

2012-03-01

Full Text Available Objectives: Repetitive transcranial magnetic stimulation (rTMS seems to be effective as an antidepressant treatment, however, some confusion remain about the best parameters to apply and the efficacy of its association with pharmacological antidepressant treatments.Method: In a single blind randomized study14 patients with unipolar resistant depression to one antidepressant treatment were enrolled to received, in combination with venlafaxine (150 mg, either 20 sessions of 10Hz rTMS (2 000 pulses per session applied over le left dorsolateral prefrontal cortex (DLPFC or 20 sessions of 1 Hz rTMS (120 stimulations per sessions applied over the right DLPFC. Results: A similar antidepressant effect was observed in both groups with a comparable antidepressant delay of action (2 weeks and a comparable number of patients in remission after 4 weeks of daily rTMS sessions (66 vs 50 %.Conclusion: Low- and high- frequency rTMS seem to be effective as an add-on treatment to venlafaxine in pharmacological refractory major depression. Due to its short duration and its safety, low frequency rTMS may be a useful alternative treatment for patients with refractory depression.

Tibialis anterior stretch reflex in early stance is suppressed by repetitive transcranial magnetic stimulation

DEFF Research Database (Denmark)

Zuur, Abraham T; Christensen, Mark Schram; Sinkjær, Thomas

2009-01-01

Abstract A rapid plantar flexion perturbation in the early stance phase of walking elicits a large stretch reflex in tibialis anterior (TA). In this study we use repetitive Transcranial Magnetic Stimulation (rTMS) to test if this response is mediated through a transcortical pathway. TA stretch...

Effect of Bilateral Prefrontal rTMS on Left Prefrontal NAA and Glx Levels in Schizophrenia Patients with Predominant Negative Symptoms : An Exploratory Study

NARCIS (Netherlands)

Dlabac-de Lange, Jozarni J.; Liemburg, Edith J.; Bais, Leonie; van de Poel-Mustafayeva, Aida T.; de Lange-de Klerk, Elly S. M.; Knegtering, Henderikus; Aleman, Andre

2017-01-01

Background: Prefrontal repetitive Transcranial Magnetic Stimulation (rTMS) may improve negative symptoms in patients with schizophrenia, but few studies have investigated the underlying neural mechanism. Objective: This study aims to investigate changes in the levels of glutamate and glutamine (Glx,

Tremor entities and their classification: an update.

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Gövert, Felix; Deuschl, Günther

2015-08-01

This review focuses on important new findings in the field of tremor and illustrates the consequences for the current definition and classification of tremor. Since 1998 when the consensus criteria for tremor were proposed, new variants of tremors and new diagnostic methods were discovered that have changed particularly the concepts of essential tremor and dystonic tremor. Accumulating evidence exists that essential tremor is not a single entity rather different conditions that share the common symptom action tremor without other major abnormalities. Tremor is a common feature in patients with adult-onset focal dystonia and may involve several different body parts and forms of tremor. Recent advances, in particular, in the field of genetics, suggest that dystonic tremor may even be present without overt dystonia. Monosymptomatic asymmetric rest and postural tremor has been further delineated, and apart from tremor-dominant Parkinson's disease, there are several rare conditions including rest and action tremor with normal dopamine transporter imaging (scans without evidence of dopaminergic deficit) and essential tremor with tremor at rest. Increasing knowledge in the last decades changed the view on tremors and highlights several caveats in the current tremor classification. Given the ambiguous assignment between tremor phenomenology and tremor etiology, a more cautious definition of tremors on the basis of clinical assessment data is needed.

Neuropeptide Y as a possible homeostatic element for changes in cortical excitability induced by repetitive transcranial magnetic stimulation.

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Jazmati, Danny; Neubacher, Ute; Funke, Klaus

2018-02-24

Repetitive transcranial magnetic stimulation (rTMS) is able to modify cortical excitability. Rat rTMS studies revealed a modulation of inhibitory systems, in particular that of the parvalbumin-expressing (PV+) interneurons, when using intermittent theta-burst stimulation (iTBS). The potential disinhibitory action of iTBS raises the questions of how neocortical circuits stabilize excitatory-inhibitory balance within a physiological range. Neuropeptide Y (NPY) appears to be one candidate. Analysis of cortical expression of PV, NPY and vesicular glutamate transporter type 1 (vGluT1) by immunohistochemical means at the level of cell counts, mean neuropil expression and single cell pre-/postsynaptic expression, with and without intraventricular NPY-injection. Our results show that iTBS not only reduced the number of neurons with high-PV expression in a dose-dependent fashion, but also increased the cortical expression of NPY, discussed to reduce glutamatergic transmission, and this was further associated with a reduced vGluT1 expression, an indicator of glutamateric presynaptic activity. Interneurons showing a low-PV expression exhibit less presynaptic vGluT1 expression compared to those with a high-PV expression. Intraventricular application of NPY prior to iTBS prevented the iTBS-induced reduction in the number of high-PV neurons, the reduction in tissue vGluT1 level and that presynaptic to high-PV cells. We conclude that NPY, possibly via a global but also slow homeostatic control of glutamatergic transmission, modulates the strength and direction of the iTBS effects, likely preventing pathological imbalance of excitatory and inhibitory cortical activity but still allowing enough disinhibition beneficial for plastic changes as during learning. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Resting state brain dynamics and its transients: a combined TMS-EEG study.

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Bonnard, Mireille; Chen, Sophie; Gaychet, Jérôme; Carrere, Marcel; Woodman, Marmaduke; Giusiano, Bernard; Jirsa, Viktor

2016-08-04

The brain at rest exhibits a spatio-temporally rich dynamics which adheres to systematic behaviours that persist in task paradigms but appear altered in disease. Despite this hypothesis, many rest state paradigms do not act directly upon the rest state and therefore cannot confirm hypotheses about its mechanisms. To address this challenge, we combined transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to study brain's relaxation toward rest following a transient perturbation. Specifically, TMS targeted either the medial prefrontal cortex (MPFC), i.e. part of the Default Mode Network (DMN) or the superior parietal lobule (SPL), involved in the Dorsal Attention Network. TMS was triggered by a given brain state, namely an increase in occipital alpha rhythm power. Following the initial TMS-Evoked Potential, TMS at MPFC enhances the induced occipital alpha rhythm, called Event Related Synchronisation, with a longer transient lifetime than TMS at SPL, and a higher amplitude. Our findings show a strong coupling between MPFC and the occipital alpha power. Although the rest state is organized around a core of resting state networks, the DMN functionally takes a special role among these resting state networks.

Repetitive transcranial magnetic stimulation in psychiatry

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Biswa Ranjan Mishra

2011-01-01

Full Text Available Repetitive transcranial magnetic stimulation (rTMS is a non-invasive and relatively painless tool that has been used to study various cognitive functions as well as to understand the brain-behavior relationship in normal individuals as well as in those with various neuropsychiatric disorders. It has also been used as a therapeutic tool in various neuropsychiatric disorders because of its ability to specifically modulate distinct brain areas. Studies have shown that repeated stimulation at low frequency produces long-lasting inhibition, which is called as long-term depression, whereas repeated high-frequency stimulation can produce excitation through long-term potentiation. This paper reviews the current status of rTMS as an investigative and therapeutic modality in various neuropsychiatric disorders. It has been used to study the cortical and subcortical functions, neural plasticity and brain mapping in normal individuals and in various neuropsychiatric disorders. rTMS has been most promising in the treatment of depression, with an overall milder adverse effect profile compared with electroconvulsive therapy. In other neuropsychiatric disorders such as schizophrenia, mania, epilepsy and substance abuse, it has been found to be useful, although further studies are required to establish therapeutic efficacy. It appears to be ineffective in the treatment of obsessive compulsive disorder. There is a paucity of studies of efficacy and safety of rTMS in pediatric and geriatric population. Although it appears safe, further research is required to optimize its efficacy and reduce the side-effects. Magnetic seizure therapy, which involves producing seizures akin to electroconvulsive therapy, appears to be of comparable efficacy in the treatment of depression with less cognitive adverse effects.

Distinguishing the Central Drive to Tremor in Parkinson's Disease and Essential Tremor

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Brittain, John-Stuart; Cagnan, Hayriye; Mehta, Arpan R.; Saifee, Tabish A.; Edwards, Mark J.

2015-01-01

Parkinson's disease (PD) and essential tremor (ET) are the two most common movement disorders. Both have been associated with similar patterns of network activation leading to the suggestion that they may result from similar network dysfunction, specifically involving the cerebellum. Here, we demonstrate that parkinsonian tremors and ETs result from distinct patterns of interactions between neural oscillators. These patterns are reflected in the tremors' derived frequency tolerance, a novel measure readily attainable from bedside accelerometry. Frequency tolerance characterizes the temporal evolution of tremor by quantifying the range of frequencies over which the tremor may be considered stable. We found that patients with PD (N = 24) and ET (N = 21) were separable based on their frequency tolerance, with PD associated with a broad range of stable frequencies whereas ET displayed characteristics consistent with a more finely tuned oscillatory drive. Furthermore, tremor was selectively entrained by transcranial alternating current stimulation applied over cerebellum. Narrow frequency tolerances predicted stronger entrainment of tremor by stimulation, providing good evidence that the cerebellum plays an important role in pacing those tremors. The different patterns of frequency tolerance could be captured with a simple model based on a broadly coupled set of neural oscillators for PD, but a more finely tuned set of oscillators in ET. Together, these results reveal a potential organizational principle of the human motor system, whose disruption in PD and ET dictates how patients respond to empirical, and potentially therapeutic, interventions that interact with their underlying pathophysiology. PMID:25589772

Language pathway tracking: comparing nTMS-based DTI fiber tracking with a cubic ROIs-based protocol.

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Negwer, Chiara; Sollmann, Nico; Ille, Sebastian; Hauck, Theresa; Maurer, Stefanie; Kirschke, Jan S; Ringel, Florian; Meyer, Bernhard; Krieg, Sandro M

2017-03-01

OBJECTIVE Diffusion tensor imaging (DTI) fiber tracking (FT) has been widely used in glioma surgery in recent years. It can provide helpful information about subcortical structures, especially in patients with eloquent space-occupying lesions. This study compared the newly developed navigated transcranial magnetic stimulation (nTMS)-based DTI FT of language pathways with the most reproducible protocol for language pathway tractography, using cubic regions of interest (ROIs) for the arcuate fascicle. METHODS Thirty-seven patients with left-sided perisylvian lesions underwent language mapping by repetitive nTMS. DTI FT was performed using the cubic ROIs-based protocol and the authors' nTMS-based DTI FT approach. The same minimal fiber length and fractional anisotropy were chosen (50 mm and 0.2, respectively). Both protocols were performed with standard clinical tractography software. RESULTS Both methods visualized language-related fiber tracts (i.e., corticonuclear tract, arcuate fascicle, uncinate fascicle, superior longitudinal fascicle, inferior longitudinal fascicle, arcuate fibers, commissural fibers, corticothalamic fibers, and frontooccipital fascicle) in all 37 patients. Using the cubic ROIs-based protocol, 39.9% of these language-related fiber tracts were detected in the examined patients, as opposed to 76.0% when performing nTMS-based DTI FT. For specifically tracking the arcuate fascicle, however, the cubic ROIs-based approach showed better results (97.3% vs 75.7% with nTMS-based DTI FT). CONCLUSIONS The cubic ROIs-based protocol was designed for arcuate fascicle tractography, and this study shows that it is still useful for this intention. However, superior results were obtained using the nTMS-based DTI FT for visualization of other language-related fiber tracts.

Repetitive transcranial magnetic stimulation in cervical dystonia: effect of site and repetition in a randomized pilot trial.

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Sarah Pirio Richardson

Full Text Available Dystonia is characterized by abnormal posturing due to sustained muscle contraction, which leads to pain and significant disability. New therapeutic targets are needed in this disorder. The objective of this randomized, sham-controlled, blinded exploratory study is to identify a specific motor system target for non-invasive neuromodulation and to evaluate this target in terms of safety and tolerability in the cervical dystonia (CD population. Eight CD subjects were given 15-minute sessions of low-frequency (0.2 Hz repetitive transcranial magnetic stimulation (rTMS over the primary motor cortex (MC, dorsal premotor cortex (dPM, supplementary motor area (SMA, anterior cingulate cortex (ACC and a sham condition with each session separated by at least two days. The Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS score was rated in a blinded fashion immediately pre- and post-intervention. Secondary outcomes included physiology and tolerability ratings. The mean change in TWSTRS severity score by site was 0.25 ± 1.7 (ACC, -2.9 ± 3.4 (dPM, -3.0 ± 4.8 (MC, -0.5 ± 1.1 (SHAM, and -1.5 ± 3.2 (SMA with negative numbers indicating improvement in symptom control. TWSTRS scores decreased from Session 1 (15.1 ± 5.1 to Session 5 (11.0 ± 7.6. The treatment was tolerable and safe. Physiology data were acquired on 6 of 8 subjects and showed no change over time. These results suggest rTMS can modulate CD symptoms. Both dPM and MC are areas to be targeted in further rTMS studies. The improvement in TWSTRS scores over time with multiple rTMS sessions deserves further evaluation.

Repetitive Transcranial Magnetic Stimulation for Clinical Applications in Neurological and Psychiatric Disorders: An Overview

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Machado, Sergio; Arias-Carrión, Oscar; Paes, Flávia; Vieira, Renata Teles; Caixeta, Leonardo; Novaes, Felipe; Marinho, Tamires; Almada, Leonardo Ferreira; Silva, Adriana Cardoso; Nardi, Antonio Egidio

2013-01-01

Neurological and psychiatric disorders are characterized by several disabling symptoms for which effective, mechanism-based treatments remain elusive. Consequently, more advanced non-invasive therapeutic methods are required. A method that may modulate brain activity and be viable for use in clinical practice is repetitive transcranial magnetic stimulation (rTMS). It is a non-invasive procedure whereby a pulsed magnetic field stimulates electrical activity in the brain. Here, we focus on the basic foundation of rTMS, the main stimulation parametters, the factors that influence individual responses to rTMS and the experimental advances of rTMS that may become a viable clinical application to treat neurological and psychiatric disorders. The findings showed that rTMS can improve some symptoms associated with these conditions and might be useful for promoting cortical plasticity in patients with neurological and psychiatric disorders. However, these changes are transient and it is premature to propose these applications as realistic therapeutic options, even though the rTMS technique has been evidenced as a potential modulator of sensorimotor integration and neuroplasticity. Functional imaging of the region of interest could highlight the capacity of rTMS to bring about plastic changes of the cortical circuitry and hint at future novel clinical interventions. Thus, we recommend that further studies clearly determine the role of rTMS in the treatment of these conditions. Finally, we must remember that however exciting the neurobiological mechanisms might be, the clinical usefulness of rTMS will be determined by its ability to provide patients with neurological and psychiatric disorders with safe, long-lasting and substantial improvements in quality of life. PMID:25610279

Where and what TMS activates: Experiments and modeling.

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Laakso, Ilkka; Murakami, Takenobu; Hirata, Akimasa; Ugawa, Yoshikazu

Despite recent developments in navigation and modeling techniques, the type and location of the structures that are activated by transcranial magnetic stimulation (TMS) remain unknown. We studied the relationships between electrophysiological measurements and electric fields induced in the brain to locate the TMS activation site. The active and resting motor thresholds of the first dorsal interosseous muscle were recorded in 19 subjects (7 female, 12 male, age 22 ± 4 years) using anteromedially oriented monophasic TMS at multiple locations over the left primary motor cortex (M1). Structural MR images were used to construct electric field models of each subject's head and brain. The cortical activation site was estimated by finding where the calculated electric fields best explained the coil-location dependency of the measured MTs. The experiments and modeling showed individual variations both in the measured motor thresholds (MTs) and in the computed electric fields. When the TMS coil was moved on the scalp, the calculated electric fields in the hand knob region were shown to vary consistently with the measured MTs. Group-level analysis indicated that the electric fields were significantly correlated with the measured MTs. The strongest correlations (R 2  = 0.69), which indicated the most likely activation site, were found in the ventral and lateral part of the hand knob. The site was independent of voluntary contractions of the target muscle. The study showed that TMS combined with personalized electric field modeling can be used for high-resolution mapping of the motor cortex. Copyright © 2017 Elsevier Inc. All rights reserved.

Differences in striatal dopamine transporter density between tremor dominant and non-tremor Parkinson's disease

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Kaasinen, Valtteri; Kinos, Maija; Joutsa, Juho [University of Turku and Turku University Hospital, Division of Clinical Neurosciences, Turku (Finland); University of Turku and Turku University Hospital, Turku PET Centre, Turku (Finland); Seppaenen, Marko [University of Turku and Turku University Hospital, Turku PET Centre, Turku (Finland); University of Turku and Turku University Hospital, Department of Clinical Physiology and Nuclear Medicine, Turku (Finland); Noponen, Tommi [University of Turku and Turku University Hospital, Department of Clinical Physiology and Nuclear Medicine, Turku (Finland)

2014-10-15

Parkinson's disease (PD) can manifest with a tremor-dominant or a non-tremor (akinetic-rigid) phenotype. Although the tremor-dominant subtype may show a better prognosis, there is limited information on the phenotypic differences regarding the level of striatal dopamine transmission. The present study investigated striatal dopamine transporter (DAT) binding characteristics in a large sample of patients with and without tremor. [{sup 123}I]FP-CIT SPECT scans of 231 patients with a clinical diagnosis of PD and abnormal FP-CIT binding (157 with tremor, 74 without tremor) and 230 control patients with normal FP-CIT binding (148 with tremor, 82 without tremor) were analysed using an automated region-of-interest analysis of the scans (BRASS). Specific striatal binding ratios were compared between phenotypes and groups using age, sex, and symptom duration, predominant side of symptoms, dopaminergic medications and scanner as covariates. Patients with PD had 28.1 - 65.0 % lower binding in all striatal regions compared to controls (p < 0.001). The mean FP-CIT caudate nucleus uptake and the left caudate nucleus uptake were higher in PD patients with tremor than in PD patients without tremor (mean 9.0 % higher, left 10.5 % higher; p < 0.05), whereas there were no differences between tremor and non-tremor control patients. No significant effects of tremor on DAT binding were observed in the anterior or posterior putamen. The motor phenotype is associated with the extent of caudate dopamine terminal loss in PD, as dopamine function is relatively more preserved in tremor patients. Symptom type is related to caudate dopamine function only in association with Parkinsonian dopaminergic degeneration, not in intact dopamine systems in patients with non-PD tremor. (orig.)

Is tremor related to celiac disease?

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Ameghino, Lucia; Rossi, Malco Damian; Cerquetti, Daniel; Merello, Marcelo

2017-06-14

Neurological features in celiac disease (CD) are not rare (5%-36%), but tremor is scarcely described. Subjects with CD and healthy controls completed an online survey using WHIGET tremor rating scale. One thousand five hundred and twelve subjects completed the survey, finally 674 CD patients and 290 healthy subjects were included. A higher prevalence of tremor in CD patients was observed in comparison to controls (28% vs 14%, P tremor in CD patients with and without tremor was 25% and 20% ( P = 0.2), while in the control group it was 41% and 10% ( P tremor showed a higher frequency of family history of tremor when compared to CD patients with tremor (41.5% vs 24.6%, P = 0.03). The results suggested that tremor in CD might be more frequent and possibly related to the disease itself and not due to associated essential tremor.

Bilateral Hypertrophic Olivary Degeneration and Holmes Tremor without Palatal Tremor: An Unusual Association

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Carlos Cosentino

2016-07-01

Full Text Available Background: Lesions in the Guillain–Mollaret triangle or dentate-rubro-olivary pathway may lead to hypertrophic olivary degeneration (HOD, a secondary trans-synaptic degeneration of the inferior olivary nucleus. HOD is usually associated with palatal tremor and rarely with Holmes tremor. Bilateral HOD is a very unusual condition and very few cases are reported. Case Report: We report here two cases of bilateral HOD after two different vascular lesions located at the decussation of superior cerebellar peduncles, thus impairing both central tegmental tracts and interrupting bilaterally the dentate-rubral-olivary pathway. Interestingly, both developed bilateral Holmes tremor but not palatal tremor. Discussion: Lesions in some of the components in the Guillain–Mollaret triangle may develop Holmes tremor with HOD and without palatal tremor. Magnetic resonance imaging is an invaluable tool in these cases. Better understanding of the pathways in this loop is needed.

Acoustic Characteristics of Simulated Respiratory-Induced Vocal Tremor

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Lester, Rosemary A.; Story, Brad H.

2013-01-01

Purpose: The purpose of this study was to investigate the relation of respiratory forced oscillation to the acoustic characteristics of vocal tremor. Method: Acoustical analyses were performed to determine the characteristics of the intensity and fundamental frequency (F[subscript 0]) for speech samples obtained by Farinella, Hixon, Hoit, Story,…

Is it time to introduce repetitive transcranial magnetic stimulation into standard clinical practice for the treatment of depressive disorders?

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Fitzgerald, Paul

2003-02-01

To examine issues relating to the potential introduction of repetitive transcranial magnetic stimulation (rTMS) into clinical practice as a treatment for depression. A review of the outcomes literature accompanied by an analysis of issues relating to the potential advantages and pitfalls of the introduction of rTMS as a treatment strategy. Evidence is progressively accumulating that rTMS has antidepressant properties that are clinically relevant. These effects are biologically plausible and supported by basic research. Patients with therapy-resistant depression have few treatment alternatives and experience significant suffering, thus justifying the early introduction of a new treatment such as rTMS for this patient group. However, this must be balanced by a need to foster considerable further research and not to raise expectations unreasonably. It is timely for rTMS to be made more available to patients with treatment-resistant mood disorders. This need not be limited to clinical research trials but should only occur in medical settings where continual evaluation and research is conducted.

The many roads to tremor.

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Brittain, John-Stuart; Brown, Peter

2013-12-01

Tremor represents one of the most prominent examples of aberrant synchronisation within the human motor system, and Essential Tremor (ET) is by far the most common tremor disorder. Yet, even within ET there is considerable variation, and patients may have contrasting amounts of postural and intention tremor. Recently, Pedrosa et al. (2013) challenged tremor circuits in a cohort of patients presenting with ET, by applying low-frequency deep brain stimulation within thalamus. This interventional approach provided strong evidence that distinct (yet possibly overlapping) neural substrates are responsible for postural and intention tremor in ET. Intention tremor, and not postural tremor, was exacerbated by low frequency stimulation, and the effect was localised in the region of the ventrolateral thalamus in such a way as to implicate cerebello-thalamic pathways. These results, taken in conjunction with the contemporary literature, reveal that pathological changes exaggerate oscillatory synchrony in selective components of an extensive and distributed motor network, and that synchronisation within these networks is further regulated according to motor state. Through a combination of pathological and more dynamic physiological factors, activity then spills out into the periphery in the form of tremor. The findings of Pedrosa et al. (2013) are timely as they coincide with an emerging notion that tremor may result through selective dysregulation within a broader tremorgenic network. © 2013.

Lateralized Contribution of Prefrontal Cortex in Controlling Task-Irrelevant Information during Verbal and Spatial Working Memory Tasks: rTMS Evidence

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Sandrini, Marco; Rossini, Paolo Maria; Miniussi, Carlo

2008-01-01

The functional organization of working memory (WM) in the human prefrontal cortex remains unclear. The present study used repetitive transcranial magnetic stimulation (rTMS) to clarify the role of the dorsolateral prefrontal cortex (dlPFC) both in the types of information (verbal vs. spatial), and the types of processes (maintenance vs.…

A Lack of Clinical Effect of High-frequency rTMS to Dorsolateral Prefrontal Cortex on Bulimic Symptoms: A Randomised, Double-blind Trial.

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Gay, Aurelia; Jaussent, Isabelle; Sigaud, Torrance; Billard, Stephane; Attal, Jerome; Seneque, Maude; Galusca, Bogdan; Van Den Eynde, Frederique; Massoubre, Catherine; Courtet, Philippe; Guillaume, Sebastien

2016-11-01

Studies suggest that stimulation of the left dorsolateral prefrontal cortex (DLPFC) reduces food craving in bulimic patients, but evidence supporting repetitive transcranial magnetic stimulation (rTMS) as a therapeutic tool is lacking. We investigated the safety and therapeutic efficacy of an adjunct high-frequency rTMS programme targeting the left DLPFC. Forty-seven women with bulimia nervosa were randomised to a real or sham stimulation group. The real group underwent 10 rTMS sessions, each consisting of 20 trains of 5 seconds with 55-second intervals between trains, at a frequency of 10 Hz. The main outcome was the number of binge episodes in the 15 days following the end of stimulation. Overall, no significant improvement in bingeing and purging symptoms was noted after the programme. rTMS was well tolerated. This suggests that 10 sessions of high-frequency rTMS to the left DLPFC provide no greater benefit than placebo. Future studies should consider methodological issues as well as alternative targets. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

Effect of electroconvulsive therapy in repetitive transcranial magnetic stimulation non-responder MDD patients: a preliminary study.

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Dannon, P N; Grunhaus, L

2001-09-01

The aim of this study was to measure the effectiveness of ECT in-patients who had failed to respond to a course of repetitive transcranial magnetic stimulation (rTMS) treatment. Seventeen patients with severe MDD who had not responded to a course of rTMS were switched to receive ECT treatments. All the patients were assessed with the Hamilton Rating Scale for Depression, the Global Assessment Functioning Scale, the Global Depression Scale, and the Pittsburgh Sleep Quality Index. Response to the treatment was defined as a 50% decrease in HDRS final score and a final GAS higher than 60. Seven out of 17 patients responded to ECT. Three out of 5 non-psychotics and 4 out of 12 psychotic patients responded. ECT seems to be an effective treatment for 40% of patients who failed to respond to rTMS treatment. Whether this is a result of reduced responsiveness to ECT in rTMS-resistant patients or a consequence of small sample size requires further study.

Rest tremor in idiopathic adult-onset dystonia.

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Gigante, A F; Berardelli, A; Defazio, G

2016-05-01

Tremor in dystonia has been described as a postural or kinetic abnormality. In recent series, however, patients with idiopathic adult-onset dystonia also displayed rest tremor. The frequency and distribution of rest tremor were studied in a cohort of 173 consecutive Italian patients affected by various forms of idiopathic adult-onset dystonia attending our movement disorder clinic over 8 months. Examination revealed tremor in 59/173 patients (34%): 12 patients had head tremor, 34 patients had arm tremor, whilst 13 patients presented tremor in both sites. Head tremor was postural in all patients, whereas arm tremor was postural/kinetic in 28 patients, only at rest in one and both postural/kinetic and at rest in 18 patients. Patients with tremor were more likely to have segmental/multifocal dystonia. Patients who had rest tremor (either alone or associated with action tremor) had a higher age at dystonia onset and a greater frequency of dystonic arm involvement than patients with action tremor alone or without tremor. Both action and rest tremor are part of the tremor spectrum of adult-onset dystonia and are more frequently encountered in segmental/multifocal dystonia. The higher age at dystonia onset and the greater frequency of arm dystonia in patients with rest tremor may have pathophysiological implications and may account, at least in part, for the previous lack of identification of rest tremor as one possible type of tremor present in dystonia. © 2016 EAN.

Streaking tremor in Cascadia

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Vidale, J. E.; Ghosh, A.; Sweet, J. R.; Creager, K. C.; Wech, A.; Houston, H.

2009-12-01

Details of tremor deep in subduction zones is damnably difficult to glimpse because of the lack of crisp initial arrivals, low waveform coherence, uncertain focal mechanisms, and the probability of simultaneous activity across extended regions. Yet such details hold out the best hope to illuminate the unknown mechanisms underlying episodic tremor and slip. Attacking this problem with brute force, we pointed a small, very dense seismic array down at the migration path of a good-sized episodic tremor and slip (ETS) event. In detail, it was an 84-element, 1300-m-aperture temporary seismic array in northern Washington, and the migration path of the May 2008 ETS event was 30-40 km directly underneath. Our beamforming technique tracked the time, incident angle, and azimuth of tremor radiation in unprecedented detail. We located the tremor by assuming it occurs on the subduction interface, estimated relative tremor moment released by each detected tremor window, and mapped it on the interface [Ghosh et al., GRL, 2009]. Fortunately for our ability to image it, the tremor generally appears to emanate from small regions, and we were surprised by how steadily the regions migrated with time. For the first time in Cascadia, we found convergence-parallel transient streaks of tremor migrating at velocities of several tens of km/hr, with movement in both up- and down-dip directions. Similar patterns have been seen in Japan [Shelly, G3, 2007]. This is in contrast to the long-term along-strike marching of tremor at 10 km/day. These streaks tend to propagate steadily and often repeat the same track on the interface multiple times. They light up persistent moment patches on the interface by a combination of increased amplitude and longer residence time within the patches. The up- and down-dip migration dominates the 2 days of tremor most clearly imaged by our array. The tendency of the streaks to fill in bands is the subject of the presentation of Ghosh et al. here. The physical

Bilateral Repetitive Transcranial Magnetic Stimulation Combined with Intensive Swallowing Rehabilitation for Chronic Stroke Dysphagia: A Case Series Study

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Ryo Momosaki

2014-03-01

Full Text Available The purpose of this study was to clarify the safety and feasibility of a 6-day protocol of bilateral repetitive transcranial magnetic stimulation (rTMS combined with intensive swallowing rehabilitation for chronic poststroke dysphagia. In-hospital treatment was provided to 4 poststroke patients (age at treatment: 56-80 years; interval between onset of stroke and treatment: 24-37 months with dysphagia. Over 6 consecutive days, each patient received 10 sessions of rTMS at 3 Hz applied to the pharyngeal motor cortex bilaterally, followed by 20 min of intensive swallowing rehabilitation exercise. The swallowing function was evaluated by the Penetration Aspiration Scale (PAS, Modified Mann Assessment of Swallowing Ability (MMASA, Functional Oral Intake Scale (FOIS, laryngeal elevation delay time (LEDT and Repetitive Saliva-Swallowing Test (RSST on admission and at discharge. All patients completed the 6-day treatment protocol and none showed any adverse reactions throughout the treatment. The combination treatment improved laryngeal elevation delay time in all patients. Our proposed protocol of rTMS plus swallowing rehabilitation exercise seems to be safe and feasible for chronic stroke dysphagia, although its efficacy needs to be confirmed in a large number of patients.

Seeing touch in the somatosensory cortex: a TMS study of the visual perception of touch.

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Bolognini, Nadia; Rossetti, Angela; Maravita, Angelo; Miniussi, Carlo

2011-12-01

Recent studies suggest the existence of a visuo-tactile mirror system, comprising the primary (SI) and secondary (SII) somatosensory cortices, which matches observed touch with felt touch. Here, repetitive transcranial magnetic stimulation (rTMS) was used to determine whether SI or SII play a functional role in the visual processing of tactile events. Healthy participants performed a visual discrimination task with tactile stimuli (a finger touching a hand) and a control task (a finger moving without touching). During both tasks, rTMS was applied over either SI or SII, and to the occipital cortex. rTMS over SI selectively reduced subject performance for interpreting whether a contralateral visual tactile stimulus contains a tactile event, whereas SII stimulation impaired visual processing regardless of the tactile component. These findings provide evidence for a multimodal sensory-motor system with mirror properties, where somatic and visual properties of action converge. SI, a cortical area traditionally viewed as modality-specific, is selectively implicated in the visual processing of touch. These results are in line with the existence of a sensory mirror system mediating the embodied simulation concept. Copyright © 2010 Wiley Periodicals, Inc.

Seismic wave triggering of nonvolcanic tremor, episodic tremor and slip, and earthquakes on Vancouver Island

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Rubinstein, Justin L.; Gomberg, Joan; Vidale, John E.; Wech, Aaron G.; Kao, Honn; Creager, Kenneth C.; Rogers, Garry

2009-02-01

We explore the physical conditions that enable triggering of nonvolcanic tremor and earthquakes by considering local seismic activity on Vancouver Island, British Columbia during and immediately after the arrival of large-amplitude seismic waves from 30 teleseismic and 17 regional or local earthquakes. We identify tremor triggered by four of the teleseismic earthquakes. The close temporal and spatial proximity of triggered tremor to ambient tremor and aseismic slip indicates that when a fault is close to or undergoing failure, it is particularly susceptible to triggering of further events. The amplitude of the triggering waves also influences the likelihood of triggering both tremor and earthquakes such that large amplitude waves triggered tremor in the absence of detectable aseismic slip or ambient tremor. Tremor and energy radiated from regional/local earthquakes share the same frequency passband so that tremor cannot be identified during these smaller, more frequent events. We confidently identify triggered local earthquakes following only one teleseism, that with the largest amplitude, and four regional or local events that generated vigorous aftershock sequences in their immediate vicinity. Earthquakes tend to be triggered in regions different from tremor and with high ambient seismicity rates. We also note an interesting possible correlation between large teleseismic events and episodic tremor and slip (ETS) episodes, whereby ETS events that are "late" and have built up more stress than normal are susceptible to triggering by the slight nudge of the shaking from a large, distant event, while ETS events that are "early" or "on time" are not.

Illusory sensation of movement induced by repetitive transcranial magnetic stimulation

DEFF Research Database (Denmark)

Christensen, Mark Schram; Lundbye-Jensen, Jesper; Grey, Michael James

2010-01-01

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 with ischemic nerve block, and in the leg with spinal nerve block. Movement sensation was assessed following trains of high-frequency repetitive transcranial magnetic stimulation applied over...... premotor cortex stimulation was less affected by sensory and motor deprivation than was primary motor cortex stimulation. We propose that repetitive transcranial magnetic stimulation over dorsal premotor cortex produces a corollary discharge that is perceived as movement....

Repetitive deep transcranial magnetic stimulation improves verbal fluency and written language in a patient with primary progressive aphasia-logopenic variant (LPPA).

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Trebbastoni, Alessandro; Raccah, Ruggero; de Lena, Carlo; Zangen, Abraham; Inghilleri, Maurizio

2013-07-01

To date, no therapies are available for the logopenic variant of primary progressive aphasia (LPPA). Even though deep repetitive transcranial magnetic stimulation (rTMS) may improve cognitive functions in some neurodegenerative disorders, no previous studies investigated its effects in patients with LPPA. Our aim was to investigate the effects on cognitive function of high frequency rTMS (hf-rTMS) delivered over the left dorso-lateral prefrontal cortex (DLPFC) through a coil designed for deep rTMS, compared to a SHAM stimulation, in a right-handed patient with LPPA. The patient presented a progressive language impairment (phonological errors in speech and naming, impaired single word retrieval and sentences repetition) and predominant left perisylvian atrophy and hypoperfusion. He received four stimulation cycles (two REAL and two SHAM) each of whom lasted 20 min for 5 consecutive days. Patient's performances in frontal, visuo-spatial and linguistic tasks were evaluated before and after each stimulation session. Test scores after REAL were compared with those obtained at baseline and after SHAM. We found a temporary and highly significant improvement in the linguistic skills (both oral and written tasks) but not in the other cognitive domains tested, after REAL, but not SHAM stimulations. Hf-rTMS delivered over the DLPFC could improve language in LPPA by enhancing long-term potentiation and synaptic plasticity within the stimulated and interconnected areas involved in language network. Our findings might prompt future researches into the feasibility and efficacy of deep hf-rTMS as a therapeutic tool in progressive aphasia syndromes and other neurodegenerative disorders. Copyright © 2013 Elsevier Inc. All rights reserved.

Assessment of Vascular Stent Heating with Repetitive Transcranial Magnetic Stimulation.

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Varnerin, Nicole; Mirando, David; Potter-Baker, Kelsey A; Cardenas, Jesus; Cunningham, David A; Sankarasubramanian, Vishwanath; Beall, Erik; Plow, Ela B

2017-05-01

A high proportion of patients with stroke do not qualify for repetitive transcranial magnetic stimulation (rTMS) clinical studies due to the presence of metallic stents. The ultimate concern is that any metal could become heated due to eddy currents. However, to date, no clinical safety data are available regarding the risk of metallic stents heating with rTMS. We tested the safety of common rTMS protocols (1 Hz and 10 Hz) with stents used commonly in stroke, nitinol and elgiloy. In our method, stents were tested in gelled saline at 2 different locations: at the center and at the lobe of the coil. In addition, at each location, stent heating was evaluated in 3 different orientations: parallel to the long axis of coil, parallel to the short axis of the coil, and perpendicular to the plane of the coil. We found that stents did not heat to more than 1°C with either 1 Hz rTMS or 10 Hz rTMS in any configuration or orientation. Heating in general was greater at the lobe when the stent was oriented perpendicularly. Our study represents a new method for ex vivo quantification of stent heating. We have found that heating of stents was well below the Food and Drug Administration standards of 2°C. Thus, our study paves the way for in vivo testing of rTMS (≤10 Hz) in the presence of implanted magnetic resonance imaging-compatible stents in animal studies. When planning human safety studies though, geometry, orientation, and location relative to the coil would be important to consider as well. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Tracing tremor: Neural correlates of essential tremor and its treatment

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Buijink, A.W.G.

2016-01-01

This thesis focusses on the neural correlates and treatment of the neurological movement disorder essential tremor (ET). ET, one of the most common movement disorders in clinical neurology, is characterized by an action and intention tremor of mainly the hands, hampering daily life activities.

Genetics Home Reference: essential tremor

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... Facebook Twitter Home Health Conditions Essential tremor Essential tremor Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Essential tremor is a movement disorder that causes involuntary, rhythmic ...

Investigating dynamical information transfer in the brain following a TMS pulse: Insights from structural architecture.

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Amico, Enrico; Van Mierlo, Pieter; Marinazzo, Daniele; Laureys, Steven

2015-01-01

Transcranial magnetic stimulation (TMS) has been used for more than 20 years to investigate connectivity and plasticity in the human cortex. By combining TMS with high-density electroencephalography (hd-EEG), one can stimulate any cortical area and measure the effects produced by this perturbation in the rest of the cerebral cortex. The purpose of this paper is to investigate changes of information flow in the brain after TMS from a functional and structural perspective, using multimodal modeling of source reconstructed TMS/hd-EEG recordings and DTI tractography. We prove how brain dynamics induced by TMS is constrained and driven by its structure, at different spatial and temporal scales, especially when considering cross-frequency interactions. These results shed light on the function-structure organization of the brain network at the global level, and on the huge variety of information contained in it.

Surgery for Dystonia and Tremor.

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Crowell, Jason L; Shah, Binit B

2016-03-01

Surgical procedures for dystonia and tremor have evolved over the past few decades, and our understanding of risk, benefit, and predictive factors has increased substantially in that time. Deep brain stimulation (DBS) is the most utilized surgical treatment for dystonia and tremor, though lesioning remains an effective option in appropriate patients. Dystonic syndromes that have shown a substantial reduction in severity secondary to DBS are isolated dystonia, including generalized, cervical, and segmental, as well as acquired dystonia such as tardive dystonia. Essential tremor is quite amenable to DBS, though the response of other forms of postural and kinetic tremor is not nearly as robust or consistent based on available evidence. Regarding targeting, DBS lead placement in the globus pallidus internus has shown marked efficacy in dystonia reduction. The subthalamic nucleus is an emerging target, and increasing evidence suggests that this may be a viable target in dystonia as well. The ventralis intermedius nucleus of the thalamus is the preferred target for essential tremor, though targeting the subthalamic zone/caudal zona incerta has shown promise and may emerge as another option in essential tremor and possibly other tremor disorders. In the carefully selected patient, DBS and lesioning procedures are relatively safe and effective for the management of dystonia and tremor.

Backprojection of volcanic tremor

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Haney, Matthew M.

2014-01-01

Backprojection has become a powerful tool for imaging the rupture process of global earthquakes. We demonstrate the ability of backprojection to illuminate and track volcanic sources as well. We apply the method to the seismic network from Okmok Volcano, Alaska, at the time of an escalation in tremor during the 2008 eruption. Although we are able to focus the wavefield close to the location of the active cone, the network array response lacks sufficient resolution to reveal kilometer-scale changes in tremor location. By deconvolving the response in successive backprojection images, we enhance resolution and find that the tremor source moved toward an intracaldera lake prior to its escalation. The increased tremor therefore resulted from magma-water interaction, in agreement with the overall phreatomagmatic character of the eruption. Imaging of eruption tremor shows that time reversal methods, such as backprojection, can provide new insights into the temporal evolution of volcanic sources.

Dystonia Associated with Idiopathic Slow Orthostatic Tremor

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Christopher Kobylecki

2016-02-01

Full Text Available Background: We aimed to characterize the clinical and electrophysiological features of patients with slow orthostatic tremor.Case Report: The clinical and neurophysiological data of patients referred for lower limb tremor on standing were reviewed. Patients with symptomatic or primary orthostatic tremor were excluded. Eight patients were identified with idiopathic slow 4–8 Hz orthostatic tremor, which was associated with tremor and dystonia in cervical and upper limb musculature. Coherence analysis in two patients showed findings different to those seen in primary orthostatic tremor.Discussion: Slow orthostatic tremor may be associated with dystonia and dystonic tremor.

Poststroke dysphagia rehabilitation by repetitive transcranial magnetic stimulation: a noncontrolled pilot study.

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Verin, E; Leroi, A M

2009-06-01

Poststroke dysphagia is frequent and significantly increases patient mortality. In two thirds of cases there is a spontaneous improvement in a few weeks, but in the other third, oropharyngeal dysphagia persists. Repetitive transcranial magnetic stimulation (rTMS) is known to excite or inhibit cortical neurons, depending on stimulation frequency. The aim of this noncontrolled pilot study was to assess the feasibility and the effects of 1-Hz rTMS, known to have an inhibitory effect, on poststroke dysphagia. Seven patients (3 females, age = 65 +/- 10 years), with poststroke dysphagia due to hemispheric or subhemispheric stroke more than 6 months earlier (56 +/- 50 months) diagnosed by videofluoroscopy, participated in the study. rTMS at 1 Hz was applied for 20 min per day every day for 5 days to the healthy hemisphere to decrease transcallosal inhibition. The evaluation was performed using the dysphagia handicap index and videofluoroscopy. The dysphagia handicap index demonstrated that the patients had mild oropharyngeal dysphagia. Initially, the score was 43 +/- 9 of a possible 120 which decreased to 30 +/- 7 (p study demonstrated that rTMS is feasible in poststroke dysphagia and improves swallowing coordination. Our results now need to be confirmed by a randomized controlled study with a larger patient population.

Thioredoxin is not a marker for treatment-resistance depression but associated with cognitive function: An rTMS study.

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Aydın, Efruz Pirdoğan; Genç, Abdullah; Dalkıran, Mihriban; Uyar, Ece Türkyilmaz; Deniz, İpek; Özer, Ömer Akil; Karamustafalıoğlu, Kayıhan Oğuz

2018-01-03

Elevated oxidative stress is known to play an important role in development of depression and cognitive dysfunction. To date, thioredoxin (TRX), an antioxidant protein, has been investigated as a marker for psychiatric disorders such as schizophrenia, bipolar disorder and autism but its relationship with depression is yet to be unknown. The aim of this study is to detect the TRX levels in patients with treatment-resistant depression (TRD), analyse the effect of rTMS (repetitive transcranial magnetic stimulation) application on TRX levels and display the relationship of TRX with cognitive areas. This study included 27 treatment-resistant unipolar depression patients and 29 healthy subjects. Patients were evaluated by Hamilton Depression Scale (HDRS), Hamilton Anxiety Scale (HARS) and Montreal Cognitive Assessment (MoCA) before and after rTMS application. 23 of TRD patients were applied high-frequency rTMS over left DLPFC for 2 to 4weeks and plasma TRX levels of patients and healthy subjects were measured. No significant difference was determined between the TRX levels of patients and healthy subjects (p>0.05). After rTMS application there were significant decrease in severity of depression (pTRX levels of the patients after rTMS application (p>0.005). High language scores of the patients were found to be associated with high TRX levels (pTRX levels cannot be used as a marker for TRD or rTMS treatment in TRD. In spite of this TRX levels have a positive correlation with language functions of the patients of TRD. More extensive studies are required to clarify the mechanism of action of TRX and the effect of TRX on cognitive functions. Copyright © 2017 Elsevier Inc. All rights reserved.

MR-based measurements and simulations of the magnetic field created by a realistic transcranial magnetic stimulation (TMS) coil and stimulator.

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Mandija, Stefano; Petrov, Petar I; Neggers, Sebastian F W; Luijten, Peter R; van den Berg, Cornelis A T

2016-11-01

Transcranial magnetic stimulation (TMS) is an emerging technique that allows non-invasive neurostimulation. However, the correct validation of electromagnetic models of typical TMS coils and the correct assessment of the incident TMS field (B TMS ) produced by standard TMS stimulators are still lacking. Such a validation can be performed by mapping B TMS produced by a realistic TMS setup. In this study, we show that MRI can provide precise quantification of the magnetic field produced by a realistic TMS coil and a clinically used TMS stimulator in the region in which neurostimulation occurs. Measurements of the phase accumulation created by TMS pulses applied during a tailored MR sequence were performed in a phantom. Dedicated hardware was developed to synchronize a typical, clinically used, TMS setup with a 3-T MR scanner. For comparison purposes, electromagnetic simulations of B TMS were performed. MR-based measurements allow the mapping and quantification of B TMS starting 2.5 cm from the TMS coil. For closer regions, the intra-voxel dephasing induced by B TMS prohibits TMS field measurements. For 1% TMS output, the maximum measured value was ~0.1 mT. Simulations reflect quantitatively the experimental data. These measurements can be used to validate electromagnetic models of TMS coils, to guide TMS coil positioning, and for dosimetry and quality assessment of concurrent TMS-MRI studies without the need for crude methods, such as motor threshold, for stimulation dose determination. Copyright © 2016 John Wiley & Sons, Ltd.

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

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

2009-01-01

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…

Treatment of essential tremor with arotinolol.

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Kuroda, Y; Kakigi, R; Shibasaki, H

1988-04-01

We investigated the effect of arotinolol, a new peripherally acting beta-adrenergic blocker, in 15 patients with essential tremor. The patients received 30 mg per day of arotinolol for 8 weeks. Accelerometer readings showed a significant reduction in amplitude of postural tremor after treatment. Action tremor also improved to essentially the same degree as postural tremor. The present findings support the view that the therapeutic effect of beta-blockers in essential tremor is mediated by peripheral beta-adrenergic receptors.

Repetitive transcranial magnetic stimulation as an adjuvant method in the treatment of depression: Preliminary results

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Jovičić Milica

2014-01-01

Full Text Available Introduction. Repetitive transcranial magnetic stimulation (rTMS is a method of brain stimulation which is increasingly used in both clinical practice and research. Up-to-date studies have pointed out a potential antidepressive effect of rTMS, but definitive superiority over placebo has not yet been confirmed. Objective. The aim of the study was to examine the effect of rTMS as an adjuvant treatment with antidepressants during 18 weeks of evaluation starting from the initial application of the protocol. Methods. Four patients with the diagnosis of moderate/severe major depression were included in the study. The protocol involved 2000 stimuli per day (rTMS frequency of 10 Hz, intensity of 120% motor threshold administered over the left dorsolateral prefrontal cortex (DLPFC for 15 days. Subjective and objective depressive symptoms were measured before the initiation of rTMS and repeatedly evaluated at week 3, 6, 12 and 18 from the beginning of the stimulation. Results. After completion of rTMS protocol two patients demonstrated a reduction of depressive symptoms that was sustained throughout the 15-week follow-up period. One patient showed a tendency of remission during the first 12 weeks of the study, but relapsed in week 18. One patient showed no significant symptom reduction at any point of follow-up. Conclusion. Preliminary findings suggest that rTMS has a good tolerability and can be efficient in accelerating the effect of antidepressants, particularly in individuals with shorter duration of depressive episodes and moderate symptom severity. [Projekat Ministarstva nauke Republike Srbije, br. III41029 i br. ON175090

Modulation of the Left Prefrontal Cortex with High Frequency Repetitive Transcranial Magnetic Stimulation Facilitates Gait in Multiple Sclerosis

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Amer M. Burhan

2015-01-01

Full Text Available Multiple Sclerosis (MS is a chronic central nervous system (CNS demyelinating disease. Gait abnormalities are common and disabling in patients with MS with limited treatment options available. Emerging evidence suggests a role of prefrontal attention networks in modulating gait. High-frequency repetitive transcranial magnetic stimulation (rTMS is known to enhance cortical excitability in stimulated cortex and its correlates. We investigated the effect of high-frequency left prefrontal rTMS on gait parameters in a 51-year-old Caucasian male with chronic relapsing/remitting MS with residual disabling attention and gait symptoms. Patient received 6 Hz, rTMS at 90% motor threshold using figure of eight coil centered on F3 location (using 10-20 electroencephalography (EEG lead localization system. GAITRite gait analysis system was used to collect objective gait measures before and after one session and in another occasion three consecutive daily sessions of rTMS. Two-tailed within subject repeated measure t-test showed significant enhancement in ambulation time, gait velocity, and cadence after three consecutive daily sessions of rTMS. Modulating left prefrontal cortex excitability using rTMS resulted in significant change in gait parameters after three sessions. To our knowledge, this is the first report that demonstrates the effect of rTMS applied to the prefrontal cortex on gait in MS patients.

Accuracy of forecast of mine tremors location

Energy Technology Data Exchange (ETDEWEB)

Jan Drzewieck [Central Mining Institute, Katowice (Poland)

2009-09-15

The Upper Silesian Coal Basin is one of the most active mining areas in the world in respect of seismicity. Underground mining in this area takes place in a special environment with a high degree of risk of unpredictable event occurrence. Especially dangerous are phenomena that occur during the extraction of deposits at great depths in the environment of compact rocks. Deep underground mining violates the balance of these rocks and induces dynamic phenomena at the longwall life (in terms of distance) referred to as mine tremors. The sources of these tremors are located in layers characterised by high strength, especially in thick sandstone strata occurring in the roof of the mined seam. In the paper a discussion is presented about the influence of mining intensity (longwall face speed) on the location of mine tremor sources, both in the direction of longwall life (in terms of distance) and towards the surface. The presented material has been prepared based on the results of tests and measurements carried out at the Central Mining Institute. 8 refs., 5 figs.

Comparative efficacy and acceptability of electroconvulsive therapy versus repetitive transcranial magnetic stimulation for major depression: A systematic review and multiple-treatments meta-analysis.

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Chen, Jian-Jun; Zhao, Li-Bo; Liu, Yi-Yun; Fan, Song-Hua; Xie, Peng

2017-03-01

The effects of electroconvulsive therapy (ECT) and bilateral, left prefrontal, and right prefrontal repetitive transcranial magnetic stimulation (rTMS) on major depressive disorder (MDD) have not been adequately addressed by previous studies. Here, a multiple-treatments meta-analysis, which incorporates evidence from direct and indirect comparisons from a network of trials, was performed to assess the efficacy and acceptability of these four treatment modalities on MDD. The literature was searched for randomized controlled trials (RCTs) on ECT, bilateral rTMS, and unilateral rTMS for treating MDD up to May 2016. The main outcome measures were response and drop-out rates. Data were obtained from 25 studies consisting of 1288 individuals with MDD. ECT was non-significantly more efficacious than B-rTMS, R-rTMS, and L-rTMS. Left prefrontal rTMS was non -significantly less efficacious than all other treatment modalities. In terms of acceptability, R-rTMS was non-significantly better tolerated than ECT, B-rTMS, and L-rTMS. ECT was the most efficacious treatment with the cumulative probabilities of being the most efficacious treatment being: ECT (65%), B-rTMS (25%), R-rTMS (8%), and L-rTMS (2%). R-rTMS was the best-tolerated treatment with the cumulative probabilities of being the best-tolerated treatment being: R-rTMS (52%), B-rTMS (17%), L-rTMS (16%), and ECT (14%). Coherence analysis detected no statistically significant incoherence in any comparisons of direct with indirect evidence for the response rate and drop-out rate. ECT was the most efficacious, but least tolerated, treatment, while R-rTMS was the best tolerated treatment for MDD. B-rTMS appears to have the most favorable balance between efficacy and acceptability. Copyright © 2016 Elsevier B.V. All rights reserved.

Multiple Resting-State Networks Are Associated With Tremors and Cognitive Features in Essential Tremor.

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Fang, Weidong; Chen, Huiyue; Wang, Hansheng; Zhang, Han; Liu, Mengqi; Puneet, Munankami; Lv, Fajin; Cheng, Oumei; Wang, Xuefeng; Lu, Xiurong; Luo, Tianyou

2015-12-01

The heterogeneous clinical features of essential tremor indicate that the dysfunctions of this syndrome are not confined to motor networks, but extend to nonmotor networks. Currently, these neural network dysfunctions in essential tremor remain unclear. In this study, independent component analysis of resting-state functional MRI was used to study these neural network mechanisms. Thirty-five essential tremor patients and 35 matched healthy controls with clinical and neuropsychological tests were included, and eight resting-state networks were identified. After considering the structure and head-motion factors and testing the reliability of the selected resting-state networks, we assessed the functional connectivity changes within or between resting-state networks. Finally, image-behavior correlation analysis was performed. Compared to healthy controls, essential tremor patients displayed increased functional connectivity in the sensorimotor and salience networks and decreased functional connectivity in the cerebellum network. Additionally, increased functional network connectivity was observed between anterior and posterior default mode networks, and a decreased functional network connectivity was noted between the cerebellum network and the sensorimotor and posterior default mode networks. Importantly, the functional connectivity changes within and between these resting-state networks were correlated with the tremor severity and total cognitive scores of essential tremor patients. The findings of this study provide the first evidence that functional connectivity changes within and between multiple resting-state networks are associated with tremors and cognitive features of essential tremor, and this work demonstrates a potential approach for identifying the underlying neural network mechanisms of this syndrome. © 2015 International Parkinson and Movement Disorder Society.

TMS over the right precuneus reduces the bilateral field advantage in visual short term memory capacity.

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Kraft, Antje; Dyrholm, Mads; Kehrer, Stefanie; Kaufmann, Christian; Bruening, Jovita; Kathmann, Norbert; Bundesen, Claus; Irlbacher, Kerstin; Brandt, Stephan A

2015-01-01

Several studies have demonstrated a bilateral field advantage (BFA) in early visual attentional processing, that is, enhanced visual processing when stimuli are spread across both visual hemifields. The results are reminiscent of a hemispheric resource model of parallel visual attentional processing, suggesting more attentional resources on an early level of visual processing for bilateral displays [e.g. Sereno AB, Kosslyn SM. Discrimination within and between hemifields: a new constraint on theories of attention. Neuropsychologia 1991;29(7):659-75.]. Several studies have shown that the BFA extends beyond early stages of visual attentional processing, demonstrating that visual short term memory (VSTM) capacity is higher when stimuli are distributed bilaterally rather than unilaterally. Here we examine whether hemisphere-specific resources are also evident on later stages of visual attentional processing. Based on the Theory of Visual Attention (TVA) [Bundesen C. A theory of visual attention. Psychol Rev 1990;97(4):523-47.] we used a whole report paradigm that allows investigating visual attention capacity variability in unilateral and bilateral displays during navigated repetitive transcranial magnetic stimulation (rTMS) of the precuneus region. A robust BFA in VSTM storage capacity was apparent after rTMS over the left precuneus and in the control condition without rTMS. In contrast, the BFA diminished with rTMS over the right precuneus. This finding indicates that the right precuneus plays a causal role in VSTM capacity, particularly in bilateral visual displays. Copyright © 2015 Elsevier Inc. All rights reserved.

Transcranial magnetic simulation in the treatment of migraine

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Lipton, Richard B.; Pearlman, Starr H.

2010-01-01

Transcranial magnetic stimulation (TMS) is a diagnostic and therapeutic modality that is being developed as both an acute and preventive treatment for migraine. TMS delivers a fluctuating magnetic field from the scalp surface to induce current in the subjacent cortex. Magnetic pulses are delivered one at a time in single-pulse TMS (sTMS) or as a train of pulses in repetitive TMS (rTMS). For most of its 30-year history, TMS has been delivered in clinical and research settings using large table...

Repetitive Transcranial Magnetic Stimulation (rTMS) Treatment in Enduring Anorexia Nervosa: A Case Series.

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McClelland, Jessica; Kekic, Maria; Campbell, Iain C; Schmidt, Ulrike

2016-03-01

This case series examined the therapeutic potential of repetitive transcranial magnetic stimulation in five women with enduring anorexia nervosa. Participants received ~20 sessions of neuronavigated high-frequency repetitive transcranial magnetic stimulation to the left dorsolateral prefrontal cortex. Body mass index, eating disorder (ED) symptoms and mood were assessed pre-treatment and post-treatment, at 6-month and 12-month follow-up (FU). Qualitative feedback regarding the intervention was obtained from participants and carers. From pre-treatment to post-treatment, ED and affective symptoms improved significantly, and body mass index remained stable. Further improvements in ED symptoms/mood were seen at 6-month FU with 3/5 and 2/5 participants deemed 'recovered' on the Eating Disorders Examination Questionnaire and Depression, Anxiety and Stress Scale, respectively. However, most participants had lost some weight, and therapeutic effects on psychopathology had waned by 12-month FU. Qualitative feedback regarding the intervention was encouraging. Repetitive transcranial magnetic stimulation was well tolerated, and preliminary evidence is provided for its therapeutic potential in anorexia nervosa. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Frequency and Factors of Tremor, Palpitation, and Cramp in Patients with COPD and Asthma

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Sema Demir

2015-04-01

Full Text Available Objective: To evaluate the frequency and predictability of side effects, including tremor, cramp, and palpitation, due to treatment in patients with chronic obstructive pulmonary disease and asthma. Methods: We prepared a standard questionnaire for 299 patients concerning their diagnosis, treatment, and side effects of the treatment in February 2007 at Hacettepe University, Faculty of Medicine, Department of Pulmonary Diseases. We prospectively examined the clinical status of the patients and side effects of the treatment at the 15th, 30th, and 180th days of the treatment. Results: In our study, there were 38 (12.7% patients with drug-induced tremor. Of these, 27 (71.1% had asthma (p=0.004 and 18 (47.4% had anamnestic palpitation. Drug-induced tremor risk was 15.3 times higher in patients who used a beta-mimetic compared with those who used any drugs. Cramp risk increased with beta-mimetic use only. In our study, drug-induced tremor was still present at the 180th day of examination in 32 (84.2% patients. Conclusion: This study demonstrated that side effects, including tremor, palpitation, and cramp, were more common in our patients compared with those in other studies. These side effects were directly related to the primary disease and the use of beta-2-agonists. Another finding of our study is that tolerance did not develop as much as that reported in literature.

Parietal theta burst TMS: Functional fractionation observed during bistable perception not evident in attention tasks.

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Schauer, Georg; Kanai, Ryota; Brascamp, Jan W

2016-02-01

When visual input is ambiguous, perception spontaneously alternates between interpretations: bistable perception. Studies have identified two distinct sites near the right intraparietal sulcus where inhibitory transcranial magnetic stimulation (TMS) affects the frequency of occurrence of these alternations, but strikingly with opposite directions of effect for the two sites. Lesion and TMS studies on spatial and sustained attention have also indicated a parcellation of right parietal cortex, into areas serving distinct attentional functions. We used the exact TMS procedure previously employed to affect bistable perception, yet measured its effect on spatial and sustained attention tasks. Although there was a trend for TMS to affect performance, trends were consistently similar for both parietal sites, with no indication of opposite effects. We interpret this as signifying that the previously observed parietal fractionation of function regarding the perception of ambiguous stimuli is not due to TMS-induced modification of spatial or sustained attention. Copyright © 2016 Elsevier Inc. All rights reserved.

Global search of triggered non-volcanic tremor

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Chao, Tzu-Kai Kevin

Deep non-volcanic tremor is a newly discovered seismic phenomenon with low amplitude, long duration, and no clear P- and S-waves as compared with regular earthquake. Tremor has been observed at many major plate-boundary faults, providing new information about fault slip behaviors below the seismogenic zone. While tremor mostly occurs spontaneously (ambient tremor) or during episodic slow-slip events (SSEs), sometimes tremor can also be triggered during teleseismic waves of distance earthquakes, which is known as "triggered tremor". The primary focus of my Ph.D. work is to understand the physical mechanisms and necessary conditions of triggered tremor by systematic investigations in different tectonic regions. In the first chapter of my dissertation, I conduct a systematic survey of triggered tremor beneath the Central Range (CR) in Taiwan for 45 teleseismic earthquakes from 1998 to 2009 with Mw ≥ 7.5. Triggered tremors are visually identified as bursts of high-frequency (2-8 Hz), non-impulsive, and long-duration seismic energy that are coherent among many seismic stations and modulated by the teleseismic surface waves. A total of 9 teleseismic earthquakes has triggered clear tremor in Taiwan. The peak ground velocity (PGV) of teleseismic surface waves is the most important factor in determining tremor triggering potential, with an apparent threshold of ˜0.1 cm/s, or 7-8 kPa. However, such threshold is partially controlled by the background noise level, preventing triggered tremor with weaker amplitude from being observed. In addition, I find a positive correlation between the PGV and the triggered tremor amplitude, which is consistent with the prediction of the 'clock-advance' model. This suggests that triggered tremor can be considered as a sped-up occurrence of ambient tremor under fast loading from the passing surface waves. Finally, the incident angles of surface waves also play an important rule in controlling the tremor triggering potential. The next

Smoking cessation induced by deep repetitive transcranial magnetic stimulation of the prefrontal and insular cortices: a prospective, randomized controlled trial.

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Dinur-Klein, Limor; Dannon, Pinhas; Hadar, Aviad; Rosenberg, Oded; Roth, Yiftach; Kotler, Moshe; Zangen, Abraham

2014-11-01

Tobacco smoking is the leading cause of preventable death in developed countries. Our previous studies in animal models and humans suggest that repeated activation of cue-induced craving networks followed by electromagnetic stimulation of the dorsal prefrontal cortex (PFC) can cause lasting reductions in drug craving and consumption. We hypothesized that disruption of these circuitries by deep transcranial magnetic stimulation (TMS) of the PFC and insula bilaterally can induce smoking cessation. Adults (N = 115) who smoke at least 20 cigarettes/day and failed previous treatments were recruited from the general population. Participants were randomized to receive 13 daily sessions of high-frequency, low-frequency or sham stimulation following, or without, presentation of smoking cues. Deep TMS was administered using an H-coil version targeting the lateral PFC and insula bilaterally. Cigarette consumption was evaluated during the treatment by measuring cotinine levels in urine samples and recording participants' self-reports as a primary outcome variable. Dependence and craving were assessed using standardized questionnaires. High (but not low) frequency deep TMS treatment significantly reduced cigarette consumption and nicotine dependence. The combination of this treatment with exposure to smoking cues enhanced reduction in cigarette consumption leading to an abstinence rate of 44% at the end of the treatment and an estimated 33% 6 months following the treatment. This study further implicates the lateral PFC and insula in nicotine addiction and suggests the use of deep high-frequency TMS of these regions following presentation of smoking cues as a promising treatment strategy. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Consensus Statement on the classification of tremors. from the task force on tremor of the International Parkinson and Movement Disorder Society.

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Bhatia, Kailash P; Bain, Peter; Bajaj, Nin; Elble, Rodger J; Hallett, Mark; Louis, Elan D; Raethjen, Jan; Stamelou, Maria; Testa, Claudia M; Deuschl, Guenther

2018-01-01

Consensus criteria for classifying tremor disorders were published by the International Parkinson and Movement Disorder Society in 1998. Subsequent advances with regard to essential tremor, tremor associated with dystonia, and other monosymptomatic and indeterminate tremors make a significant revision necessary. Convene an international panel of experienced investigators to review the definition and classification of tremor. Computerized MEDLINE searches in January 2013 and 2015 were conducted using a combination of text words and MeSH terms: "tremor", "tremor disorders", "essential tremor", "dystonic tremor", and "classification" limited to human studies. Agreement was obtained using consensus development methodology during four in-person meetings, two teleconferences, and numerous manuscript reviews. Tremor is defined as an involuntary, rhythmic, oscillatory movement of a body part and is classified along two axes: Axis 1-clinical characteristics, including historical features (age at onset, family history, and temporal evolution), tremor characteristics (body distribution, activation condition), associated signs (systemic, neurological), and laboratory tests (electrophysiology, imaging); and Axis 2-etiology (acquired, genetic, or idiopathic). Tremor syndromes, consisting of either isolated tremor or tremor combined with other clinical features, are defined within Axis 1. This classification scheme retains the currently accepted tremor syndromes, including essential tremor, and provides a framework for defining new syndromes. This approach should be particularly useful in elucidating isolated tremor syndromes and syndromes consisting of tremor and other signs of uncertain significance. Consistently defined Axis 1 syndromes are needed to facilitate the elucidation of specific etiologies in Axis 2. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

What is said or how it is said makes a difference: role of the right fronto-parietal operculum in emotional prosody as revealed by repetitive TMS.

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van Rijn, Sophie; Aleman, André; van Diessen, Eric; Berckmoes, Celine; Vingerhoets, Guy; Kahn, René S

2005-06-01

Emotional signals in spoken language can be conveyed by semantic as well as prosodic cues. We investigated the role of the fronto-parietal operculum, a somatosensory area where the lips, tongue and jaw are represented, in the right hemisphere to detection of emotion in prosody vs. semantics. A total of 14 healthy volunteers participated in the present experiment, which involved transcranial magnetic stimulation (TMS) in combination with frameless stereotaxy. As predicted, compared with sham stimulation, TMS over the right fronto-parietal operculum differentially affected the reaction times for detection of emotional prosody vs. emotional semantics, showing that there is a dissociation at a neuroanatomical level. Detection of withdrawal emotions (fear and sadness) in prosody was delayed significantly by TMS. No effects of TMS were observed for approach emotions (happiness and anger). We propose that the right fronto-parietal operculum is not globally involved in emotion evaluation, but sensitive to specific forms of emotional discrimination and emotion types.

Slip rate and tremor genesis in Cascadia

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Wech, Aaron G.; Bartlow, Noel M.

2014-01-01

At many plate boundaries, conditions in the transition zone between seismogenic and stable slip produce slow earthquakes. In the Cascadia subduction zone, these events are consistently observed as slow, aseismic slip on the plate interface accompanied by persistent tectonic tremor. However, not all slow slip at other plate boundaries coincides spatially and temporally with tremor, leaving the physics of tremor genesis poorly understood. Here we analyze seismic, geodetic, and strainmeter data in Cascadia to observe for the first time a large, tremor-generating slow earthquake change from tremor-genic to silent and back again. The tremor falls silent at reduced slip speeds when the migrating slip front pauses as it loads the stronger adjacent fault segment to failure. The finding suggests that rheology and slip-speed-regulated stressing rate control tremor genesis, and the same section of fault can slip both with and without detectable tremor, limiting tremor's use as a proxy for slip.

Treatment of Essential Tremor

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... for PATIENTS and their FAMILIES TREATMENT OF ESSENTIAL TREMOR This fact sheet is provided to help you understand which therapies help treat essential tremor. Neurologists from the American Academy of Neurology are ...

Identification of a Divergent Lineage Porcine Pestivirus in Nursing Piglets with Congenital Tremors and Reproduction of Disease following Experimental Inoculation.

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Arruda, Bailey L; Arruda, Paulo H; Magstadt, Drew R; Schwartz, Kent J; Dohlman, Tyler; Schleining, Jennifer A; Patterson, Abby R; Visek, Callie A; Victoria, Joseph G

2016-01-01

Congenital tremors is a sporadic disease of neonatal pigs characterized by action-related repetitive myoclonus. A majority of outbreaks of congenital tremors have been attributed to an unidentified virus. The objectives of this project were to 1) detect potential pathogen(s) in samples from piglets with congenital tremors and 2) develop an infection model to reproduce disease. Using next-generation sequencing, a divergent lineage pestivirus was detected in piglets with congenital tremors. The virus was originally most closely related to a bat pestivirus but is now more closely related to a recently published novel porcine pestivirus provisionally named atypical porcine pestivirus. A quantitative real-time PCR detected the virus in samples from neonatal piglets with congenital tremors from two separate farms, but not in samples from unaffected piglets from the same farm. To fulfill the second objective, pregnant sows were inoculated with either serum containing the pestivirus or PBS (control) by intravenous and intranasal routes simultaneously with direct inoculation of fetal amniotic vesicles by ultrasound-guided surgical technique. Inoculations were performed at either 45 or 62 days of gestation. All sows inoculated with the novel pestivirus farrowed piglets affected with congenital tremors while PBS-inoculated control piglets were unaffected. Tremor severity for each piglet was scored from videos taken 0, 1 and 2 days post-farrowing. Tremor severity remained relatively constant from 0 to 2 days post-farrowing for a majority of piglets. The prevalence of congenital tremors in pestivirus-inoculated litters ranged from 57% (4 out of 7 affected piglets) to 100% (10 out of 10 affected piglets). The virus was consistently detected by PCR in tissues from piglets with congenital tremors but was not detected in control piglets. Samples positive by PCR in greater than 90% of piglets sampled included brainstem (37 out of 41), mesenteric lymph node (37 out of 41

Identification of a Divergent Lineage Porcine Pestivirus in Nursing Piglets with Congenital Tremors and Reproduction of Disease following Experimental Inoculation.

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Bailey L Arruda

Full Text Available Congenital tremors is a sporadic disease of neonatal pigs characterized by action-related repetitive myoclonus. A majority of outbreaks of congenital tremors have been attributed to an unidentified virus. The objectives of this project were to 1 detect potential pathogen(s in samples from piglets with congenital tremors and 2 develop an infection model to reproduce disease. Using next-generation sequencing, a divergent lineage pestivirus was detected in piglets with congenital tremors. The virus was originally most closely related to a bat pestivirus but is now more closely related to a recently published novel porcine pestivirus provisionally named atypical porcine pestivirus. A quantitative real-time PCR detected the virus in samples from neonatal piglets with congenital tremors from two separate farms, but not in samples from unaffected piglets from the same farm. To fulfill the second objective, pregnant sows were inoculated with either serum containing the pestivirus or PBS (control by intravenous and intranasal routes simultaneously with direct inoculation of fetal amniotic vesicles by ultrasound-guided surgical technique. Inoculations were performed at either 45 or 62 days of gestation. All sows inoculated with the novel pestivirus farrowed piglets affected with congenital tremors while PBS-inoculated control piglets were unaffected. Tremor severity for each piglet was scored from videos taken 0, 1 and 2 days post-farrowing. Tremor severity remained relatively constant from 0 to 2 days post-farrowing for a majority of piglets. The prevalence of congenital tremors in pestivirus-inoculated litters ranged from 57% (4 out of 7 affected piglets to 100% (10 out of 10 affected piglets. The virus was consistently detected by PCR in tissues from piglets with congenital tremors but was not detected in control piglets. Samples positive by PCR in greater than 90% of piglets sampled included brainstem (37 out of 41, mesenteric lymph node (37 out of 41

Using Portable Transducers to Measure Tremor Severity

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Rodger Elble

2016-05-01

Full Text Available Background: Portable motion transducers, suitable for measuring tremor, are now available at a reasonable cost. The use of these transducers requires knowledge of their limitations and data analysis. The purpose of this review is to provide a practical overview and example software for using portable motion transducers in the quantification of tremor. Methods: Medline was searched via PubMed.gov in December 2015 using the Boolean expression “tremor AND (accelerometer OR accelerometry OR gyroscope OR inertial measurement unit OR digitizing tablet OR transducer.” Abstracts of 419 papers dating back to 1964 were reviewed for relevant portable transducers and methods of tremor analysis, and 105 papers written in English were reviewed in detail. Results: Accelerometers, gyroscopes, and digitizing tablets are used most commonly, but few are sold for the purpose of measuring tremor. Consequently, most software for tremor analysis is developed by the user. Wearable transducers are capable of recording tremor continuously, in the absence of a clinician. Tremor amplitude, frequency, and occurrence (percentage of time with tremor can be computed. Tremor amplitude and occurrence correlate strongly with clinical ratings of tremor severity. Discussion: Transducers provide measurements of tremor amplitude that are objective, precise, and valid, but the precision and accuracy of transducers are mitigated by natural variability in tremor amplitude. This variability is so great that the minimum detectable change in amplitude, exceeding random variability, is comparable for scales and transducers. Research is needed to determine the feasibility of detecting smaller change using averaged data from continuous long-term recordings with wearable transducers.

Combined rTMS treatment targeting the Anterior Cingulate and the Temporal Cortex for the Treatment of Chronic Tinnitus

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Kreuzer, Peter M.; Lehner, Astrid; Schlee, Winfried; Vielsmeier, Veronika; Schecklmann, Martin; Poeppl, Timm B.; Landgrebe, Michael; Rupprecht, Rainer; Langguth, Berthold

2015-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a tinnitus treatment option. Promising results have been obtained by consecutive stimulation of lateral frontal and auditory brain regions. We investigated a combined stimulation paradigm targeting the anterior cingulate cortex (ACC) with double cone coil rTMS, followed by stimulation of the temporo-parietal junction area with a figure-of-eight coil. The study was conducted as a randomized, double-blind pilot trial in 40 patients suffering from chronic tinnitus. We compared mediofrontal stimulation with double-cone-coil, (2000 stimuli, 10 Hz) followed by left temporo-parietal stimulation with figure-of-eight-coil (2000 stimuli, 1 Hz) to left dorsolateral-prefrontal-cortex stimulation with figure-of-eight-coil (2000 stimuli, 10 Hz) followed by temporo-parietal stimulation with figure-of-eight-coil (2000 stimuli, 1 Hz). The stimulation was feasible with comparable dropout rates in both study arms; no severe adverse events were registered. Responder rates did not differ in both study arms. There was a significant main effect of time for the change in the TQ score, but no significant time x group interaction. This pilot study demonstrated the feasibility of combined mediofrontal/temporoparietal-rTMS-stimulation with double cone coil in tinnitus patients but failed to show better outcome compared to an actively rTMS treated control group. PMID:26667790

Differing Time of Onset of Concurrent TMS-fMRI during Associative Memory Encoding: A Measure of Dynamic Connectivity

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Colin Hawco

2017-08-01

Full Text Available There has been a distinct shift in neuroimaging from localization of function into a more network based approach focused on connectivity. While fMRI has proven very fruitful for this, the hemodynamic signal is inherently slow which limits the temporal resolution of fMRI-only connectivity measures. The brain, however, works on a time scale of milliseconds. This study utilized concurrent transcranial magnetic stimulation (TMS-fMRI in a novel way to obtain measures of dynamic connectivity by measuring changes in fMRI signal amplitude in regions distal to the site of stimulation following differing TMS onset times. Seventeen healthy subjects completed an associative memory encoding task known to involve the DLPFC, viewing pairs of objects which could be semantically related or unrelated. Three pulses of 10 Hz repetitive TMS were applied over the left DLPFC starting either at 200, 600, or 1000 ms after stimulus onset. Associations for related pairs were better remembered than unrelated pairs in a post-scan cued recall test. Differences in neural activity were assessed across different TMS onsets, separately for related and unrelated pairs. Time specific TMS effects were observed in several regions, including those associated with higher-level processing (lateral frontal, anterior cingulate, visual areas (occipital, and regions involved in semantic processing (e.g., left mid-temporal and medial frontal. Activity in the frontal cortex was decreased at 200 ms post-stimulus for unrelated pairs, and 1000 ms post-stimulus for related pairs. This suggests differences in the timing across conditions in which the DLFPC interacts with other PFC regions, consistent with the notion that the DLPFC is facilitating extended semantic processing for related items. This study demonstrates that time-varying TMS onset inside the MRI can be used to reliably measure fast dynamic connectivity with a temporal resolution in the hundreds of milliseconds.

Tremor-tide correlations and near-lithostatic pore pressure on the deep San Andreas fault.

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Thomas, Amanda M; Nadeau, Robert M; Bürgmann, Roland

2009-12-24

Since its initial discovery nearly a decade ago, non-volcanic tremor has provided information about a region of the Earth that was previously thought incapable of generating seismic radiation. A thorough explanation of the geologic process responsible for tremor generation has, however, yet to be determined. Owing to their location at the plate interface, temporal correlation with geodetically measured slow-slip events and dominant shear wave energy, tremor observations in southwest Japan have been interpreted as a superposition of many low-frequency earthquakes that represent slip on a fault surface. Fluids may also be fundamental to the failure process in subduction zone environments, as teleseismic and tidal modulation of tremor in Cascadia and Japan and high Poisson ratios in both source regions are indicative of pressurized pore fluids. Here we identify a robust correlation between extremely small, tidally induced shear stress parallel to the San Andreas fault and non-volcanic tremor activity near Parkfield, California. We suggest that this tremor represents shear failure on a critically stressed fault in the presence of near-lithostatic pore pressure. There are a number of similarities between tremor in subduction zone environments, such as Cascadia and Japan, and tremor on the deep San Andreas transform, suggesting that the results presented here may also be applicable in other tectonic settings.

ECT, rTMS, and deepTMS in pharmacoresistant drug-free patients with unipolar depression: a comparative review

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Salviati M

2012-01-01

Full Text Available Amedeo Minichino¹, Francesco Saverio Bersani¹, Enrico Capra¹, Rossella Pannese¹, Celeste Bonanno², Massimo Salviati¹, Roberto Delle Chiaie¹, Massimo Biondi¹¹Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, ²Aldo Moro University of Bari, Bari, ItalyBackground: Biological treatments are considered as additional options for the treatment of resistant unipolar depression. Controversial data exist about the efficacy and tolerability of three of the most used somatic treatments: electroconvulsive therapy (ECT, transcranial magnetic stimulation (rTMS, and deep transcranial magnetic stimulation (deepTMS. The aim of this review is to investigate and compare the efficacy and tolerability of these three techniques in drug-free patients with pharmacoresistant unipolar depression.Methods: Three independent reviewers extracted data and assessed the quality of methodological reporting of selected studies. The first outcome was the clinical response to the three different techniques defined as a percentage improvement of Hamilton Depression Rating Scale (HDRS. The second outcome was the evaluation of their neuropsychological effects. The third outcome was the evaluation of the number of remitted patients; remission was defined as an absolute HDRS-24 score of ≤11 or as an absolute HDRS-17 score of ≤8. Tolerability was the fourth outcome; it was evaluated by examining the number of dropped-out patients.Results: The comparative evaluation of HDRS percentage variations shows ECT as the most effective method after 4 weeks of therapy; on the other hand, a better efficacy is obtainable by deepTMS after 2 weeks of therapy. DeepTMS is the technique that gives the best improvement of cognitive performances. The percentage of remitted patients obtained with ECT treatment is the same obtained in the deepTMS group. Both techniques have a remitted patients percentage two times larger than the rTMS. DeepTMS shows a tolerability

Efficacy of bilateral repetitive transcranial magnetic stimulation for negative symptoms of schizophrenia : results of a multicenter double-blind randomized controlled trial

NARCIS (Netherlands)

Dlabac-de Lange, J. J.; Bais, L.; van Es, F. D.; Visser, B. G. J.; Reinink, E.; Bakker, B.; van den Heuvel, E. R.; Aleman, A.; Knegtering, H.

Background. Few studies have investigated the efficacy of repetitive transcranial magnetic stimulation (rTMS) treatment for negative symptoms of schizophrenia, reporting inconsistent results. We aimed to investigate whether 10 Hz stimulation of the bilateral dorsolateral prefrontal cortex during 3

Medical and surgical treatment of tremors.

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Schneider, Susanne A; Deuschl, Günther

2015-02-01

Tremor is a hyperkinetic movement disorder characterized by rhythmic oscillations of one or more body parts. Disease severity ranges from mild to severe with various degrees of impact on quality of life. Essential tremor and parkinsonian tremor are the most common etiologic subtypes. Treatment may be challenging; although several drugs are available, response may be unsatisfactory. For some tremor forms, controlled data are scarce or completely missing and treatment is often based on anecdotal evidence. In this article, we review the current literature on tremor treatment, with a focus on common forms. Copyright © 2015 Elsevier Inc. All rights reserved.

Anaesthesia, not number of sessions, influences the magnitude and duration of an aHF-rTMS in dogs.

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Robrecht Dockx

Full Text Available Currently, the rat has been a useful animal model in brain stimulation research. Nevertheless, extrapolating results from rodent repetitive Transcranial Magnetic Stimulation (rTMS research to humans contains several hurdles. This suggests the desperate need for a large animal model in translational rTMS research. The dog would be a valid choice, not only due to the fact that humans and dogs share a neurophysiological background, but a similar neuropathological background as well.In order to evaluate the feasibility of the canine rTMS animal model, this study aimed to evaluate the neurophysiological response in dogs on a, clinically used, accelerated high frequency (aHF rTMS protocol. This aHF-rTMS (20 Hz protocol was performed under anaesthesia or sedation and either 20 sessions or 5 sessions were given to each dog.21 healthy dogs were randomly subjected to one of the four aHF-rTMS protocols (1 sham and 3 active protocols. For each dog, the perfusion indices (PI, of a [99mTc]HMPAO scan at 4 time points, for the left frontal cortex (stimulation target were calculated for each protocol.Concerning sham stimulation, the average PI remained at the baseline level. The main result was the presence of a direct transitory increase in rCBF at the stimulation site, both under anaesthesia and sedation. Nevertheless the measured increase in rCBF was higher but shorter duration under sedation. The magnitude of this increase was not influenced by number of sessions. No changes in rCBF were found in remote brain regions.This study shows that, despite the influence of anaesthesia and sedation, comparable and clinically relevant effects on the rCBF can be obtained in dogs. Since less methodological hurdles have to be overcome and comparable results can be obtained, it would be acceptable to put the dog forward as an alternative translational rTMS animal model.

Standardized handwriting to assess bradykinesia, micrographia and tremor in Parkinson's disease.

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Esther J Smits

Full Text Available OBJECTIVE: To assess whether standardized handwriting can provide quantitative measures to distinguish patients diagnosed with Parkinson's disease from age- and gender-matched healthy control participants. DESIGN: Exploratory study. Pen tip trajectories were recorded during circle, spiral and line drawing and repeated character 'elelelel' and sentence writing, performed by Parkinson patients and healthy control participants. Parkinson patients were tested after overnight withdrawal of anti-Parkinsonian medication. SETTING: University Medical Center Groningen, tertiary care, the Netherlands. PARTICIPANTS: Patients with Parkinson's disease (n = 10; mean age 69.0 years; 6 male and healthy controls (n = 10; mean age 68.1 years; 6 male. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Movement time and velocity to detect bradykinesia and the size of writing to detect micrographia. A rest recording to investigate the presence of a rest-tremor, by frequency analysis. RESULTS: Mean disease duration in the Parkinson group was 4.4 years and the patients were in modified Hoehn-Yahr stages 1-2.5. In general, Parkinson patients were slower than healthy control participants. Median time per repetition, median velocity and median acceleration of the sentence task and median velocity of the elel task differed significantly between Parkinson patients and healthy control participants (all p<0.0014. Parkinson patients also wrote smaller than healthy control participants and the width of the 'e' in the elel task was significantly smaller in Parkinson patients compared to healthy control participants (p<0.0014. A rest-tremor was detected in the three patients who were clinically assessed as having rest-tremor. CONCLUSIONS: This study shows that standardized handwriting can provide objective measures for bradykinesia, tremor and micrographia to distinguish Parkinson patients from healthy control participants.

Low-frequency rTMS with language therapy over a 3-month period for sensory-dominant aphasia: case series of two post-stroke Japanese patients.

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Kakuda, Wataru; Abo, Masahiro; Uruma, Go; Kaito, Nobuyoshi; Watanabe, Motoi

2010-01-01

To examine the safety and feasibility of therapeutic application of low-frequency repetitive transcranial magnetic stimulation (rTMS) combined with language therapy for post-stroke patients with sensory-dominant aphasia. Two post-stroke Japanese patients with sensory-dominant aphasia were studied. In both patients, 10 sessions of 20-minute low-frequency rTMS with 1 Hz to the Wernicke's area were provided throughout 6-day hospitalization, followed by weekly outpatient rTMS treatment for 3 months. The language therapy was also provided through the period of in- and out-patient treatment. Language function was evaluated using the Token test and the Standard Language Test of Aphasia (SLTA) at the start and end of the in-patient treatment and the end of the outpatient treatment. The therapeutic protocol was well tolerated throughout the in- and out-patient treatments, without any adverse effects. The scores of the Token test and certain sub-categories of SLTA increased in both patients after the in-patient rTMS treatment. Persistent improvement of the score was noted over the 3-month post-discharge period. The proposed protocol of long-term application of low-frequency rTMS to the Wernicke's area and language therapy is considered a safe and feasible therapeutic approach for post-stroke patients with sensory-dominant aphasia.

Tremor in neurodegenerative ataxias, Huntington disease and tic disorder.

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Rudzińska, M; Krawczyk, M; Wójcik-Pędziwiatr, M; Szczudlik, A; Tomaszewski, T

2013-01-01

Tremor is the most prevalent movement disorder, defined as rhythmic oscillations of a body part, caused by alternating or synchronic contractions of agonistic or antagonistic muscles. The aim of the study was to assess prevalence and to characterize parameters of tremor accompanying de-generative ataxias, Huntington disease (HD) and tic disorders in comparison with a control group. Forty-three patients with degenerative ataxias, 28 with HD and 26 with tic disorders together with 51 healthy controls were included in the study. For each participant, clinical and instrumental assessment (accelerometer, electromyography [EMG], graphic tablet) of hand tremor was performed. Frequency and severity of tremor were assessed in three positions: at rest (rest tremor), with hands extended (postural tremor), during the 'finger-to-nose' test and during Archimedes spiral drawing (kinetic tremor). Based on the mass load test, the type of tremor was determined as essential tremor type or enhanced physiological tremor type. The incidence of tremor in the accelerometry in patients with degenerative ataxia (50%) significantly differs from controls (10%) (p = 0.001). The dominant tremor was postural, low-intense, with 7-Hz frequency, essential tremor (23%) or other tremor type (23%), while enhanced physiological tremor was the least frequent (2%). Tremor in patients with HD and tic disorders was found in 10% and 20% of patients, respectively, similarly to the control group. Tremor was mild, postural and of essential tremor type, less frequently of enhanced physiological tremor type. No correlation between severity of tremor and severity of disease was found. The prevalence of tremor is considerably higher among patients with degenerative ataxias compared with HD, tic disorder and the control group. The most common type of tremor accompanying ataxias, HD and tic disorders is essential tremor type.

Repetitive Transcranial Magnetic Stimulation Improves Handwriting in Parkinson’s Disease

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Bubblepreet K. Randhawa

2013-01-01

Full Text Available Background. Parkinson disease (PD is characterized by hypometric movements resulting from loss of dopaminergic neurons in the substantia nigra. PD leads to decreased activation of the supplementary motor area (SMA; the net result of these changes is a poverty of movement. The present study determined the impact of 5 Hz repetitive transcranial magnetic stimulation (rTMS over the SMA on a fine motor movement, handwriting (writing cursive “l”s, and on cortical excitability, in individuals with PD. Methods. In a cross-over design, ten individuals with PD were randomized to receive either 5 Hz or control stimulation over the SMA. Immediately following brain stimulation right handed writing was assessed. Results. 5 Hz stimulation increased vertical size of handwriting and diminished axial pressure. In addition, 5 Hz rTMS significantly decreased the threshold for excitability in the primary motor cortex. Conclusions. These data suggest that in the short term 5 Hz rTMS benefits functional fine motor task performance, perhaps by altering cortical excitability across a network of brain regions. Further, these data may provide the foundation for a larger investigation of the effects of noninvasive brain stimulation over the SMA in individuals with PD.

Double-Cone Coil TMS Stimulation of the Medial Cortex Inhibits Central Pain Habituation.

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Federico D'Agata

Full Text Available The aim of this study was to investigate whether Transcranial Magnetic Stimulation (TMS applied over the medial line of the scalp affects the subjective perception of continuous pain induced by means of electric stimulation. In addition, we wanted to identify the point of stimulation where this effect was maximum.Superficial electrical stimulation was used to induce continuous pain on the dominant hand. At the beginning of the experiment we reached a pain rating of 5 on an 11-point numeric rating scale (NRS; 0 = no pain and 10 = maximum tolerable pain for each subject by setting individually the current intensity. The TMS (five pulses at increasing intensities was applied on 5 equidistant points (one per session over the medial line of the scalp in 13 healthy volunteers using a double-cone coil to stimulate underlying parts of the brain cortex. In every experimental session the painful stimulation lasted 45 minutes, during which pain and distress intensities NRS were recorded continuously. We calculated the effect of adaptation and the immediate effect of the TMS stimulation for all locations. Additionally, an ALE (Activation Likelihood Estimation meta-analysis was performed to compare our results with the neuroimaging literature on subjective pain rating.TMS stimulation temporarily decreased the pain ratings, and pain adaptation was suppressed when applying the TMS over the FCz site on the scalp. No effect was found for distress ratings.The present data suggest that the medial cortex in proximity of the cingulated gyrus has a causal role in adaptation mechanisms and in processing ongoing pain and subjective sensation of pain intensity.

Stimulating Language: Insights from TMS

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Devlin, Joseph T.; Watkins, Kate E.

2007-01-01

Fifteen years ago, Pascual-Leone and colleagues used transcranial magnetic stimulation (TMS) to investigate speech production in pre-surgical epilepsy patients and in doing so, introduced a novel tool into language research. TMS can be used to non-invasively stimulate a specific cortical region and transiently disrupt information processing. These…

Autosomal dominant cortical tremor, myoclonus, and epilepsy (ADCME: Probable first family from India

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Chandra Mohan Sharma

2014-01-01

Full Text Available Autosomal dominant cortical tremor, myoclonus, and epilepsy (ADCME is an extremely rare syndrome characterized by familial occurrence of postural and action-induced tremors of the hands but showing electrophysiologic findings of cortical reflex myoclonus. Patients also have cognitive decline and tonic-clonic seizures, often precipitated by sleep deprivation or photic stimulation. We describe probably the first family from India of this ill-defined syndrome.

Low-Intensity Repetitive Exercise Induced Rhabdomyolysis

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Mina Tran

2015-01-01

Full Text Available Rhabdomyolysis is a rare condition caused by the proteins of damaged muscle cells entering the bloodstream and damaging the kidneys. Common symptoms of rhabdomyolysis are muscle pain and fatigue in conjunction with dark urine; kidney damage is a common symptom among these patients. We present a case of a 23-year-old woman who displayed myalgia in the upper extremities caused by low-intensity and high-repetition exercise. She was successfully diagnosed and treated for exertional rhabdomyolysis. This patient had no significant medical history that would induce this condition. We urge the emergency medical community to observe and monitor patients that complain of myalgia to ensure they are not suffering from rhabdomyolysis even in atypical cases.

The long-term outcome of orthostatic tremor.

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Ganos, Christos; Maugest, Lucie; Apartis, Emmanuelle; Gasca-Salas, Carmen; Cáceres-Redondo, María T; Erro, Roberto; Navalpotro-Gómez, Irene; Batla, Amit; Antelmi, Elena; Degos, Bertrand; Roze, Emmanuel; Welter, Marie-Laure; Mestre, Tiago; Palomar, Francisco J; Isayama, Reina; Chen, Robert; Cordivari, Carla; Mir, Pablo; Lang, Anthony E; Fox, Susan H; Bhatia, Kailash P; Vidailhet, Marie

2016-02-01

Orthostatic tremor is a rare condition characterised by high-frequency tremor that appears on standing. Although the essential clinical features of orthostatic tremor are well established, little is known about the natural progression of the disorder. We report the long-term outcome based on the largest multicentre cohort of patients with orthostatic tremor. Clinical information of 68 patients with clinical and electrophysiological diagnosis of orthostatic tremor and a minimum follow-up of 5 years is presented. There was a clear female preponderance (76.5%) with a mean age of onset at 54 years. Median follow-up was 6 years (range 5-25). On diagnosis, 86.8% of patients presented with isolated orthostatic tremor and 13.2% had additional neurological features. At follow-up, seven patients who initially had isolated orthostatic tremor later developed further neurological signs. A total 79.4% of patients reported worsening of orthostatic tremor symptoms. These patients had significantly longer symptom duration than those without reported worsening (median 15.5 vs 10.5 years, respectively; p=0.005). There was no change in orthostatic tremor frequency over time. Structural imaging was largely unremarkable and dopaminergic neuroimaging (DaTSCAN) was normal in 18/19 cases. Pharmacological treatments were disappointing. Two patients were treated surgically and showed improvement. Orthostatic tremor is a progressive disorder with increased disability although tremor frequency is unchanged over time. In most cases, orthostatic tremor represents an isolated syndrome. Drug treatments are unsatisfactory but surgery may hold promise. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Protective effects of repetitive transcranial magnetic stimulation in a rat model of transient cerebral ischaemia: a microPET study

International Nuclear Information System (INIS)

Gao, Feng; Wang, Shuang; Guo, Yi; Lou, Min; Wu, Jimin; Ding, Meiping; Wang, Jing; Zhang, Hong; Tian, Mei

2010-01-01

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive method to excite neurons in the brain. However, the underlying mechanism of its therapeutic effects in stroke remains unclear. The aim of this study was to investigate the neuroprotective effect of high-frequency rTMS in a rat model of transient cerebral ischaemia using positron emission tomography (PET). Sprague-Dawley rats (n=30) were anaesthetized with chloral hydrate and subjected to 90 min of intraluminal middle cerebral artery occlusion (MCAO) with subsequent reperfusion in three groups: control (n=10), rTMS (n=10), or sham-rTMS groups (n=10). In the rTMS group, rTMS was given 1 h after ischaemia and every 24 h for 7 days after MCAO. In all three groups, small-animal PET (microPET) imaging with 18 F-FDG was used to evaluate brain glucose metabolism. Apoptotic molecules were measured in the infarct margin using immunohistochemical staining. The neurological scores of the rats in the rTMS group were higher than in those of the control group over the whole 7-day observation period. The total, cortical and striatal infarct volumes were significantly less in the rTMS group than in the control group, as measured by 2,3,5-triphenyltetrazolium chloride staining. 18 F-FDG microPET images showed significantly higher standardized uptake values in the cortex and striatum in the rTMS group than in the control group in the affected hemisphere. The number of cells positive for caspase-3 was significantly lower in the rTMS group than in the control group, while the Bcl-2/Bax ratio was significantly higher in the rTMS group than in the control group. rTMS therapy increased glucose metabolism and inhibited apoptosis in the ischaemic hemisphere. 18 F-FDG PET could be used to monitor rTMS therapy in transient cerebral ischaemia in animal studies and in future clinical trials. (orig.)

Protective effects of repetitive transcranial magnetic stimulation in a rat model of transient cerebral ischaemia: a microPET study

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Gao, Feng [Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Neurology, Hangzhou, Zhejiang (China); Zhejiang University Medical PET Center, Hangzhou, Zhejiang (China); Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, Zhejiang (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, Zhejiang (China); Wang, Shuang; Guo, Yi; Lou, Min; Wu, Jimin; Ding, Meiping [Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Neurology, Hangzhou, Zhejiang (China); Wang, Jing; Zhang, Hong [Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Zhejiang University Medical PET Center, Hangzhou, Zhejiang (China); Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, Zhejiang (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, Zhejiang (China); Tian, Mei [The University of Texas M.D. Anderson Cancer Center, Department of Experimental Diagnostic Imaging, Houston, TX (United States)

2010-05-15

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive method to excite neurons in the brain. However, the underlying mechanism of its therapeutic effects in stroke remains unclear. The aim of this study was to investigate the neuroprotective effect of high-frequency rTMS in a rat model of transient cerebral ischaemia using positron emission tomography (PET). Sprague-Dawley rats (n=30) were anaesthetized with chloral hydrate and subjected to 90 min of intraluminal middle cerebral artery occlusion (MCAO) with subsequent reperfusion in three groups: control (n=10), rTMS (n=10), or sham-rTMS groups (n=10). In the rTMS group, rTMS was given 1 h after ischaemia and every 24 h for 7 days after MCAO. In all three groups, small-animal PET (microPET) imaging with {sup 18}F-FDG was used to evaluate brain glucose metabolism. Apoptotic molecules were measured in the infarct margin using immunohistochemical staining. The neurological scores of the rats in the rTMS group were higher than in those of the control group over the whole 7-day observation period. The total, cortical and striatal infarct volumes were significantly less in the rTMS group than in the control group, as measured by 2,3,5-triphenyltetrazolium chloride staining. {sup 18}F-FDG microPET images showed significantly higher standardized uptake values in the cortex and striatum in the rTMS group than in the control group in the affected hemisphere. The number of cells positive for caspase-3 was significantly lower in the rTMS group than in the control group, while the Bcl-2/Bax ratio was significantly higher in the rTMS group than in the control group. rTMS therapy increased glucose metabolism and inhibited apoptosis in the ischaemic hemisphere. {sup 18}F-FDG PET could be used to monitor rTMS therapy in transient cerebral ischaemia in animal studies and in future clinical trials. (orig.)

GC-ECNICI-MS/MS of eicosanoids as pentafluorobenzyl-trimethylsilyl (TMS) derivatives: Evidence of CAD-induced intramolecular TMS ether-to-ester rearrangement using carboxy-18O-labelled eicosanoids and possible implications in quantitative analysis.

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Tsikas, Dimitrios

2017-03-15

GC-MS and GC-MS/MS of pentafluorobenzyl (PFB) ester trimethylsilyl (TMS) ether (PFB-TMS) derivatives of hydroxylated long-chain fatty acids including arachidonic acid metabolites, the eicosanoids, in the electron-capture negative-ion chemical ionization (ECNICI) mode are the most sensitive and accurate approaches to quantify carboxyl groups-containing compounds in complex biological fluids such as plasma and urine. Under ECNICI conditions, PFB-TMS derivatives of eicosanoids ionize to form very few ions, with the carboxylates [M-PFB] - being typically the most intense. Less intense ions may be additionally formed by consecutive neutral loss (NL) of trimethylsilanol (TMSOH, 90Da) groups ([M-PFB-(TMSOH) n ] - ). By using [1,1- 18 O 2 ]- and [1,ω- 18 O 2 ]-eicosanoids, we studied ion processes following collisionally activated dissociation (CAD) of the precursor ions [M-PFB] - . We found that CAD resulted in formation of product ions due to NL of a TMS 18 OH (92Da) group in monocarboxylic and of a PFB 18 OH (200Da) group in dicarboxylic eicosanoids. TMS 18 OH NL implies an intra-molecular transfer of the TMS group from hydroxyl groups to their carboxylate anions [M-PFB] - . From a mechanistic point of view, this rearrangement may explain formation of unique product ions in GC-MS/MS of eicosanoids under ECNICI conditions. From the quantitative point of view, quantification by GC-MS/MS of product ions due to [M-PFB-(TMSOH) n ] - and [M-PFB-TMS 18 OH-(TMSOH) n-1 ] - would reveal incorrect data, if [1,1- 18 O 2 ]-eicosanoids are used as internal standards and if no correction for the 18 O-loss is performed. In 18 O-labelled dicarboxylic eicosanoids, such as the major urinary metabolite (MUM) of E prostaglandins, i.e., [1,ω- 18 O 2 ]-PGE-MUM), no TMS ester/TMS ether rearrangement was observed. Yet, 18 O-loss occurred upon CAD of [M-PFB] - due to NL of PFB 18 OH (200Da). In both cases the extent of 18 O-loss needs to be determined and considered for accurate quantification

Extended Remediation of Sleep Deprived-Induced Working Memory Deficits Using fMRI-guided Transcranial Magnetic Stimulation

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Luber, Bruce; Steffener, Jason; Tucker, Adrienne; Habeck, Christian; Peterchev, Angel V.; Deng, Zhi-De; Basner, Robert C.; Stern, Yaakov; Lisanby, Sarah H.

2013-01-01

Study Objectives: We attempted to prevent the development of working memory (WM) impairments caused by sleep deprivation using fMRI-guided repetitive transcranial magnetic stimulation (rTMS). Novel aspects of our fMRI-guided rTMS paradigm included the use of sophisticated covariance methods to identify functional networks in imaging data, and the use of fMRI-targeted rTMS concurrent with task performance to modulate plasticity effects over a longer term. Design: Between-groups mixed model. Setting: TMS, MRI, and sleep laboratory study. Participants: 27 subjects (13 receiving Active rTMS, and 14 Sham) completed the sleep deprivation protocol, with another 21 (10 Active, 11 Sham) non-sleep deprived subjects run in a second experiment. Interventions: Our previous covariance analysis had identified a network, including occipital cortex, which demonstrated individual differences in resilience to the deleterious effects of sleep deprivation on WM performance. Five Hz rTMS was applied to left lateral occipital cortex while subjects performed a WM task during 4 sessions over the course of 2 days of total sleep deprivation. Measurements and Results: At the end of the sleep deprivation period, Sham sleep deprived subjects exhibited degraded performance in the WM task. In contrast, those receiving Active rTMS did not show the slowing and lapsing typical in sleep deprivation, and instead performed similarly to non- sleep deprived subjects. Importantly, the Active sleep deprivation group showed rTMS-induced facilitation of WM performance a full 18 hours after the last rTMS session. Conclusions: Over the course of sleep deprivation, these results indicate that rTMS applied concurrently with WM task performance affected neural circuitry involved in WM to prevent its full impact. Citation: Luber B; Steffener J; Tucker A; Habeck C; Peterchev AV; Deng ZD; Basner RC; Stern Y; Lisanby SH. Extended remediation of sleep deprived-induced working memory deficits using f

Normalizing biased spatial attention with parietal rTMS in a patient with focal hand dystonia

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Ricci, Raffaella; Salatino, Adriana; Siebner, Hartwig R

2014-01-01

We report the following case to highlight the possible relevance of biased spatial attention in focal hand dystonia (FHD). Deficient sensorimotor inhibition is a prominent pathophysiological feature of FHD [1,2]. Low-frequency repetitive Trascranial Magnetic Stimulation (rTMS) over contralateral...... premotor cortex (PMC) can reinforce cortical inhibition and improve motor performance and dystonic symptoms in some patients [3,4]. Here we report the case of a 41-year-old right-handed man (23 years of education) with severe task-dependent FHD, affecting the right hand index and middle fingers....

Characterizing Orthostatic Tremor Using a Smartphone Application.

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Balachandar, Arjun; Fasano, Alfonso

2017-01-01

Orthostatic tremor is one of the few tremor conditions requiring an electromyogram for definitive diagnosis since leg tremor might not be visible to the naked eye. An iOS application (iSeismometer, ObjectGraph LLC, New York) using an Apple iPhone 5 (Cupertino, CA, USA) inserted into the patient's sock detected a tremor with a frequency of 16.4 Hz on both legs. The rapid and straightforward accelerometer-based recordings accomplished in this patient demonstrate the ease with which quantitative analysis of orthostatic tremor can be conducted and, importantly, demonstrates the potential application of this approach in the assessment of any lower limb tremor.

Repetitive transcranial magnetic stimulation for treatment of major depressive disorder with comorbid generalized anxiety disorder.

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White, Daniela; Tavakoli, Sason

2015-08-01

Repetitive transcranial magnetic stimulation (rTMS) has shown promising results in treating individuals with behavioral disorders such as major depressive disorder (MDD), posttraumatic stress disorder, obsessive-compulsive disorder, and social anxiety disorder. A number of applications of rTMS to different regions of the left and right prefrontal cortex have been used to treat these disorders, but no study of treatment for MDD with generalized anxiety disorder (GAD) has been conducted with application of rTMS to both the left and right prefrontal cortex. We hypothesized that applying low-frequency rTMS to the right dorsolateral prefrontal cortex (DLPFC) before applying it to the left DLPFC for the treatment of depression would be anxiolytic in patients with MDD with GAD. Thirteen adult patients with comorbid MDD and GAD received treatment with rTMS in an outpatient setting. The number of treatments ranged from 24 to 36 over 5 to 6 weeks. Response was defined as a ≥ 50% reduction in symptoms from baseline, and remission was defined as a score of anxiety symptoms on the 7-item Generalized Anxiety Disorder (GAD-7) scale and depressive symptoms on the 21-item Hamilton Rating Scale for Depression (HAM-D-21). At the end of the treatment period, for the GAD-7 scale, 11 out of 13 (84.6%) patients' anxiety symptoms were in remission, achieving a score of depressive symptoms. In this small pilot study of 13 patients with comorbid MDD and GAD, significant improvement in anxiety symptoms along with depressive symptoms was achieved in a majority of patients after bilateral rTMS application.

Internal tremor in Parkinson's disease, multiple sclerosis, and essential tremor.

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Cochrane, Graham D; Rizvi, Syed; Abrantes, Ana; Crabtree, Brigid; Cahill, Jonathan; Friedman, Joseph H

2015-10-01

Internal tremor (IT) is a poorly recognized symptom that has been described in Parkinson's disease (PD). Described as a feeling of tremor in the extremities or trunk without actual movement, ITs are not debilitating but can be bothersome to patients. The origin of the sensation is unknown., and ITs may be prevalent in other diseases than PD. The present study sought to expand knowledge about IT by confirming their presence in PD, and determining their prevalence in Multiple Sclerosis (MS), and Essential Tremor (ET). A survey was developed in order to determine the prevalence of IT in PD, MS, and ET and to learn what associations with various disease characteristics were present. The survey was administered to 89 consecutive PD, 70 MS, and 11 ET patients. ITs were found to be a prevalent symptom in all three disorders (32.6% of PD, 35.9% of MS, and 54.5% of ET subjects reported experiencing ITs). ITs were found to be associated both with the subjects' perceived levels of anxiety and the presence of visible tremors. ITs appear to be a common symptom in all three disorders studied. These results need to be confirmed and compared to appropriate control populations. Copyright © 2015. Published by Elsevier Ltd.

Adjuvant low-frequency rTMS in treating auditory hallucinations in recent-onset schizophrenia: a randomized controlled study investigating the effect of high-frequency priming stimulation.

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Ray, Prasenjit; Sinha, Vinod Kumar; Tikka, Sai Krishna

2015-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been found to be effective in reducing frequency and duration of auditory verbal hallucinations (AVH). Priming stimulation, which involves high-frequency rTMS stimulation followed by low-frequency rTMS, has been shown to markedly enhance the neural response to the low-frequency stimulation train. However, this technique has not been investigated in recent onset schizophrenia patients. The aim of this randomized controlled study was to investigate whether the effects of rTMS on AVH can be enhanced with priming rTMS in recent onset schizophrenia patients. Forty recent onset schizophrenia patients completed the study. Patients were randomized over two groups: one receiving low-frequency rTMS preceded by priming and another receiving low-frequency rTMS without priming. Both treatments were directed at the left temporo-parietal region. The severity of AVH and other psychotic symptoms were assessed with the auditory hallucination subscale (AHRS) of the Psychotic Symptom Rating Scales (PSYRATS), the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression (CGI). We found that all the scores of these ratings significantly reduced over time (i.e. baseline through 1, 2, 4 and 6 weeks) in both the treatment groups. We found no difference between the two groups on all measures, except for significantly greater improvement on loudness of AVH in the group with priming stimulation during the follow-ups (F = 2.72; p low-frequency rTMS alone and high-frequency priming of low-frequency rTMS do not elicit significant differences in treatment of overall psychopathology, particularly AVH when given in recent onset schizophrenia patients. Add on priming however, seems to be particularly better in faster reduction in loudness of AVH.

The Clinical Evaluation of Parkinson's Tremor

NARCIS (Netherlands)

Zach, H.; Dirkx, M.; Bloem, B.R.; Helmich, R.C.

2015-01-01

Parkinson's disease harbours many different tremors that differ in distribution, frequency, and context in which they occur. A good clinical tremor assessment is important for weighing up possible differential diagnoses of Parkinson's disease, but also to measure the severity of the tremor as a

How to treat tremor.

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Rektor, Ivan; Rektorová, Irena; Suchý, Václav

2004-05-01

This paper presents an example of 18(th) century medical thinking. The author, Dr Georg Ernst Stahl (1659-1734) was the founder of the phlogiston theory in the field of chemistry, a medical professor, and a court physician in Saxony and Prussia. His description includes a definition of tremor, the internal and external causes of tremor, the types of tremor, the diagnostic and prognostic signs, and the treatment. From a present (contemporary) point of view, some compounds that were then used in treatment may have had a limited therapeutic effect on some kinds of tremor. Protopin has an anticholinergic and GABA-ergic effect, and rhoeadin (tetrahydrobenzazepin) may have had an effect similar to that of neuroleptics. Nevertheless, it is not clear whether the recommended quantity of these compounds was sufficient for a clinical effect. Most of the prescribed drugs could only have had a placebo effect.

[Disappearance of essential neck tremor after pontine base infarction].

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Urushitani, M; Inoue, H; Kawamura, K; Kageyama, T; Fujisawa, M; Nishinaka, K; Udaka, F; Kameyama, M

1996-08-01

Mechanism of essential tremor remains unknown. Central oscillators, postulated in thalamus, inferior olive, and spinal cord are thought to be important to form rhythmicity, and finally to stimulate spinal or medullary motor cells, leading trembling muscle contraction, tremor. Among several subtypes of essential familial tremor, including hand tremor, neck tremor, and voice tremor, essential neck tremor is a common disorder, and its pathophysiology seems different from that of typical essential hand tremor, since patients with essential hand tremor are responsive to beta blocker, whereas those with neck tremor are usually not. We experienced a 41-year-old left handed woman with essential neck tremor in whom neck titubation disappeared shortly after pontine base infarct. She was our patient in the outpatient clinic with the diagnosis of essential neck tremor. The tremor developed when she was teenage, and has been localized in the neck muscles. Alcohol intake had apparently diminished it transiently. Her mother also had the tremor in her neck. She was admitted to our hospital with sudden onset of right-sided limb weakness and speech disturbance. Neurological examination showed right hemiparesis including the ipsilateral face, scanning speech, and cerebellar limb ataxia on the same side. In addition, there was no tremor in her neck. Brain MR imaging revealed a pontine base infarct at the level of middle pons, which was consistent with paramedian artery territory. The hemiparesis and speech disturbance improved almost completely after treatment, and her neck tremor has never occurred in one year follow-up. In our patient, efficacy of alcohol imply that essential neck tremor and hand tremor had same central nervous pathway including central oscillator in common, and descending cortical fibers is seemingly associated with diminishing patient's tremor. Pathophysiology of essential neck tremor was discussed with reviewing previous literature.

Ground-motion prediction from tremor

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Baltay, Annemarie S.; Beroza, Gregory C.

2013-01-01

The widespread occurrence of tremor, coupled with its frequency content and location, provides an exceptional opportunity to test and improve strong ground-motion attenuation relations for subduction zones. We characterize the amplitude of thousands of individual 5 min tremor events in Cascadia during three episodic tremor and slip events to constrain the distance decay of peak ground acceleration (PGA) and peak ground velocity (PGV). We determine the anelastic attenuation parameter for ground-motion prediction equations (GMPEs) to a distance of 150 km, which is sufficient to place important constraints on ground-motion decay. Tremor PGA and PGV show a distance decay that is similar to subduction-zone-specific GMPEs developed from both data and simulations; however, the massive amount of data present in the tremor observations should allow us to refine distance-amplitude attenuation relationships for use in hazard maps, and to search for regional variations and intrasubduction zone differences in ground-motion attenuation.

Equivalent brain SPECT perfusion changes underlying therapeutic efficiency in pharmacoresistant depression using either high-frequency left or low-frequency right prefrontal rTMS.

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Richieri, Raphaëlle; Boyer, Laurent; Padovani, Romain; Adida, Marc; Colavolpe, Cécile; Mundler, Olivier; Lançon, Christophe; Guedj, Eric

2012-12-03

Functional neuroimaging studies have suggested similar mechanisms underlying antidepressant effects of distinct therapeutics. This study aimed to determine and compare functional brain patterns underlying the antidepressant response of 2 distinct protocols of repetitive transcranial magnetic stimulation (rTMS). 99mTc-ECD SPECT was performed before and after rTMS of dorsolateral prefrontal cortex in 61 drug-resistant right-handed patients with major depression, using high frequency (10Hz) left-side stimulation in 33 patients, and low frequency (1Hz) right-side stimulation in 28 patients. Efficiency of rTMS response was defined as at least 50% reduction of the baseline Beck Depression Inventory score. We compared the whole-brain voxel-based brain SPECT changes in perfusion after rTMS, between responders and non-responders in the whole sample (pleft- and right-stimulation. Before rTMS, the left- and right-prefrontal stimulation groups did not differ from clinical data and brain SPECT perfusion. rTMS efficiency (evaluated on % of responders) was statistically equivalent in the two groups of patients. In the whole-group of responder patients, a perfusion decrease was found after rTMS, in comparison to non-responders, within the left perirhinal cortex (BA35, BA36). This result was secondarily confirmed separately in the two subgroups, i.e. after either left stimulation (p=0.017) or right stimulation (pbrain functional changes associated to antidepressive efficiency, consisting to a remote brain limbic activity decrease within the left perirhinal cortex. However, these results will have to be confirmed in a double-blind randomized trial using a sham control group. Copyright © 2012 Elsevier Inc. All rights reserved.

Effects of Multi-Session Repetitive Transcranial Magnetic Stimulation on Motor Control and Spontaneous Brain Activity in Multiple System Atrophy: A Pilot Study

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Zhu Liu

2018-05-01

Full Text Available Background: Impaired motor control is one of the most common symptoms of multiple system atrophy (MSA. It arises from dysfunction of the cerebellum and its connected neural networks, including the primary motor cortex (M1, and is associated with altered spontaneous (i.e., resting-state brain network activity. Non-invasive repetitive transcranial magnetic stimulation (rTMS selectively facilitates the excitability of supraspinal networks. Repeated rTMS sessions have been shown to induce long-term changes to both resting-state brain dynamics and behavior in several neurodegenerative diseases. Here, we hypothesized that a multi-session rTMS intervention would improve motor control in patients with MSA, and that such improvements would correlate with changes in resting-state brain activity.Methods: Nine participants with MSA received daily sessions of 5 Hz rTMS for 5 days. rTMS targeted both the cerebellum and the bilateral M1. Before and within 3 days after the intervention, motor control was assessed by the motor item of the Unified Multiple System Atrophy Rating Scale (UMSARS. Resting-state brain activity was recorded by blood-oxygen-level dependency (BOLD functional magnetic resonance imaging. The “complexity” of resting-state brain activity fluctuations was quantified within seven well-known functional cortical networks using multiscale entropy, a technique that estimates the degree of irregularity of the BOLD time-series across multiple scales of time.Results: The rTMS intervention was well-attended and was not associated with any adverse events. Average motor scores were lower (i.e., better performance following the rTMS intervention as compared to baseline (t8 = 2.3, p = 0.003. Seven of nine participants exhibited such pre-to-post intervention improvements. A trend toward an increase in resting-state complexity was observed within the motor network (t8 = 1.86, p = 0.07. Participants who exhibited greater increases in motor network resting

Stereotactic neurosurgery for tremor

NARCIS (Netherlands)

Speelman, Johannes D.; Schuurman, Richard; de Bie, Rob M. A.; Esselink, Rianne A. J.; Bosch, D. Andries

2002-01-01

The role of the motor thalamus as surgical target in stereotactic neurosurgery for different kinds of tremor is discussed. For tremor in Parkinson's disease. the subthalamic nucleus becomes more and more often the surgical target, because this target also gives relief of other and more

Linking Essential Tremor to the Cerebellum: Physiological Evidence.

Science.gov (United States)

Filip, Pavel; Lungu, Ovidiu V; Manto, Mario-Ubaldo; Bareš, Martin

2016-12-01

Essential tremor (ET), clinically characterized by postural and kinetic tremors, predominantly in the upper extremities, originates from pathological activity in the dynamic oscillatory network comprising the majority of nodes in the central motor network. Evidence indicates dysfunction in the thalamus, the olivocerebellar loops, and intermittent cortical engagement. Pathology of the cerebellum, a structure with architecture intrinsically predisposed to oscillatory activity, has also been implicated in ET as shown by clinical, neuroimaging, and pathological studies. Despite electrophysiological studies assessing cerebellar impairment in ET being scarce, their impact is tangible, as summarized in this review. The electromyography-magnetoencephalography combination provided the first direct evidence of pathological alteration in cortico-subcortical communication, with a significant emphasis on the cerebellum. Furthermore, complex electromyography studies showed disruptions in the timing of agonist and antagonist muscle activation, a process generally attributed to the cerebellum. Evidence pointing to cerebellar engagement in ET has also been found in electrooculography measurements, cerebellar repetitive transcranial magnetic stimulation studies, and, indirectly, in complex analyses of the activity of the ventral intermediate thalamic nucleus (an area primarily receiving inputs from the cerebellum), which is also used in the advanced treatment of ET. In summary, further progress in therapy will require comprehensive electrophysiological and physiological analyses to elucidate the precise mechanisms leading to disease symptoms. The cerebellum, as a major node of this dynamic oscillatory network, requires further study to aid this endeavor.

Effects of timolol and atenolol on benign essential tremor: placebo-controlled studies based on quantitative tremor recording.

Science.gov (United States)

Dietrichson, P; Espen, E

1981-08-01

Two different beta-adrenoreceptor antagonists, atenolol and timolol, were separately compared with a placebo in the suppression of essential tremor. In two-week single-blind placebo-controlled studies with cross-over, timolol (5 mg twice daily) and atenolol (100 mg once daily) produced an equal reduction in sitting heart rate and sitting blood pressure. Timolol was effective in reducing tremor while atenolol failed to reduce tremor amplitude. These results indicate that essential tremor can be reduced but not blocked, by the adrenergic blocker timolol with both beta 1 and beta 2 blocking properties; but not by the relatively selective beta 1 blocking drug atenolol. Possibly, the tremor reduction is medicated by a peripheral effect on beta 2 adrenoreceptors.

Characterizing Orthostatic Tremor Using a Smartphone Application

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Arjun Balachandar

2017-07-01

Full Text Available Background: Orthostatic tremor is one of the few tremor conditions requiring an electromyogram for definitive diagnosis since leg tremor might not be visible to the naked eye.Phenomenology Shown: An iOS application (iSeismometer, ObjectGraph LLC, New York using an Apple iPhone 5 (Cupertino, CA, USA inserted into the patient’s sock detected a tremor with a frequency of 16.4 Hz on both legs.Educational Value: The rapid and straightforward accelerometer-based recordings accomplished in this patient demonstrate the ease with which quantitative analysis of orthostatic tremor can be conducted and, importantly, demonstrates the potential application of this approach in the assessment of any lower limb tremor. 

No influence of one right-sided prefrontal HF-rTMS session on alcohol craving in recently detoxified alcohol-dependent patients: results of a naturalistic study.

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Herremans, S C; Baeken, C; Vanderbruggen, N; Vanderhasselt, M A; Zeeuws, D; Santermans, L; De Raedt, R

2012-01-01

Prior research in substance dependence has suggested potential anti-craving effects of repetitive transcranial magnetic stimulation (rTMS) when applied to the dorsolateral prefrontal cortex (DLPFC). However, no single sham-controlled session studies applied to the right DLPFC have been carried-out in recently detoxified alcohol-dependent patients. Furthermore, no studies examined the effect of a single HF-rTMS session on craving in these patients' natural habitat. To further investigate the effect of high-frequency (HF)-rTMS of the right DLPFC on alcohol craving, we performed a prospective, single-blind, sham-controlled study involving 36 hospitalized patients with alcohol dependence syndrome. After successful detoxification, patients were allocated receiving one active or one sham HF-rTMS session. The obsessive-compulsive drinking scale (OCDS) was administered to evaluate the extent of craving just before and after the HF-rTMS session (on Friday), on Saturday and Sunday during the weekend at home, and on Monday when the patient returned to the hospital. One single blind sham-controlled HF-rTMS session applied to the right DLPFC did not result in changes in craving (neither immediately after the stimulation session, nor in patients' natural environment during the weekend). One HF-rTMS stimulation session applied to the right DLPFC had no significant effects on alcohol craving in alcohol dependent patients. One such session could have been too short to alter alcohol craving in a sample of alcohol dependent patients. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Electronically switchable sham transcranial magnetic stimulation (TMS system.

Directory of Open Access Journals (Sweden)

Fumiko Hoeft

Full Text Available Transcranial magnetic stimulation (TMS is increasingly being used to demonstrate the causal links between brain and behavior in humans. Further, extensive clinical trials are being conducted to investigate the therapeutic role of TMS in disorders such as depression. Because TMS causes strong peripheral effects such as auditory clicks and muscle twitches, experimental artifacts such as subject bias and placebo effect are clear concerns. Several sham TMS methods have been developed, but none of the techniques allows one to intermix real and sham TMS on a trial-by-trial basis in a double-blind manner. We have developed an attachment that allows fast, automated switching between Standard TMS and two types of control TMS (Sham and Reverse without movement of the coil or reconfiguration of the setup. We validate the setup by performing mathematical modeling, search-coil and physiological measurements. To see if the stimulus conditions can be blinded, we conduct perceptual discrimination and sensory perception studies. We verify that the physical properties of the stimulus are appropriate, and that successive stimuli do not contaminate each other. We find that the threshold for motor activation is significantly higher for Reversed than for Standard stimulation, and that Sham stimulation entirely fails to activate muscle potentials. Subjects and experimenters perform poorly at discriminating between Sham and Standard TMS with a figure-of-eight coil, and between Reverse and Standard TMS with a circular coil. Our results raise the possibility of utilizing this technique for a wide range of applications.

Pressure pain thresholds increase after preconditioning 1 Hz repetitive transcranial magnetic stimulation with transcranial direct current stimulation.

Science.gov (United States)

Moloney, Tonya M; Witney, Alice G

2014-01-01

The primary motor cortex (M1) is an effective target of non-invasive cortical stimulation (NICS) for pain threshold modulation. It has been suggested that the initial level of cortical excitability of M1 plays a key role in the plastic effects of NICS. Here we investigate whether transcranial direct current stimulation (tDCS) primed 1 Hz repetitive transcranial magnetic stimulation (rTMS) modulates experimental pressure pain thresholds and if this is related to observed alterations in cortical excitability. 15 healthy, male participants received 10 min 1 mA anodal, cathodal and sham tDCS to the left M1 before 15 min 1 Hz rTMS in separate sessions over a period of 3 weeks. Motor cortical excitability was recorded at baseline, post-tDCS priming and post-rTMS through recording motor evoked potentials (MEPs) from right FDI muscle. Pressure pain thresholds were determined by quantitative sensory testing (QST) through a computerized algometer, on the palmar thenar of the right hand pre- and post-stimulation. Cathodal tDCS-primed 1 Hz-rTMS was found to reverse the expected suppressive effect of 1 Hz rTMS on cortical excitability; leading to an overall increase in activity (ppain thresholds (ppain. This study demonstrates that priming the M1 before stimulation of 1 Hz-rTMS modulates experimental pressure pain thresholds in a safe and controlled manner, producing a form of analgesia.

Disorders of balance and gait in essential tremor are associated with midline tremor and age.

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Hoskovcová, Martina; Ulmanová, Olga; Sprdlík, Otakar; Sieger, Tomáš; Nováková, Jana; Jech, Robert; Růžička, Evžen

2013-02-01

Disorders of balance and gait have been observed in patients with essential tremor (ET), but their association with tremor severity remains unclear. This study aimed to evaluate postural instability and gait changes in ET patients and to investigate their relationship to tremor characteristics with regard to cerebellar dysfunction as a possible common pathogenetic mechanism in ET. Thirty ET patients (8F, mean (SD) age 55.8 (17.8), range 19-81 years) and 25 normal controls (7F, 53.0 (17.7), 19-81) were tested with the scales of Activities-specific Balance Confidence (ABC), Fullerton Advanced Balance (FAB), and International Cooperative Ataxia Rating Scale (ICARS). Posturography and gait were assessed using a Footscan® system. Tremor was evaluated by the Fahn-Tolosa-Marin Tremor Rating Scale (TRS) and accelerometry in five upper limb positions. A mean (SD) TRS sum score of 27.0 (13.2) corresponded to mild to moderate tremor severity in most patients. In comparison with controls, ET subjects exhibited lower tandem gait velocity (0.21 vs. 0.26 m/s, P = 0.028), more missteps (0.57 vs. 0.12, P = 0.039), and increased postural sway in tandem stance (sway area 301.1 vs. 202.9 mm(2), P = 0.045). In normal gait, step width increased with the midline tremor subscore of TRS (Pearson r = 0.60, P = 0.046). Moreover, significant correlations were found between age and quantitative measures of normal and tandem gait in ET patients but not in controls. ABC, FAB, and ICARS scores did not significantly differ between patients and controls. In conclusion, gait and balance alterations in ET patients occur even without subjective complaints. Their relationship with midline tremor and dependence on age suggest a connection with cerebellar dysfunction.

Kinetic Tremor: Differences Between Smokers and Non-smokers

OpenAIRE

Louis, Elan D.

2006-01-01

Tremor is among the acute effects of nicotine exposure. Published studies have focused on smoking-related postural (static) hand tremor rather than kinetic tremor (tremor during hand use), and gender differences in smoking-related tremor have not been examined. In a group of adults who were sampled from a population (mean ± SD = 65.7 ± 11.5 years, range = 18 - 92 years), the investigator assessed whether the severity of postural and kinetic tremors differed in smokers versus non-smokers, and ...

Comparing TMS perturbations to occipital and parietal cortices in concurrent TMS-fMRI studies-Methodological considerations

DEFF Research Database (Denmark)

Leitao, Joana; Thielscher, Axel; Tuennerhoff, Johannes

2017-01-01

the effect of transient perturbations on functional brain organization. This concurrent TMS-fMRI study applied TMS perturbation to occipital and parietal cortices with the aim to 'mimick' neglect and hemianopia. Based on the challenges and interpretational limitations of our own study we aim to provide...

Repetitive transcranial magnetic stimulation is as effective as electroconvulsive therapy in the treatment of nondelusional major depressive disorder: an open study.

Science.gov (United States)

Grunhaus, L; Dannon, P N; Schreiber, S; Dolberg, O H; Amiaz, R; Ziv, R; Lefkifker, E

2000-02-15

Repetitive transcranial magnetic stimulation (rTMS), a new method for the stimulation of the central nervous system, is being proposed as a potential new treatment in patients with major depressive disorder (MDD). We tested the hypothesis that rTMS would be as effective as electroconvulsive therapy (ECT) in patients with MDD. Forty patients with MDD referred for ECT were randomly assigned to either ECT or rTMS. Repetitive transcranial magnetic stimulation was performed at 90% power of the motor threshold. The stimulation frequency was 10 Hz for either 2 sec (first eight patients) or 6 sec (final 12 patients) for 20 trains. Patients were treated for up to 20 treatment days. Electroconvulsive therapy was performed according to standard protocols. Overall patients responded best to ECT (chi(2) = 3.8, p <.05). Patients with MDD and psychosis responded significantly better to ECT (chi(2) = 9.2, p <. 01), whereas MDD patients without psychosis responded similarly to both treatments (chi(2) = 0.0, ns). The analysis of variance with repeated measures of clinical variables for the whole sample revealed significant treatment effects for both groups; however, interaction between group and treatment was seen only for the Global Assessment of Function and the Sleep assessment. When the psychosis-nonpsychosis grouping was considered, patients with psychosis responded dramatically better to ECT in all assessments, whereas those without psychosis responded similarly to both treatments. Overall ECT was a more potent treatment for patients with MDD, this being particularly evident in patients with MDD and psychosis; however, in patients with MDD without psychosis the effects of rTMS were similar to those of ECT. The results we report are encouraging and support an important role for rTMS in the treatment of severe MDD; however, additional blinded studies are needed to precisely define this role.

Olfaction and essential tremor Olfato no tremor essencial

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Lucas Barasnevicius Quagliato

2009-03-01

Full Text Available OBJECTIVE: To characterize the olfactory identification in 40 essential tremor (ET patients, with the University of Pennsylvania 12 Smell Identification Test (UPSIT, to correlate UPSIT scores to clinical and epidemiological data and to compare it to 89 aged matched controls. METHOD: Patients were assessed using ET Clinical Scale of Evaluation and UPSIT. RESULTS: In patients with ET, the UPSIT medium score was 9.10, similar to the control group (9.11, which was also observed in all age groups. ET severity did not correlate to UPSIT scores. CONCLUSION: This study demonstrated normality of olfactory identification on ET, qualifying UPSIT to be an important tool on tremor differential diagnosis of undetermined origin.OBJETIVO: Caracterizar a identificação olfatória em 40 pacientes com tremor essencial, através do Teste de Identificação de 12 Cheiros da Universidade de Pensilvânia (TICUP, correlacioná-la aos dados clínicos e epidemiológicos e compará-la com 89 indivíduos normais. MÉTODO: Os pacientes foram avaliados com a Escala Clínica de Avaliação do TE e com o TICUP. RESULTADOS: A média de acertos no TICUP nos pacientes com TE foi 9,10, semelhante à do grupo controle (9,11, sendo isso observado em todas as faixas etárias. A gravidade do TE não se correlacionou com o resultado do TICUP. CONCLUSÃO: Este estudo demonstrou normalidade da identificação olfatória no TE, qualificando o TICUP como ferramenta importante no diagnóstico diferencial dos tremores de causa indeterminada.

Therapeutic administration of atomoxetine combined with rTMS and occupational therapy for upper limb hemiparesis after stroke: a case series study of three patients.

Science.gov (United States)

Kinoshita, Shoji; Kakuda, Wataru; Yamada, Naoki; Momosaki, Ryo; Okuma, Ryo; Watanabe, Shu; Abo, Masahiro

2016-03-01

Atomoxetine, a selective noradrenaline reuptake inhibitor, has been reported to enhance brain plasticity, but has not yet been used in stroke patients. We reported the feasibility and clinical benefits on motor functional recovery of the combination of repetitive transcranial magnetic stimulation (rTMS) and intensive occupational therapy (OT) in stroke patients. This pilot study was designed to evaluate the additive effects of oral atomoxetine to rTMS/OT in post-stroke hemiparetic patients. The study included three post-stroke patients with upper limb hemiparesis. Treatment with 40 mg/day atomoxetine commenced 2 weeks before admission. After confirming tolerance, the dose was increased to 120 mg/day. Low-frequency rTMS/OT was provided daily for 15 days during continued atomoxetine therapy. Motor function of the affected upper limb was evaluated with the Fugl-Meyer Assessment and Wolf Motor Function test. All patients completed the protocol and showed motor improvement up to 4 weeks after the treatment. No atomoxetine-related side effects were noted. Our protocol of triple therapy of atomoxetine, low-frequency rTMS, and OT is safe and feasible intervention for upper limb hemiparesis after stroke.

Triggered tremor sweet spots in Alaska

Science.gov (United States)

Gomberg, Joan; Prejean, Stephanie

2013-01-01

To better understand what controls fault slip along plate boundaries, we have exploited the abundance of seismic and geodetic data available from the richly varied tectonic environments composing Alaska. A search for tremor triggered by 11 large earthquakes throughout all of seismically monitored Alaska reveals two tremor “sweet spots”—regions where large-amplitude seismic waves repeatedly triggered tremor between 2006 and 2012. The two sweet spots locate in very different tectonic environments—one just trenchward and between the Aleutian islands of Unalaska and Akutan and the other in central mainland Alaska. The Unalaska/Akutan spot corroborates previous evidence that the region is ripe for tremor, perhaps because it is located where plate-interface frictional properties transition between stick-slip and stably sliding in both the dip direction and laterally. The mainland sweet spot coincides with a region of complex and uncertain plate interactions, and where no slow slip events or major crustal faults have been noted previously. Analyses showed that larger triggering wave amplitudes, and perhaps lower frequencies (tremor. However, neither the maximum amplitude in the time domain or in a particular frequency band, nor the geometric relationship of the wavefield to the tremor source faults alone ensures a high probability of triggering. Triggered tremor at the two sweet spots also does not occur during slow slip events visually detectable in GPS data, although slow slip below the detection threshold may have facilitated tremor triggering.

Cataloging tremor at Kilauea Volcano, Hawaii

Science.gov (United States)

Thelen, W. A.; Wech, A.

2013-12-01

Tremor is a ubiquitous seismic feature on Kilauea volcano, which emanates from at least three distinct sources. At depth, intermittent tremor and earthquakes thought to be associated with the underlying plumbing system of Kilauea (Aki and Koyanagi, 1981) occurs approximately 40 km below and 40 km SW of the summit. At the summit of the volcano, nearly continuous tremor is recorded close to a persistently degassing lava lake, which has been present since 2008. Much of this tremor is correlated with spattering at the lake surface, but tremor also occurs in the absence of spattering, and was observed at the summit of the volcano prior to the appearance of the lava lake, predominately in association with inflation/deflation events. The third known source of tremor is in the area of Pu`u `O`o, a vent that has been active since 1983. The exact source location and depth is poorly constrained for each of these sources. Consistently tracking the occurrence and location of tremor in these areas through time will improve our understanding of the plumbing geometry beneath Kilauea volcano and help identify precursory patterns in tremor leading to changes in eruptive activity. The continuous and emergent nature of tremor precludes the use of traditional earthquake techniques for automatic detection and location of seismicity. We implement the method of Wech and Creager (2008) to both detect and localize tremor seismicity in the three regions described above. The technique uses an envelope cross-correlation method in 5-minute windows that maximizes tremor signal coherency among seismic stations. The catalog is currently being built in near-realtime, with plans to extend the analysis to the past as time and continuous data availability permits. This automated detection and localization method has relatively poor depth constraints due to the construction of the envelope function. Nevertheless, the epicenters distinguish activity among the different source regions and serve as

What is This Thing Called Tremor?

Science.gov (United States)

Rubin, A. M.; Bostock, M. G.

2017-12-01

Tremor has many enigmatic attributes. The LFEs that comprise it have a dearth of large events, implying a characteristic scale. Bostock et al. (2015) found LFE duration beneath Vancouver Island to be nearly independent of magnitude. That duration ( 0.4 s), multiplied by a shear wave speed, defines a length scale far larger than the spatial separation between consecutive but non-colocated detections. If one LFE ruptures multiple brittle patches in a ductile matrix its propagation speed can be slowed to the extent that consecutive events don't overlap, but then why aren't there larger and smaller LFEs with larger and smaller durations? Perhaps there are. Tremor seismograms from Vancouver Island are often saturated with direct arrivals, by which we mean time lags between events shorter than typical event durations. Direct evidence of this, given the small coda amplitude of LFE stacks, is that seismograms at stations many kilometers apart often track each other wiggle for wiggle. We see this behavior over the full range tremor amplitudes, from close to the noise level on a tremor-free day to 10 times larger. If the LFE magnitude-frequency relation is time-independent, this factor of 10 implies that the LFE occurrence rate during loud tremor is 10^2=100 times that during quiet tremor (>250 LFEs per second). We investigate the implications of this by comparing observed seismograms to synthetics made from the superposition of "LFEs" that are Poissonian in time over a range of average rates. We find that provided the LFEs have a characteristic scale (whether exponential or power law), saturation completely obscures the moment-duration scaling of the contributing events; that is, the moment-duration scaling of LFEs may be identical to that of regular earthquakes. Nonetheless, there are subtle differences between our synthetics and real seismograms, remarkably independent of tremor amplitude, that remain to be explained. Foremost among these is a slightly greater affinity of

Effect of Bilateral Prefrontal rTMS on Left Prefrontal NAA and Glx Levels in Schizophrenia Patients with Predominant Negative Symptoms: An Exploratory Study.

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Dlabac-de Lange, Jozarni J; Liemburg, Edith J; Bais, Leonie; van de Poel-Mustafayeva, Aida T; de Lange-de Klerk, Elly S M; Knegtering, Henderikus; Aleman, André

Prefrontal repetitive Transcranial Magnetic Stimulation (rTMS) may improve negative symptoms in patients with schizophrenia, but few studies have investigated the underlying neural mechanism. This study aims to investigate changes in the levels of glutamate and glutamine (Glx, neurotransmitter and precursor) and N-Acetyl Aspartate (NAA) in the left dorsolateral prefrontal cortex of patients with schizophrenia treated with active bilateral prefrontal rTMS as compared to sham-rTMS, as measured with 1 H-Magnetic Resonance Spectroscopy ( 1 H-MRS). Patients were randomized to a 3-week course of active or sham high-frequency rTMS. Pre-treatment and post-treatment 1 H-MRS data were available for 24 patients with schizophrenia with moderate to severe negative symptoms (Positive and Negative Syndrome Scale (PANSS) negative subscale ≥ 15). Absolute metabolite concentrations were calculated using LCModel with the water peak as reference. To explore the association between treatment condition and changes in concentration of Glx and NAA, we applied a linear regression model. We observed an increase of Glx concentration in the active treatment group and a decrease of Glx concentration in the group receiving sham treatment. The association between changes in Glx concentration and treatment condition was significant. No significant associations between changes in NAA and treatment condition were found. Noninvasive neurostimulation with high-frequency bilateral prefrontal rTMS may influence Glx concentration in the prefrontal cortex of patients with schizophrenia. Larger studies are needed to confirm these findings and further elucidate the underlying neural working mechanism of rTMS. Copyright © 2016 Elsevier Inc. All rights reserved.

Control of lithium tremor with propranolol.

Science.gov (United States)

Lapierre, Y D

1976-04-03

Lithium tremor is an irregular, nonrhythmic tremor of the distal extremities, variable in both intensity and frequency. It is clinically differentiated from essential tremor and tremors due to anxiety and neuroleptics. The pathophysiologic mechanisms are hypothesized to be of perpheral origin. Five patients were successfully treated with propranolol. In general, the dosage of propranolol must be individually adjusted and is usually from 30 to 40 mg daily in divided doses. This blocker of beta-adrenergic receptors remains effective with long-term administration and increases in dosage are not required.

Unilateral rubral tremors in Wilson′s disease treated with dimercaprol

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Rahul T Chakor

2015-01-01

Full Text Available Tremors are reported as the most frequent neurological manifestation of Wilson′s disease (WD in some series. Postural tremors, rest tremors, action tremors and wing-beating (rubral tremors are the different types of tremors seen in WD. We report a patient of WD with unilateral rubral tremors refractory to 1-year therapy with Penicillamine and anti-tremor medications. The tremors decreased considerably after adding chelation therapy with dimercaprol. Combination of Penicillamine and dimercaprol is an effective decoppering measure in rubral tremors of WD.

Peripheral beta-adrenergic blockade treatment of parkinsonian tremor.

Science.gov (United States)

Foster, N L; Newman, R P; LeWitt, P A; Gillespie, M M; Larsen, T A; Chase, T N

1984-10-01

The effect of nadolol, a peripherally acting beta-adrenergic blocker, on resting, postural, and intention tremor was examined in 8 patients with idiopathic Parkinson's disease whose motor symptoms, other than tremor, were well controlled with conventional medications. In a double-blind, placebo-controlled, crossover design, patients received 80 to 320 mg of nadolol for six weeks while continuing their previous therapeutic regimen. Accelerometer readings showed a 34% reduction (p less than 0.025) in tremor distance, but no change in tremor frequency, during nadolol therapy. Maximum benefit was achieved with a dose of 240 mg, when resting tremor improved 54%, postural tremor 32%, and intention tremor 54%. Physician ratings and patient reports supported the accelerometer results. Nadolol appears to be a safe, effective adjunct to current dopaminergic and anticholinergic therapy for severe tremor in Parkinson's disease.

Primary motor cortex functionally contributes to language comprehension: An online rTMS study.

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Vukovic, Nikola; Feurra, Matteo; Shpektor, Anna; Myachykov, Andriy; Shtyrov, Yury

2017-02-01

Among various questions pertinent to grounding human cognitive functions in a neurobiological substrate, the association between language and motor brain structures is a particularly debated one in neuroscience and psychology. While many studies support a broadly distributed model of language and semantics grounded, among other things, in the general modality-specific systems, theories disagree as to whether motor and sensory cortex activity observed during language processing is functional or epiphenomenal. Here, we assessed the role of motor areas in linguistic processing by investigating the responses of 28 healthy volunteers to different word types in semantic and lexical decision tasks, following repetitive transcranial magnetic stimulation (rTMS) of primary motor cortex. We found that early rTMS (delivered within 200ms of word onset) produces a left-lateralised and meaning-specific change in reaction speed, slowing down behavioural responses to action-related words, and facilitating abstract words - an effect present only during semantic, but not lexical, decision. We interpret these data in light of action-perception theory of language, bolstering the claim that motor cortical areas play a functional role in language comprehension. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Neuroprotective Mechanism of Low-Frequency rTMS on Nigral Dopaminergic Neurons of Parkinson's Disease Model Mice.

Science.gov (United States)

Dong, Qiaoyun; Wang, Yanyong; Gu, Ping; Shao, Rusheng; Zhao, Li; Liu, Xiqi; Wang, Zhanqiang; Wang, Mingwei

2015-01-01

Background. Parkinson's disease is a neurodegenerative disease in elder people, pathophysiologic basis of which is the severe deficiency of dopamine in the striatum. The purpose of the present study was to evaluate the neuroprotective effect of low-frequency rTMS on Parkinson's disease in model mice. Methods. The effects of low-frequency rTMS on the motor function, cortex excitability, neurochemistry, and neurohistopathology of MPTP-induced Parkinson's disease mice were investigated through behavioral detection, electrophysiologic technique, high performance liquid chromatography-electrochemical detection, immunohistochemical staining, and western blot. Results. Low-frequency rTMS could improve the motor coordination impairment of Parkinson's disease mice: the resting motor threshold significantly decreased in the Parkinson's disease mice; the degeneration of nigral dopaminergic neuron and the expression of tyrosine hydroxylase were significantly improved by low-frequency rTMS; moreover, the expressions of brain derived neurotrophic factor and glial cell line derived neurotrophic factor were also improved by low-frequency rTMS. Conclusions. Low-frequency rTMS had a neuroprotective effect on the nigral dopaminergic neuron which might be due to the improved expressions of brain derived neurotrophic factor and glial cell line-derived neurotrophic factor. The present study provided a theoretical basis for the application of low-frequency rTMS in the clinical treatment and recovery of Parkinson's disease.

Clinical improvement in patients with borderline personality disorder after treatment with repetitive transcranial magnetic stimulation: preliminary results.

Science.gov (United States)

Reyes-López, Julian; Ricardo-Garcell, Josefina; Armas-Castañeda, Gabriela; García-Anaya, María; Arango-De Montis, Iván; González-Olvera, Jorge J; Pellicer, Francisco

2018-01-01

Current treatment of borderline personality disorder (BPD) consists of psychotherapy and pharmacological interventions. However, the use of repetitive transcranial magnetic stimulation (rTMS) could be beneficial to improve some BPD symptoms. The objective of this study was to evaluate clinical improvement in patients with BPD after application of rTMS over the right or left dorsolateral prefrontal cortex (DLPFC). Twenty-nine patients with BPD from the National Institute of Psychiatry, Mexico, were randomized in two groups to receive 15 sessions of rTMS applied over the right (1 Hz, n=15) or left (5 Hz, n=14) DLPFC. Improvement was measured by the Clinical Global Impression Scale for BPD (CGI-BPD), Borderline Evaluation of Severity Over Time (BEST), Beck Depression Inventory (BDI), Hamilton Anxiety Rating Scale (HAM-A), and Barratt Impulsiveness Scale (BIS). Intragroup comparison showed significant (p < 0.05) reductions in every psychopathologic domain of the CGI-BPD and in the total scores of all scales in both groups. Both protocols produced global improvement in severity and symptoms of BPD, particularly in impulsiveness, affective instability, and anger. Further studies are warranted to explore the therapeutic effect of rTMS in BPD. NCT02273674

Tremor

Science.gov (United States)

... and down or closing and opening the eyes. Intention tremor is produced with purposeful movement toward a ... by any movement such as holding a heavy book or a dumbbell in the same position. top ...

Psychogenic Tremor: A Video Guide to Its Distinguishing Features

Directory of Open Access Journals (Sweden)

Joseph Jankovic

2014-08-01

Full Text Available Background: Psychogenic tremor is the most common psychogenic movement disorder. It has characteristic clinical features that can help distinguish it from other tremor disorders. There is no diagnostic gold standard and the diagnosis is based primarily on clinical history and examination. Despite proposed diagnostic criteria, the diagnosis of psychogenic tremor can be challenging. While there are numerous studies evaluating psychogenic tremor in the literature, there are no publications that provide a video/visual guide that demonstrate the clinical characteristics of psychogenic tremor. Educating clinicians about psychogenic tremor will hopefully lead to earlier diagnosis and treatment. Methods: We selected videos from the database at the Parkinson's Disease Center and Movement Disorders Clinic at Baylor College of Medicine that illustrate classic findings supporting the diagnosis of psychogenic tremor.Results: We include 10 clinical vignettes with accompanying videos that highlight characteristic clinical signs of psychogenic tremor including distractibility, variability, entrainability, suggestibility, and coherence.Discussion: Psychogenic tremor should be considered in the differential diagnosis of patients presenting with tremor, particularly if it is of abrupt onset, intermittent, variable and not congruous with organic tremor. The diagnosis of psychogenic tremor, however, should not be simply based on exclusion of organic tremor, such as essential, parkinsonian, or cerebellar tremor, but on positive criteria demonstrating characteristic features. Early recognition and management are critical for good long-term outcome.

Essential Tremor Is More Than a Tremor

Medline Plus

Full Text Available Home About the IETF Volunteer For Healthcare Providers Giving Options Donate Prev Next IETF > About Essential Tremor > Video Video Click to share on Facebook (Opens in new window) Click ...

TMS-induced neural noise in sensory cortex interferes with short-term memory storage

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Tyler D Bancroft

2014-03-01

Full Text Available In a previous study, Harris et al. (2002 found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation to primary somatosensory cortex (SI early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence from human EEG and single-cell recording in primates that instead points to prefrontal cortex as the storage substrate for vibrotactile memory. In the present study, we use computational methods to demonstrate how Harris et al.’s results can be reproduced by TMS-induced activity in sensory cortex and subsequent feedforward interference with memory traces stored in prefrontal cortex, thereby reconciling discordant findings in the tactile memory literature.

Prognostic Value of Cortically Induced Motor Evoked Activity by TMS in Chronic Stroke: Caveats from a Revealing Single Clinical Case

LENUS (Irish Health Repository)

Amengual, Julià L

2012-06-08

AbstractBackgroundWe report the case of a chronic stroke patient (62 months after injury) showing total absence of motor activity evoked by transcranial magnetic stimulation (TMS) of spared regions of the left motor cortex, but near-to-complete recovery of motor abilities in the affected hand.Case presentationMultimodal investigations included detailed TMS based motor mapping, motor evoked potentials (MEP), and Cortical Silent period (CSP) as well as functional magnetic resonance imaging (fMRI) of motor activity, MRI based lesion analysis and Diffusion Tensor Imaging (DTI) Tractography of corticospinal tract (CST). Anatomical analysis revealed a left hemisphere subinsular lesion interrupting the descending left CST at the level of the internal capsule. The absence of MEPs after intense TMS pulses to the ipsilesional M1, and the reversible suppression of ongoing electromyographic (EMG) activity (indexed by CSP) demonstrate a weak modulation of subcortical systems by the ipsilesional left frontal cortex, but an inability to induce efficient descending volleys from those cortical locations to right hand and forearm muscles. Functional MRI recordings under grasping and finger tapping patterns involving the affected hand showed slight signs of subcortical recruitment, as compared to the unaffected hand and hemisphere, as well as the expected cortical activations.ConclusionsThe potential sources of motor voluntary activity for the affected hand in absence of MEPs are discussed. We conclude that multimodal analysis may contribute to a more accurate prognosis of stroke patients.

Prognostic value of cortically induced motor evoked activity by TMS in chronic stroke: Caveats from a revealing single clinical case

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Amengual Julià L

2012-06-01

Full Text Available Abstract Background We report the case of a chronic stroke patient (62 months after injury showing total absence of motor activity evoked by transcranial magnetic stimulation (TMS of spared regions of the left motor cortex, but near-to-complete recovery of motor abilities in the affected hand. Case presentation Multimodal investigations included detailed TMS based motor mapping, motor evoked potentials (MEP, and Cortical Silent period (CSP as well as functional magnetic resonance imaging (fMRI of motor activity, MRI based lesion analysis and Diffusion Tensor Imaging (DTI Tractography of corticospinal tract (CST. Anatomical analysis revealed a left hemisphere subinsular lesion interrupting the descending left CST at the level of the internal capsule. The absence of MEPs after intense TMS pulses to the ipsilesional M1, and the reversible suppression of ongoing electromyographic (EMG activity (indexed by CSP demonstrate a weak modulation of subcortical systems by the ipsilesional left frontal cortex, but an inability to induce efficient descending volleys from those cortical locations to right hand and forearm muscles. Functional MRI recordings under grasping and finger tapping patterns involving the affected hand showed slight signs of subcortical recruitment, as compared to the unaffected hand and hemisphere, as well as the expected cortical activations. Conclusions The potential sources of motor voluntary activity for the affected hand in absence of MEPs are discussed. We conclude that multimodal analysis may contribute to a more accurate prognosis of stroke patients.

Interhemispheric Inhibition Induced by Transcranial Magnetic Stimulation Over Primary Sensory Cortex.

Science.gov (United States)

Iwata, Yasuyuki; Jono, Yasutomo; Mizusawa, Hiroki; Kinoshita, Atsushi; Hiraoka, Koichi

2016-01-01

The present study investigated whether the long-interval interhemispheric inhibition (LIHI) is induced by the transcranial magnetic stimulation over the primary sensory area (S1-TMS) without activation of the conditioning side of the primary motor area (M1) contributing to the contralateral motor evoked potential (MEP), whether the S1-TMS-induced LIHI is dependent on the status of the S1 modulated by the tactile input, and whether the pathways mediating the LIHI are different from those mediating the M1-TMS-induced LIHI. In order to give the TMS over the S1 without eliciting the MEP, the intensity of the S1-TMS was adjusted to be the sub-motor-threshold level and the trials with the MEP response elicited by the S1-TMS were discarded online. The LIHI was induced by the S1-TMS given 40 ms before the test TMS in the participants with the attenuation of the tactile perception of the digit stimulation (TPDS) induced by the S1-TMS, indicating that the LIHI is induced by the S1-TMS without activation of the conditioning side of the M1 contributing to the contralateral MEP in the participants in which the pathways mediating the TPDS is sensitive to the S1-TMS. The S1-TMS-induced LIHI was positively correlated with the attenuation of the TPDS induced by the S1-TMS, indicating that the S1-TMS-induced LIHI is dependent on the effect of the S1-TMS on the pathways mediating the TPDS at the S1. In another experiment, the effect of the digit stimulation given before the conditioning TMS on the S1- or M1-TMS-induced LIHI was examined. The digit stimulation produces tactile input to the S1 causing change in the status of the S1. The S1-TMS-induced LIHI was enhanced when the S1-TMS was given in the period in which the tactile afferent volley produced by the digit stimulation just arrived at the S1, while the LIHI induced by above-motor-threshold TMS over the contralateral M1 was not enhanced by the tactile input. Thus, the S1-TMS-induced LIHI is dependent on the status of the S1

Transcranial magnetic stimulation (TMS): compared sensitivity of different motor response parameters in ALS.

Science.gov (United States)

Pouget, J; Trefouret, S; Attarian, S

2000-06-01

Owing to the low sensitivity of clinical signs in assessing upper motor neuron (UMN) involvement in ALS, there is a need for investigative tools capable of detecting abnormal function of the pyramidal tract. Transcranial magnetic stimulation (TMS) may contribute to the diagnosis by reflecting a UMN dysfunction that is not clinically detectable. Several parameters for the motor responses to TMS can be evaluated with different levels of significance in healthy subjects compared with ALS patients. The central motor conduction time, however, is not sensitive in detecting subclinical UMN defects in individual ALS patients. The amplitude of the motor evoked potential (MEP), expressed as the percentage of the maximum wave, also has a low sensitivity. In some cases, the corticomotor threshold is decreased early in the disease course as a result of corticomotor neuron hyperexcitability induced by glutamate. Later, the threshold increases, indicating a loss of UMN. In our experience, a decreased silent period duration appears to be the most sensitive parameter when using motor TMS in ALS. TMS is also a sensitive technique for investigating the corticobulbar tract, which is difficult to study by other methods. TMS is a widely available, painless and safe technique with a good sensitivity that can visualize both corticospinal and corticobulbar tract abnormalities. The sensitivity can be improved further by taking into account the several MEP parameters, including latency and cortical silent period decreased duration.

Pressure pain thresholds increase after preconditioning 1 Hz repetitive transcranial magnetic stimulation with transcranial direct current stimulation.

Directory of Open Access Journals (Sweden)

Tonya M Moloney

Full Text Available BACKGROUND: The primary motor cortex (M1 is an effective target of non-invasive cortical stimulation (NICS for pain threshold modulation. It has been suggested that the initial level of cortical excitability of M1 plays a key role in the plastic effects of NICS. OBJECTIVE: Here we investigate whether transcranial direct current stimulation (tDCS primed 1 Hz repetitive transcranial magnetic stimulation (rTMS modulates experimental pressure pain thresholds and if this is related to observed alterations in cortical excitability. METHOD: 15 healthy, male participants received 10 min 1 mA anodal, cathodal and sham tDCS to the left M1 before 15 min 1 Hz rTMS in separate sessions over a period of 3 weeks. Motor cortical excitability was recorded at baseline, post-tDCS priming and post-rTMS through recording motor evoked potentials (MEPs from right FDI muscle. Pressure pain thresholds were determined by quantitative sensory testing (QST through a computerized algometer, on the palmar thenar of the right hand pre- and post-stimulation. RESULTS: Cathodal tDCS-primed 1 Hz-rTMS was found to reverse the expected suppressive effect of 1 Hz rTMS on cortical excitability; leading to an overall increase in activity (p<0.001 with a parallel increase in pressure pain thresholds (p<0.01. In contrast, anodal tDCS-primed 1 Hz-rTMS resulted in a corresponding decrease in cortical excitability (p<0.05, with no significant effect on pressure pain. CONCLUSION: This study demonstrates that priming the M1 before stimulation of 1 Hz-rTMS modulates experimental pressure pain thresholds in a safe and controlled manner, producing a form of analgesia.

Safety and tolerability of repetitive transcranial magnetic stimulation in patients with pathologic positive sensory phenomena: a review of literature

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Muller, Paul A; Pascual-Leone, Alvaro; Rotenberg, Alexander

2013-01-01

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. PMID:22322098

Added value of multiple versus single sessions of repetitive transcranial magnetic stimulation in predicting motor cortex stimulation efficacy for refractory neuropathic pain.

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Pommier, Benjamin; Quesada, Charles; Fauchon, Camille; Nuti, Christophe; Vassal, François; Peyron, Roland

2018-05-18

OBJECTIVE Selection criteria for offering patients motor cortex stimulation (MCS) for refractory neuropathic pain are a critical topic of research. A single session of repetitive transcranial magnetic stimulation (rTMS) has been advocated for selecting MCS candidates, but it has a low negative predictive value. Here the authors investigated whether multiple rTMS sessions would more accurately predict MCS efficacy. METHODS Patients included in this longitudinal study could access MCS after at least four rTMS sessions performed 3-4 weeks apart. The positive (PPV) and negative (NPV) predictive values of the four rTMS sessions and the correlation between the analgesic effects of the two treatments were assessed. RESULTS Twelve MCS patients underwent an average of 15.9 rTMS sessions prior to surgery; nine of the patients were rTMS responders. Postoperative follow-up was 57.8 ± 15.6 months (mean ± standard deviation). Mean percentage of pain relief (%R) was 21% and 40% after the first and fourth rTMS sessions, respectively. The corresponding mean durations of pain relief were respectively 2.4 and 12.9 days. A cumulative effect of the rTMS sessions was observed on both %R and duration of pain relief (p < 0.01). The %R value obtained with MCS was 35% after 6 months and 43% at the last follow-up. Both the PPV and NPV of rTMS were 100% after the fourth rTMS session (p = 0.0045). A significant correlation was found between %R or duration of pain relief after the fourth rTMS session and %R at the last MCS follow-up (R 2 = 0.83, p = 0.0003). CONCLUSIONS Four rTMS sessions predicted MCS efficacy better than a single session in neuropathic pain patients. Taking into account the cumulative effects of rTMS, the authors found a high-level correlation between the analgesic effects of rTMS and MCS.

TMS320C31

International Nuclear Information System (INIS)

Park, Gwi Tae; Lee, Sang Rak

1998-01-01

This book is divided into four parts, which introduces TMS320C31 with C language. The first part deals with digital signal processor on what is DPS?, types of DPS and structure of TMS320C31. The second part introduces program development by C language, cstartup cord and C compiler. The third part describes OS30, Emile 30 and BIOS. The last part is for application board design of T31 and test examples of T31 board : external flag test, ram test, external read port test and communication test.

Dopamine controls Parkinson's tremor by inhibiting the cerebellar thalamus.

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Dirkx, Michiel F; den Ouden, Hanneke E M; Aarts, Esther; Timmer, Monique H M; Bloem, Bastiaan R; Toni, Ivan; Helmich, Rick C

2017-03-01

Parkinson's resting tremor is related to altered cerebral activity in the basal ganglia and the cerebello-thalamo-cortical circuit. Although Parkinson's disease is characterized by dopamine depletion in the basal ganglia, the dopaminergic basis of resting tremor remains unclear: dopaminergic medication reduces tremor in some patients, but many patients have a dopamine-resistant tremor. Using pharmacological functional magnetic resonance imaging, we test how a dopaminergic intervention influences the cerebral circuit involved in Parkinson's tremor. From a sample of 40 patients with Parkinson's disease, we selected 15 patients with a clearly tremor-dominant phenotype. We compared tremor-related activity and effective connectivity (using combined electromyography-functional magnetic resonance imaging) on two occasions: ON and OFF dopaminergic medication. Building on a recently developed cerebral model of Parkinson's tremor, we tested the effect of dopamine on cerebral activity associated with the onset of tremor episodes (in the basal ganglia) and with tremor amplitude (in the cerebello-thalamo-cortical circuit). Dopaminergic medication reduced clinical resting tremor scores (mean 28%, range -12 to 68%). Furthermore, dopaminergic medication reduced tremor onset-related activity in the globus pallidus and tremor amplitude-related activity in the thalamic ventral intermediate nucleus. Network analyses using dynamic causal modelling showed that dopamine directly increased self-inhibition of the ventral intermediate nucleus, rather than indirectly influencing the cerebello-thalamo-cortical circuit through the basal ganglia. Crucially, the magnitude of thalamic self-inhibition predicted the clinical dopamine response of tremor. Dopamine reduces resting tremor by potentiating inhibitory mechanisms in a cerebellar nucleus of the thalamus (ventral intermediate nucleus). This suggests that altered dopaminergic projections to the cerebello-thalamo-cortical circuit have a role

5 Hz repetitive transcranial magnetic stimulation over the ipsilesional sensory cortex enhances motor learning after stroke

Directory of Open Access Journals (Sweden)

Sonia M Brodie

2014-03-01

Full Text Available Sensory feedback is critical for motor learning, and thus to neurorehabilitation after stroke. Whether enhancing sensory feedback by applying excitatory repetitive transcranial magnetic stimulation (rTMS over the ipsilesional primary sensory cortex (IL-S1 might enhance motor learning in chronic stroke has yet to be investigated. The present study investigated the effects of 5 Hz rTMS over IL-S1 paired with skilled motor practice on motor learning, hemiparetic cutaneous somatosensation, and motor function. Individuals with unilateral chronic stroke were pseudo-randomly divided into either Active or Sham 5 Hz rTMS groups (n=11/group. Following stimulation, both groups practiced a Serial Tracking Task (STT with the hemiparetic arm; this was repeated for 5 days. Performance on the STT was quantified by response time, peak velocity, and cumulative distance tracked at baseline, during the 5 days of practice, and at a no-rTMS retention test. Cutaneous somatosensation was measured using two-point discrimination. Standardized sensorimotor tests were performed to assess whether the effects might generalize to impact hemiparetic arm function. The active 5Hz rTMS + training group demonstrated significantly greater improvements in STT performance [response time (F1,286.04=13.016, p< 0.0005, peak velocity (F1,285.95=4.111, p=0.044, and cumulative distance (F1,285.92=4.076, p=0.044] and cutaneous somatosensation (F1,21.15=8.793, p=0.007 across all sessions compared to the sham rTMS + training group. Measures of upper extremity motor function were not significantly different for either group. Our preliminary results suggest that, when paired with motor practice, 5Hz rTMS over IL-S1 enhances motor learning related change in individuals with chronic stroke, potentially as a consequence of improved cutaneous somatosensation, however no improvement in general upper extremity function was observed.

Treatment of resting tremor by beta-adrenergic blockade.

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Foster, N L; Newman, R P; LeWitt, P A; Gillespie, M M; Chase, T N

1984-10-01

The effect of nadolol, a peripherally acting beta-adrenergic blocker, on resting tremor was examined in eight patients with idiopathic Parkinson's disease. With the use of a double-blind, placebo-controlled study of crossover design, patients received 80 to 320 mg of nadolol for 6 weeks while continuing their previous treatment regimen. Accelerometer readings showed a progressive reduction in tremor amplitude, but no change in tremor frequency, with increasing nadolol dosage. Maximum benefit was achieved at 240 mg, when resting tremor improved 50% (p less than 0.01). Physician ratings confirmed these findings. The results suggest that response to beta-adrenergic blockade may not be limited to postural or intention tremor and that such agents may not reliably differentiate between the tremor of Parkinson's disease and essential tremor.

San Andreas tremor cascades define deep fault zone complexity

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Shelly, David R.

2015-01-01

Weak seismic vibrations - tectonic tremor - can be used to delineate some plate boundary faults. Tremor on the deep San Andreas Fault, located at the boundary between the Pacific and North American plates, is thought to be a passive indicator of slow fault slip. San Andreas Fault tremor migrates at up to 30 m s-1, but the processes regulating tremor migration are unclear. Here I use a 12-year catalogue of more than 850,000 low-frequency earthquakes to systematically analyse the high-speed migration of tremor along the San Andreas Fault. I find that tremor migrates most effectively through regions of greatest tremor production and does not propagate through regions with gaps in tremor production. I interpret the rapid tremor migration as a self-regulating cascade of seismic ruptures along the fault, which implies that tremor may be an active, rather than passive participant in the slip propagation. I also identify an isolated group of tremor sources that are offset eastwards beneath the San Andreas Fault, possibly indicative of the interface between the Monterey Microplate, a hypothesized remnant of the subducted Farallon Plate, and the North American Plate. These observations illustrate a possible link between the central San Andreas Fault and tremor-producing subduction zones.

Combined rTMS and virtual reality brain-computer interface training for motor recovery after stroke

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Johnson, N. N.; Carey, J.; Edelman, B. J.; Doud, A.; Grande, A.; Lakshminarayan, K.; He, B.

2018-02-01

Objective. Combining repetitive transcranial magnetic stimulation (rTMS) with brain-computer interface (BCI) training can address motor impairment after stroke by down-regulating exaggerated inhibition from the contralesional hemisphere and encouraging ipsilesional activation. The objective was to evaluate the efficacy of combined rTMS  +  BCI, compared to sham rTMS  +  BCI, on motor recovery after stroke in subjects with lasting motor paresis. Approach. Three stroke subjects approximately one year post-stroke participated in three weeks of combined rTMS (real or sham) and BCI, followed by three weeks of BCI alone. Behavioral and electrophysiological differences were evaluated at baseline, after three weeks, and after six weeks of treatment. Main results. Motor improvements were observed in both real rTMS  +  BCI and sham groups, but only the former showed significant alterations in inter-hemispheric inhibition in the desired direction and increased relative ipsilesional cortical activation from fMRI. In addition, significant improvements in BCI performance over time and adequate control of the virtual reality BCI paradigm were observed only in the former group. Significance. When combined, the results highlight the feasibility and efficacy of combined rTMS  +  BCI for motor recovery, demonstrated by increased ipsilesional motor activity and improvements in behavioral function for the real rTMS  +  BCI condition in particular. Our findings also demonstrate the utility of BCI training alone, as shown by behavioral improvements for the sham rTMS  +  BCI condition. This study is the first to evaluate combined rTMS and BCI training for motor rehabilitation and provides a foundation for continued work to evaluate the potential of both rTMS and virtual reality BCI training for motor recovery after stroke.

Repetitive transcranial magnetic stimulation of the superior frontal gyrus modulates craving for cigarettes.

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Rose, Jed E; McClernon, F Joseph; Froeliger, Brett; Behm, Frédérique M; Preud'homme, Xavier; Krystal, Andrew D

2011-10-15

Previous functional magnetic resonance imaging studies have shown strong correlations between cue-elicited craving for cigarettes and activation of the superior frontal gyrus (SFG). Repetitive transcranial magnetic stimulation (rTMS) offers a noninvasive means to reversibly affect brain cortical activity, which can be applied to testing hypotheses about the causal role of SFG in modulating craving. Fifteen volunteer smokers were recruited to investigate the effects of rTMS on subjective responses to smoking versus neutral cues and to controlled presentations of cigarette smoke. On different days, participants were exposed to three conditions: 1) high-frequency (10 Hz) rTMS directed at the SFG; 2) low-frequency (1 Hz) rTMS directed at the SFG; and 3) low-frequency (1 Hz) rTMS directed at the motor cortex (control condition). Craving ratings in response to smoking versus neutral cues were differentially affected by the 10-Hz versus 1-Hz SFG condition. Craving after smoking cue presentations was elevated in the 10-Hz SFG condition, whereas craving after neutral cue presentations was reduced. Upon smoking in the 10-Hz SFG condition, ratings of immediate craving reduction as well as the intensity of interoceptive airway sensations were also attenuated. These results support the view that the SFG plays a role in modulating craving reactivity; moreover, the results suggest that the SFG plays a role in both excitatory and inhibitory influences on craving, consistent with prior research demonstrating the role of the prefrontal cortex in the elicitation as well as inhibition of drug-seeking behaviors. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Vertical components of surface vibrations induced by mining tremors in the Upper Silesian Coalfield, Poland

International Nuclear Information System (INIS)

Maciag, E.; Kowalski, W.

1997-01-01

Characteristics of vertical components of surface vibration is epicentral zones due to mining tremors in the Upper Silesian Coalfield (USC) are analysed. Both maximum acceleration amplitudes and dominant frequencies of vertical (Z) and horizontal (N-S and E-W) components of vibrations are compared. The role played by the vertical components of vibrations in estimates of hazard for surface structures excited by mining tremors is discussed. 8 refs., 7 figs

Repetitive Transcranial Magnetic Stimulation for Treatment-Resistant Depression in Adult and Youth Populations: A Systematic Literature Review and Meta-Analysis

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Leggett, Laura E.; Soril, Lesley J. J.; Coward, Stephanie; Lorenzetti, Diane L.; MacKean, Gail; Clement, Fiona M.

2015-01-01

Background: Between 30% and 60% of individuals with major depressive disorder will have treatment-resistant depression (TRD): depression that does not subside with pharmaceutical treatment. Repetitive transcranial magnetic stimulation (rTMS) is an emerging treatment for TRD. Objective: To establish the efficacy and optimal protocol for rTMS among adults and youth with TRD. Data Sources: Two systematic reviews were conducted: one to determine the efficacy of rTMS for adults with TRD and another to determine the effectiveness of rTMS for youth with TRD. For adults, MEDLINE, Cochrane Central Register of Controlled Trials, PubMed, EMBASE, PsycINFO, Cochrane Database of Systematic Reviews, and Health Technology Assessment Database were searched from inception until January 10, 2014 with no language restrictions. Terms aimed at capturing the target diagnosis, such as depression and depressive disorder, were combined with terms describing the technology, such as transcranial magnetic stimulation and rTMS. Results were limited to studies involving human participants and designed as a randomized controlled trial. For youth, the search was altered to include youth only (aged 13–25 years) and all study designs. When possible, meta-analysis of response and remission rates was conducted. Study Selection: Seventy-three articles were included in this review: 70 on adult and 3 on youth populations. Results: Meta-analysis comparing rTMS and sham in adults found statistically significant results favoring rTMS for response (RR: 2.35 [95% CI, 1.70–3.25]) and remission (RR: 2.24 [95% CI, 1.53–3.27]). No statistically significant differences were found when comparing high- and low-frequency, unilateral and bilateral, low- and high-intensity rTMS or rTMS and electroconvulsive therapy (ECT). While meta-analysis of results from the youth literature was not possible, the limited evidence base suggests that rTMS may be effective for treating TRD in youth. Conclusions: The evidence

[Treatment of lithium tremor with the beta receptor blocker, pindolol].

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Floru, L; Tegeler, J; Wolmsen, H

1979-01-01

In a cross-over study with Pindolol, 15 mg/day, against placebo, we studied during 4 weeks 22 patients aged between 20 and 65 years who where treated by means of lithium carbonate retard (Quilonum Retard). The tremor was measured twice a week by means of three apparative methods: an accelerometer, a 'hole-plate' and an 'aimed tapping plate', both constructed by Janke, and was also studied by means of a self-evaluation rating-scale. We obtained a positive therapeutic effect of Pindolol on lithium-induced tremor, which was statistically significant by means of the 'hole-plate' and of self-evaluation. Differences in results are discussed.

Changes of Physiological Tremor Following Maximum Intensity Exercise in Male and Female Young Swimmers

Directory of Open Access Journals (Sweden)

Gajewski Jan

2015-12-01

Full Text Available Purpose. The aim of this study was to determine the changes in postural physiological tremor following maximum intensity effort performed on arm ergometer by young male and female swimmers. Methods. Ten female and nine male young swimmers served as subjects in the study. Forearm tremor was measured accelerometrically in the sitting position before the 30-second Wingate Anaerobic Test on arm ergometer and then 5, 15 and 30 minutes post-test. Results. Low-frequency tremor log-amplitude (L1−5 increased (repeated factor: p < 0.05 from −7.92 ± 0.45 to −7.44 ± 0.45 and from −6.81 ± 0.52 to −6.35 ± 0.58 in women and men, respectively (gender: p < 0.05 5 minute post-test. Tremor log-amplitude (L15−20 increased (repeated factor: p < 0.001 from −9.26 ± 0.70 to −8.59 ± 0.61 and from −8.79 ± 0.65 to −8.39 ± 0.79 in women and men, respectively 5 minute post-test. No effect of gender was found for high frequency range.The increased tremor amplitude was observed even 30 minute post-exercise. Mean frequency of tremor spectra gradually decreased post-exercises (p < 0.001. Conclusions. Exercise-induced changes in tremor were similar in males and females. A fatigue produced a decrement in the mean frequency of tremor what suggested decreased muscle stiffness post-exercise. Such changes intremorafter exercise may be used as the indicator of fatigue in the nervous system.

The left visual-field advantage in rapid visual presentation is amplified rather than reduced by posterior-parietal rTMS

DEFF Research Database (Denmark)

Verleger, Rolf; Möller, Friderike; Kuniecki, Michal

2010-01-01

) either as effective or as sham stimulation. In two experiments, either one of these two factors, hemisphere and effectiveness of rTMS, was varied within or between participants. Again, T2 was much better identified in the left than in the right visual field. This advantage of the left visual field......In the present task, series of visual stimuli are rapidly presented left and right, containing two target stimuli, T1 and T2. In previous studies, T2 was better identified in the left than in the right visual field. This advantage of the left visual field might reflect dominance exerted...... by the right over the left hemisphere. If so, then repetitive transcranial magnetic stimulation (rTMS) to the right parietal cortex might release the left hemisphere from right-hemispheric control, thereby improving T2 identification in the right visual field. Alternatively or additionally, the asymmetry in T2...

Validating computationally predicted TMS stimulation areas using direct electrical stimulation in patients with brain tumors near precentral regions.

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Opitz, Alexander; Zafar, Noman; Bockermann, Volker; Rohde, Veit; Paulus, Walter

2014-01-01

The spatial extent of transcranial magnetic stimulation (TMS) is of paramount interest for all studies employing this method. It is generally assumed that the induced electric field is the crucial parameter to determine which cortical regions are excited. While it is difficult to directly measure the electric field, one usually relies on computational models to estimate the electric field distribution. Direct electrical stimulation (DES) is a local brain stimulation method generally considered the gold standard to map structure-function relationships in the brain. Its application is typically limited to patients undergoing brain surgery. In this study we compare the computationally predicted stimulation area in TMS with the DES area in six patients with tumors near precentral regions. We combine a motor evoked potential (MEP) mapping experiment for both TMS and DES with realistic individual finite element method (FEM) simulations of the electric field distribution during TMS and DES. On average, stimulation areas in TMS and DES show an overlap of up to 80%, thus validating our computational physiology approach to estimate TMS excitation volumes. Our results can help in understanding the spatial spread of TMS effects and in optimizing stimulation protocols to more specifically target certain cortical regions based on computational modeling.

Essential Tremor Is More Than a Tremor

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