Trains Of Transcranial Magnetic Stimulation Research Articles

The effects of combined application of transcranial magnetic stimulation and language training on children with language retardation.

The objective of the present manuscript was to explore the effects of combined application of transcranial magnetic stimulation (TMS) and language training on children with language retardation. Forty-five children with language retardation were selected as subjects and randomly divided into the treatment group with 24 patients and the control group with 21 patients. The control group was treated with traditional language training, while the treatment group was treated with TMS combined with language training. According to the Gesell pediatric neuropsychological development schedules, the development quotient of children in the two groups were observed and compared before and after two courses of treatment. The evaluation of mouth movement was conducted with Dr. Speech supervised by East China Normal University. Development quotient scores and mouth movement evaluation scores of all Gesell parameters of children in the two groups after treatment were significantly higher than those before treatment (P<0.05). The body movement ability, linguistic competence, development quotient scores, and mouth movement evaluation scores in the treatment group after treatment were higher than those of the control group, and the differences were statistically significant (P<0.05). The combined application of TMS and language training can effectively improve linguistic competence, action ability, and mouth movement in children with language retardation.

Motor cortex oscillates at its intrinsic post-movement beta rhythm following real (but not sham) single pulse, rhythmic and arrhythmic transcranial magnetic stimulation

We aimed to test the idea that rhythmic transcranial magnetic stimulation (TMS) entrains cortical oscillations. To do this, we examined oscillatory responses in the electroencephalogram (EEG) to TMS over primary motor cortex. In particular, we contrasted responses to real TMS with those to sham TMS in order to dissociate the contributions of direct (transcranial) activation and indirect activation (via auditory/sensory input) of the brain. We first showed that real single pulse TMS elicited a brief (∼200 ms) increase in sensorimotor beta power whose frequency closely matched that of each individual's post-movement beta rebound (PMBR, ∼18 Hz). Sham TMS triggered minimal oscillatory activity. Together this implies that real TMS interacts with endogenous oscillations via direct brain activation. We then showed that although trains of real rhythmic TMS delivered at each individuals PMBR frequency produced a brief increase in beta power at the same frequency, real arrhythmic TMS also elicited an equivalent increase in beta. The implication is that the oscillatory response is independent of the rhythm of stimulation. By contrast, sham stimulation elicited minimal activity in the beta band, and the responses to rhythmic and arrhythmic sham TMS were broadly similar, showing that sham rhythmic stimulation did not produce entrainment via sensory rhythms. Together, the data demonstrate that the beta oscillatory response of M1 to real TMS predominantly reflects direct activation of the underlying cortex. However, the data do not support the notion of rhythmic TMS enhancing oscillatory activity via entrainment-like mechanisms, at least within the constraints of the current experimental set-up.

Transcranial Magnetic Stimulation Trains at 1 Hz Frequency of the Right Posterior Parietal Cortex Facilitate Recognition Memory

Neuroimaging, neuropsychological, and brain stimulation studies have led to contrasting findings regarding the potential roles of the lateral parietal lobe in episodic memory. Studies using brain stimulation methods reported in the literature do not offer unequivocal findings on the interactions with stimulation location (left vs. right hemisphere) or timing of the stimulation (encoding vs. retrieval). To address these issues, active and sham 1 Hz repetitive transcranial magnetic stimulation (rTMS) trains of 600 stimuli were applied over the right or left posterior parietal cortex (PPC) before the encoding or before the retrieval phase of a recognition memory task of unknown faces in a group of 40 healthy subjects. Active rTMS over the right but not the left PPC significantly improved non-verbal recognition memory performance without any significant modulation of speed of response when applied before the retrieval phase. In contrast, rTMS over the right or the left PPC before the encoding phase did not modulate memory performance. Our results support the hypothesis that the PPC plays a role in episodic memory retrieval that appears to be dependent on both the hemispheric lateralization and the timing of the stimulation (encoding vs. retrieval).

Efficacy of TMS and Cognitive Training in Mild Cognitive Impairment: A Pilot Study

Purpose: Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique with the potential to improve memory. Mild cognitive impairment (MCI), which still lacks a specific therapy, is a clinical syndrome associated with increased risk of dementia. This study aims to assess the effects of deep TMS (dTMS) on a group of 10 patients diagnosed with amnesic MCI. Methods: We compared the effects of TMS COG treatment (dTMS delivered with H7 helmet for ten daily sessions together with cognitive training of memory and attention), with those of COG treatment (cognitive training alone) of the same duration. Results: Neuropsychological evaluation at baseline, after TMS COG treatment, after COG treatment and at six months follow up, compared with ANOVA, revealed a significant group-by-time interaction (𝑝 = 0.05), favoring the TMS COG treatment for memory tests. The improvement was kept after six months. Other neuropsychological tests were not significantly affected by treatment. Conclusions: These findings suggest that dTMS might be effective as a therapy for MCI and probably a tool to delay cognitive deterioration.

Combining transcranial magnetic stimulation with functional magnetic resonance imaging for probing and modulating neural circuits relevant to affective disorders.

Combining transcranial magnetic stimulation (TMS) with functional magnetic resonance imaging offers an unprecedented tool for studying how brain networks interact in vivo and how repetitive trains of TMS modulate those networks among patients diagnosed with affective disorders. TMS compliments neuroimaging by allowing the interrogation of causal control among brain circuits. Together with TMS, neuroimaging can provide valuable insight into the mechanisms underlying treatment effects and downstream circuit communication. Here we provide a background of the method, review relevant study designs, consider methodological and equipment options, and provide statistical recommendations. We conclude by describing emerging approaches that will extend these tools into exciting new applications. This article is categorized under: Psychology > Emotion and Motivation Psychology > Theory and Methods Neuroscience > Clinical Neuroscience.

Feasibility of TMS in patients with new generation cochlear implants

ObjectiveThe presence of a cochlear implant is being considered an absolute contraindication for experiments and/or treatments. We aimed to verify TMS (Transcranial Magnetic Stimulation) compatibility of a new generation of cochlear implants. MethodsIn a series of experiments, we test if MED-EL cochlear implants -compatible with stable fields of magnetic resonance imaging scanning- are fully resistant even to rapidly varying magnetic fields as those generated by single pulses and low and high-frequency trains of repetitive TMS (rTMS) applied with a figure of eight coil and different magnetic stimulators. ResultsWith a TMS intensity equal or below 2.2 Tesla (T) the cochlear implant and all its electronic components remain fully functional, even when the combination of frequency, intensity and number of pulses exceeds the currently available safety guidelines. Induced forces on the implant are negligible. With higher magnetic fields (i.e., 3.2 T), one device was corrupted. ConclusionsResults exclude the risk of electronic damaging, demagnetizing or displacements of the studied cochlear implants when exposed to magnetic fields of up to 2.2 T delivered through a focal coil. SignificanceThey open the way to use focal rTMS protocols with the aim of promoting neural plasticity in auditory networks, possibly helping the post-implant recovery of speech perception performance.

Cognitive Enhancement via Neuromodulation and Video Games: Synergistic Effects?

Transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique able to modulate cortical excitability. This modulation may influence areas and networks responsible for specific cognitive processes, and the repetition of the induced temporary changes can produce long-lasting effects. TMS effectiveness may be enhanced when used in conjunction with cognitive training focused on specific cognitive functions. Playing video games can be an optimal cognitive training since it involves different cognitive components and high levels of engagement and motivation. The goal of this study is to assess the synergistic effects of TMS and video game training to enhance cognition, specifically, working memory and executive functions. We conducted a randomized 2 × 3 repeated measures (stimulation × time) study, randomly assigning 27 healthy volunteers to an active intermittent theta-burst stimulation or a sham stimulation group. Participants were assessed using a comprehensive neuropsychological battery before, immediately after, and 15 days after finishing the video game+TMS training. The training consisted of 10 sessions where participants played a 3D platform video game for 1.5 h. After each gaming session, TMS was applied over the right dorsolateral prefrontal cortex (DLPFC). All participants improved their video gaming performance, but we did not find a synergistic effect of stimulation and video game training. Neither had we found cognitive improvements related to the stimulation. We explored possible confounding variables such as age, gender, and early video gaming experience through linear regression. The early video gaming experience was related to improvements in working memory and inhibitory control. This result, although exploratory, highlights the influence of individual variables and previous experiences on brain plasticity.

Contralesional motor cortex is causally engaged during more dexterous actions of the paretic hand after stroke—A Preliminary report

Bilateral activation in motor cortex is observed during paretic hand performance after stroke; however the functional significance of contralesional motor cortex (C-M1) activation is highly debated. Particularly, it is not known if task characteristics such as dexterity influence the causal engagement of C-M1 during paretic hand performance. Transcranial magnetic stimulation (TMS) was used to quantify motor corticospinal physiology of the CM1 projecting to the contralateral resting extensor carpi radialis brevis (ECRB) and first dorsal interosseous (FDI) while eleven participants with unilateral stroke performed unimanual tasks of differing dexterity with their paretic hand. The novel finding was that compared to rest and less dexterous task (LDT), more dexterous task (MDT) performance led to increased corticospinal excitability and decreased intracortical inhibition of the C-M1 projecting to the resting FDI, but not resting ECRB. Further, using trains of repetitive TMS during MDT and LDT, we tested the behavioral relevance of C-M1 for paretic hand performance. Online rTMS perturbation to C-M1, but not to the vertex or sham stimulation led to significantly more movement errors during MDT without consistently affecting LDT performance. The present results argue for a beneficial role of C-M1 for accurate performance during dexterous motor actions with the paretic hand after stroke.

Evaluation of evoked responses to pulse-matched high frequency and intermittent theta burst transcranial magnetic stimulation using simultaneous functional near-infrared spectroscopy.

Transcranial magnetic stimulation (TMS) is a noninvasive method used to excite or inhibit cortical activity for experimental, diagnostic, and therapeutic interventions. However, nonmotor regions of the brain targeted in TMS therapies, such as the dorsolateral prefrontal cortex (DLPFC), offer no extrinsic response to stimulation, resulting in a need for a practical method for the evaluation of treatment. We sought to determine the capability of a continuous-wave light emitting diodes (LED)-based functional near-infrared spectroscopy (fNIRS) system to measure evoked cortical hemoglobin changes in the DLPFC during the simultaneous application of TMS to the left-DLPFC under brief stimulation paradigms used in the clinic. Seventeen healthy participants received short TMS trains at F3 in four different stimulation conditions (single pulse, high frequency, intermittent theta burst, and sham) while adjacent fNIRS measurements were recorded. Ten 2-s trains of each stimulation type were delivered with an intertrial interval of 40s. Results indicated that high-frequency stimulation produces a larger and more evident response than other measured conditions. These findings show that a continuous-wave LED-based fNIRS system can be used to measure TMS-evoked responses and that future TMS applications can benefit from concurrent assessment of localized cortical activation changes.

'Virtual lesion' in pain research; a study on magnetic stimulation of the primary motor cortex.

'Virtual lesion' ('VL') is a transient disruption of cortical activity during task performance. It can be induced by single pulses or short trains of transcranial magnetic stimulation (TMS) directed to functionally relevant brain areas. We applied 'VL' methodology of a short train of TMS given on top of experimental tonic pain, expecting to see changes in pain scores. Thirty young healthy subjects (15 women) were assessed with active ('VL') or 'sham' TMS in different sessions, randomly. In each session, 30 sec-long contact heat (47.5 °C, right forearm) was applied stand-alone ('baseline') and with 5 sec-long 10 Hz-TMS over left primary motor cortex (M1) starting at 17 sec of the heat stimulation. Pain scores decreased after 'VL' or 'sham' (p < 0.001). Independently of the type of TMS, pain reduction was stronger in women (p = 0.012). A triple Sex x Stimulation type ('VL' or 'sham') x Condition ('baseline' heat pain vs. heat pain with TMS) interaction (p = 0.027) indicated stronger pain reduction by 'VL' in women (p = 0.008) and not in men (p = 0.78) as compared to 'baseline'. Pain catastrophizing and perceived stress ratings affected the model (p = 0.010 and p < 0.001, respectively), but without sex differences. This study indicates that interactions between cortical excitability of the motor cortex and nociceptive processing may be gender-related.

Transcranial magnetic stimulation (TMS) therapy for autism: an international consensus conference held in conjunction with the international meeting for autism research on May 13th and 14th, 2014.

Transcranial magnetic stimulation (TMS) therapy for autism: an international consensus conference held in conjunction with the international meeting for autism research on May 13th and 14th, 2014.

No Change in Neuropsychological Functioning After Receiving Repetitive Transcranial Magnetic Stimulation Treatment for Major Depression

Early studies of transcranial magnetic stimulation (TMS) have shown no adverse effects on neuropsychological function. However, further research using higher TMS intensities as well as a greater number of TMS pulses and with larger sample sizes is needed. We studied 68 patients with major depressive disorder who were randomized to receive either 15 sessions of sham or real TMS at 110% of the estimated prefrontal cortex threshold to the left dorsolateral prefrontal cortex. Each session consisted of 32 5-second trains of 10-Hz repetitive TMS at 110% adjusted motor threshold. A total of 24,000 pulses were given. Neuropsychological function was assessed before and immediately after TMS treatment with a battery of 8 tests. Using a higher TMS intensity as well as a greater number of pulses and having a larger sample size compared with most previous studies, this study found no negative neuropsychological effects of TMS. Changes in neuropsychological function were unrelated to changes in depression.

P 251. Effects of slow frequency repetitive-transcranial magnetic stimulation in patients with corticobasal syndrome

Corticobasal syndrome (CBS) is characterized by asymmetric cortical sensorimotor dysfunction and parkinsonism diagnosed during life. Transcranial magnetic stimulation (TMS) in CBS has shown many cortical physiological abnormalities, on the whole indicating a reduced inhibition and increased excitability in some cortical circuits and a reduced excitability in other circuits ( Pal et al., 2008 ). Repetitive low-frequency TMS trains (<1 Hz) decrease cortical excitability in the motor cortex when delivered for 5 min or more ( Cincotta et al., 2003 ). To explore in CBS motor cortical excitability and the effects of a single session of LF-rTMS. We studied with TMS two CBS patients: a 70-year-old man, (disease duration 3 years; right alien hand syndrome) and a 56-year-old woman (disease duration 1 year; vertical gaze palsy; postural instability; left hand dystonic posture). We used a Magstim 200 stimulator with figure-of-eight coils at the hot-spot for the FDI muscle. We measured bilaterally: relaxed (rT) and active Threshold (aT); and Contralateral Silent Period (CSP) 1.3xrT, 20% maximum effort. In a random order-active/sham-we used a 10′ low frequency (0,3 Hz) rTMS over the more affected M1. We used two focal coils, which were one above the other, for “active” stimulation, the coil directly contacting the scalp was connected to the stimulator, whereas the other was not. We evaluated immediately after the active/sham treatment (T1) and after 30′ (T2) rT, CSP length and clinical effect. For the statistic we compared with t-test in each of the subject the separately values from individual trials for the less affected side (LA) and more affected side (MA) and before-after rTMS. In CBS CSP was shortened ( Fig. 1 ) and rT/aT were increased especially in the MA. The novel finding was the effects of active LF-rTMS on the contralateral silent period ( Fig. 2 ), although we did not observed any clinical effect, that disappeared after 30 min. In CBS TMS confirmed a decrease of cortical inhibitory phenomenon bilaterally as shown by CSP reduction and increased of cortical excitability. TMS changes differed among our two patients more prominent on the more affected side and in the patient with longer disease duration. A brief LF-rTMS applied on the MA hand prolonged transiently CSP length probably through a GABA-B modulation. This report represents the first experience with slow frequency rTMS in CBS and it might well be that with the same experimental setting with a longer train repeated over the course of several days would be able to induce more pronounced effects on cortical excitability.

Álvaro Pascual-Leone: a pioneer of non-invasive brain stimulation

Álvaro Pascual-Leone: a pioneer of non-invasive brain stimulation

What Has Transcranial Magnetic Stimulation Taught Us About Neural Adaptations To Strength Training? A Brief Review

The evidence for neural mechanisms underpinning rapid strength increases has been investigated and discussed for over 30 years using indirect methods, such as surface electromyography, with inferences made toward the nervous system. Alternatively, electrical stimulation techniques such as the Hoffman reflex, volitional wave, and maximal wave have provided evidence of central nervous system changes at the spinal level. For 25 years, the technique of transcranial magnetic stimulation (TMS) has allowed for noninvasive supraspinal measurement of the human nervous system in a number of areas such as fatigue, skill acquisition, clinical neurophysiology, and neurology. However, it has only been within the last decade that this technique has been used to assess neural changes after strength training. The aim of this brief review is to provide an overview of TMS, discuss specific strength training studies that have investigated changes, after short-term strength training in healthy populations in upper and lower limbs, and conclude with further research suggestions and the application of this knowledge for the strength and conditioning coach.

Magnetic-Stimulation-Related Physiological Artifacts in Hemodynamic Near-Infrared Spectroscopy Signals

Hemodynamic responses evoked by transcranial magnetic stimulation (TMS) can be measured with near-infrared spectroscopy (NIRS). This study demonstrates that cerebral neuronal activity is not their sole contributor. We compared bilateral NIRS responses following brain stimulation to those from the shoulders evoked by shoulder stimulation and contrasted them with changes in circulatory parameters. The left primary motor cortex of ten subjects was stimulated with 8-s repetitive TMS trains at 0.5, 1, and 2 Hz at an intensity of 75% of the resting motor threshold. Hemoglobin concentration changes were measured with NIRS on the stimulated and contralateral hemispheres. The photoplethysmograph (PPG) amplitude and heart rate were recorded as well. The left shoulder of ten other subjects was stimulated with the same protocol while the hemoglobin concentration changes in both shoulders were measured. In addition to PPG amplitude and heart rate, the pulse transit time was recorded. The brain stimulation reduced the total hemoglobin concentration (HbT) on the stimulated and contralateral hemispheres. The shoulder stimulation reduced HbT on the stimulated shoulder but increased it contralaterally. The waveforms of the HbT responses on the stimulated hemisphere and shoulder correlated strongly with each other (r = 0.65–0.87). All circulatory parameters were also affected. The results suggest that the TMS-evoked NIRS signal includes components that do not result directly from cerebral neuronal activity. These components arise from local effects of TMS on the vasculature. Also global circulatory effects due to arousal may affect the responses. Thus, studies involving TMS-evoked NIRS responses should be carefully controlled for physiological artifacts and effective artifact removal methods are needed to draw inferences about TMS-evoked brain activity.

Estimulación magnética transcraneal en la rehabilitación del ictus

Objective To review the use of transcranial magnetic stimulation (TMS) in stroke rehabilitation, current evidence of its effectiveness and mechanisms of neuroplasticity that could be induced. Search strategy Bibliographic search of articles published over the last ten years in PubMed, Tripdatabase, and The Cochrane Library databases. MesH key words used were: neuroplasticity, rehabilitation, stroke, transcranial magnetic stimulation. Study selection Randomized controlled trials, cohorts studies, and case-control studies, in acute, subacute and chronic poststroke patients. Data synthesis TMS and motor training can induce neuroplasticity mechanisms (long-term potentiation [LTP], long-term depression [LTD]). Repetitive 1 Hz TMS reduces transcallosal inhibition from the contralesional hemisphere to the affected cortex. The result is an augmented excitability of damaged brain areas that facilitates recovery of motor impairment, neglect, aphasia, and dysphagia in poststroke patients. Conclusions TMS could be used in stroke rehabilitation as an adjunct therapy. Future studies are needed to confirm its real effectiveness.

Repetitive transcranial magnetic stimulator with controllable pulse parameters

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.

Transcranial magnetic stimulation and connectivity mapping: tools for studying the neural bases of brain disorders

There has been an increasing emphasis on characterizing pathophysiology underlying psychiatric and neurological disorders in terms of altered neural connectivity and network dynamics. Transcranial magnetic stimulation (TMS) provides a unique opportunity for investigating connectivity in the human brain. TMS allows researchers and clinicians to directly stimulate cortical regions accessible to electromagnetic coils positioned on the scalp. The induced activation can then propagate through long-range connections to other brain areas. Thus, by identifying distal regions activated during TMS, researchers can infer connectivity patterns in the healthy human brain and can examine how those patterns may be disrupted in patients with different brain disorders. Conversely, connectivity maps derived using neuroimaging methods can identify components of a dysfunctional network. Nodes in this dysfunctional network accessible as targets for TMS by virtue of their proximity to the scalp may then permit TMS-induced alterations of components of the network not directly accessible to TMS via propagated effects. Thus TMS can provide a portal for accessing and altering neural dynamics in networks that are widely distributed anatomically. Finally, when long-term modulation of network dynamics is induced by trains of repetitive TMS, changes in functional connectivity patterns can be studied in parallel with changes in patient symptoms. These correlational data can elucidate neural mechanisms underlying illness and recovery. In this review, we focus on the application of these approaches to the study of psychiatric and neurological illnesses.

Facilitation of bottom-up feature detection following rTMS-interference of the right parietal cortex

In visual search tasks the optimal strategy should utilize relevant information ignoring irrelevant one. When the information at the feature and object levels are in conflict, un-necessary processing at higher level of object shape can interfere with detection of lower level orientation feature.We explored the effects of inhibitory trains of transcranial magnetic stimulation (rTMS) on the right and left parietal cortex in healthy subjects performing two visual search tasks. One task (Task A) was characterised by an object-to-feature interference. The other task (Task B) was without such interference. We found that rTMS of the right parietal cortex significantly reduced reaction times (RTs) in Task A, where object recognition interferes with detection of orientation. This significant RT reduction was present only for the first 10 trials. Interestingly, right parietal rTMS had no effect on Task B. Moreover, rTMS of the left parietal cortex did not modify subjects’ RTs in either task. Subjects’ accuracy was equally affected by rTMS in both tasks over time.We suggest that inhibition of the right parietal cortex by means of rTMS facilitates feature-based visual search by inhibiting the interfering feature binding and spatial attentional processes. This allows subjects to accomplish Task A faster.