Influence Of Transcranial Magnetic Stimulation Research Articles

Neuro-cardiac-guided transcranial magnetic stimulation: Unveiling the modulatory effects of low-frequency and high-frequency stimulation on heart rate.

Transcranial magnetic stimulation (TMS) is pivotal in the field of major depressive disorder treatment. Due to its unsatisfied response rate, an increasing number of researchers have turned their attention towards optimizing TMS site localization. Since the influence of TMS in reducing heart rate (HR) offers insights into its regulatory impact on the autonomic nervous system, a novel approach, called neurocardiac-guided TMS (NCG-TMS), has been proposed to pinpoint the brain region eliciting the maximal individual reduction in HR as a personalized optimal stimulation target. The present study intends to systematically explore the effects of stimulation frequency, left and right hemispheres, stimulation positions, and individual differences on HR modulation using the NCG-TMS method. In experiment 1, low-frequency TMS was administered to 30 subjects, and it was found that low-frequency NCG-TMS significantly downregulated HR, with more significant effects in the right hemisphere than in the left hemisphere and the prefrontal cortex than in other brain areas. In experiment 2, high-frequency NCG-TMS stimulation was administered to 30 subjects, showing that high-frequency NCG-TMS also downregulated HR and had the greatest modulatory effect in the right prefrontal region. Simultaneously, both experiments revealed sizeable individual variability in the optimal stimulation site, which in turn validated the feasibility of the NCG-TMS method. In conclusion, the present experiments independently replicated the effect of NCG-TMS, provided an effect of high-/low-frequency TMS stimulation to downregulate HR, and identified a right lateralization of the HR modulation effect.

Treatment of Apathy in Parkinson's Disease and Implications for Underlying Pathophysiology.

Apathy is a prevalent and highly debilitating non-motor symptom of Parkinson's disease (PD) that is often overlooked in clinical practice due to its subtle nature. This review aims to provide a comprehensive overview of the current evidence for the treatment of apathy in PD, highlighting recent advancements and emerging therapeutic avenues. In this review, we analyse a diverse array of treatment strategies for apathy in PD, including pharmacological interventions, non-pharmacological approaches, and emerging neuromodulation techniques. We evaluate the efficacy, safety, and limitations of established pharmacotherapies, such as dopaminergic agents, antidepressants, and cognitive enhancers. Additionally, we examine the promising role of non-pharmacological interventions, encompassing psychotherapies and behavioural interventions, in ameliorating apathetic symptoms. Furthermore, this review explores the effects of neuromodulation techniques on apathy, including the modulation of apathy via deep brain stimulation and emerging data on the potential influence of transcranial magnetic stimulation (TMS) on apathy in PD. Ultimately, a deeper understanding of effective treatment strategies for apathy has the potential to significantly improve the quality of life and overall well-being of individuals living with PD.

Personalized brain stimulation of memory networks

BackgroundThe finding that transcranial magnetic stimulation (TMS) can enhance memory performance via stimulation of parietal sites within the Cortical-Hippocampal Network counts as one of the most exciting findings in this field in the past decade. However, the first independent effort aiming to fully replicate this finding found no discernible influence of TMS on memory performance. ObjectiveWe examined whether this might relate to interindividual spatial variation in brain connectivity architecture, and the capacity of personalisation methodologies to overcome the noise inherent across independent scanners and cohorts. MethodsWe implemented recently detailed personalisation methodology to retrospectively compute individual-specific parietal targets and then examined relation to TMS outcomes. ResultsCloser proximity between actual and novel fMRI-personalized targets associated with greater improvement in memory performance. ConclusionThese findings demonstrate the potential importance of aligning brain stimulation targets according to individual-specific differences in brain connectivity, and extend upon recent findings in prefrontal cortex.

Rationale for the efficiency of transcranial magnetic stimulation in multiple sclerosis

The aim. Based on the analysis and comprehensive clinical and neurological evaluation of the results to substantiate the effectiveness of transcranial magnetic stimulation (TMS) in the treatment and rehabilitation of patients with multiple sclerosis (MS).
 Methods. A total of 110 MS patients were included in the study. The control group consisted of 30 patients who received pathogenetic therapy and 80 patients who underwent a course of rhythmic transcranial magnetic stimulation (rTMS) together with pathogenetic therapy.
 Results. The results obtained during the study indicate the complex multifactorial nature of fatigue and its significant impact on the clinical manifestations of MS. Also, the use of rTMS reduced the severity of the main neurological symptoms of MS. The improvement in the overall EDSS scale in the group of patients receiving rTMS was statistically significant: from 5.0±1.9 points to 4.5±2.0 points (p<0.01), in the comparison group (p>0.05). Under the influence of TMS, gait function improved, but these indicators were statistically insignificant (p>0.05). The greatest effect of rTMS was obtained on the manifestations of fatigue and also extended to its cognitive and psychosocial components. The obtained patterns are confirmed in the analysis of indicators on the SCA and FS scales. Involvement in the treatment of patients with MS rTMS allowed to achieve a significant reduction in the manifestations of all components of fatigue: from 76.0±20.9 points to 75.5±20.5 points (p<0.05).
 The data obtained during the study confirm the effectiveness, safety and viability of non-invasive neuromodulation by rTMS in the treatment and rehabilitation of patients with MS.
 Conclusions. The use of rTMS has a positive effect on the manifestations of fatigue, both motor and cognitive, in patients with MS at all types of course and at different stages of progression. Non-invasiveness, safety and ease of use, the possibility of differentiated use allow the use of rTMS in the clinic of rehabilitation treatment and become an important component of active drug and non-drug rehabilitation of patients with MS.

Transcranial Magnetic Stimulation in Alzheimer's Disease: Are We Ready?

Transcranial magnetic stimulation (TMS) is among a growing family of noninvasive brain stimulation techniques being developed to treat multiple neurocognitive disorders, including Alzheimer's disease (AD). Although small clinical trials in AD have reported positive effects on cognitive outcome measures, significant knowledge gaps remain, and little attention has been directed at examining the potential influence of TMS on AD pathogenesis. Our review briefly outlines some of the proposed neurobiological mechanisms of TMS benefits in AD, with particular emphasis on the modulatory effects on excitatory/inhibitory balance. On the basis of converging evidence from multiple fields, we caution that TMS therapeutic protocols established in young adults may have unexpected detrimental effects in older individuals or in the brain compromised by AD pathology. Our review surveys clinical studies of TMS in AD alongside basic research as a guide for moving this important area of work forward toward effective treatment development.

P43-F The influence of transcranial magnetic stimulation on the recognition and processing of visual information

Processes of focused attention allow to focus the stream of attention on a specific visual stimulus from the environmental context. The posterior parietal cortex (PPC, Posterior Parietal Cortex) is a region of the cortex engaged in focused attention processes, related to the search for goals of a specific visual context. Transcranial magnetic stimulation with a series of stimuli (repetitive transcranial magnetic stimulation - rTMS) is a method of modulating brain plasticity. We have investigated the effect of rTMS in 20 healthy volunteers. All of them gave written informed consent to the study. rTMS was applied on posterior parietal cortices V1 on both hemispheres with the inhibitory Theta Bursts paradigm with the intensity of 70% of motor threshold. The targets were visualized with the neuronavigation system. Immediately after the stimulation, the functional MRI was performed with the protocol of recognizing of significant military objects from the visual field. In subgroup of participants (n = 15) after the stimulation there were significant reductions in blood flow within V1 cortices. The studies of reaction times after the rTMS also revealed the inhibitory effect of rTMS on the reaction times and recognition performance of significant (military) objects in the visual field. There were no side effects reported by participants and observed by researchers during the whole study.

The application of transcranial magnetic stimulation for the treatment of metabolic syndrome

This article is focused n the analysis of the influence of transcranial magnetic stimulation on the hormonal regulation of carbohydrate and lipid metabolism in the patients presenting with metabolic syndrome. It is shown that the transcranial application of a magnetic field stimulates sensitivity of the tissues to insulin and thereby facilitates the reduction of arterial pressure and optimization of lipid and glucose metabolism.

Simultaneous transcranial magnetic stimulation and single-neuron recording in alert non-human primates.

Transcranial magnetic stimulation (TMS) is a widely used, noninvasive method for stimulating nervous tissue, yet its mechanisms of effect are poorly understood. Here we report novel methods for studying the influence of TMS on single neurons in the brain of alert non-human primates. We designed a TMS coil that focuses its effect near the tip of a recording electrode and recording electronics that enable direct acquisition of neuronal signals at the site of peak stimulus strength minimally perturbed by stimulation artifact in intact, awake monkeys (Macaca mulatta). We recorded action potentials within ~1 ms after 0.4 ms TMS pulses and observed changes in activity that differed significantly for active stimulation as compared to sham stimulation. The methodology is compatible with standard equipment in primate laboratories, allowing for easy implementation. Application of these new tools will facilitate the refinement of next generation TMS devices, experiments, and treatment protocols.

The Perceived Position of Moving Objects: Transcranial Magnetic Stimulation of Area MT+ Reduces the Flash-Lag Effect

How does the visual system assign the perceived position of a moving object? This question is surprisingly complex, since sluggish responses of photoreceptors and transmission delays along the visual pathway mean that visual cortex does not have immediate information about a moving object's position. In the flash-lag effect (FLE), a moving object is perceived ahead of an aligned flash. Psychophysical work on this illusion has inspired models for visual localization of moving objects. However, little is known about the underlying neural mechanisms. Here, we investigated the role of neural activity in areas MT+ and V1/V2 in localizing moving objects. Using short trains of repetitive Transcranial Magnetic Stimulation (TMS) or single pulses at different time points, we measured the influence of TMS on the perceived location of a moving object. We found that TMS delivered to MT+ significantly reduced the FLE; single pulse timings revealed a broad temporal tuning with maximum effect for TMS pulses, 200 ms after the flash. Stimulation of V1/V2 did not significantly influence perceived position. Our results demonstrate that area MT+ contributes to the perceptual localization of moving objects and is involved in the integration of position information over a long time window.

PTMS2 Influence of transcranial magnetic stimulation waveforms on the ipsilateral silent period of a small hand muscle

PTMS2 Influence of transcranial magnetic stimulation waveforms on the ipsilateral silent period of a small hand muscle

Influence of transcranial magnetic stimulation on muscle activity during finger movement

AbstractIn the present study, muscle activity was measured after transcranial magnetic stimulation (TMS) was applied over the primary motor cortex during finger tapping. The duration of finger tapping was increased by the application of TMS. A remarkable change in electromyogram (EMG) of hand muscles was also observed during and after finger tapping. The silent period, in which voluntary EMG during the finger tapping was suppressed by TMS, was observed. Integral EMG revealed that TMS increased muscle activity at the completion of the finger tap after silent period. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Suppression of Electromyogram of Hand Muscle Elicited by Transcranial Magnetic Stimulation Over the Primary Motor Cortex

Cortical motor neuronal activation by transcranial magnetic stimulation (TMS) over the primary motor cortex area (M1) produces efferent signals that pass through the cortico-spinal tracts. As a result, motor evoked potentials (MEPs) are observed at muscles innervated by the stimulated motor neurons. It is well known that TMS can cause a silent period in the voluntary electromyogram (EMG). In the present study, TMS was applied to the Ml during thumb tapping. The influence of TMS on voluntary muscle contraction was discussed. Thumb trajectory was observed with a three-dimensional tracking device, and EMG of the abductor pollicis brevis (APB) muscle was also measured. The authors confirmed a change in thumb velocity in the downward direction during voluntary movement when TMS was applied, indicating that tissue excitation elicited by TMS causes loss of control of peripheral muscle motor control during voluntary movement.

TMS of the posterior parietal cortex delays the latency of unpredictable saccades but not when they are combined with predictable divergence

This study tests the influence of transcranial magnetic stimulation (TMS) of the posterior parietal cortex (PPC) on the initiation of horizontal and vertical saccades, alone or combined with a predictable divergence. A gap paradigm was used; TMS was applied 100 ms after target onset. TMS of the left PPC increased the latency of unpredictable rightward saccades, while TMS of the right PPC increased the latency of unpredictable downward saccades. Yet, when unpredictable saccades were combined with predictable divergence, neither component was affected. We suggest that in the latter case, the initiation of both components was taken in charge by another area, e.g. frontal. Thus, even when one component was predictable, a common mechanism controls the initiation of both components. The results confirm that TMS only modifies the latency when the cortical area stimulated is involved in the triggering of the eye movement.