Intrinsic Plasticity Mechanisms of Repetitive Transcranial Magnetic Stimulation

Effect of high frequency repetitive transcranial magnetic stimulation (rTMS) on the balance and the white matter integrity in patients with relapsing-remitting multiple sclerosis: A long-term follow-up study

OBJECTIVES

Repetitive Transcranial Magnetic Stimulation (rTMS) is considered as a safe and non-invasive developing technique used as a therapeutic method for patients with Relapsing-Remitting Multiple Sclerosis (RRMS) who suffer from disturbances in gait and balance. The aim of our study is to evaluate the long-term effect of high frequency rTMS as a therapeutic option for truncal ataxia in RRMS patients and to assess its impact on the integrity of the white matter (WMI), measured in the form of anisotropy metrics using diffusion tensor imaging (DTI).

METHODS

The study was conducted in two phases: phase I; a randomized, single-blind, sham-controlled phase and phase II was a 12 months longitudinal open-label prospective phase. Phase I of the trial involved the randomization of 43 patients with RRMS and truncal ataxia to either real (n = 20) or sham (n = 19) rTMS (2 participants from each treatment group were excluded from the study; one developed a relapse before treatment, 2 declined to participate, and one did not show up). Phase II involved providing 12 actual treatments cycles to all patients; each cycle length is 4 weeks, repeated four times on a trimonthly basis, forming a total of 48 sessions. DTI was used for assessment of the WMI. All patients performed DTI 3 times: Imaging sessions were conducted at the screening visit, at the end of phase I, and after the last session in phase II for the first, second and third sessions respectively. A figure-of-8-shape coil, employing rTMS protocol and located over the cerebellum, was used. rTMS protocol is formed of 20 trains formed of 50 stimuli with 20 s apart (5 Hz of 80 % of resting Motor Threshold "MT"). The Berg Balance Scale (BBS), Time up and go (TUG) test, and 10-m walk test (10MWT) were first evaluated at the start of each cycle and just after the final rTMS session.

RESULTS

The genuine rTMS group's 10MWT, TUG, and BBS showed substantial improvement (p < 0.01), which is continued to be improved throughout the study Timeline, with a significant difference observed following the final rTMS session (P< 0.001). A longitudinal increase in FA was observed in both the Cerebello-Thalamo-Cortical (CTC) and Cortico-Ponto-Cerebellar (CPC) bilateral, as indicated by means of Fractional Anisotropy (FA) measures (p < 0.05).

CONCLUSION

In ataxic RRMS patients, high frequency rTMS over the cerebellum has a long-term beneficial impact on both balance and WMI.

Advancements in Transcranial Magnetic Stimulation Research and the Path to Precision

Transcranial magnetic stimulation (TMS) has become increasingly popular in clinical practice in recent years, and there have been significant advances in the principles and stimulation modes of TMS. With the development of multi-mode and precise stimulation technology, it is crucial to have a comprehensive understanding of TMS. The neuroregulatory effects of TMS can vary depending on the specific mode of stimulation, highlighting the importance of exploring these effects through multimodal application. Additionally, the use of precise TMS therapy can help enhance our understanding of the neural mechanisms underlying these effects, providing us with a more comprehensive perspective. This article aims to review the mechanism of action, stimulation mode, multimodal application, and precision of TMS.

The cognitive effects of adjunctive repetitive transcranial magnetic stimulation for late-onset depression: a randomized controlled trial with 4 week follow-up

Objectives

Cognitive impairment is common and linked to poor outcomes in patients with late-onset depression (LOD). The cognitive effects of repetitive transcranial magnetic stimulation (rTMS) for LOD are not well understood. This study aimed to investigate the effects of rTMS on cognitive function in elderly patients with LOD.

Methods

In total, 58 elderly patients (aged 60 to 75 years) with depression were enrolled and randomly assigned to an active rTMS group or a sham group. The participants received active or sham rTMS over the left dorsolateral prefrontal cortex for 4 weeks, 5 days a week, at a frequency of 10 Hz rTMS and 120% of the motor threshold (MT). Cognitive function was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) at baseline, the end of the 4 week treatment period, and at the 4 week follow-up.

Results

The active rTMS group showed significant improvements in immediate memory and attention scores on the RBANS compared to the sham group. However, no significant differences were observed between the two groups in other cognitive domains assessed by the RBANS. No serious adverse events related to rTMS treatment were observed.

Conclusion

Treatment with 120% MT rTMS was associated with improvement in cognitive defects related to the active phase of LOD. These findings suggest that rTMS could provide early improvements in cognitive function in clinical settings for elderly patients with LOD.Clinical trial registration: https://www.chictr.org.cn/showproj.html?proj=40698, identifier ChiCTR1900024445.

Case report: A combination of mirror therapy and magnetic stimulation to the sacral plexus relieved phantom limb pain in a patient

Phantom limb pain (PLP) is a common sequela of amputation, experienced by 50-80% of amputees. Oral analgesics as the first-line therapy have limited effects. Since PLP usually affects activities of daily living and the psychological conditions of patients, effective treatments are imperatively needed. In this case study, a 49-year-old man was admitted to our hospital because of uncontrollable paroxysmal pain in his missing and residual leg. Due to severe injuries in a truck accident, the right lower limb of the patient was surgically amputated ~5 years ago. Around 1 month after amputation, he felt pain in his lost leg and PLP was diagnosed. Then, he started taking oral analgesics, but the pain still occurred. After admission on July 9, 2022, the patient received treatments of mirror therapy and magnetic stimulation to the sacral plexus. 1-month treatments reduced the frequency and intensity of pain in the phantom limb and the stump, without any adverse events. Analysis of high-resolution three-dimensional T1-weighted brain volume images at the end of 2-month treatments showed alterations in the thickness of cortex regions related to pain processing, compared to that before treatment. This case study gives us hints that one or both interventions of mirror therapy and sacral plexus magnetic stimulation effectively relieved PLP and stump limb pain. These non-invasive, low-cost and easily conducted treatments could be good options for PLP. But randomized controlled trials with a large number of cases are required to confirm their efficacy and safety.

Impact of transcranial magnetic stimulation on motor function in children with acquired brain injury: a scoping review protocol

BACKGROUND

Children with severe acquired brain injury (ABI) require early and effective neurorehabilitation provision to promote a good long-term functional outcome. Transcranial magnetic stimulation (TMS) has been used to improve motor skills for children with cerebral palsy but there is limited material supporting its use in children with ABI who have a motor disorder.

OBJECTIVE

To systematically answer what the TMS intervention effects are on motor function in children with ABI as reported in the literature.

METHODS AND ANALYSIS

This scoping review will follow Arksey and O'MaIIey's scoping review methodological framework. A comprehensive computerised bibliographic databases search will be performed in MEDLINE, EMBASE, CINAHL, Allied and Complementary Medicine, BNI, Ovid Emcare, PsyclNFO, Physiotherapy Evidence Database, Cochrane Central Register using keywords related to TMS and children with ABI.Studies that examine the effect of TMS intervention on motor function as either a primary or secondary objective will be included for this review. Study design and publication detail, participant demographic details, type and severity of ABI and other clinical information, TMS procedure, associated therapy intervention, comparator/control parameters and the outcome measure used data will be gathered.The International Classification of Functioning, Disability and Health for Children and Youth framework will be used to report the TMS effect in children with ABI. A narrative synthesis of the findings describing the therapeutic effects of TMS intervention, limitations and adverse effects will be synthesised and reported. This review will help to summarise the existing knowledge base and to guide further research areas. This review outcome may help to evolve therapists' role to next-generation technology-based neurorehabilitation programmes.

ETHICS AND DISSEMINATION

No ethical approval is required for this review as we will be collecting data from previously published studies. We will present the findings at scientific conferences and publish in a peer-review journal.

Effects of noninvasive brain stimulation on dual-task performance in different populations: A systematic review

Background

Increasing research has investigated the use of noninvasive brain stimulation (NIBS) on augmenting dual-task (DT) performance.

Objective

To investigate the effects of NIBS on DT performance in different populations.

Methods

Extensive electronic database search (from inception to November 20, 2022) was conducted in PubMed, Medline, Cochrane Library, Web of Science and CINAHL to identify randomized controlled trials (RCTs) that investigated the effects of NIBS on DT performance. Main outcomes were balance/mobility and cognitive function under both single-task (ST) and DT conditions.

Results

Fifteen RCTs were included, involving two types of intervention techniques: transcranial direct current stimulation (tDCS) (twelve RCTs) and repetitive transcranial magnetic stimulation (rTMS) (three RCTs); and four different population groups: healthy young adults, older adults, Parkinson's disease (PD), and stroke. For tDCS, under DT condition, significant improvement in speed was only observed in one PD and one stroke RCT, and stride time variability in one older adults RCT. Reduction in DTC in some gait parameters was demonstrated in one RCT. Only one RCT showed significant reduction in postural sway speed and area during standing under DT condition in young adults. For rTMS, significant improvements in fastest walking speed and time taken to Timed-up-and-go test under both ST and DT conditions were observed at follow-up in one PD RCT only. No significant effect on cognitive function in any RCT was observed.

Conclusion

Both tDCS and rTMS showed promising effects in improving DT walking and balance performance in different populations, however, due to the large heterogeneity of included studies and insufficient data, any firm conclusion cannot be drawn at present.