Effects of Non-invasive Brain Stimulation on Hereditary Ataxia: a Systematic Review and Meta-analysis

Transcranial magnetic stimulation use with chronic vestibular disorders: A scoping review

BackgroundTranscranial magnetic stimulation (TMS) is extensively studied as a neuromodulation tool in neurological disorders. However, its use with the central vestibular disorders is limited.ObjectiveTo evaluate the utility of TMS as an assessment and treatment of chronic vestibular disorders and propose recommendations for future work.MethodsA comprehensive search of four electronic databases (PubMed, CINAHL, PsycINFO, and Rehabilitation and Sports Medicine Source) identified 206 records of which 16 studies were included.ResultsOne study used TMS as a neurophysiological assessment tool and 15 used repetitive TMS (rTMS) as a neuromodulatory intervention. Mal de Debarquement syndrome was the most frequently explored diagnosis. Dorsolateral prefrontal cortex and the cerebellum were the most frequent sites for rTMS application. Statistically significant improvements were noted on the Dizziness Handicap Inventory (3/7 studies) but clinically significant improvements were not observed. Postural control (7/7 studies) showed improvements along with VOR gain (1/1 studies).ConclusionsTMS shows promise as both a neurophysiological assessment tool and a neuromodulatory intervention for chronic vestibular disorders. Methodological limitations of the studies warrant caution while interpreting the results. Larger sample sizes, control groups, optimal neuroanatomical targeting, and dosing along with active rehabilitation are required to determine effectiveness in chronic vestibular disorders.

Repeated transcranial magnetic stimulation on the bilateral cerebellum to improve symptoms of ataxia with multiple system atrophy: a prospective, randomized, sham-controlled pilot study

OBJECTIVES

Ataxia is a common symptom in patients with Cerebellar subtype of Multiple system atrophy (MSA-C), but effective treatments remain elusive. The present study aims to investigate whether repetitive transcranial magnetic stimulation (rTMS) over the bilateral cerebellum could relieve ataxia in patients with MSA-C.

PATIENTS AND METHODS

This is a single-center, randomized and double-blind trial. 26 patients with MSA-C were randomly divided into experimental group and control group. The experimental group underwent (rTMS) in both cerebellum for 10 consecutive days, while the control group was given sham rTMS. The participants underwent clinical assessments at baseline (T0), and three follow-up timepoints, that is, immediately after the tenth treatment session (T1), 2 weeks (T2), and 4 weeks (T3) after T1. The Scale for the Assessment and Rating of Ataxia scores (SARA) was used as the primary outcome measure, with the Fatigue Severity Scale-9 (FSS-9), the Hamilton Anxiety Scale (HAMA) and the Hamilton Depression Rating Scale-24 (HAMD-24) as secondary outcomes.

RESULTS

Two-way repeated ANOVAs showed significant group × time interactions among SARA (p < 0.001), FSS-9 (p < 0.001), HAMA (p < 0.001) and HAMD-24 (p < 0.001). Post-hoc analyses showed that compared with T0, the activity group showed significant improvement in SARA, HAMA and HAMD-24 scores at T1, T2 and T3, and significant improvement in FSS-9 scores at T1 and T2, but no significant improvement in T3.

CONCLUSION

rTMS over bilateral cerebellum could provide short-term improvements for alleviating ataxia and the symptoms of fatigue, depression anxiety, but the beneficial effects last no more than 4 weeks.

Efficacy of brain stimulation therapies across psychiatric, movement, and cognitive disorders: an umbrella review synthesizing meta-analyses of randomized controlled trials

BACKGROUND

Brain stimulation therapy (BST) has significant potential in treating psychiatric, movement, and cognitive disorders. Given the high prevalence of comorbidities among these disorders, we conducted an umbrella review to comprehensively assess the efficacy of BSTs in treating the core symptoms across these three categories of disorders.

METHODS

We systematically searched for meta-analyses and network meta-analyses of randomized controlled trials with sham controls up to September 25, 2024, from databases including PubMed, PsycINFO, Embase, and the Cochrane Library. Our primary outcome was improvements in core symptoms. We evaluated quality using 11 criteria. We calculated pooled effect estimates for core symptoms based on the largest meta-analyses, then conducted sensitivity and subgroup analyses, and assessed heterogeneity, publication bias, and small-study effects. Finally, we synthesized effect sizes from all meta-analyses to provide a comprehensive overview of BSTs' efficacy. PROSPERO registration: CRD42023439090.

FINDINGS

We included 198 articles with 108,377 patients evaluating 14 BSTs across 21 disorders. The largest meta-analysis showed a moderate standardized mean difference (SMD) of 0.56 (95% CI: 0.49, 0.64; I2 = 70%). Subgroup analyses revealed significant SMDs for psychiatric disorders (0.60; 95% CI: 0.49, 0.71; I2 = 66%), movement disorders (0.56; 95% CI: 0.42, 0.69; I2 = 79%), and cognitive disorders (0.46; 95% CI: 0.32, 0.61; I2 = 48%). SMDs were 0.44 (95% CI: 0.23, 0.65; I2 = 70%) for follow-up ≤1 month and 0.69 (95% CI: 0.43, 0.94; I2 = 84%) for follow-up >1 month. Compared to other conditions, BSTs show better therapeutic effects in treating depression, post-traumatic stress disorder, obsessive-compulsive disorder, pain, fibromyalgia, and post-stroke motor recovery.

INTERPRETATION

This review explored the potential of BSTs for comorbidities of the three disorders from a disorder-specific perspective, providing a roadmap for their clinical application and future research.

FUNDING

This work was supported by the Anhui Natural Science Foundation (2023AH040086), Key Laboratory of Philosophy and Social Science of Anhui Province on Adolescent Mental Health and Crisis Intelligence Intervention (SYS2023B08), and the Joint Funds of the National Natural Science Foundation of China (U23A20424).

Effect of Regional Brain Activity Following Repeat Transcranial Magnetic Stimulation in SCA3: A Secondary Analysis of a Randomized Clinical Trial

Repetitive transcranial magnetic stimulation (rTMS), a noninvasive neuroregulatory technique used to treat neurodegenerative diseases, holds promise for spinocerebellar ataxia type 3 (SCA3) treatment, although its efficacy and mechanisms remain unclear. This study aims to observe the short-term impact of cerebellar rTMS on motor function in SCA3 patients and utilize resting-state functional magnetic resonance imaging (RS-fMRI) to assess potential therapeutic mechanisms. Twenty-two SCA3 patients were randomly assigned to receive actual rTMS (AC group, n = 11, three men and eight women; age 32-55 years) or sham rTMS (SH group, n = 11, three men and eight women; age 26-58 years). Both groups underwent cerebellar rTMS or sham rTMS daily for 15 days. The primary outcome measured was the ICARS scores and parameters for regional brain activity. Compared to baseline, ICARS scores decreased more significantly in the AC group than in the SH group after the 15-day intervention. Imaging indicators revealed increased Amplitude of Low Frequency Fluctuation (ALFF) values in the posterior cerebellar lobe and cerebellar tonsil following AC stimulation. This study suggests that rTMS enhances motor functions in SCA3 patients by modulating the excitability of specific brain regions and associated pathways, reinforcing the potential clinical utility of rTMS in SCA3 treatment. The Chinese Clinical Trial Registry identifier is ChiCTR1800020133.