Cerebellar Neuromodulation via Non-invasive Brain Stimulation vs. Conventional therapy: A Meta-analysis and Systematic Review of Spinocerebellar Ataxia Patients
Waqas Ahmad1, Rana Mushtaq1, Hafsa Iqbal1, Arbaz Hassan1, Maryam Sial1, Mahnoor Fatima1, Jamil Numan2, Atif Malik1, Anfal Hamza1, Syed Inam3
1Sheikh Zayed Medical College/Hospital, 2Marshall University/ MUSOM, 3Louisiana State University School of Medicine New Orleans Neurology
Objective:
Our study analyzes the efficacy of non-invasive techniques—repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and transcranial alternating current stimulation—in improving motor and functional outcomes in patients with Spino Cerebellar Ataxia (SCA).
Background:
Spinocerebellar ataxia (SCA) is a hereditary neurodegenerative disorder marked by progressive cerebellar dysfunction, impaired motor coordination, and diverse neurological deficits. Despite better understanding of its mechanisms, effective therapeutic options remain limited, creating an urgent need for novel interventions.
Design/Methods:
Following PRISMA guidelines (PROSPERO: 1502246451002180), we systematically searched PubMed, Google Scholar, Cochrane Library, ClinicalTrials.gov, Embase, Scopus, and ScienceDirect for RCTs evaluating non-invasive brain stimulation in spinocerebellar ataxia patients. Primary outcomes were motor function assessed by SARA and ICARS scales; secondary outcome was double-support time variability (DSSD). We included eight RCTs involving 309 participants. The analysis was conducted using RevMan (v5.4.1) to pool mean and standard deviation. Sensitivity analysis was done using R-studio (v2025.05.0+496) through metainf() function.
Results:
We included eight randomized controlled trials involving 309 patients (154 intervention, 155 control), mostly with SCA-3. Non-invasive brain stimulation (NIBS) significantly improved motor function compared to sham/control. SARA scores decreased at 2 weeks (3 studies, n=178; MD: -1.88, 95% CI: -3.09 to -0.66, p=0.002) and 6 weeks (2 studies, n=84; MD: -3.24, 95% CI: -5.76 to -0.71, p=0.01). Double-support time variability improved at 2 weeks (MD: -1.09, 95% CI: -2.07 to -0.11, p=0.03) and 6 weeks (MD: -1.51, 95% CI: -2.63 to -0.40, p=0.008). Other ICARS sub-scores (limb kinetics, oculomotor disorders, posture and speech disorders) showed no significant differences. Overall heterogeneity remained low-to-moderate, with no serious adverse events reported.
Conclusions:
Non-invasive brain stimulation improves motor function and gait stability in SCA, especially SCA3, with no major safety issues. Larger trials and multidisciplinary approaches are needed to confirm long-term efficacy.
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