Effectiveness of Transcranial Direct Current Stimulation in Treating Drug-Resistant Focal Epilepsy: A Systematic Review and Meta-Analysis.

Abstract

Introduction: Epilepsy is a prevalent neurological disorder globally, with about 30% of patients developing resistance despite optimal antiseizure drug therapies. Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation technique and offers a potential therapeutic alternative for drug-resistant focal epilepsy, aiming to reduce seizure frequency and improve patient quality of life.

Methods: Following PRISMA guidelines, a search was performed on MEDLINE, Web of Science, and Cochrane Library from inception to June 2024. Included articles were randomized controlled trials reporting seizure frequency, IEDs, and adverse events in patients with focal epilepsy treated with tDCS. Quality assessment was conducted using RoB2, and data were analyzed using a random-effects model.

Results: Nine studies involving 253 patients met the inclusion criteria. tDCS significantly reduced seizure frequency at 1- and 2-month follow-up compared to placebo, with a mean difference (MD) of -2.62, 95% CI (-5.20, -0.04), p = 0.05 at 1 month and MD of -2.80, 95% CI (-5.08, -0.53), p = 0.02 at 2 months. No significant changes in IEDs were observed. Adverse events were generally mild and consisted of itching, skin rash, and headache being the most common.

Conclusion: tDCS reduces seizure frequency in patients with drug-resistant focal epilepsy and is associated with minimal adverse effects. However, there was no significant impact on IEDs, and the studies included exhibited considerable heterogeneity. More standardized research is required to validate these findings and optimize treatment protocols.