Antiepileptic effects of low frequency repetitive transcranial magnetic stimulation: A meta-analysis

Purpose: To evaluate the antiepileptic efficacy of low frequency repetitive transcranial magnetic stimulation (rTMS) in medically intractable epilepsy. Methods: A comprehensive literature search was performed on articles published from 1990 to 2010 in Medline, Pubmed, CINAHL, and Cochrane using the following keywords: epilepsy, seizure, transcranial magnetic stimulation, repetitive transcranial magnetic stimulation. Two reviewers assessed article eligibility and extracted the data independently. For outcome measures, effect size and 95% confidence interval (CI) were calculated for seizure frequency, spike number, duration of epileptiform abnormalities (EAs), and resting motor threshold (RMT) by using fixed and random effect models. Results: Eleven articles were identified, with a total of 164 participants. Based on seizure frequency, a significant effect size was found (effect size: 0.34, with a 95% CI at 0.10-0.57). Considering between-study heterogeneity, we conducted a second meta-analysis, and the underlying etiology was considered important for the treatment effect. Cortical dysplasia or neocortical epilepsy showed an effect size of 0.71, with a 95% CI at 0.30-1.12. In contrast, other epileptic disorders showed an effect size of 0.22. Conclusion: Low frequency rTMS has a favorable effect on seizure reduction, particularly evident in patients with neocortical epilepsy or cortical dysplasia.