A Meta-Analysis of the Effectiveness of Transcranial Magnetic Stimulation and Transcranial Direct Current Stimulation as Therapy of Insomnia

Abstract

Objective: Insomnia serves as the most common sleep disorder. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are amongst most popular treatment for insomnia. This research aimed to determine the comparative effectiveness of TMS and tDCS as therapies for insomnia.Methods: PubMed/MEDLINE, ScienceDirect, Google Scholar, ResearchGate, Wiley Library Online, and Neurona were used to search for randomized controlled trials (RCTs) comparing TMS/tDCS with sham group in insomnia. Meta-analysis was done to determine the effectiveness of TMS and tDCS as a therapy for insomnia. Weighted mean difference were computed and reported with its 95% CI. Heterogeneity was reported with I<sup>2</sup>. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool. Subjective pooled-analysis was done using Mann-Whitney U test with p<0.05.Results: From a total 1,000 publications, 15 studies were included, revealing varying types of insomnia as follows: 26.7% comorbid depression, 13.3% comorbid pain, 13.3% involving athletes, 13.3% primary insomnia, 6.7% due to medication, 6.7% comorbid polio, 6.7% comorbid Sjogren’s syndrome, 6.7% comorbid stroke, and 6.7% comorbid Parkinson’s disease. From 15 studies, four homogenous articles were made for pooled-analyses, which included two studies on TMS and two studies on tDCS in insomnia comorbid depression. tDCS improved sleep onset latency, N2, and REM latency better than sham. TMS (2.29, 95% CI: 1.82–2.76) was superior to sham in improving the subjective quality of sleep, and tDCS (1.05, 0.68–1.43) with p=0.121.Conclusion: No significant differences were found between TMS and tDCS as therapies for insomnia. Most RCTs studying TMS/tDCS in insomnia reported high comorbidity with depression.