Electrical vestibular nerve stimulation as a novel therapeutic approach for insomnia: a systematic review and meta-analysis.

BACKGROUND: Insomnia affects over 850 million adults globally, representing a significant public health burden. Current treatments, including cognitive behavioral therapy for insomnia (CBT-I) and pharmacological interventions, face accessibility barriers and safety concerns, respectively. Electrical vestibular nerve stimulation (VeNS) has emerged as a promising non-invasive neuromodulation technique, leveraging connections between the vestibular system and sleep-regulating brain regions. This systematic review and meta-analysis aimed to evaluate the effect of VeNS on insomnia severity in adults with clinically significant insomnia. METHODS: Following PRISMA guidelines, we systematically searched multiple databases up to July 19, 2025. Eligible studies included adults (≥ 18 years) with clinically significant insomnia (ISI ≥ 15) receiving transcutaneous VeNS versus sham stimulation. The primary outcome was the change in Insomnia Severity Index (ISI), a validated subjective measure scale. Secondary outcomes included the Pittsburgh Sleep Quality Index (PSQI) and quality of life measures, all assessed through self-reported instruments. RESULTS: Three randomized controlled trials encompassing 289 participants met the inclusion criteria. VeNS demonstrated a statistically significant reduction in insomnia severity compared to sham control (ISI mean difference: -3.65 [95% CI: -6.84, -0.46]). Secondary analysis revealed significant improvements in sleep quality (PSQI mean difference: -0.98 [95% CI: -1.88, -0.08]). CONCLUSIONS: VeNS demonstrated statistically significant improvements in insomnia and sleep quality. However, the findings should be interpreted cautiously given the small number of available trials, reliance on subjective outcome measures, considerable heterogeneity, and limited safety data. Larger standardized trials are needed to establish its clinical utility and optimal implementation. CLINICAL TRIAL NUMBER: Not applicable.