Cerebellar High Frequency Transcranial Pulsed Current Stimulation Increases Total Sleep Time in Chronic Insomnia: A Pilot Study

Abstract Chronic insomnia is characterized by reduced sleep duration and is associated with substantial physical and psychological morbidity. Existing treatments are limited by accessibility, tolerability, and persistent residual symptoms. Given emerging evidence implicating the cerebellum in sleep–wake regulation, we evaluated the safety and efficacy of cerebellar high-frequency transcranial pulsed current stimulation (tPCS) in individuals with chronic insomnia. In this double-blind, randomized, sham-controlled pilot trial, thirty adults on stable pharmacotherapy were assigned 1: 1 to receive 12 sessions of bilateral cerebellar active tPCS (400 Hz, 0.6 mA average current, 30 minutes/session) or sham stimulation over two weeks. The primary outcome was actigraphy-derived total sleep time (TST). Between-group comparisons were performed using rank analysis of covariance adjusting for baseline values. Compared with sham stimulation, active tPCS significantly increased TST (adjusted mean difference, 34.25 minutes; 95% CI, 1.60–66.89; P = 0.022; partial η² = 0.180) and improved Pittsburgh Sleep Quality Index (PSQI) global score, including subjective sleep quality and sleep duration. Exploratory analyses demonstrated greater reductions in anxiety and depressive symptoms. No serious adverse events occurred. These findings suggest that cerebellar high-frequency tPCS may improve objective sleep duration and subjective sleep quality in insomnia and warrant confirmation in larger randomized controlled trials. Trial Registration: Chinese Clinical Trial Registry ChiCTR2300072403, Date of registration: Jun 12, 2023; (URL: https://www.chictr.org.cn/showproj.html?proj=199226)