Effects of non-invasive brain stimulation in the treatment of sleep disorders : a protocol for a systematic review and meta-analysis of randomized controlled trials

Introduction: Sleep disorders are prevalent conditions that significantly impact health and quality of life, often linked to underlying issues such as neurological and psychiatric disorders, chronic pain, and aging. These disturbances, including insomnia and excessive daytime sleepiness, contribute to cognitive decline, mood disorders, and decreased physical health. Non-invasive brain stimulation (NIBS) techniques, including transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), have emerged as potential treatments for various conditions, with growing interest in their application for sleep disorders. While some studies suggest positive effects, the evidence remains inconsistent, with variations in study designs, protocols, and outcomes. Furthermore, existing meta-analyses have not adequately addressed subgroup analyses, which are crucial for identifying more specific treatment parameters and patient characteristics. This systematic review and meta-analysis aim to fill this gap by evaluating the efficacy of NIBS for sleep disturbances, focusing on the quality of evidence, treatment parameters, and potential moderators, ultimately informing clinical practice and guiding future research in this field. Method and analysis: This systematic review and meta-analysis will include randomized controlled trials (RCTs) that compare the effects of NIBS with sham stimulation on sleep disorders. A thorough literature search will be conducted, covering the period from the beginning of each database’s record to January 2025. The following databases will be searched: PubMed, EMBASE, Web of Science (WOS), Physiotherapy Evidence Database (PEDro), and The Chinese National Knowledge Infrastructure (CNKI). Two independent reviewers will evaluate the articles and assess their methodological quality using the Cochrane Risk of Bias tool. Data will be extracted using a standardized template. The meta-analysis will determine the overall effect of NIBS on sleep outcomes, with heterogeneity assessed through I². Subgroup and sensitivity analyses will be performed to investigate treatment variables and the robustness of the results. Ethics and dissemination: This systematic review does not require ethical approval. The results of the study will be shared at scientific conferences and published in journals with peer review. Systematic review registration: PROSPERO registration number CRD42025645170.