Optimizing tDCS parameters for post-stroke upper limb recovery: a systematic review and meta-analysis protocol

Stroke is a leading cause of death and disability globally, with significant impairments in upper limb motor function affecting the quality of life of survivors. Despite the potential of transcranial direct current stimulation (tDCS) as a noninvasive neuromodulation technique for enhancing post-stroke recovery, current findings regarding its efficacy and optimal parameters remain heterogeneous and controversial. The purpose of this study is to systematically evaluate the effects of different tDCS parameters on upper limb motor impairments in stroke patients and provide guidance for selecting optimal stimulation parameters via a meta-analysis of available literature.

A comprehensive literature search (up to 31 December 2024) will be conducted in MEDLINE via PubMed, Cochrane Library, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), and Wanfang Data to gather relevant data on tDCS interventions for post-stroke upper limb impairments. We will use EndNote 21 software for study selection and Stata 16.0 software for data analysis. Studies included will be randomized controlled trials involving adult stroke patients receiving tDCS interventions, with primary outcomes focusing on upper limb motor function scores and secondary outcomes including activities of daily living and adverse events.

This study aims to provide the most up-to-date evidence and recommendations for clinicians and stroke patients to choose an optimal type of tDCS intervention. It will elucidate the impact of different stimulation parameters (e.g., current density, stimulation duration, and target location) on therapeutic outcomes.

tDCS has the potential to positively impact upper limb motor function in stroke patients. This study will provide insights into optimal stimulation parameters, encouraging the integration of tDCS into clinical rehabilitation protocols.