Bright light therapy for post-stroke sleep disturbances: a systematic review and meta-analysis

Objective Sleep disturbances are common after stroke and may adversely affect neurological recovery. Although post-stroke sleep disturbances encompass insomnia symptoms, circadian rhythm sleep–wake disturbances, and sleep-disordered breathing, research has focused predominantly on obstructive sleep apnea. This review evaluated the effects of bright light therapy (BLT), a non-pharmacological intervention that may influence circadian regulation, on sleep outcomes after stroke. Methods Ten electronic databases covering English-and Chinese-language literature were searched from inception to April 9, 2026. Randomized controlled trials involving adults with stroke that evaluated validated subjective or objective sleep outcomes were eligible. Data were pooled using random-effects models when studies were sufficiently comparable clinically and methodologically. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool. The primary outcomes were wake after sleep onset (WASO) and subjective sleep quality. The protocol was registered in PROSPERO (CRD420251111617). Results Five randomized controlled trials involving 343 participants were included. Three trials involving 181 participants contributed to the WASO analysis; the pooled estimate was not statistically significant (MD = −39.17 min, 95% CI −115.34 to 36.99; P = 0.31), and heterogeneity was substantial (I 2 = 96%). Four trials involving 300 participants contributed to the subjective sleep quality analysis; the pooled estimate favored BLT (SMD = −0.85, 95% CI −1.38 to −0.32; P = 0.002), although heterogeneity was substantial (I 2 = 78%). After exclusion of Song Chang-yu, the pooled effect remained statistically significant but was attenuated, and heterogeneity decreased to 0% (SMD = −0.55, 95% CI −0.83 to −0.28). Conclusion BLT may improve subjective sleep quality after stroke; however, evidence for objective sleep continuity remains uncertain because of the small evidence base and substantial heterogeneity. Larger, methodologically rigorous trials using standardized light parameters, standardized outcome measures, and direct circadian assessments are needed to clarify the clinical effects of BLT and identify optimal treatment protocols. Systematic Review Registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420251111617 , identifier CRD420251111617.