Chronic Insomnia and Stroke Risk—A Real Bidirectional Issue

Chronic insomnia is a prevalent and disabling sleep disorder with growing evidence linking it to cardiovascular and cerebrovascular morbidity. Stroke, a leading cause of mortality and a long-term disability worldwide, may be influenced by sleep disturbances through multiple physiological mechanisms. While traditional risk factors such as hypertension, atrial fibrillation, diabetes, obesity, smoking, and sedentary lifestyle remain dominant drivers of stroke burden, accumulating evidence suggests that sleep disturbances, particularly chronic insomnia, may act as both independent risk factors for incident stroke and as outcomes of cerebrovascular injury. Chronic insomnia, affecting approximately 10% of the global population, is characterized by persistent difficulties with sleep initiation, maintenance, or quality, accompanied by daytime dysfunction. Beyond its impact on quality of life and mental health, insomnia has been linked to cardiometabolic dysregulation, inflammation, and vascular dysfunction. Importantly, sleep disturbances after stroke can impair recovery and functional outcomes, underscoring a bidirectional relationship between stroke and sleep. Several recent reviews have examined the connection between insomnia and stroke. Our review differs by focusing specifically on (1) the stroke-specific epidemiological evidence for chronic insomnia as a risk factor, (2) the bidirectional interplay between insomnia and post-stroke sleep disturbances, and (3) the role of emerging technologies in monitoring and prognosis. By addressing these gaps, we aim to refine the current understanding and highlight priorities for future research and clinical translation.