Acupuncture for Ischemic Stroke: A Critical Evaluation of Biological Mechanisms and Methodological Challenges.

Ischemic stroke (IS) is a leading cause of long-term disability worldwide, creating an urgent need for effective adjunctive therapies to complement conventional treatments. Acupuncture has emerged as a widely investigated intervention for post-stroke recovery. This review provides a critical evaluation of the proposed biological mechanisms underlying acupuncture's effects in IS. We synthesize evidence from preclinical and clinical studies on its potential to promote the dynamic repair of the neurovascular unit (NVU), modulate intercellular communication, improve cerebral hemodynamics, enhance angiogenesis, and support neurorestoration. While a significant body of preclinical evidence suggests multifaceted benefits, we highlight a critical translational gap and the methodological limitations that currently temper clinical certainty. Key challenges include the heterogeneity of treatment protocols, the complexity of sham controls, and a frequent lack of objective biomarkers. Consequently, we conclude by outlining a clear agenda for future research, emphasizing the need for protocol standardization, rigorous large-scale randomized controlled trials (RCTs), and the integration of biomarkers to bridge the gap between proposed mechanisms and validated clinical outcomes. This critical perspective aims to guide future research toward definitively establishing acupuncture's role in the stroke care continuum.