Temporal Vulnerability of the Blood-Brain Interface in Stroke: Molecular Mechanisms of Circadian Dynamics, Inflammation, and Aging.

Stroke remains one of the leading causes of long-term disability and death worldwide. Growing evidence suggests that both stroke onset and severity exhibit strong circadian patterns. This blood-brain interface (BBI), which regulates bidirectional communication between the peripheral circulation and the central nervous system, plays a critical role in cerebrovascular injury. Aging further exacerbates these processes by dampening the molecular clock function and increasing inflammatory activation. In this review, we examine the circadian regulation of the BBI, aging, and its implications in stroke vulnerability. Understanding how circadian biology modulates neurovascular function may reveal novel therapeutic targets and time-of-day-dependent approaches for stroke prevention and treatment.