Progression of Blood Brain Barrier Permeability in patients with Acute Ischemic Stroke: from acute to early subacute phase

Introduction: Stroke is currently the third leading cause of death and disability in North America [1]. Blood–brain barrier (BBB) disruption following ischemia–reperfusion is associated with clinically important consequences including edema and hemorrhagic transformation (HT). Previous data on BBB permeability changes after acute ischemic stroke (AIS) is limited to the first several hours and virtually non-existent in the subacute phase (days to weeks) [2,3]. No longitudinal data exists. We therefore reviewed our existing data that included data points over one hour to several days. Precise knowledge of BBB dynamics after ischemic stroke is of importance in considering future treatment possibilities including BBB leakage-blocking agents, and neuroprotective and neurorestorative strategies [4,5]. The purpose of this study was to evaluate the time course of BBB disruption from acute to early subacute phase of AIS. We hypothesized that BBB permeability measured by DCE-MRI would continuously increase with time, a response caused initially by direct ischemic endothelial injury and subsequently by inflammatory reaction [6].