Capsular warning syndrome: Nighttime blood pressure drops, clinical awareness, and therapeutic approach

Capsular warning syndrome (CWS) is a rare condition marked by recurrent, stereotypical transient ischemic attacks (TIAs) affecting the face, arm, and leg, without cortical involvement. It is associated with a high risk of a full-blown stroke within 7 days. The exact pathophysiological mechanism and optimal management strategies remain debated. It is crucial to distinguish CWS from crescendo TIAs and consider reperfusion therapy if new episodes occur within the therapeutic window for systemic reperfusion, in order to prevent a disabling stroke. We present the case of a 53-year-old male who arrived at the emergency department (ED) with right hemiparesis and facial weakness lasting for 1 h. He had experienced four recurrent, stereotypical episodes over the past 7 h and was diagnosed with a TIA, despite being within the therapeutic window for thrombolysis. He was started on dual antiplatelet therapy, high-dose statins, and management of other vascular risk factors. However, within 24 h, his condition progressed to a complete stroke with severe hemiparesis and facial weakness. Magnetic resonance imaging confirmed infarction in the left hemisphere, while a computed tomography angiogram was normal. This case underscores the importance of prompt recognition of CWS in the ED, enabling activation of stroke services and the consideration of reperfusion therapy when appropriate, to minimize the risk of a disabling stroke.