Capsular warning syndrome—a case of atrial fibrillation and corona radiata infarct

BACKGROUND: Capsular warning syndrome (CWS) is a rare clinical syndrome characterised by recurrent and transient episodes of focal neurological deficits with high risk of infarction. The exact physiological mechanism of CWS remains unclear but is most commonly believed to be a result of haemodynamic insufficiency in diseased, small penetrating vessels. There are no defined treatment guidelines or established effective therapy. CASE PRESENTATION: We describe the case of a 65-year-old man who presented to the emergency department with recurrent episodes of dysarthria coupled with right facial droop and right-sided weakness. Symptoms recurred a total of ten times within a span of 3 h. He had new onset atrial fibrillation. An initial cerebral angiogram showed mild intracranial atherosclerotic disease with no proximal large vessel occlusion or acute infarct. Magnetic resonance imaging 1 h later demonstrated an infarct in the left corona radiata. CONCLUSIONS: This case illustrates an uncommon etiology of CWS. We will also discuss the lack of consensus in treatment options for CWS to mitigate a complete stroke.