The hypereosinophilic syndrome - an unusual cause of myocarditis and cardioembolic strokes.

Hypereosinophilic syndrome is a rare disorder characterized by excessive peripheral eosinophilia and eosinophil associated end-organ damage. Clinical presentations are heterogenous and can involve skin, pulmonary, cardiac and neurologic dysfunction. Eosinophilic myocarditis is a life-threatening complication that increases the risk of cardiac microemboli, which can subsequently lead to embolic strokes. Secondary to changes in blood viscosity, impaired clearance of microemboli, impaired cerebral blood flow, and pro-thrombotic conditions in the setting of hypereosinophilia, infarcts often present in vascular border zone regions. Here we present two cases of cardioembolic strokes involving borderzone regions in the setting of hypereosinophilic syndrome.