Cerebral arteriolar thromboembolism in idiopathic hypereosinophilic syndrome

Objective: To describe imaging findings as well as postmortem brain and cardiac pathology in a patient with fulminant idiopathic hypereosinophilic syndrome Design: Case report. Setting: University hospital. Patient: A 48-year-old right-handed man with hypere- osinophilia, rapidly progressive encephalopathy, and focal neurological deficits who died 22 days after presentation. Main Outcome Measures: Physical examination, ra- diologic, and neuropathologic examination results. Results: Imaging of the brain revealed bihemispheric is- chemic changes in and beyond the watershed distributions. Pathology review demonstrated mural cardiac thrombus that likely caused cardioembolism as well as diffuse microangiopathy despite resolution of the hy- pereosinophilia. Conclusions: Timely recognition of idiopathic hypere- osinophilic syndrome may enable aggressive treatment prior to widespread cardioembolism and degranulation that result in devastating cerebrovascular complications.