Objective:

To describe a case of stroke caused by hypereosinophilic syndrome (HES) in a young, otherwise healthy patient, highlighting the importance of early recognition and treatment.

Background:

Hypereosinophilic syndrome (HES) is a rare disorder characterized by persistently elevated eosinophils, leading to multi-organ damage. Eosinophilic proteins cause endothelial injury, promoting hypercoagulability and thromboembolism, which can result in stroke. HES-associated strokes often present as multifocal infarcts, especially in arterial border zones, including the cerebellum.

Design/Methods:

NA

Results:

A 23-year-old previously healthy female presented with acute onset of ataxia, left hemiparesthesia, and hemiparesis. She had no history of smoking, hormonal contraceptive use, or other risk factors. Initial workup, including urine toxicology, CT head and CTA head and neck was unremarkable, except for an elevated eosinophil count of 21%. Brain MRI showed multiple acute bilateral infarcts in a watershed distribution, including the cerebellum, a pattern consistent with HES-associated stroke. Extensive evaluation, including lumbar puncture, testing for hypercoagulable, autoimmune, and malignant disorders, as well as a transesophageal echocardiogram, was negative for other causes. The patient was started on corticosteroids, which led to improvement in eosinophil count and full recovery of her neurological symptoms. Persistent eosinophilia on follow-up confirmed the diagnosis of HES.

Conclusions:

This case demonstrates that HES can be a significant, modifiable risk factor for stroke, even in young, healthy individuals. The absence of other stroke risk factors and the presence of multifocal watershed infarcts should raise suspicion for HES. Early recognition and treatment with corticosteroids may improve outcomes and prevent recurrence in patients with HES-associated stroke.