Background: Ischemic stroke due to hypereosinophilic syndromes (HES) is a rare but severe neurological emergency. HES may be secondary to infections, autoimmune conditions, severe allergic reactions, or hematologic disorders. Among these, clonal forms associated with myeloproliferation are particularly aggressive and can lead to recurrent cerebral infarctions with high mortality.
Purpose: We report the case of an elderly patient with newly diagnosed extreme eosinophilia who developed multiple progressive strokes and ultimately died despite early and aggressive treatment.
Conclusions: This case emphasizes the importance of rapid recognition, highlights the unique radiological signature of border-zone infarctions in this context, and raises concern about the critical role of granulocytes in cerebral microcirculation. It also underscores that partial reduction of eosinophils may be insufficient for stroke prevention and that full normalization may be necessary.