Moyamoya disease associated with hereditary spherocytosis.

A 5-year-old girl with hereditary spherocytosis presented with two episodes of transient ischemic attacks within a month. Cranial magnetic resonance imaging angiography revealed a left internal carotid artery and middle cerebral artery stenosis, with an extensive vascular mesh in the thalamic area indicative of moyamoya disease. Treatment consisted of supporting cerebral perfusion with blood transfusions, and splenectomy to prevent recurrence. Moyamoya disease is a very unusual cerebrovascular disorder in childhood and its association with hereditary spherocytosis is rarely reported.