Case Presentation: We present a case of 26-year-old female presented with acute ischemic stroke. She presented with altered mental status from Rehabilitation center. She has history of sickle cell and recurrent strokes in the past. Extensive prior work up for recurrent strokes was done and she was thought to have Moyamoya disease. Before this presentation, she had a left intraventricular hemorrhage and required hospitalization for about 11 days. She had a cerebral angiogram and no neurosurgical intervention is done since it is related to Moyamoya disease. She presented back again with altered mental status and MRI imaging showed large new acute right temporal ischemic infarct extending into insula along with small left intraventricular hemorrhage. EEG monitoring showed no evidence of seizures. Since the patient had acute stroke with sickle cell anemia, an Exchange transfusion was done. The patient stayed in the hospital for about 8 days and was later on discharged to Rehab with follow-ups and treatment of stroke and sickle cell disease. The patient is on Hydroxyurea, which is the mainstay of treatment to prevent strokes along with chronic exchange transfusions.

Discussion: Moyamoya disease (MMD) is a unique chronic progressive cerebrovascular disease characterized by bilateral stenosis or occlusion of the arteries around the circle of Willis with prominent arterial collateral circulation. “Moyamoya” is a Japanese word meaning puffy, obscure, or hazy like a puff of smoke in the air. Thus, the term was used to describe the smoky angiographic appearance of the vascular collateral network. Moyamoya disease was first described in Japan in 1957 and is found less frequently in North America and Europe than in Asia.

Conclusions: This case highlights the importance of considering Moyamoya disease to be one of the classic etiologies of acute and recurrent ischemic strokes in children and young people. Moyamoya disease can be either congenital or acquired. Patients with Down syndrome, sickle cell anemia, neurofibromatosis type 1, congenital heart disease, fibromuscular dysplasia, activated protein C resistance, or head trauma can develop Moyamoya malformations. Ischemic cerebrovascular events, either transient ischemic attack or infarction, are more prevalent than hemorrhagic events in children with Moyamoya, while hemorrhagic stroke is more common in adults. Our case is unique that this young adult presented with both hemorrhagic and ischemic strokes in different hospital admissions. Anti Platelet therapy could not be offered to her ischemic strokes because of recent hemorrhagic strokes. The main pathological change noted in Moyamoya disease is the stenotic segments caused by the proliferative disease in the intima, which cause vasocclusion. Hemorrhage in Moyamoya disease could be due to weakened primary vessels or fragile collateral vessels.