Posterior reversible encephalopathy syndrome (PRES) in a patient with moyamoya disease: A case report.

INTRODUCTION Moyamoya disease (MMD) and posterior reversible encephalopathy syndrome (PRES) share similar pathophysiological characteristics of endothelial dysfunction and impaired cerebral autoregulation. However, there have never been any published studies to demonstrate the relationship between these 2 rare diseases. PATIENT CONCERNS A 26-year-old Asian man presented with a throbbing headache, blurred vision, and extremely high blood pressure. We initially suspected acute cerebral infarction based on the cerebral computed tomography, underlying MMD, and prior ischemic stroke. However, the neurological symptoms deteriorated progressively. DIAGNOSIS Cerebral magnetic resonance imaging indicated the presence of vasogenic edema rather than cerebral infarction. INTERVENTIONS AND OUTCOMES An appropriate blood pressure management prevents the patient from disastrous outcomes successfully. Cerebral magnetic resonance imaging at 2 months post treatment disclosed the complete resolution of cerebral edema. The patient's recovery from clinical symptoms and the neuroimaging changes supported the PRES diagnosis. CONCLUSION This report suggests that patients with MMD may be susceptible to PRES. It highlights the importance of considering PRES as a differential diagnosis while providing care to MMD patients with concurrent acute neurological symptoms and a prompt intervention contributes to a favorable clinical prognosis.