Isolated Catatonia as a Rare Initial Manifestation of Moyamoya Disease.

Moyamoya disease (MMD) is a rare, idiopathic, and life-threatening cerebrovascular disorder characterized by progressive stenosis and occlusion of the intracranial internal carotid arteries, leading to the formation of abnormal collateral vessels. The incidence of MMD is high in Asian countries but has also been reported in other regions with lower prevalence. Clinically, the disease can manifest with ischemic, hemorrhagic, or epileptic symptoms. Psychiatric manifestations are atypical and may be mistaken for primary psychiatric disorders, necessitating a specialized approach to management. We report a rare clinical case of a patient who was admitted with isolated catatonia and was diagnosed with MMD through neuroimaging. We discuss the possible mechanisms underlying this association, radiological findings, and strategies for managing such an uncommon presentation.