Pediatric Moyamoya Presenting as a Subarachnoid Hemorrhage from a Ruptured Anterior Cerebral Artery Aneurysm.

BACKGROUND: The incidence of Moyamoya disease (MMD)-associated intracranial aneurysms ranges from 3% to 14% in adult patients, whereas this complication has rarely been reported in children. CASE DESCRIPTION: We herein report the first case, to our knowledge, of an extremely rare subarachnoid hemorrhage presentation of a child with a ruptured anterior cerebral artery dissecting aneurysm secondary to a newly discovered, unilateral Moyamoya-like pathology. CONCLUSIONS: MMD-associated aneurysms are extremely rare in children, and hemorrhage may be the initial presentation of the disease. Prompt intervention is essential to exclude the ruptured aneurysm that is at risk of rebleeding because of persistent hemodynamic stress.