[Dissecting Aneurysm of the Distal Middle Cerebral Artery Formed the Out Pouch during Long-term Follow-up:A Case Report].

A 40-year-old man with a rare case of dissecting aneurysm of the distal middle cerebral artery(MCA, M2 segment)presented with ischemic stroke, manifesting as headache, nausea, and visual disorder. Computed tomography(CT)scan revealed cerebral infarction, and three-dimensional CT angiogram revealed stenotic change at the M2 segment. The patient was conservatively treated and remained neurologically stable.