Progressive occlusion of the middle cerebral artery as the main feeder in a cerebral arteriovenous malformation: A case report.

Background: Cerebral arteriovenous malformation (AVM) is a congenital condition characterized by abnormal direct connections between arteries and veins through a nidus. Occlusion of major feeding arteries in AVMs is rare and typically associated with moyamoya disease. To date, only three cases have been reported where a previously patent major feeding artery became occluded during follow-up in AVMs without moyamoya disease. Case Description: A 36-year-old man presented with a seizure and was diagnosed with a left temporal lobe AVM. He was treated conservatively with antiepileptic medication. At age 49, follow-up angiography revealed middle cerebral artery (MCA) stenosis at the M1 segment. Eleven years later, at age 60, the MCA was occluded at the M1 segment, with collateral flow through M1-M1 micro-anastomoses and increased leptomeningeal and transdural anastomoses. Despite this angiographic progression, the patient remained asymptomatic except for well-controlled seizures, and conservative management was continued. Conclusion: This case illustrates a rare instance of spontaneous progressive occlusion of the MCA - the main feeder of an AVM - unrelated to moyamoya disease, with collateral revascularization captured over a 24-year follow-up. It underscores the importance of ongoing imaging surveillance, even in clinically stable patients, to anticipate treatment complexity resulting from dynamic hemodynamic changes.