Moyamoya Syndrome Associated With Gamma Knife Surgery for Cerebral Arteriovenous Malformation

Abstract

A 30-year-old female developed moyamoya syndrome after gamma knife surgery (GKS) for cerebral arteriovenous malformation (AVM), and was treated with bypass surgery. She suffered from flittering scotoma, right transient hemianopsia, and headache for 1 year. Cerebral angiography revealed a Spetzler-Martin grade III AVM located in the left occipital lobe. After staged embolization, GKS was performed with a minimum dose of 20 Gy to the periphery of the nidus at the 50% isodose level of the maximum target dose. Gradual nidus regression was achieved, and the clinical symptoms disappeared completely. However, at 30 months after GKS, the patient suffered transient ischemic attack. Cerebral angiography showed left middle cerebral artery occlusion with moyamoya vessels. The patient underwent direct and indirect bypass surgery. After surgery, the patient was free from ischemic symptoms. Chronic inflammation and long-term changes in expression of cytokines and growth factors after GKS may have triggered this case.

Delayed Perilesional Ischemic Stroke after Gamma-knife Radiosurgery for Unruptured Deep Arteriovenous Malformation: Two Case Reports of Radiation-induced Small Artery Injury as Possible Cause

“…Although rare, radiation-induced vasculopathy is one of the most serious complications after GKRS. 3) 10) The basal ganglia and thalamus are extremely sensitive to radiation, therefore, GKRS for a deep seated AVM has increased risk of side effects during the latency period. 9) 14) Complication of large intracranial arteries related to GKRS has occasionally been reported.…”