Spontaneous regression of brain arteriovenous malformations

Abstract Objective and importance Complete spontaneous obliteration of a brain arteriovenous malformation (AVM) is a rare event, with 67 angiographically proven cases in the world literature. We present a new case and a systematic literature review to determine possible mechanisms underlying this unusual phenomenon. Clinical presentation One patient with a brain AVM was referred for radiosurgical treatment. Shortly before treatment however, complete spontaneous regression occurred. This patient had experienced a hemorrhage in the months before referral. Results We found 38 articles in which 67 cases of complete and spontaneous regression of a brain AVM were presented. Male to female ratio was 1.2, with a mean age of 37 years (range 1–81). Regression occurred in 72% without new neurological events. Median size of the nidus was 2 cm (range 1–7). There was a single arterial feeder in 46 % and a single draining vein in 59%. Conclusion Spontaneous regression of a brain AVM is the result of multiple interacting factors. Intracranial hemorrhage and the presence of a single draining vein seem to play a major role in this process.