[Disappearance of the co-existing aneurysm and arteriovenous malformation after wrapping of aneurysm (author's transl)].

The authors reported a case of an arteriovenous malformation associated with an aneurysm on its feeding vessel that is the left anterior inferior cerebellar artery. A housewife, aged 56-years, was admitted to our hospital with severe headache, nausea and vomiting. On admission, lumbar puncture revealed grossly bloody CSF. Neurological examination revealed meningeal irritation sign, horizontal nystgmus and disturbance of left auditory acuity. Bilateral carotid and retrograde brachial arteryography revealed an AVM near the left cerebellopontine angle and a small aneurysm of the left anterior inferior cerebellar artery at the left internal auditory meatus. At operation, the aneurysm was wrapped with a muscle piece and no surgical intervention for AVM. Post-operative course was uneventful except for disterbance of the left auditory acuity. Follow-up angiographies revealed a change of size the aneurysm and AVM and finaly failed to demonstrate the aneurysm and AVM demonstrated preoperatively. The spontaneous regression of the AVM might be due to the post-operative brain swelling and adhesion. We also speculated that the spontaneous disappearance of the aneurysm might be due to the decreased blood flow of parent artery by the spontaneous regression of the AVM. It is very rare that an aneurysm of anterior inferior cerebellar artery co-existed with AVM, and resulted in thrombosis of the aneurysm and regression of the AVM after wrapping alone.