[Anterior inferior cerebellar artery aneurysm with a sudden onset of caudal cranial nerve symptoms].

A case of the anterior inferior cerebellar artery aneurysm with a sudden onset of caudal cranial nerve symptoms was reported. A 20-year-old female suffered from sudden onset of dysphagia and throat pain. Three days later, she was admitted to our hospital, suffering from sudden onset of headache, nausea, vomiting and consciousness disturbance. On admission, consciousness disturbance, bilateral abducent nerve palsy, and left caudal cranial nerve palsy was observed. CT scan revealed a subarachnoid hemorrhage in the basal cisterns with the densest area in the left ambient cistern. Left vertebral angiogram revealed an aneurysm at the left anterior inferior cerebellar artery (AICA). On the third day after admission, operation was performed. The aneurysm was found near the jugular foramen, surrounded by thick clots. The dome was attached to the caudal cranial nerves, and the neck was located at the bending portion of AICA without branches. Neck ligation and clipping was performed. On the fortieth day after the operation, the patient was discharged from our hospital without neurological deficits. To our knowledge, aneurysm at the AICA is rare and only 33 cases have been reported. However, a case with a sudden onset of caudal cranial nerve symptoms, before evident symptoms due to subarachnoid hemorrhage, has never been reported previously.