[A case of accessory middle cerebral artery associated with internal carotid artery aneurysm (author's transl)].

A case of accessory middle cerebral artery associated with internal carotid artery aneurysm was reported. A 50-year-old female was admitted to our hospital with complaints of headache, nausea, vomiting and conciousness disturbance. Lumbar puncture showed bloody CSF. Right carotid angiogram revealed saccular aneurysm of the internal carotid-posterior communicating artery and accessory middle cerebral artery originating from the horizontal portion of the right anterior cerebral artery. No other vascular lesion was observed on other angiograms. Operation was performed 2 days after admission. The neck of the aneurysm was clipped. Postoperative aseptic meningitis was cured by frequent lumbar punctures, and her course was uneventful. The etiological hypothesis of these cerebral vascular anomalies was briefly discussed.