A case of aneurysm of the posterior temporal artery branched from the fetal posterior cerebral artery.

The authors report a case of a ruptured saccular aneurysm located on the posterior temporal artery branched from the fetal posterior cerebral artery. This site of aneurysmal origin is extremely rare. The aneurysmal neck clipping successfully performed via a middle subtemporal route. Key w01·ds: Cerebral aneurysm, Subarachnoidal hemorrhage, Posterior cerebral artery Posterior cerebral artery (PCA) aneurysms are not commonly seen. They constitute 0.3 to 2.9% of all cerebral aneurysms15·16•18) and 4.9 to 15.4 % of those of the vertebro-basilar system •18). PCA aneurysms arise principally in two places, mainly at the origin of the first major branch around the midbrain, and at the junction with the posterior communicating artery). Twenty four cases of PCA aneurysms, which were located on the posterior branch from the pulvinar in the quadrigeminal cistern and located on the posterior choroidal artery, have been reported1,3-5,9-12,14,17,1s,21-23,25-27). We are presenting a case of the posterior temporal artery aneurysm of an extremely rate site. CASE REPORT This 67-year-old woman with a medical history of hypertension suddenly experienced severe headache associated with restless confusion on November 4, 1985. She was transferred to Futami Central Hospital 3 hrs after the onset of symptoms. At admission, she rapidly became semi-comatose and left hemiparesis was remarkable. Her blood pressure was 190/110 mmHg. There were no other abnormal signs on physical examination or laboratory data available. Computerized tomography (CT) on admission showed a high density area in the right suprasellar cistern and ambient cistern, through the right hippocampal gyrus, and into the right lateral ventricle and the 3rd ventricle with moderate ventricular dilatation. Bilateral common carotid angiograms and vertebral angiograms revealed no abnormal findings except for unrolling of the anterior cerebral arteries (Fig. 1). After ventricular drainage was immediately undertaken, her consciousness improved to be somFig. 1. Right common carotid angiography, lateral view, showing no aneurysm and unrolling of the anterior cerebral arteries. nolent. A ventriculoperitoneal shunt was performed because of the remaining obstructive hydrocephalus 2 weeks after admission. On November 27, she again showed stuporous consciousness with left hemiplegia and became bedridden. CT at that time revealed a high density area in the right hippocampal gyrus and the right trigone of the lateral ventricle. On January 8, a repeated right carotid angiography demonstrated a saccular aneurysm of the right posterior temporal artery branched from the fetal PCA arising from the right internal carotid artery. The aneurysmal dome was persistently visible at the venous phase (Fig. 2). Her neurological symptoms gradually improved and she could ride in a wheel chair with the signs of left hemiparesis and disorientation remaining.