[Inferior branch palsy of the oculomotor nerve following clipping of basilar apex aneurysm]

Abstract

A 67-year-old woman experienced a severe headache and vomiting. A computed tomographic (CT) scan showed a mild subarachnoid hemorrhage. Cerebral angiography revealed a saccular aneurysm at the apex of the basilar artery. Several days later, she noticed mild hemiparesis of the left extremities. She underwent a clipping operation on the aneurysm by approaching from the right temporal love. Postoperatively, she developed diplopia and dilatation of the left pupil. Cerebral angiography revealed an occlusion of the left posterior cerebral artery. She was admitted to another hospital in order to continue rehabilitation. General physical examination was normal. Neurological examination revealed paralysis of the left medial and left inferior rectus muscles and palsy of the left inferior oblique muscle. The pupil of the left eye was dilated, measuring 5 mm in diameter, and it did not constrict to any stimuli. The left superior rectus and levator palpebrae superioris functioned normally. Visual acuity and visual fields were normal except for the influence of a senile cataract. She had a mild left hemiparesis, slight left ataxia and slurred speech. She had numbness of the left half of the body. A CT scan showed small low density areas in the right thalamus and left cerebellar hemisphere. Her ophthalmologic findings were compatible with the inferior branch palsy of the oculomotor nerve. The ophthalmoplegia of this case seems to be due to partial damage of the oculomotor nerve induced by ischemia of vascular supply. It is supposed to be caused by a vasospasm of the left posterior cerebral artery following a clipping operation of the basilar apex aneurysm.