Internal carotid-posterior communicating artery aneurysm manifesting as an unusual ocular motor paresis after minor head trauma--case report.

Abstract

A 75-year-old female fell down in the road and hit her head. Two days later her right eye abduction was slightly limited on right lateral gaze. Cerebral angiography revealed an ipsilateral internal carotid-posterior communicating artery aneurysm. Craniotomy found the aneurysm had compressed the oculomotor nerve and was successfully clipped. The ocular motor paresis completely resolved after the operation. Therefore, the ocular motor paresis was possibly due to the aneurysmal compression to the oculomotor nerve. The oculomotor nerve stretched over the aneurysm was probably vulnerable to sudden mechanical stress, and aberrant innervation of the oculomotor nerve might be responsible for this unusual ocular motor paresis. Minor head trauma might precipitate ocular motor paresis in patients harboring an otherwise occult mass lesion at the skull base.