Ophthalmic segment aneurysmal subarachnoid hemorrhage presenting with contralateral abducens nerve palsy: a false localizing sign.

BACKGROUND

Neuro-ophthalmic manifestations of aneurysmal subarachnoid hemorrhage are commonly linked to a palsy of the cranial nerve in close proximity to the aneurysm or to chronic intracranial hypertension.

CASE REPORT: A patient with subarachnoid hemorrhage secondary to a rupture of an intracranial right ophthalmic segment internal carotid artery aneurysm presented with an acute-onset contralateral abducens nerve palsy. There were no clinical or radiologic features of chronic intracranial hypertension. Magnetic resonance imaging showed a co-existent ectatic basilar artery on the left side of the pons in close relation to the sixth nerve.

CONCLUSION

Abducens weakness in the above-50 age group is most commonly caused by a vascular etiology. The authors discuss the pathogenesis of this rare clinical entity and present pertinent literature review.