Peripheral and midbrain oculomotor palsies from operations for basilar bifurcation aneurysm in a series of 31 cases.

We evaluated oculomotor complications that occurred following surgical treatment of basilar bifurcation aneurysms in a series of 31 patients at the University of California Medical Center, San Francisco. Twenty-one of these patients developed an oculomotor palsy following operation. In 9 patients, the oculomotor palsy was the only complication. In 3 others, the oculomotor palsy was bilateral, suggesting injury to the oculomotor nucleus. In 9 additional patients, the oculomotor palsy was accompanied by a hemiparesis, indicating vascular injury to the peduncle. Recovery from isolated oculomotor palsy was excellent; when injury to the brain stem accompanied the oculomotor palsy, recovery was incomplete.