Ocular bobbing with ruptured giant distal posterior inferior cerebellar artery aneurysm.

A patient presented comatose with an intraventricular hemorrhage of unknown etiology, and manifested the unusual clinical phenomenon of ocular bobbing. Further evaluation revealed a giant aneurysm of the distal posterior inferior cerebellar artery, which was successfully treated surgically. The pathophysiology of ocular bobbing is discussed as well as the association of this unusual sign with a rare aneurysm.