Fusiform basilar artery aneurysm in a 33-month-old child.

A 33-month-old girl presented with acute subarachnoid hemorrhage from a ruptured multilobulated fusiform aneurysm of the midbasilar artery. This rare lesion was treated surgically by occluding the basilar artery. Intraoperative brain stem auditory evoked potential and somatosensory evoked potential monitoring results did not change with basilar artery occlusion, suggesting that the occlusion would be tolerated. However, the amplitudes of brain stem auditory evoked potential Waves III-V to right ear stimulation were transiently reduced during left pontine retraction during the aneurysm exposure. The patient made a complete clinical recovery.