Aneurysm of the posterior inferior cerebellar artery of a 5-year-old girl.

A case of a congenital aneurysm located on the left posterior inferior cerebellar artery, which ruptured producing subarachnoid hemorrhage and death in a 5-year-old girl, is presented. The very low incidence of congenital aneurysms in young children and the relatively rare occurrence of aneurysms of the vertebral-basilar system are two additional unusual features of this case.