Subarachnoid hemorrhage in neurofibromatosis type 1: case report of extracranial cerebral aneurysm rupture into a meningocele.

Described here is a case of subarachnoid hemorrhage due to rupture of an extracranial vertebral artery (V3 segment) aneurysm in a patient with neurofibromatosis type 1 (NF-1). The pathophysiology of this never-before reported complication of NF-1 is examined in the light of a focused literature review and with illustrations characteristic of this unique case, involving complex malformations of the spine and meningeal spaces, as well as of the vertebral artery wall itself. All these abnormalities are directly related to the underlying NF-1 disease.