Traumatic aneurysm of the basilar artery

Aneurysms develop following closed or penetrating trauma in relation to the severity of the arterial injury sustained. Anatomic structures protect certain arteries more than others, thereby reducing but not precluding the occurrence of traumatic aneurysms in these vessels. A recent reveiw of the world literature revealed 41 intracerebral traumatic aneurysms. This case constitutes the first known report of a traumatic aneurysm involving the basilar artery. Both blunt and penetrating head trauma can cause intracranial traumatic aneurysms. The present case emphasizes the role of the orbit and superior orbital fissure in allowing a relatively low velocity projectile to injure the basilar artery deep within the confines of the cranial vault.