Extracranial vertebral artery pseudoaneurysm presenting as subarachnoid hemorrhage.

BACKGROUND AND PURPOSE True aneurysms of the extracranial vertebral artery are rare. The usual pathogenesis of aneurysms in this location is either penetrating or blunt trauma with resultant pseudoaneurysm formation. We report a postpartum patient with a presumed traumatic pseudoaneurysm of the extracranial vertebral artery presenting with subarachnoid hemorrhage. CASE DESCRIPTION A 41-year-old woman had three episodes of neck stiffness 1 month after an uncomplicated vaginal delivery. The last episode, 3 days before admission, was accompanied by intense neck and head pain and paresthesias that extended into the left arm, thumb, and forefinger. RESULTS Lumbar puncture showed subarachnoid hemorrhage. Angiography revealed a left vertebral artery dissection from C6-7 to C3 with pseudoaneurysm at C5-6. Computed tomography demonstrated impingement of the C6 root at the foramen by this lesion. The lesion was successfully treated by balloon occlusion of the vertebral artery. CONCLUSION We present a patient with an extracranial vertebral pseudoaneurysm with subarachnoid hemorrhage and cervical root impingement. To our knowledge, this is the first case of such a lesion presenting as subarachnoid hemorrhage. The lesion was successfully treated using endovascular techniques.