Two autopsy cases with ruptured dissecting aneurysm of the intracranial vertebral artery.

Two autopsy cases with ruptured dissecting aneurysm of the intracranial portion of the vertebral artery are reported. Both patients developed subarachnoid hemorrhage and died within 9 days after onset. Autopsy disclosed dissecting aneurysms symmetrically on the bilateral vertebral arteries but there was no evidence of underlying vasculopathy in either patient. The etiology of the dissecting aneurysm of the intracranial vertebral artery is obscure, but the repeated minor trauma associated with head movement is considered as an important factor.