Spontaneous dissecting aneurysms of the cervical internal carotid artery.

Spontaneous dissecting aneurysm of the cervical internal carotid artery is a rare condition. Three cases are described, all in the younger age group, and the clinical features and characteristic radiological findings are discussed. One case demonstrated concomitant unruptured saccular intracranial aneurysms, an even more uncommon association, and the implications of this association for the pathogenesis of the dissecting aneurysm are considered. Attention is also drawn to the fact that marked clinical and angiographic improvement may occur spontaneously, indicating that conservative management should be considered as well as surgical treatment.