Compression of the Optic Nerve by a Fusiform Aneurysm of the Carotid Artery

The symptomatology of congenital saccular and arteriovenous aneurysms as well as of other vascular abnormalities of the brain have been carefully des-cribed by a number of authors, and there seems to be little to add to this interesting chapter of surgical neurology. However, there is a type of vascular lesion characterized by fusiform enlargement, generally bilateral, of the subclinoid portion of the carotid artery which is less well known (Fig. 1). This lesion was first described, so far as we know, by Adson, who published two of these cases in 1942. He does not consider it a true aneurysm and regards it as being due to hardening of the wall and abnormal internal rotation of the intracranial carotid. Later Tassman (1944) published a similar