In 1936, Egas Moniz, Almeida Lima, and de Lacerda (17) reported a group of four cases of cervical occlusion of the internal carotid artery in which the diagnosis was established by carotid arteriography. Prior to this, the diagnosis had rarely been made antemortem. Following Moniz's demonstration, reports by other workers soon appeared in he literature. Lohr (14), Shimidzu (21), Chao et al. (4), Riechert (19), Siegert (22), Sorgo (23, 24), Andrell (1, 2), and many others (5, 8, 12, 15, 25, 26, 29) published similar cases. The increasing number of such reports indicates that internal carotid thrombosis is not infrequent as a cause of neurological disturbances. As a matter of fact, cervical thrombosis of the internal carotid artery accounted for 0.8 per cent of all cases of suspected brain lesions in Moniz's arteriographic material (16) Etiology and Pathology The following conditions have been responsible for occlusion of the internal carotid artery: 1. Embolism 2. Thrombosis a. Arteriosclerosis b. Thro...