Internal Carotid Artery Occlusion Manifesting Only as Oculomotor Nerve Palsy

Oculomotor nerve palsy is very rare as the only manifestation of internal carotid artery (ICA) occlusion, and the angiographic findings have not been described in detail. We present a case of ipsilateral ICA occlusion manifesting as only sudden onset of oculomotor nerve palsy. Cerebral angiography showed occlusion of the ICA from the cervical portion to the ophthalmic portion. Distal blood flow was compensated through an anastomosis from other arteries. Ischemia of the oculomotor nerve was thought to be caused by loss of supply from branches arising from the occluded cavernous portion of the ICA.