[Two cases of spontaneous occlusion of the internal carotid artery due to a giant intracranial internal carotid artery aneurysm].

Although spontaneous thrombosis of a giant intracranial aneurysm is comparatively common, its parent artery occlusion is rare. Recently we experienced two cases in which spontaneous thrombosis of giant intracranial internal carotid artery aneurysm and occlusion of its parent artery were occurred. Case 1. A 49-year-old man, complaining esotropia was referred to us by an ophthalmologist. He had no particular past history. Neurological examination revealed left oculomotor, abducens palsy and disturbance of left trigeminal first branch. CT scan revealed a round high density mass in the left middle fossa. The size was 3 cm in diameter. Left CAG revealed severe stenosis of left internal carotid artery and in delayed phase, faint shadow was seen near posterior clinoid process. MRI revealed a high intensity mass of the intraaneurysmal thrombus in the left middle fossa with small low intensity area indicating residual lumen. With conservative treatment, the symptom was gradually improved and one month after admission, complete occlusion of the left internal carotid artery was seen by angiography. The patient returned to his previous occupation. Case 2. A 21-year-old man was admitted to our hospital complaining dysarthria and left hemiparesis. He had been diagnosed as left internal carotid giant aneurysm 5 years before when he had suffered from right visual disturbance. Neurological examination revealed left hemiparesis and dysarthria. CT scan revealed high density mass which extended from the base of the right middle fossa to the third ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)