[A Case of Contralateral Oculomotor Nerve Palsy due to Internal Carotid Artery-Anterior Choroidal Artery Ruptured Aneurysm].

Sudden oculomotor palsy with severe headache is known to suggest a ruptured ipsilateral internal carotid artery aneurysm. We encountered a case of contralateral oculomotor nerve palsy due to internal carotid artery-anterior choroidal artery ruptured aneurysm. A 63-year-old woman presented with severe headache and sudden right oculomotor palsy. Computed tomography(CT)showed subarachnoid hemorrhage, and three-dimensional CT showed a left internal carotid artery-anterior choroidal artery aneurysm. We performed neck clipping via a left pterional approach. After the surgery, right oculomotor palsy was not observed. We think the causes of oculomotor nerve palsy in this case were hematoma and elevated intracranial pressure. Once these factors were removed, we think that oculomotor nerve palsy was not observed.