Background: In Weber syndrome, one side of the cerebral peduncle of the midbrain is infarcted due to the occlusion of the interpeduncular branch of the posterior cerebral artery and the posterior choroidal artery, resulting in ipsilateral oculomotor nerve palsy and contralateral hemiparesis. However, Weber syndrome induced by simple anterior choroidal artery lesions has rarely been reported.
Case Description: Computed tomographic angiography revealed occlusion of the left internal carotid artery in a 57-year-old male patient who was admitted to the Beijing Haidian Hospital with cerebral infarction. Thrombectomy to clear the occlusion of the left internal carotid artery and the middle cerebral artery was successfully performed in the emergency department. However, postoperative digital subtraction angiography indicated occlusion of the middle and distal segments of the left anterior choroidal artery. After recovery from anesthesia, the patient had left blepharoptosis, inability to abduct the left eye, limitation of the upward and downward gaze, left mydriasis, absence of response to light, and right hemiplegia. Complete head magnetic resonance imaging suggested left cerebral peduncle and basal ganglia infarction. Therefore, the diagnosis was that the patient had left Weber syndrome caused by a left anterior choroidal arterial embolism.
Conclusion: When the anterior choroidal artery is the dominant supplier of blood to the medial region of the ipsilateral cerebral peduncle, the occlusion of this artery may lead to ipsilateral Weber syndrome.
Keywords: cerebral infarction, mechanical thrombectomy, anterior choroidal artery, oculomotor nerve palsy, Weber syndrome