Unilateral Oculomotor Nerve Palsy as a Rare Manifestation of Isolated Pre-Communicating Segment of Posterior Cerebral Artery Thrombosis.

Ipsilateral mydriasis (IM) is usually not acute. However, the acute occurrence of unilateral dilated pupil may result in acute ischemic stroke. Herein, we present 3 patients with IM, lateral eye deviation, ptosis, and contralateral hemiparesis due to isolated occlusion of the pre-communicating segment of the posterior cerebral artery with preservation of the posterior communicating artery, which was successfully treated by emergent mechanical thrombectomy.