A Rare Case of Oculomotor Nerve Palsy after Endovascular Treatment in a Patient with Internal Carotid Artery Dissection.

BACKGROUND

The oculomotor nerve has two major fibers: the outer autonomic fiber innervates the ciliary muscles and sphincter pupillae involved in pupil constriction, and the inner somatic fiber innervates the levator palpebrae superioris in the eyelid and four extraocular muscles involved in oculomotor dysfunction. We present a rare case of oculomotor nerve palsy with internal carotid artery (ICA) dissection and discuss the vascular anatomical feature of interest to be considered during treatment.

CASE REPORT: A 56-year-old man presented with language impairment, right visual field loss, and right-sided facial sensory loss, weakness, and hypesthesia 30 hours after the last seen normal. CT perfusion imaging revealed a large left middle cerebral artery distribution and possible salvageable ischemic penumbra. Angiography showed occlusion of the communicating segment of the left ICA. We performed mechanical thrombectomy for left ICA occlusion that led to partial recanalization after several attempts. A control digital subtraction angiography showed dissection features in the communicating part of the left ICA. The recanalized ICA got blocked again within ten minutes. Angioplasty was performed and the flow improved. Five hours after thrombectomy, the patient developed complete left oculomotor palsy with ptosis, a fixed mydriatic pupil, and lateral and downwards eyeball deviation suggesting oculomotor nerve palsy. MRI on the 23rd day after symptom onset revealed enhancement of the left oculomotor nerve.

CONCLUSIONS

The clinical and imaging course described in this case shows an injury to the oculomotor nerve with compressive plus ischemic injury in a patient with ICA dissection who received endovascular treatment.