A Case of Posttraumatic Peripheral Oculomotor Nerve Palsy in a Child

Abstract

Purpose: We reported a case of a posttraumatic peripheral oculomotor nerve palsy in a child.

Case: A 7-year-old boy developed ptosis and eye movement disorder in the right eye immediatly after sustaining an injury to the eye with a chopstick. At the first visit, he presented with a red eye, ptosis, mild mydriasis, and limitations in upward and inward eye movements in the right eye. Fluorescein staining revealed no puncture sites in the conjunctiva. Visual acuity in that eye was 1.2, and no abnormalities were detected in the eyeball. We diagnosed the patient with oculomotor nerve palsy. Computed tomography showed a high-density area and an air bubble at the inferior medial canthus in the right orbit. To avoid orbital infection, we administered oral antibiotics to the patient. Light reaction improved in 2 weeks, ptosis in 2 months, and eye movement limitation in 4 months after the injury.

Conclusion: We reported a case of posttraumatic peripheral oculomotor nerve palsy in a child that showed complete remission in 4 months. The patient's visual acuity was normal, suggesting that the optic nerve was intact. We inferred that the trauma pathway included mydriasis, caused by a direct injury to the inferior branch of the oculomotor nerve through the inferior nasal orbit, and ptosis and eye movement disorder, caused by an indirect injury（compressive peripheral neuropathy due to inflammatory tissue swelling）to the superior branch of the peripheral oculomotor nerve. In patients with oculomotor nerve palsy with no visible trauma on the ocular surface, imaging is important for a definitive and correct diagnosis.