A young mother brings her 4-year-old daughter to her pediatrician after noticing that her right eyelid is "droopy." Neurological examination reveals the absence of direct pupillary light reflex and downward abducted gaze in the right eye. These deficits are consistent with a lesion involving which of the following structures?

Question

Quizplus · Accepted Answer

The symptoms described, including ptosis (droopy eyelid), absence of direct pupillary light reflex, and a downward abducted gaze in the right eye, are indicative of a lesion affecting the right oculomotor nerve (cranial nerve III). This nerve innervates the majority of the extraocular muscles, controls eyelid elevation, and conveys parasympathetic fibers to the pupil, hence its impairment can lead to the observed symptoms.

A Young Mother Brings Her 4-Year-Old Daughter to Her Pediatrician