Which observation during a pediatric exam demonstrates the function of the oculomotor nerve?

Which observation during a pediatric exam demonstrates the function of the oculomotor nerve?

• A. The child frowns during the examination
• B. The child offers appropriate verbal responses to the nurse practitioner during the examination
• C. The child visually tracks the parent's movements around the room during the examination
• D. The child sticks out the tongue during the examination

Answer: (C)

The oculomotor nerve controls most of the eye’s movements by innervating the major extraocular muscles that move the eye up, down, and inward, as well as lifting the upper eyelid. When a child visually tracks a moving object, like a parent walking around the room, the eyes must move smoothly in all directions to follow the target. This uses those extraocular muscles, many of which are innervated by the oculomotor nerve, so observing good tracking indicates the nerve’s motor function is intact. If CN III were impaired, you’d expect limited eye movements, misalignment, or diplopia, and tracking would be impaired. The other observations involve different nerves or actions (facial movement, language, or tongue movement) and do not test the oculomotor pathway.

The oculomotor nerve controls most of the eye’s movements by innervating the major extraocular muscles that move the eye up, down, and inward, as well as lifting the upper eyelid. When a child visually tracks a moving object, like a parent walking around the room, the eyes must move smoothly in all directions to follow the target. This uses those extraocular muscles, many of which are innervated by the oculomotor nerve, so observing good tracking indicates the nerve’s motor function is intact. If CN III were impaired, you’d expect limited eye movements, misalignment, or diplopia, and tracking would be impaired. The other observations involve different nerves or actions (facial movement, language, or tongue movement) and do not test the oculomotor pathway.