The parents of a 2-year-old girl notice that she is constantly tilting her head to one side and her right eye is deviated upward. Ophthalmologic exam reveals that the girl is unable to move her right eye downward after first looking left. All other eye movements are normal. These deficits are consistent with a lesion involving which of the following?

Question

Quizplus · Accepted Answer

The symptoms described are consistent with a lesion involving the right trochlear nerve, which innervates the superior oblique muscle. This muscle is responsible for depression and intorsion of the eye, particularly when the eye is adducted. Difficulty moving the right eye downward after looking left (adduction) and a head tilt to compensate for the vertical diplopia are classic signs of trochlear nerve dysfunction.

The Parents of a 2-Year-Old Girl Notice That She Is