Which cranial nerve controls the movement of the superior oblique muscle of the eye?

The trochlear nerve is responsible for the movement of the superior oblique muscle of the eye. This muscle plays a crucial role in controlling the downward and lateral rotation of the eye, particularly when the eye is adducted. The trochlear nerve is unique among the cranial nerves because it is the only one that exits the brainstem dorsally and has the longest intracranial course, which reflects its connection to the superior oblique muscle.

Understanding the specific functions of cranial nerves is essential for recognizing their clinical significance. For instance, a dysfunction in the trochlear nerve could lead to difficulties in eye movement, such as double vision, particularly with activities that require looking down or to the side. This highlights the importance of the trochlear nerve's role in eye muscle control.