The six cardinal directions test assesses movement controlled by which cranial nerves?

• A. II, III, and IV
• B. I, II, and III
• C. V, VI, and VII
• D. III, IV, and VI

Answer: (D)

Movement in the six cardinal gaze directions relies on the extraocular muscles that move the eye, and these muscles are controlled by three cranial nerves. The oculomotor nerve supplies most of the eye muscles (medial, inferior, and superior recti, plus the inferior oblique) and also lifts the eyelid. The trochlear nerve controls the superior oblique, and the abducens nerve controls the lateral rectus. Coordinated activity of these nerves allows the eye to move in all six directions tested. The six-cardinal gaze exam specifically assesses this motor function, not the sensory input from the optic nerve.