Only one nerve has axons that cross the midline to control contralateral muscles. This is the trochlear nerve originating deep in the midbrain. Further the emergence point is dorsal on the brainstem while all other nerves exit ventrally.

• Only one nerve has axons that cross the midline to control contralateral muscles. This is the trochlear nerve originating deep in the midbrain. Further the emergence point is dorsal on the brainstem while all other nerves exit ventrally.