<prompt> All are true about trochlear nerve EXCEPT:-Innervates contralateral superior obliqueCauses depression of eyeball in adducted positionLies outside the ring of ZinnIn lesion patient attains ipsilateral head tilt.  <response>: The patient develops contralateral not ipsilateral head tilt to compensate for extoed eye on the affected side. Trochlear nucleus in the midbrain, send fibers to innervate the contralateral superior oblique muscle. Superior oblique muscle causes inward rotation intoion of the eyeball. Additionally, it also causes depression and abduction of eyeball. It is the chief muscle to cause depression of the adducted eye and is assisted by inferior rectus for the movement.. Trochlear nerve is rarely paralyzed alone. It results in veical diplopia double vision on looking down, e.g. when going down stairs. This happens because the superior oblique normally assists the inferior rectus in pulling the eye downward, especially when the eye is in a medial adducted position. 