All are true about trochlear nerve EXCEPT:-
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.
Innervates contralateral superior oblique
Causes depression of eyeball in adducted position
Lies outside the ring of Zinn
In lesion patient attains ipsilateral head tilt.
Neuroanatomy, Head and Neck