Congenital fourth nerve palsy, also known as congenital superior oblique palsy, is a condition that affects the function of the fourth cranial nerve. This condition causes the affected individual to experience difficulty moving their eye in certain directions. Some synonyms for congenital fourth nerve palsy include superior oblique muscle palsy, fourth cranial nerve palsy, superior oblique tendon sheath syndrome, and congenital trochlear nerve palsy. Other terms that may be used to describe this condition include strabismus and amblyopia. While there is currently no cure for congenital fourth nerve palsy, treatment options are available to help alleviate symptoms and improve overall vision.