chwannoma in patient with iolated unilateral trochlear nerve paly Original Reearch Article

PURPOE: To decribe the clinical feature of patient with iolated unilateral trochlear nerve paly econdary to imaging-defined chwannoma of the trochlear nerve. METHOD: A chart review of all patient een at the Neuro-Ophthalmology Unit at Emory Univerity ince 1989. Of 221 patient with trochlear nerve paly, ix had a leion conitent with a trochlear nerve chwannoma. REULT: The ix patient had iolated unilateral trochlear nerve paly. Duration of diplopia before diagnoi averaged 6 month. Magnetic reonance imaging demontrated circumcribed, enhancing leion along the citernal coure of the trochlear nerve, all meauring le than 5 mm in greatet dimenion. Five of the patient were een in follow-up, over period ranging from 11 to 26 month from initial preentation (mean, 15.6 month; tandard deviation, 6.0 month). All of thee patient remained table except one, who wa lightly wore at 15 month by clinical meaurement and magnetic reonance imaging. None of thee patient have developed additional ymptom or ign of cranial nerve or central nervou ytem involvement. CONCLUION: The differential diagnoi of an iolated unilateral fourth cranial nerve paly hould include an intrinic neoplam of the trochlear nerve. Magnetic reonance imaging i ueful, both for diagnoi and follow-up. Thee patient can remain table and may not require neurourgical intervention.