title: Bilateral trochlear nerve paresis in hydrocephalus.
abstract: Three patients with nonneoplastic hydrocephalus had bilateral paresis of the trochlear nerves. Associated signs, including paresis of upgaze, light-near dissociation of the pupils, and convergence-retraction nystagmus, suggested rostral involvement of the mesencephalon. Trochlear nerve paresis and accompanying signs improved after revision of ventricular shunts in two patients. Bilateral trochlear nerve paresis may be a localizing sign of involvement of the superior medullary velum (the anatomic site of trochlear nerve decussation) by a dilated sylvian aqueduct and/or downward pressure from an enlarged III ventricle.
authors.affiliation: Department of Ophthalmology, University of Florida, College of Medicine, Gainesville 32610.
authors.forename: J R
authors.initials: JR
authors.lastname: Guy
authors.forename: W F
authors.initials: WF
authors.lastname: Friedman
authors.forename: J P
authors.initials: JP
authors.lastname: Mickle
mesh_terms: D000293:Adolescent; D000328:Adult; D003389:Cranial Nerve Diseases / Q000150:complications* / Q000473:pathology; D005133:Eye Movements; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000150:complications*; D008297:Male; D010291:Paresis / Q000150:complications* / Q000473:pathology; D010536:Peritoneovenous Shunt; D014057:Tomography, X-Ray Computed; D014321:Trochlear Nerve / Q000473:pathology / Q000601:surgery; D014792:Visual Acuity