title: Epidemiology of CN IV Palsies.
abstract: OBJECTIVE
  To examine the etiologies of CN IV palsies based on age and aid the clinician in more effective work-up and treatment.
  
  
  METHODS
  Retrospective chart review of 124 patients presenting to Houston Eye Associates between 1968 and January 1999 with superior oblique palsies. Patients were divided into the following age groups: birth to 10 years, 11-20 years, 21-40 years, 41-60 years and over 60 years. Etiologies and treatment were then examined within each age group. Etiologies were categorized as congenital, traumatic, vascular, neoplastic, and idiopathic. Treatment was classified as observation, prisms alone, surgical repair, and surgical repair combined with prisms. Bilateral, unilateral, and masked bilateral palsies were included.
  
  
  RESULTS
  Nine of 13 bilateral palsies were due to trauma. The masked bilateral palsy was congenital. Between the ages of birth and 10 years 26 of 37 (70.1%) palsies were congenital. Between the ages of 21 and 40 years 17/35 (48.6%) were due to trauma. Within the remaining age groups 11-20 years, 41-60 years, and over 60 years, the most common etiology was idiopathic 7/13 (53.8%), 11/24 (45.8%), and 7/15 (46.7%) respectively. Surgery was the most common treatment option within all age groups with the exception of the over 60 group. In this age group, prisms alone was most common.
authors.forename: C A
authors.initials: CA
authors.lastname: Gunderson
authors.forename: M L
authors.initials: ML
authors.lastname: Mazow
authors.forename: C W
authors.initials: CW
authors.lastname: Avilla