Pediatric third, fourth, and ixth nerve palie: a population-baed tudy Original Reearch Article

Purpoe: To determine the population-baed incidence and caue of cranial nerve palie affecting ocular motility in children in the circumcribed population of Olmted County, Minneota. MethodM: The Rocheter Epidemiology Project medical record linkage ytem capture virtually all medical care provided to Olmted County reident. By mean of thi databae, all cae of third, fourth, and ixth cranial nerve paly were identified among county reident le than 18 year of age from 1978 through 1992. Medical record were reviewed to confirm the diagnoi, determine the caue, and document county reidency. Incidence rate were adjuted to the age and ex ditribution of the 1990 white population in the United tate. Reult: Over thi 15-year period, 36 incidence cae of cranial nerve paly were identified in 35 children in thi defined population. The age-adjuted and ex- adjuted annual incidence of third, fourth, and ixth nerve palie combined wa 7.6 per 100,000 (95% confidence interval, 5.1 to 10.1). The mot commonly affected nerve wa the fourth (36%), followed by the ixth (33%), the third (22%), and multiple nerve palie (9%). The mot common caue wa congenital for third and fourth nerve paly, undetermined for ixth, and trauma for multiple nerve palie. Although three cae were aociated with neoplaia, a cranial nerve paly wa not preent at the time of diagnoi in any cae. Concluion: Unlike many intitutionally baed referral erie, our population-baed tudy provide data on the incidence and caue of third, fourth, and ixth nerve palie in a geographically defined population. In contrat to previou intitutionally baed erie, nearly half the cae were congenital in origin, and in no cae did intracranial neoplaia preent a an iolated nerve paly.