The prevalence of neurologic dysfunction in children with strabismus who have superior oblique overaction.

Background: Children with certain neurologic diseases (hydrocephalus, meningomyelocele, or cerebral palsy) have been reported to manifest a high frequency of A-pattern strabismus and superior oblique overaction. However, it is not generally recognized whether children with strabismus who have superior oblique overaction are more likely to have concurrent neurologic diseases than those without superior oblique overaction. In this study, the authors examine this issue. Methods: The authors retrospectively reviewed the medical records of all patients (n = 168) with overdepression of the downturned eye in adduction, who were examined between October 1989 and March 1992. A randomly selected population of children with strabismus who did not have overdepression of the eye on infraduction and adduction served as controls (n = 98). Patients with simulating or confounding conditions such as pseudo-superior oblique overaction, inferior rectus skew deviation (alternating skew on lateral gaze), and restrictive or paralytic strabismus, and who were older than 20 years of age, were excluded. Results: One hundred twelve patients with true superior oblique overaction were analyzed. Of these 112 patients, 45 (40.2%) had concurrent neurologic abnormalities, compared with less than one fifth (17.3%) of control subjects (17 of 98) ( P ≤ 0.001). Conclusions: Children with strabismus who have superior oblique overaction were found to have higher prevalence of concurrent neurologic diseases than control subjects. Superior oblique overaction may represent a clinical marker for an associated neurologic dysfunction, possibly representing a form of skew deviation in some cases.