Oculographic and clinical characterization of thirty-seven children with anomalous head postures, nystagmus, and strabismus: The basis of a clinical algorithm

Background and Purpose: We studied children with nystagmus who also had ano malous head postures and strabismus to determine the etiology of the condit ions and present a diagnostic clinical algorithm. Methods: The patients for this study were among the 560 patients evaluated in the ocular motor neuro physiology laboratory between the years 1991 and 1997, Clinical characteris tics, infrared oculography data, and medical and surgical treatments were e ntered into a database for analysis. Oculography was performed on all patie nts according to a standard protocol, and data were stored and analyzed off -line. Etiology of anomalous head posture was determined with both clinical and oculography information. Results: Thirty-seven children are the subjec ts of this report. The etiology of anomalous head posture was a "gaze null" due to congenital nystagmus in 23 (62%) patients, an "adduction null" due to manifest latent nystagmus in 12 (32%) patients, spasmus nutans in 1 (3%) patient, and strabismus in 1 (3%) patient. The patients' ages ranged from 9 months to 12 years and averaged 4.4 years. Sixty-nine percent were male p atients. Nineteen (63%) of 30 patients had abnormal recognition (linear opt otype) acuity in at least 1 eye on monocular cover; the recognition remaine d abnormal in 5 (17%) of 30 patients under binocular conditions. Thirty per cent of patients had amblyopia, 16% had some structural disease of the eyes , 22% had some systemic syndrome or abnormality, 57% had a significant refr active error, and 27% had some ability to fuse. Conclusions: The major etio logy for anomalous head posture in these patients was to adopt a gaze null due to congenital nystagmus (62% of patients) regardless of the direction o f their anomalous head posture or type of strabismus. Moving the fixing eye as the first step for the anomalous head posture, combined with moving the nonfixing eye for the resulting strabismus may help treat these patients.