Opsoclonus-Ataxia Caused by Childhood Neuroblastoma: Developmental and Neurologic Sequelae

Abstract

Objective. Opsoclonus-ataxia, also called “dancing eye syndrome,” is a serious neurologic condition that is often a paraneoplastic manifestation of occult neuroblastoma in early childhood. Despite resection of tumor and immunosuppressive therapy, outcome generally includes significant developmental and behavioral sequelae. There is controversy about how treatment alters outcome. The goals of this study were to understand the ongoing neurologic and developmental deficits of children who are treated for opsoclonus-ataxia with associated neuroblastoma; to relate treatment history to outcome; and to quantify objectively the acute changes in motor function, speech, mood, and behavior related to intravenous immunoglobulin (IVIg) treatment. Methods. Patients were children with opsoclonus-ataxia caused by neuroblastoma, regardless of interval since diagnosis. Records were reviewed, and children underwent comprehensive evaluations, including neurologic examination and tests of cognitive and adaptive function, speech and language, and fine and gross motor abilities. Psychiatric interview and questionnaires were used to assess current and previous behavior. In 6 children, a videotaped standardized examination of eye movements was performed. Additional examinations were performed immediately before and 2 to 3 days after treatment with IVIg in 5 children. Results. Seventeen children, ages 1.75 to 12.62 years, were examined. All had a stage I or II neuroblastoma resected 3 months to 11 years previously. None received any other treatment for the tumor. All but 1 had received at least 1 year of either oral corticosteroids or corticotropin (ACTH); 12 had received 1 or more courses of IVIg, 2 g/kg. Three had received other immunosuppressive treatment, including cyclophosphamide. Cognitive development and adaptive behavior were delayed or abnormal in nearly all children. Expressive language was more impaired than receptive language. Speech was impaired, including both intelligibility and overall output. Fine and gross motor abilities were impaired. Increased age was strikingly associated with lower scores in all areas. Behavioral problems early in the course included severe irritability and inconsolability in all; later, oppositional behavior and sleep disorders were reported. Opsoclonus abated in all, but abnormalities in pursuit eye movements were found in all 6 children cooperative with standardized examination. Outcome did not differ in children who were treated with ACTH versus oral steroids. Three children who had received cyclophosphamide fared poorly. Immediate versus delayed treatment was not associated with better outcome. IVIg improved both gross and fine motor and speech function acutely, but we could not confirm long-term benefit of IVIg. Total number of courses of IVIg was not associated with outcome. Conclusions. Opsoclonus-ataxia caused by neuroblastoma causes substantial developmental sequelae that are not adequately prevented by current treatment. The increased deficits in older children raise concern that this represents a progressive encephalopathy rather than a time-limited single insult. Although the study is cross-sectional and neither randomized nor blinded, we were unable to confirm a purported advantage of either ACTH over corticosteroids or of cyclophosphamide. A randomized study is needed but is difficult for this rare condition.