Effect of Increased Immunosuppression on Developmental Outcome of Opsoclonus Myoclonus Syndrome (OMS)

Opsoclonus myoclonus syndrome (OMS) produces long-term cognitive, behavioral, and motor deficits. Objective was to see if more aggressive treatment improved outcome. Assessment included opsoclonus myoclonus syndrome rating, developmental/cognitive and motor assessment, and adaptive behavior. Fourteen subjects completed testing. Nine had neuroblastoma. Onset was at 10 to 35 months; onset to diagnosis: 2 days to 14 months, and onset to first treatment: 5 days to 15 months. Initial treatment was corticotropin (12), oral steroids (3), plus intravenous immunoglobulin in all. Ten received rituximab, 5 cyclophosphamide. Age at testing ranged from 2.5 to 10.3 years. Adaptive Behavior Score (11 subjects), mean 93.5; estimated Intelligence Quotient/Developmental Quotient mean 93.5; Motor: mean 92.8. Residual opsoclonus myoclonus syndrome symptoms at the time of the evaluation were generally minor; opsoclonus myoclonus syndrome scores ranged from 0 to 6. Comparison to previously reported opsoclonus myoclonus syndrome subjects showed improved outcomes: Adaptive behavior, cognitive and motor scores were significantly higher (P < .001) in new subjects. Outcomes have improved with more aggressive immunosuppression, with most opsoclonus myoclonus syndrome survivors now functioning at or near normal.