Improvement of neurological status and quality of life in children with opsoclonus myoclonus syndrome at long-term follow-up.

Background: Kinsbourne syndrome or opsoclonus myoclonus syndrome (OMS) is characterized by rapid, involuntary, irregular conjugate eye movements (opsoclonus), myoclonic jerking of the limbs and trunk, ataxia, and behavioral disturbances. In general, the outcome of neurologic and behavioral symptoms is poor. Studies on quality of life (Qol) and recovery after very long-term follow-up of children with OMS are lacking.
Methods: We studied long-term cancer survival, neurologic recovery, and Qol of a consecutive series of eight patients with OMS that were treated in our center. Two cross-sectional follow-up evaluations were conducted at a 3-year interval (T1 and T2).
Results: In four out of eight children with OMS a neuroblastoma (NBL) was diagnosed and surgically removed completely. All children received immuno-modulatory therapy, consisting of prednisone (three children), prednisone and ACTH (four children), or prednisone, ACTH, and gammaglobulin (one child). At T1, median follow-up time was 9.5 years (range 3-14 years) after OMS onset and at T2, 11.6 years (range 6-17 years). Neurologic functioning improved in all children, reflected by a significant improvement of the mean Z-score in the motor domain of the Qol questionnaire at T2 as compared to T1. In contrast, seven children continued to have a severe developmental delay at T2. No significant difference in any of the variables was found between NBL survivors and OMS patients without NBL.
Conclusion: Cognitive and behavioral impairments and not a motor impairment, such as ataxia, appear to be predominant at long-term in children with OMS.