Long-term outcome of 10 patients with opsoclonus-myoclonus syndrome

Objective: Retrospective studies of long-term follow-up of opsoclonus-myoclonus syndrome (OMS) have been published, mostly of patients with associated neuroblastoma. OMS is more often not associated with neuroblastoma. We were especially interested in the cognitive outcome of our patients.

Methods: We reviewed the records and reassessed the patients clinically.

Results: Between 1987 and 2002 10 patients (8 girls, 2 boys) with OMS were seen. In one patient a ganglioneuroma was found, in one a neuroblastoma. Removal of the tumor did not influence the OMS. The age at diagnosis was 10–24 months, the follow-up period was 1–15 years (average 6.4 years). Nine patients were unable to sit during the acute stage. The interval between first symptoms and start of therapy was 2–12 weeks. At follow-up 4 patients have mild, one marked ataxia. IQ testing was possible in 7. IQ scores were between 40 and 80 in 4. Attention deficit and visuomotor difficulties led to school problems with special needs also in those 3 children with normal IQ. Only 2 children attend regular school. Behavior problems were prominent in 5, speech difficulties present in 7.

Conclusion: The long-term outcome of OMS is dominated by cognitive and neuropsycological problems. The ataxia is getting better and is not relevant in every day life. Larger studies and uniform treatment protocols are needed to see if prolonged immunosupressant therapy has a favourable influence on outcome.

Keywords: opsoclonus-myoclonus syndrome, long-term follow-up