Long-Term Follow-Up of Neuroblastoma-Associated Opsoclonus-Myoclonus-Ataxia Syndrome

Abstract

The aim of this study is to describe the long-term neurological, neuropsychological and neuroradiological sequelae and to determine prognostic factors for neurological outcome in children with neuroblastoma-associated opsoclonus-myoclonus-ataxia (OMA) syndrome. Data on medical history were collected for the study patients. Examinations with grading of neurological signs, neuropsychological tests and brain magnetic resonance imaging with spectroscopy were performed during a follow-up clinic. Fourteen subjects entered the study. All had localized neuroblastoma and they were evaluated after a median of 7.8 years. Patients with a chronic/multiphasic neurological course received steroids combined with intravenous immunoglobulins in the majority of cases. 71% presented neurological sequelae and 62% had a full-scale IQ below the normal range. All patients showed at least some deficit in the neuropsychological functions assessed (language, visual-motor integration, memory, attention and motor ability). Long-term deficits were more frequently detected in patients with an interval of more than 2 months between OMA onset and its diagnosis, even if in most comparisons statistical significance was not reached. Cerebellar atrophy, observed in 36% of patients, was not associated with the neurological outcome. Persisting disability is present in most children with neuroblastoma-associated OMA. However, our results support the role of an early diagnosis of OMA in reducing sequelae and encourage the use of new immunosuppressive therapies.