Electrophysiological evidence of cerebral dysfunction in childhood opsoclonus-myoclonus syndrome.

To address cerebral involvement in childhood opsoclonus-myoclonus syndrome (OMS), electrophysiological investigations including electroencephalograms and evoked potentials were performed in three children affected by nonparaneoplastic OMS. Most patients displayed abnormalities in visual- and somatosensory-evoked potentials, consisting of delayed latency or disorganization of cortical components. Symptoms of OMS have been attributed primarily to an abnormality in the cerebellum and its associated pathway. This theory was consistent with cerebellar lesions detected by neuroimaging. Electrophysiological evidence of cerebral dysfunction observed in this study, however, implies additional involvement of the cerebral cortex, which may contribute to the accompanying psychiatric and cognitive disorders.