Cognitive impairment and event-related potentials in paediatric multiple sclerosis: 2-year study.

Approximately, 3-10% of patients with multiple sclerosis (MS) present a disease onset before the age of 18 years. Although growing attention is dedicated to cognitive impairment and its functional consequences in paediatric MS, so far no study has explored possible neurophysiologic correlates. The study's aim was to describe event-related potentials in relationship with cognitive performance in children and adolescents with MS compared with demographically matched healthy controls (HC), providing two-year follow-up data. Six MS subjects aged between 9 and 17 years were assessed through an extensive neuropsychological battery at two time points. Event-related potentials with an odd-ball acoustic paradigm were also recorded in the patients and in nine HC. At baseline, four out of six patients failed three or more cognitive tasks and were classified as cognitively impaired. In all the cognitively impaired patients, we found abnormal latencies and amplitudes of the P300. After 2 years, five patients exhibited a deteriorating cognitive performance and a corresponding deterioration of the P300 parameters. In our group of children and adolescents with MS, changes in P300 parameters proceeded in parallel with deteriorating cognitive performance. P300 might represent an objective parameter to monitor cognitive changes in paediatric MS.