Evaluation of long term cognitive risks associated with the presence of seizure during acute disseminated encephalomyelitis

A small percentage of paediatric acute disseminated encephalomyelitis (ADEM) presents with seizures. The association of epileptic activity with demyelination could represent an increased risk for long-lasting cognitive sequelae; however, this risk has not yet been explored in the literature. Objective of this study was to compare long-term neuropsychological outcomes among children and adolescents with history of ADEM with or without seizures. A neuropsychological evaluation (explored areas: general intelligence, language, attention, memory, visuo-motor skills and executive functions) was administered to 20 children and adolescents with history of ADEM (12 boys; mean age at ADEM onset 6.5 years (DS 4.23), mean age at follow-up 13.8 years (DS 5.65) and mean length of follow-up 6.8 years (DS 3.7). Multichannel-EEG recordings during hospitalization for ADEM were evaluated by a neurophysiologist trained in the identification of epileptic activity. 4/20 patients had EEG confirmed seizures. Neuropsychological scores of patients with and without seizures were compared using the Mann–Whitney test. No significant differences were found among children with and without seizures, in none of the cognitive domains explored. In conclusion, the presence of seizures during ADEM does not appear to represent a risk factor for developing long-term cognitive impairment.