Comorbidity of DCD and SLI: significance of epileptiform activity during sleep

Abstract

In children affected by specific language impairment (SLI), many authors have investigated a link between language and epileptiform discharges during sleep resembling the focal sharp waves typical of benign epilepsy with centro-temporal spikes (BECTS), the so-called rolandic spikes. On the other hand, the same electroencephalographic trait occurs in more than 50% of children affected by learning or behavioural disabilities without seizures, supporting the hypothesis of a common genetic disposition. The biological background of Developmental Coordination Disorder (DCD) is currently unknown, but a genetic liability may be assumed. The aims of our study were first to estimate the prevalence of sleep-related epileptiform discharges in children affected by DCD and second to investigate the occurrence of DCD in a population of children affected by BECTS. We selected a group of eight children with severe DCD. In this group, the presence of epileptiform activity was investigated. We also searched for DCD among a group of 13 children affected by BECTS. We found rolandic spikes in more than 70% of the children with severe DCD and severe DCD in more than 30% of the children with BECTS. In children with severe DCD other disabilities are frequently associated. In these children, epileptiform activity during sleep is very frequently found and in our opinion, this represents a hallmark of 'Hereditary Impairment of Brain Maturation', a term only partially resembling 'Atypical Brain Development'.