Comorbidity of DCD and SLI: Significance of epileptiform activity during sleep.

BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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'.