[Focal hypersynchronous activity in the EEG of children with specific developmental deficits: is there a clinical relevance?].

Focal hypersynchronous activity in children with specific developmental deficits: Are there any clinical implications? To determine the frequency of focal hypersynchronous activity (HSA) in the EEGs of a child and adolescent psychiatry client population we evaluated 762 patients between 3 and 15 years old. Children with neurological problems, including epilepsy, craniocerebral trauma and psychotic disorders, and children on medication were excluded, as well as those with general developmental delays or abnormal EEG findings (except focal HSA). We then compared our data with those of two epidemiological investigations, in which 1.9% and 2.4%, respectively, of the children without psychiatric problems were found to have focal HSA. The children in our study with dyslexia or disorders of motor function had significantly higher rates of HSA. The boys with psychiatric findings (except those with speech and language disorders) appeared to have a higher rate of HSA. These findings support the hypothesis that focal HSA is probably an expression of a cerebral dysfunction of genetic origin. The symptomatology seems to depend on the moment of manifestation and the localization.