Altered information processing in children with focal epilepsies with and without intellectual disability

The aim of this exploratory study was to investigate the relationship between focal interictal epileptiform discharges (IEDs), intellectual disability and cortical information processing in children with partial epilepsy. Two groups of patients--Group 1 (n = 9 patients) with focal IEDs and normal IQ and Group 2 (n = 10 patients) with focal IEDs and intellectual disability--were compared with 14 healthy control participants. A computerized choice reaction time task (go/no-go paradigm) was performed and event-related potentials (ERPs) were recorded. When an IED occurred during the period between the presentation of the stimulus and the response, the response was defined as a response with IED. Omission errors, commission errors and reaction time were evaluated in temporal relationship to IEDs. The Group 1 patients did not differ from the healthy children in neurophysiological functions and ERP amplitudes. The Group 2 children showed inferior Altered information processing in children with focal epilepsies with and without intellectual disability performances in verbal learning and memory, cognitive flexibility and selective attention, and were characterized by low ERP amplitudes compared with the epilepsy patients with normal IQ and the healthy children. We were not able to identify any significant relationship between IEDs and cognitive functions in either group of patients. Our findings suggest that the impact of IEDs on the overall intellectual abilities of epilepsy patients may not be as significant as previously thought. Moreover, it is likely that abnormalities in cognitive information processing as revealed by lower ERP amplitudes, occurrence of IEDs, and intellectual disabilities may represent common abnormal processes and may not be causally related to each other.