ABSTRACT
The interaction between lateralization of subclinical epileptiform discharges and cognitive tasks was investigated in 21 children (12 girls and 9 boys, mean age 10.6 years). Seventeen had a diagnosis of epilepsy (partial or secondarily generalized). Testing was by reading, arithmetic, and intelligence subtests during continuous telemetric EEG and video monitoring. Children with left-sided discharges had significantly lower reading performance than children with right-sided discharges. During reading, epileptiform discharges occurred relatively less frequently and with a shorter total duration over the left hemisphere than the right. This supports the view that cognitive tasks suppress epileptiform discharges when they activate a region of the brain within the epileptogenic zone. Discharges from other epileptogenic zones not directly activated by the tasks are increased, however.
