The cognitive effects of interictal epileptiform EEG discharges and short nonconvulsive epileptic seizures Epilepsia, 05/24/2012

Nicolai J et al. – The authors concluded that although the effect is less pronounced in number of areas involved and magnitude, the type of association between frequent epileptiform activity (>1% of the time) and cognitive function in children with epilepsy is comparable to the association between short nonconvulsive seizures and cognitive function.

• A cross–sectional study of 188 children with epilepsy.
• Electroencephalography (EEG)–video recordings and cognitive testing were performed simultaneously.
• The results of children with short nonconvulsive seizures during a 2–h testing session were compared with all children with epilepsy without seizures during the 2–h cognitive testing session and with controls without epilepsy.
• In a second analysis the cognitive effects of frequency of epileptiform EEG discharges were analyzed.

• The cognitive effects of short nonconvulsive seizures were large, ranging from 0.5 to 1 standard deviation and concerned global cognitive function, speed of central information processing, and memory function.
• In children without seizures during cognitive testing, the occurrence of frequent epileptiform discharges showed more subtle effects.
• These effects were independent from the occurrence of short nonconvulsive seizures.