The role of cognitive-motor function in precipitation and inhibition of epileptic seizures

To examine the effects of cognitive-motor function on EEG discharges and the neuropsychological mechanisms of seizure induction in patients sensitive to cognitive-motor tasks.

Four hundred eighty patients with epilepsies were subjected to cognitive tasking, termed "neuropsychological EEG activation (NPA)." It consisted of reading, speaking, writing, written calculation, mental calculation, and spatial construction. Furthermore, patients showing a provocative NPA effect were subjected to a detailed NPA protocol to identify the possible precipitating factors, which consisted of simple hand movements, action programming requiring hand movement, and thinking activity not requiring hand movement.

NPA had an inhibitory effect on EEG discharges in 133 (63.9%) of 208 patients with discharges in the awake EEG. Conversely, NAP had a provocative effect in 38 (7.9%) of 480 patients. In 32 of the 38 patients, the precipitating factor was action programming. Among them, five showed a precipitating factor restricted to linguistic activity, and the remaining 27 were affected by various action-programming factors including both linguistic and praxic activities. In four of 38 patients, the precipitating factor was thinking, predominantly linguistic tasks in one patient and spatial tasks in three patients. No patient had a precipitating factor identified as motor activity.

These results suggest that cognitive-motor function has an inhibitory effect on EEG discharges in the majority of epilepsy patients and a provocative effect in some patients, and that seizures of the patients showing a provocative NPA effect are precipitated by action programming or thinking activity.