Thirteen male and six female subjects, all experienced drivers despite a firm diagnosis of either idiopathic generalized or cryptogenic localization-related epilepsy were investigated with continuous EEG registration during driving in the city, on the highway and resting. In the majority of patients (79%) a significant decrease in the amount of generalized and focal epileptiform EEG discharges was found while driving in the city as compared to resting. Waiting for a traffic light, however, temporarily increased the amount of spontaneous epileptiform discharges. No relation was found between type of epileptic seizures, years of seizure freedom and driving ability. Also the number of subclinical discharges during driving per sé appeared to be of no relevance for general driving skills. Nevertheless, it is of importance to detect the minority (10%) of patients who will have an increase in spontaneous epileptiform discharges during a higher mental arousal state and consequently a higher risk of getting seizures in that situation. The increase or decrease of epileptiform EEG discharges during performance of a short-term memory test in the EEG-laboratory compared to resting proved to be a reliable predictor of this effect.
Samenvatting