The influence of subclinical epileptiform EEG discharges on driving behaviour.

EEG and driving behaviour were monitored in 6 patients with subclinical focal and generalised epileptiform EEG discharges during 420 km of actual motorway driving in a suitably instrumented vehicle. Evidence of impaired driving performance during subclinical discharges was significant in 3 subjects (P less than 0.025 or less than 0.05) and was suggestive (P less than 0.1) in 1. The two patients with greatest impairment had active epilepsy, whereas the others had been seizure-free for upwards of 4 years. No other features appeared to be predictive of altered driving behaviour during discharges.