Abstracts

Rationale: To analyze effects of interictal epileptic activity (IEA) on reactivity with various tests including a realistic driving simulator in adolescent epilepsy patients. Methods: Eighteen 14 to 17-years-old epilepsy patients performed a single flash test, car driving test on a laptop, or drove in a realistic simulator while electroencephalography (EEG) was simultaneously recorded. Reaction times (RT) in the flash and car tests, and RT and breaking distances in the simulator were registred in response to visual stimuli during IEA in IEA-burst triggered fashion and compared to RTs obtained in normal EEG within the same individual session. As breaking distances are dependent on initial speed and patients drove the simulator at variable velocities, breaking distances were mathematically speed-adjusted. Results: In the simulator, IEA prolonged RT on average by 145ms (p=0.002) and breaking distance, set to an initial speed of 100km/h, by 4.0m (p=0.002; Figure 1: normal, RT during normal EEG; pathological, RT during IEA). If speed-adjusted to 45km/h, the maximal speed of a moped, calculated mean breaking distance was 1.8m (p=0.002). Mean IEA-associated RT prolongations were 71ms (p=0.008) in the car and 98ms (p < 0.001) in the flash test. RT prolongation did not differ among the 3 tests (p=0.064), indicating similar sensitivity to detect IEA effects. Conclusions: IEA prolonged RT in adolescents with epilepsy in 3 tests of different complexity. The tests mutually validated IEA-associated RT prolongations. Calculated breaking distance prolongations may indicate IEA relevance beyond a driving simulator context. Funding: No extra funds were used in this study.