Is the computerized assessment of psychomotor speed more sensitive to cognitive effects of antiepileptic pharmacotherapy than tests with a focus on higher-order cognitive processing? Implications for the choice of sensitive test parameters

Abstract The study evaluated whether it is psychomotor speed or higher-order cognitive processing which is primarily affected by antiepileptic drug (AED) treatment in epilepsy and whether computerized testing versus paper-pencil testing of executive functions is more sensitive. In this retrospective observational study, 55 patients with epilepsy underwent NeuroCog FXⓇ, a computerized battery assessing “psychomotor speed/alertness” and “cognitive processing” via 8 tasks, and EpiTrackⓇ, a paper-pencil screening of “executive functions and working memory” based on 6 subtests. Test performance was related to the number of drugs and the Defined Daily Dose and the presence/absence of AEDs with known adverse psychotropic effects. EpiTrackⓇ performance correlated with "cognitive processing" of the NeuroCog FXⓇ but not with "psychomotor speed/alertness". Significant correlations with drug load were mainly yielded for EpiTrackⓇ (number of AEDs: r = –0.551, total DDD: r = –0.452) and "cognitive processing" (number of AEDs: r = -0.433, total DDD: r = –0.415). "Psychomotor speed/alertness" was less related to drug load (number of AEDs: r = -0.285, total DDD: r = –0.232). Statistical control for “psychomotor speed/alertness” hardly changed the correlations of EpiTrackⓇ or “cognitive processing” with drug load indices. AEDs with known adverse profiles negatively affected EpiTrackⓇ and the "cognitive processing" but not the “psychomotor speed/alertness” domain of the computerized test. The results demonstrate that it is less basal psychomotor speed than higher-order cognitive processing which is negatively affected by antiepileptic pharmacotherapy. The results question the value of (computer-)tests with a major emphasis on psychomotor speed and alertness for cognitive drug monitoring.