Event-related potentials in complex partial seizures.

Both early (N1 and P2) and late (N2 and P3) event-related potentials (ERP) were obtained in 16 patients with complex partial seizures, 12 with left hemispheric ictal focus and 4 with right, to see if they help in lateralizing the seizure focus, and also to determine if they correlate with behavioral (MMPI, Bear-Fedio), attentional (Trails A and B), cognitive (WAIS-R, Boston Naming, Warrington Word and Face recognition) and mental speed (Stroop color naming and reading) tasks. Early waves were more often lateralized than late waves but both were often falsely lateralizing. Early waves were better correlated with behavioral tasks whereas late waves were better with those measuring mental speed, attention and cognition. These data tentatively discourage the utility of ERP in preoperative lateralization of seizure focus but argue for their potential value in psychophysiological correlations.