Surface mapping of spike potential fields: visual vs. quantitative EEG analysis.

Interictal EEG spike field potentials by visual and quantitative EEG analysis were studied in 17 patients with intractable localization related epilepsy. Quantitative EEG analysis was done using commercially available window based computer program (Focus) that displayed digitally acquired EEG data and performed spline mapping. Routine EEG localized 20 spikes. Fourteen spikes had excellent congruence between manual and computer generated mapping, 6 had good congruence, and 1 had fair congruence. This study clearly proves the usefulness of spline interpolation mapping technique in localizing and characterizing the epileptiform focus.