A comparison of visual and computer-generated measures of "seizure quality"

We report on the first direct comparison of measures of seizure quality generated by visual rating of electroencephalographic (EEG) regularity and postictal suppression with THYMATRON-DGx computer-generated indices of seizure energy and postictal suppression. Thirty-two consecutive patients referred for electroconvulsive therapy (166 consecutive treatments) were studied. Blinded ratings of seizure duration, regularity, and postictal EEG amplitude suppression derived from the paper EEG were compared against computer-rated measures of seizure duration, seizure energy index, mean ictal amplitude, and postictal suppression. Our results confirm previous findings of high correlations between computer and visual determinations of seizure duration. Significant differences were found for computer-derived postictal suppression, seizure energy index and mean ictal amplitude for different levels of the visual rating scales. Our results provide preliminary support for the concurrent validity of these measures.