Fig. 8.
Characterization of burst suppression. (A) The spectrogram in figure 6B from minutes 4 to 20. Burst suppression in the spectrogram shows as periods of blue (isoelectric activity) interspersed with periods of red-yellow (slow-delta and alpha oscillations). The horizontal red line shows the principal period of burst suppression. (B) Unprocessed electroencephalogram recordings corresponding to the spectrogram in A. The horizontal red lines at ±5 μV are the thresholds that separate burst events (amplitude ≥5 μV) from suppression events (amplitude < 5 μV). (C) The burst suppression probability provides an estimate of the instantaneous probability of the electroencephalogram being suppressed.98 Although it is apparent in the spectrogram and in the unprocessed electroencephalogram that the period of strong burst suppression extends from minutes 8 to 16, the burst suppression probability analysis shows that it does not completely subside until minute 17.