Figure 8.

Severe CNS depression produces increased amplitude in the delta band (<4 Hz) and very reduced activity in the other frequencies. (a) This patient with extremely toxic levels of ethyl alcohol was completely unresponsive on total life support, including mechanical ventilation. (b) The EEG tracing of a patient with certified brain death, established by EEG and clinical criteria. The activity line shifts to the right from electrical activity of the heart picked up by the monitor in the absence of brain electrical activity.