EEG may be used as an ancillary test to confirm clinical brain death. Specifications for determining electrocerebral silence (ECS, or electrophysiological brain death) by the American EEG Society (more recently confirmed and updated by the American Clinical Neurophysiology Society in 2006) require the following conditions: the patient should be warmed to a temperature greater than 32°C; no confounding sedative/hypnotic or anesthetic medications should be present; a qualified technologist should conduct the recording; the recording should be performed with at least 16-channel recording; integrity of the recording system should be manually tested by the technologist during the recording; there should be no reactivity of the patient to any somatosensory, auditory, or visual stimulus; the electrode impedances should be maintained between 10 Ω and 10 kΩ; the recording should utilize long (i.e., 10 cm minimum) interelectrode distances (to maximize the opportunity of recording highly suppressed true cerebral activity); other polygraphic variables (ECG, respiration, “dummy patient” for noise monitoring) should be monitored as needed; recording should be in bandwidth from 1 to 30 Hz low/high frequency filter settings; and higher sensitivity settings of at least 2 uV/mm should be used to ensure there is no cerebral activity present for at least 30 minutes in duration. If there is doubt, a repeat study should be performed (38).
Electrocerebral silence (brain death). Note the prominent cardiac cycle artifact, especially in O1, with the absence of any discernible cerebral activity.
