[Electroencephalography and brainstem auditory evoked potential in brain death].
The usefulness of electrophysiologic examination in the diagnosis of brain death has been a controversy. This study was undertaken to examine the role of electroencephalography (EEG) and brainstem auditory evoked potential (BAEP) in the brain death diagnosis. From March to November 1986, EEG and BAEP were studied in 21 patients (14 males, 7 females; aged 26-73 years) fulfilling the diagnostic criteria of brain death proposed by a special committee organized by the Department of Health, R.O.C. All the EEG and BAEP were performed within 24 hours after the diagnosis of brain death. Of the 15 patients who underwent EEG test, isoelectric tracing (less than 2.5 microV) was found in 5 (33%), low-potential record (less than 5 V) in 3 (20%), and obvious residual activity in 7 (47%). Of the 20 patients who had BAEP examination, absence of all waveforms was noted in 11 (55%), and Wave-I only was preserved in 9 (45%; 6 unilateral, and 3 bilateral). Half of the preserved Wave-I were of prolonged latency (greater than 1.97 msec). Regardless of the EEG and BAEP findings, all of the 21 patients developed cardiac asystole within 77 hours after the diagnosis of brain death. During the study period, we observed 2 patients with absence of auditory evoked responses; both were deaf, but were not brain death victims. From this study, it is obvious that the EEG findings do not correlate well with the diagnosis of brain death. The reason is understandable since EEG is essentially a test of cortical function, while brain death can be diagnosed on the basis of irreversible loss of brainstem function.(ABSTRACT TRUNCATED AT 250 WORDS)
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D000328:Adult; D000368:Aged; D001926:Brain Death / Q000175:diagnosis*; D001933:Brain Stem / Q000503:physiopathology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis