The findings of auditory and somatosensory evoked potentials in brain death confirmed by the apnea test

The findings of AEP and SEP in the cases with brain death confirmed by the apnea test had not been reported. We studied the features and the characteristic changes of those evoked potentials in 7 cases of brain death. The etiology of brain death in those cases were the primary intracranial lesions in six and the brain ischemia secondary to cardiac arrest in the others. The apnea test and the recordings of AEP and SEP were performed in the same day in most cases. The mean intervals from the application of the respirator to the apnea test and to cardiac arrest were 5.8 +/- 7.1 days and 5.9 +/- 7.2 days, respectively. Cardiac arrest occurred with mean of 11.8 +/- 8.0 days after the application of the respirator. AEP showed absent responses in six cases (86%) and wave I only in the other (14%). SEP showed P 1-N 1 in four cases (57%) and no responses in three (43%). The components of AEP were disturbed earlier than those of SEP and cases were classified into three types according to those findings. Type I (one case, 13%): wave I only in AEP and P 1-N 1 in SEP. Type II (three cases, 28%): no wave in AEP and P 1-N 1 in SEP. Type III (three cases, 28%): no wave in AEP and SEP.(ABSTRACT TRUNCATED AT 250 WORDS)