BRAIN-STEM AUDITORY-EVOKED POTENTIAL MONITORING - VARIATIONS OF STIMULUS ARTIFACT IN BRAIN-DEATH

Brain-stem auditory evoked potentials (BAEPs) were recorded in 20 subj ects with brain death (mean age, 33.2 +/- 15.1 years) and 20 healthy v olunteers (mean age, 29.8 +/- 6.8 years). Brain death was due to head injury (n = 14), encephalitis (n = 3), brain-stem hemorrhage (n = 1), cerebellar hemorrhage (n = 1) or cerebral infarction (n = 1). The pres ence, latency and amplitude of the individual BAEP components and vari ations of the stimulus artifact were evaluated. The mean (+/- S.D.) am plitude of the stimulus artifact was 0.26 +/- 0.12 mu V in the brain-d ead subjects and 0.09 +/- 0.05 mu V in the control group (P < 0.001, t test). The causes of the phenomenon of increasing stimulus artifacts in the evolution of brain death remain unclear.