6. The significance of evoked potentials in confirmation of brain death

Abstract

Most countries adopt the definition which equals brain death to irreversible cessation of all its functions. In that respect, the final diagnosis of brain death requires a reliable proof that brain as a whole had ceased to function. Present clinical trials revealed that clinical tests are insufficient to confirm the brain death and the application of diagnostic methods is necessary as anticipated by the Regulations of Republic of Serbia from 2005. In different countries of the world there are significant differences in their application, ranging from total rejection to obligatory application. Today, neurophysiological methods are in use as well as methods for assessment of the cerebral flow. The purpose of their application is the reduction of waiting time from several days to 6 h, thus confirming brain death quickly and reliably except in cases of unfavorable conditions (hypothermia, metabolic disorders, intoxications). Methods: In the 10 year period, in Neurology Clinic in Nis we applied auditory evoked potentials (AEP), somatosensory evoked potentials of nervus medianus (Median SEP) and electroencephalography in order to confirm brain death in 74 patients. Results: In 10 out of 74 patients (11.90%), EEG showed certain electrocortical activity, which excludes brain death. AEP revealed only I, III and V wave in 3 out of 54 patients (3.57%), while median SEP in 5 out of 84 patients (5.95%) revealed wave N18 and N13. Our results show the advantage of AEP and median SEP compared to EEG in confirming brain death. Conclusion: In order to confirm brain death, apart from clinical criteria, the application of AEP, median SEP and EEG is also necessary.