AUDITORY AND VESTIBULAR PATHOLOGY IN BRAIN-STEM DEATH REVEALED BY AUDITORY BRAIN-STEM RESPONSE

Auditory brainstem response (ABR) before and after the cessation of brainstem activity and postmortem histological findings in the temporal bone and auditory and vestibular pathways of two cases of brainstem death are reported. A brainstem death state of at least 48 h in Case 1 and of at least 24 h for the left side and several hours for the right side in Case 2 was demonstrated by neurological examination, flat EEG, and persistent absence of ABR. Postmortem examination was performed 3 h after death in Case 1, and 1 h after death in Case 2. Pathological studies of the entire length of the auditory and vestibular pathway revealed total autolysis of the organ of Corti and vestibular endorgans and swollen cochleal and vestibular ganglia in Case 1, and, in Case 2, on the right side, preservation of the organ of Corti and vestibular endorgans and mildly swollen cochlear and vestibular ganglia, but on the left side, destruction of the organ of Corti and vestibular endorgan and markedly swollen cochlear and vestibular ganglia. We believe that distinct pathological changes in auditory and vestibular endorgans, and other changes of the cochlear and vestibular ganglia as observed in these two cases, may develop if the duration of absent ABR is prolonged.