Temporal correlates in brain death. EEG and clinical relationships to the respirator brain
J. E. Leestma, J. R. Hughes and E. R. Diamond
In a prospective study of 32 cases of brain death, gross and microscopic
pathological appearances of the CNS were statistically analyzed and
correlated with EEG and clinical findings. The diagnosis of a "respirator
brain" is best made grossly after fixation, using commonly known gross
pathological criteria. The microscopic changes are more unpredictable and
variable than the gross findings. Respirator brain changes that can be
relied on to confirm the clinical-EEG diagnosis of brain death generally
take about 12 hours to become manifest after electrocerebral silence (ECS)
and/or cerebral circulatory arrest, and are unaffected by the time interval
between termination of respiratory support and refrigeration of the body or
by delays in performance of the autopsy. Loss of brain-stem reflexes,
evidence of herniation, and deterioration of the EEG to ECS correlate
significantly with the development of a respirator brain in the
respirator-dependent, comatose patient.
