[Cranial muscle activity in dissociated brain death]

The origin of spontaneous myogenic activity during the registration of isoelectric EEGs for documentation of total brain death has not yet been explained. In nine patients with total brain death, completely abolished acoustic evoked brainstem potentials (AEP), somatosensory evoked potentials (SEP) as well as electrically evoked blink-reflexes (BR) were demonstrated. The peripheral conduction capacity of the facial nerve, however, was never impaired. These findings suggest that peripheral nerve function may be well preserved although brain stem activity is completely abolished and therefore support the thesis that the myogenic activity in cranial muscles in total brain death is not mediated by the brain stem but is of extracerebral origin.