What EEG changes are associated with brain death?

The presence of brain death is determined by a complete and irreversible loss of all cerebral and brainstem functions. The EEG changes associated with this condition reflect the total lack of electrical activity in the brain. Specifically, when brain death occurs, the EEG shows a flatline, indicating an absence of any brain wave activity. This absence of electrical activity is a critical finding in diagnosing brain death.

In contrast, other EEG changes like periodic lateralized epileptiform discharges, intermittent slowing, and asymmetrical theta waves may indicate underlying neurological conditions or states of dysfunction, but they do not signify total and irreversible loss of brain function. For example, periodic lateralized epileptiform discharges may suggest focal brain activity often seen in epilepsy, while intermittent slowing and asymmetrical theta waves can indicate various degrees of cerebral dysfunction or encephalopathy but do not equate to brain death.