Brain death and the persistent vegetative state: similarities and contrasts.

Abstract

Brain death and the persistent vegetative state (PVS) share the following features: 1.) There is death of neurons in the brain; 2.) Both require an etiology which is capable of causing neuronal death. 3.) The potential for cognition is totally and permanently lost; 4.) Intensive medical support is usually withdrawn. In contrast, the diagnosis of brain death depends on death of the brainstem, while PVS implies permanent and total loss of forebrain function. While brainstem death can be diagnosed clinically, accurate prognosis in PVS requires additional investigation. Thus far, the EEG is the most specific test of neuronal function in the cerebral cortex. Brain death is equivalent to death, while PVS is not; management of the latter is more complex because of medical, social, ethical and legal factors.