Brainstem death is a medical condition that refers to a complete and irreversible loss of brainstem function. Some common synonyms for brainstem death include brain death, total brain failure, irreversible coma, and vegetative state. In most cases, brainstem death is diagnosed as a result of severe trauma to the brain or a lack of oxygen to the brain. While the condition is irreversible, the patient's body may still be kept alive by artificial support such as mechanical ventilation. It is important to note that brainstem death is different from a coma or persistent vegetative state, as those conditions involve some level of brain function even if it is limited.