Irreversible comae, or a state of unconsciousness from which the brain cannot recover, can also be referred to as a persistent vegetative state or a permanent coma. Other synonyms for the term include brain death, irreversible unconsciousness, and the term persistent or permanent coma. Medical professionals may also use the term locked-in syndrome to describe a state in which the body is paralyzed but the individual is conscious and able to think. Regardless of the terminology used, irreversible comae represent a serious medical condition, and treatment and prognosis depend on individual factors and the extent of damage to the brain.