What is Coma, including Persistent Vegetative State?
A coma is a profound or deep state of unconsciousness. The affected individual is alive but is not able to react or respond to life around him/her. Coma may occur as an expected progression or complication of an underlying illness, or as a result of an event such as head trauma. A persistent vegetative state, which sometimes follows a coma, refers to a condition in which individuals have lost cognitive neurological function and awareness of the environment but retain noncognitive function and a perserved sleep-wake cycle. It is sometimes described as when a person is technically alive, but his/her brain is dead. However, that description is not completely accurate. In persistent vegetative state the individual loses the higher cerebral powers of the brain, but the functions of the brainstem, such as respiration (breathing) and circulation, remain relatively intact. Spontaneous movements may occur and the eyes may open in response to external stimuli, but the patient does not speak or o