Persistent vegetative state, sometimes abbreviated PVS, is a rare but serious type of coma. People in a coma usually lie with their eyes closed and cannot be aroused by shaking or other means. People in a persistent vegetative state may have their eyes open, but they are not awake. They cannot think, talk, see, hear, feel, eat, move voluntarily, or respond to other people. Physicians use the term vegetative state to describe a condition in which the body’s automatic functions—such as breathing and heartbeat—continue even though the person is unconscious. Physicians call a vegetative state “persistent” if it has lasted at least one month.
PVS is caused by damage to widespread areas of the cerebral cortex and thalamus. These brain structures govern awareness of the self and its surroundings. The damage can result from head injury, stroke, or a lack of oxygen due to drowning or cardiac arrest (heartbeat stoppage). Brain functions other than awareness often remain. For example, PVS patients usually undergo regular periods of wakefulness and sleep, despite remaining unconscious.
PVS patients require hospital treatment and long-term care in a nursing home. They can take food and water through a tube inserted into the stomach. Constant nursing care is needed to prevent infections and other complications. People who have been in a persistent vegetative state for a year or more rarely awaken and never fully recover. Family members and physicians try to understand how a PVS patient would wish to be treated. If recovery is unlikely, they may decide to discontinue treatment, allowing the patient to die.
