Persistent Vegetative State

Individuals in persistent and permanent vegetative states (both called PVS) are not dead, although philosophers still debate whether they are "people." Their brains still function at a very rudimentary level; they have sleep-wake cycles; and they normally can breathe without assistance. According to the American Academy of Neurology, about 10,000 to 25,000 PVS individuals exist in the United States at any one time. Approximately 50 percent of them have been in this state less than six months and 70 percent for less than a year.

People go into PVS after their brains suffer a lack of oxygen, a lack of sugar, or a similar event. Normally, the onset of a coma is the first stage. If they neither die nor awaken, they lapse into a "vegetative state." Usually, only young trauma victims awaken from this state; older or oxygen-deprived individuals, which is the more common situation, usually do not. After one month health practitioners call the condition a "persistent vegetative state." If their brain damage is the result of a non-traumatic event, adults and children rarely emerge from a persistent vegetative state after being in it for three months. If the damage results from trauma, children rarely recover after being in the state for one year; adults rarely emerge after six months in that state. At some indeterminate time later, the patient's condition transforms into an irreversible "permanent vegetative state."

Physicians with training and experience in PVS make the diagnosis on clinical grounds established by the American Academy of Neurology, which include:

  • • no awareness of themselves or their environment—an inability to interact with others;
  • • no reproducible, purposeful, or voluntary responses to visual, auditory, tactile, or noxious stimuli; and
  • • no ability to speak or to understand language; sleep-wake cycles with intermittent wakefulness without awareness; sufficiently preserved lower brain and brain stem functions to permit survival with medical and nursing care; bowel and bladder incontinence; variably preserved cranial nerve (pupillary, oculocephalic, corneal, vestibulo-ocular, gag) and spinal reflexes.

No diagnostic study can make the diagnosis with certainty. Except in the case of infants with anencephaly, reliable criteria do not exist for making a diagnosis of PVS in infants less than three months of age.

The American Academy of Neurology states that of the adults in a persistent vegetative state for three months after brain trauma, 35 percent will die within a year after the injury. Another 30 percent will go into a permanent vegetative state, 19 percent will recover with severe disabilities, and 16 percent will recover with a moderate or minimal disability. If they remain in a persistent vegetative state for six months, 32 percent will die, 52 percent will go on to a permanent vegetative state, 12 percent will recover with severe disabilities, and 4 percent will recover with moderate or minimal disability. Nontraumatic brain damage markedly decreases the chance of any recovery. After such patients have been in PVS three months, only 6 percent will recover with severe disabilities and 1 percent will recover with a moderate or minimal disability. After six months, no adults who remain in that state recover.

Children have a better chance of recovering from brain trauma than adults. Virtually all children in a persistent vegetative state from causes other than trauma go on to a permanent vegetative state rather than to death. Unlike adults, about 3 percent of these children recover, but always with severe disabilities.

Medical experts differ in opinion as to exactly how those in PVS should be classified. These individuals cannot interact with or experience their environment, feel pain, or communicate in any way—their thinking, feeling brain is gone. Their condition will not improve, but they can live with medical and nursing support for many decades.

See also: Cruzan, Nancy ; Do Not Resuscitate ; End-of-Life Issues ; Life Support System ; Quinlan, Karen Ann ; Resuscitation


American Academy of Neurology Quality Standards Sub-committee. "Practice Parameters: Assessment and Management of Patients in the Persistent Vegetative State." Neurology 45 (1995):1015–1018.

Iserson, Kenneth V. Death to Dust: What Happens to Dead Bodies?, 2nd edition. Tucson, AZ: Galen Press, 2001.

Iserson, Kenneth V. Grave Words: Notifying Survivors about Sudden, Unexpected Deaths. Tucson, AZ: Galen Press, 1999.


User Contributions:

I'd like to know how these statistics figured considering there is never any follow up of PVS patients. My sister has been PVS for 27 years, there isn't one physician interested in how she managed to stay alive this long or what her mental condition is today, so where does all this date on PVS come from?

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