How Persistent Vegetative State is different to a coma

Last updated at 19:21 07 September 2006


Being in a Persistent Vegetative State is different to coma or brain death.

A coma is defined as a deep state of unconsciousness in which the person is alive but totally unable to react to their environment.

In some patients, as in this case, they come out of the coma, but do not fully awaken.

Instead they enter a vegetative state in which they are still unconscious but they have a degree of 'wakefulness.'

Unlike people in a coma they will often open their eyes and can appear to follow set patterns of sleeping and being awake.

They can sometimes also swallow, smile, shed tears, moan or scream - however do not do so in reaction to external stimulus.

This can be extremely distressing for their families. If the state lasts for longer than 30 days it is judged to be a persistent vegetative state (PVS).

The outlook for patients varies widely depending on the cause and severity of the brain damage that has occurred.

Some patients die, some recover well and others remain locked in the state with little change.

Generally the longer a person is a vegetative condition, the worse their chances of recovery and the more likely they are to suffer long-term disabilities even if they do fully awaken.

Diagnosis of PVS is notoriously difficult.

A 1996 study of 40 patients in one UK ward, which was published in the British Medical Journal, found that 43 per cent of those classed as PVS had in fact been misdiagnosed.

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