Sleeping pill rouses people in a permanent vegetative state

May 25 2006

South African researchers have found that a drug commonly used as a sleeping pill can temporarily revive people in a permanent vegetative state to the point where they can have conversations.

The drug Zolpidem which is commonly used to treat insomnia has this effect within 20 minutes but wears off after four hours and the patients return to their permanent vegetative state.

The drug was used with three patients all men around 30 who had suffered brain damage in car accidents.

One had been in a vegetative state for three years and showed no reaction to touch and no response to his family, but after he was given the drug, he was able to talk to them.

Another was also able to interact with family, answer simple questions and catch a baseball.

The third who constantly uttered random screams, after he was given the drug, the screaming stopped and he started watching television and responding to his family.

Some experts in neurological rehabilitation have expressed skepticism and say it is possible the patients had a different condition.

Dr. Ralf Clauss, one of the researchers who carried out the study, says for every damaged area of the brain, there is a dormant area, which appears to be a sort of protective mechanism.

Clauss says the damaged tissue is dead and there is nothing to be done but the dormant areas can be 'woken up'.

He maintains drugs such as Zolpidem activate receptors for a chemical called GABA in nerve cells in the brain and when brain damage occurs, these receptors appear to change shape, so they cannot behave as normal.

He said the drug appears to cause the receptors in these dormant areas to change back to their normal shape, triggering nerve cell activity.

Dr. Clauss is now at the nuclear medicine department of the Royal Surrey County hospital; he says clinical trials are now needed.

He suggests the drug could have uses in other kinds of brain damage, including Parkinson's disease and Alzheimer's.

The research is published in the journal NeuroRehabilitation.