DOCTORS in Scotland have launched a ground-breaking study to help find a cure for a mystery illness.

A team based at Dundee University are investigating Bell's palsy - an unexplained condition that paralyses half the face.

The syndrome was first identified by a Scots doctor in the nineteenth century, and Pierce Brosnan and George Clooney are among known sufferers.

However, what triggers the sudden paralysis, characterised by the swelling of a nerve in the face, and how best to treat the condition, remains unknown.

The Department of Health at Westminster has invested (pounds) 500,000 in the study of sufferers across Scotland in an effort to find an effective remedy.

Dr Graeme Garden, the Aberdeen-born comic who was one of the Goodies, has spoken about his illness for the first time to support the project. He said he first noticed a change in December 2002 when he could not whistle. The left side of his mouth began to feel weak and paralysis quickly set in.

He self-diagnosed the problem as Bell's palsy but some sufferers - about 100 Scots a month - fear they have suffered a stroke. The effect it can have on appearance, causing half the face to droop and in some cases the eyes to weep and the mouth to drool, can also knock patients' self-esteem.

Perhaps helped by prompt medication, Mr Garden said his face had returned to normal by February last year. However, some patients experience problems for years.

Mr Garden said: ''You hear people who say 'I wish I had the drug treatment because it has never got better'. Other people say 'I have had everything going and I still did not get better'. Until there are new figures, one is not going to know what is best.''

Professor Frank Sullivan, a GP and researcher with Dundee University, said a third of GPs will tell the patient to wait for the problem to heal. Another third, he said, prescribe anti-inflammatory steroids. A further third prescribe anti-viral medication.

He needs to recruit 720 patients over 15 months to test which is most effective.

SYMPTOMS AND TREATMENT

Bell's palsy is a form of facial paralysis caused by damage to the seventh facial cranial nerve.

It can strike almost anyone at any age but disproportionately attacks pregnant women and sufferers of diabetes, flu, colds, and other upper respiratory ailments.

Symptoms may include hypersensitivity to sound and impairment to taste.

Some researchers believe the common cold virus, herpes simplex, and other herpes viruses are the likely causes.

Treatments include steroids and analgesics to relieve pain.

Prognosis is generally very good. With or without treatment, most patients are better within two weeks. About 80% completely recover within three months. Only a few cases never recover.