Health: It turns your world upside down

MICHAEL J FOX was astonished when a small twitch in the little finger of his left hand was diagnosed as the first symptom of Parkinson's disease.

The star of Back to the Future and Bright Light was only 30 when he was told he had the disease but, like many other young sufferers, he could have been forgiven for believing that Parkinson's affects only older people.

But new research shows that although most sufferers are aged over 60, one in 20 of them will get the disease when they are under 40, and the incurable condition has been diagnosed in patients as young as 23.

A growing realisation that younger people are getting the disease, and an awareness that the incidence of Parkinson's is increasing because of the ageing population, have both given added impetus to research.

This month a new drug, which has been shown in trials to combat tremor as well as other symptoms, with few side-effects, is being launched in Britain; other drugs are in the pipeline; the scope and range of brain surgery for controlling symptoms is increasing, too.

Although Parkinson's was first described as a disease in 1817, its causes are still not fully understood and there is as yet no sign of a cure. Latest thinking is that some people may be born with a genetic predisposition to the disease and that it is triggered in them as a result of exposure to a toxin in the environment, or to a virus.

Whatever this trigger may be, and theories have ranged from insecticides to herpes-type viruses, the result is the loss from the brain of dopamine, a chemical involved in a range of tasks including movement control and co-ordination. The loss of dopamine can result in tremor, muscle rigidity, slowed motion, a shuffling gait, dizziness, speech problems, reduced body language and loss of facial expression. These symptoms get worse over time.

New research by the European Parkinson's Disease Association has found that it is the tremor, the symptom most difficult to control with drugs, that is a major everyday problem for eight out of 10 sufferers.

For many, the twitch or tremor is also the first symptom of the degenerative disease. This involuntary movement usually begins in the hands and increases in intensity with anxiety. Over time it can also start to affect the arms and legs.

Many other symptoms can be tackled by drugs, but most have side-effects. Levadopa, for instance, one of the most widely prescribed drugs, helps restore dopamine levels for a time, then begins to wear off and can result in the patient suffering sudden, violent movements.

One of the main problems with existing drugs is that that although they prolong life, the side-effects can affect the quality. The issue of adverse effects from long-term use is heightened in cases where the patient is at the lower end of the age range for the disease.

"When you give them dopamine it reverses the clock and can put them back to normal," says Professor Leslie Findley, a consultant neurologist who is vice-chairman of the Parkinson's Disease Society in the UK, and medical adviser to the National Tremor Foundation. "There is usually a good response for four or five years, but then they start having problems.

"So in younger patients we are tending to delay treatment with drugs such as levadopa and to use reduced doses. There is a real need for doctors to consider new therapies that will prolong the window of effective treatment for people with Parkinson's."

One new drug, Mirapexin, is coming on to the market this month, and clinical trials have shown that it significantly improves the tremor symptoms.

"Mirapexin seems to be well tolerated with few side effects, and may prove to be a significant pharmacological advance," says Professor Findlay.

Surgery is also undergoing something of a renaissance. Traditionally it has been the tremor alone that has been removed, by creating a lesion in the right place inside the brain, but specialists are now looking at working on other areas of the brain for relieving symptoms such as slowness and loss of balance.

Many specialists now believe it unlikely that there will ever be a cure that will reverse the process and remove all the different symptoms. "A lot of us are thinking much more about preventive action. It may be that one day we will be able to pick up those that are genetically vulnerable and be able to take some kind of action to stop it from ever developing," adds Professor Findley.

For those who already have the disease, such as Michael J Fox, the emphasis is on prolonging life and maintaining its quality, by drugs or surgery, or both. The New York-based actor, now 37, who has already undergone one session of surgery to try to control his tremor, says that the disease has turned his world upside down, and he recognises that maintaining quality of life will be increasingly important.

"It's made me stronger, a million times wiser and more compassionate," he says. "I've realised I'm vulnerable, and that no matter how many awards I'm given or how big my bank balance is, you can be messed with like this. The end of the story is, you die. So accepting all that, the issue then becomes one about quality of life."