a brighter future for Parkinson's disease?
i'm all shook up: Parkinson's at 25 | a brighter future for Parkinson's disease? | help and info
Parkinson's Disease was first recognised as a medical condition in 1817 and affects approximately 120,000 people in the UK, but no one knows exactly what causes Parkinson's and as yet there is no cure.
But advances in research into better treatments and an effective cure, which reduce the symptoms of the condition, such as new drugs or stem cell therapy, mean a more optimistic outlook for those diagnosed with the condition, now and in the future.
what is Parkinson's?
Parkinson's is a progressive, neurological condition. It involves the gradual deterioration of cells in the brain that make dopamine. This disrupts nerve pathways, so people can no longer control normal movements. The cause is not known but symptoms tend to appear in people over 60. Approximately 10,000 people are diagnosed with the condition each year, and of these, one in 20 are under the age of 40. Diagnosis should be made by a specialist (a neurologist or a geriatrician with an interest in Parkinson's) and is usually based on clinical observations.
what are the symptoms?
A tremor in the fingers or hand may often be the first visible symptom of Parkinson's disease and it may progress to the legs or other parts of the body. Other main symptoms of Parkinson's are stiffness of muscles, making it difficult for people to stand up or roll over in bed, and slowness of movement. People with Parkinson's may also have problems smiling or making facial expressions and speaking can become difficult. There are also a range of non-motor symptoms, such as depression, sleep problems, excessive sweating, and memory problems, which can have a very negative impact on the person's quality of life.
Parkinson's is a very individual condition with each person experiencing different symptoms. Not everyone experiences all the symptoms and there is no set progression for the condition.
drug treatments
There is no cure for Parkinson's disease, but a lot can be done to relieve symptoms, especially in the early stages. The aim is to replace the missing dopamine in the brain. This can be done with a drug called levodopa – a synthetic chemical which is converted into dopamine in the brain. Levodopa is most effective at relieving rigid limbs and slow movements and, at first, it is usually very effective.
The main drawback of levodopa over time is its side effects. Nausea and a drop in blood pressure can be relieved with other drugs, but abnormal involuntary movements, including facial and other muscle spasms, are harder to deal with. After several years of treatment, over half of people with Parkinson's being treated with levodopa fluctuate in how they respond to the drug - the so-called 'on-off' effect. One minute symptoms may be relatively well controlled but the next, people can hardly move. It is a challenge for the person with Parkinson's and their consultant to find the drug regime that maximises their symptom control.
Because of these problems, doctors usually try to delay using levodopa, especially in younger people. Instead, they use other drugs that boost dopamine activity or mimic its effects, known as dopamine agonists. These drugs also have side effects and doses have to be carefully tailored to individuals needs.
Another option for people with more advanced Parkinson's, is injections of apomorphine to 'rescue' people from sudden 'off' periods or as a continuous infusion for those with severe movement fluctuations. This means that a person's dose of levodopa can be reduced.
research into improved treatments and effective cures for Parkinson's
deep brain stimulation
Deep brain stimulation (DBS) is a treatment pioneered by doctors in Grenoble, France, in the 1980s. It entails an operation under local anaesthetic, so the patient is awake, where electrodes are placed deep inside specific regions of his or her brain. Then a small unit, which generates electrical signals for the stimulation, is implanted into the person's chest. This unit, similar in size to a pacemaker, runs on battery power and has to be replaced every four to five years.
If successful, DBS can reduce tremor or dyskinesia. It is an effective way of treating symptoms in some Parkinson's patients, but it doesn't cure the underlying Parkinson's so most people who have had the surgery will still have to continue with some medication.
By August 2006, DBS has been carried out on about 760 people in the UK and was available at many centres across the country.
But it is not suitable for all. Only patients who have benefited from levodopa therapy and have symptoms which aren't adequately controlled by medication can be considered for the surgery. In addition, patients with significant cognitive decline or dementia or who are too frail for surgery, would not be suitable for DBS.
stem cell therapy
Another developing research area is stem cell therapy. Stem cells are unspecialised cells that have the ability to develop into different types of cell, such as nerve, skin, blood, brain and bone. Because they are so versatile they could potentially be used to repair and renew cells in the body and brain. The hope of studies in this area is that stem cells could be transplanted into the brain to replace the dopamine-producing nerve cells lost in Parkinson's.
Researchers are currently looking at developing a renewable source of stem cells, which can be grown in the laboratory instead of derived from embryos, but this is still at the very early stages.
gene therapy
Gene therapy is a new approach to treating medical conditions, where genes are used as drugs. It works by introducing normal genes into people to overcome the effects of defective genes that may have caused or had a part to play in the development of a condition. A condition does not have to be a genetic illness for this kind of treatment to work.
In Parkinson's, gene therapy research is mainly looking at two areas. Neurotrophic factors, such as glial-derived neurotrophic factor (GDNF), which promotes the survival and growth of the brain cells destroyed by Parkinson's; and proteins that are responsible for the production of dopamine, but don't stop the cells dying. This therapy is administered using infection-free viruses, which carry the genes, injected safely into nerve cells in the affected brain area.
Gene therapy is still in the early stages of research. GDNF has been tested on a handful of patients, but research in this area has been halted because the long-term effects of the treatment are unknown.
good support
Parkinson's specialists stress that treatments should be used as part of a coordinated plan of physio-, occupational and other therapies aimed at minimising the impact of the condition. Physiotherapy can make a real difference to someone's movement and independence; occupational therapy can help people remain as independent as possible and feel safer at home; and speech and language therapy can help with communication to reduce feelings of social isolation.
Increasingly, people with Parkinson's are being recognised as experts in their own conditions. This expertise is backed up with help and support from Parkinson's Disease Nurse Specialists all over the UK. PDNSs monitor and adjust medication, are a continuous point of contact, and provide reliable information and advice to address the concerns of people with Parkinson's.
A diagnosis of Parkinson's does not mean an immediate and irreversible decline into disability. The condition is individual and while some people may progress more quickly than others, Parkinson's does not affect life expectancy. If disability is starting to limit work opportunities, disability employment advisors and staff at the Parkinson's Disease Society, can advise about adapting skills and retraining.
Ultimately, advances in research are looking for an effective cure for Parkinson's to help people with the condition enjoy the best possible quality of life and independence. In the meantime, it is a question of health professionals and people with Parkinson's needing to continue working together to find the best treatment for each individual.
(updated August 2006)
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