Parkinson's Disease

Statistics

UK [1]

Generally, in the UK, one in 500 people, around 120,000 individuals have Parkinson's
About 10,000 people in the UK are diagnosed each year
Symptoms first appear, on average, when a patient is older than 50
One in 20 of those diagnosed each year will be aged under 40 years
Statistically, men are slightly more likely to develop Parkinson's than women

What is it?

Parkinson's is a progressive neurological condition affecting movements such as walking, talking, and writing. Average age of onset is around 60 years and the risk of getting Parkinson's increases with age. Younger people can also have Parkinson's and is known as " young-onset Parkinson's disease" if diagnosed in someone aged under 40 years.

Symptoms

Parkinson's has three main symptoms:

Tremor
Usually begins in one hand or arm and is more likely to occur when the part of the body affected is at rest. Tremor will usually decrease or disappear when the affected part is being used and often becomes more noticeable when a person with Parkinson's is anxious or excited. About 70% of people with Parkinson's have a tremor and it is slightly less common in younger people with Parkinson's

Muscular rigidity or stiffness
This is a common early sign in untreated people with Parkinson's. People may experience problems turning round, getting out of chair, turning over in bed, or making fine finger movements, such as fastening a button, because of rigidity. Some people find their posture becomes stooped, or that their face becomes stiff, making facial expressions more difficult

Bradykinesia
This means slowness of movement. People with Parkinson's often find that initiating movements becomes more difficult or that it takes them longer to perform movements. Lack of co-ordination when making movements can also be a problem

As well as these three main symptoms, people with Parkinson's may experience other symptoms, such as tiredness, depression, difficulties with handwriting and other forms of communication such as speech and facial expression and balance.

The symptoms of Parkinson's usually begin slowly, develop gradually and in no particular order. The nature and severity of symptoms and the rate at which the condition progresses will be individual. The symptoms may take years to progress to a point where they cause major problems and when they do, many of these symptoms can be treated.

Causes

In the brain, two chemical messengers, dopamine and acetylcholine work in balance to transmit messages between nerve cells and muscles. These messages enable us to perform a range of co-ordinated movements. In people with Parkinson's this balance is upset because some of the dopamine-producing cells are lost. When about 80% of the dopamine has been lost, the symptoms of Parkinson's appear and the level of dopamine will continue to fall slowly over many years.

The reason why the loss of dopamine occurs in the brains of people with Parkinson's is currently unknown. Most researchers believe that many factors may play a role in causing Parkinson's. Areas of research into the cause include genetics, environmental factors and viruses. Treatment is available.

Further information

Acknowledgements: This section has been developed with the help of the Parkinson's Disease Society.

[1] The Parkinson's Disease Society (n.d.). How many people have Parkinson's? [accessed 31/01/08].