Search the website

Parkinson's disease & parkinsonism

Updated July 2006

A progressive brain disorder causing shaking and problems with movement.

Parkinson’s disease results from degeneration of cells in a part of the brain called the basal ganglia, which controls the smoothness of muscle movements. Normally, these cells produce a neurotransmitter (a chemical that transmits nerve impulses) called dopamine, which acts with acetylcholine, another neurotransmitter, to fine-tune muscle control. In Parkinson’s disease, the level of dopamine relative to acetylcholine is reduced, adversely affecting muscle control.

The disorder tends to occur after the age of 60 and is more common in men. Although the cause is not known, genetic factors may be involved. Parkinsonism is the term used for symptoms of Parkinson’s disease when they are due to an underlying disorder or certain drugs. Repeated head injuries may cause Parkinsonism, as may some antipsychotic drugs. Cerebrovascular disease may cause symptoms and signs difficult to distinguish from Parkinson's disease, and may co-exist with it.

The main symptoms of Parkinson’s disease develop gradually over months or even years. Parkinsonism may have a gradual or sudden onset depending on the cause.

Symptoms include:

• tremor of one hand, arm, or leg, usually when resting, that later occurs on both sides
• muscle stiffness, making it difficult to start moving
• slowness of movement
• shuffling walk with loss of arm swing
• expressionless face
• stooped posture

As the disease progresses, stiffness, immobility and constant trembling of the hands may make some daily tasks difficult to perform. Speech may become slow and hesitant and swallowing may be difficult. Many people with the disorder develop depression. About three in 10 people with the disease eventually develop dementia. Some develop significant swallowing problems.

There is no specific cure for Parkinson’s disease, but drugs, physical treatments and more rarely, surgery can relieve symptoms and improve the quality of life. People can lead active lives for many years after being diagnosed. However, most people with the disorder need daily help eventually and their symptoms may be increasingly hard to control with drugs.

Further information:
- BBC Health - Parkinson's disease
- MedlinePlus Health Topics - Parkinson’s disease
- MedlinePlus Medical Encyclopaedia - Parkinson’s disease
- MedlinePlus Medical Encyclopaedia - Secondary parkinsonism
- Michael J Fox Foundation for Parkinson’s Research
- National Parkinson Foundation (US)
- NHS Direct Online - Parkinson's disease
- NHS National Institute for Health and Clinical Excellence - Parkinson's disease
- Parkinson’s Disease Foundation (US)
- Parkinson’s Disease Society
- Parkinson's Action Network (US)
- Parkinson's Institute (US)
- The National Institute of Neurological Disorders and Stroke (US)
- The Parkinson Alliance (US)