Parkinson’s disease is a chronic, progressive degenerative neurological disease which predominantly affects the older population. Parkinson’s disease is characterized by a constellation of clinical manifestations, which include slowness of movement, rigidity, tremor and postural instability (or lack of balance and coordination). It is a movement disorder and as the disease progresses, body movements such as walking and talking are affected.
How many people does Parkinson’s disease affect?
Parkinson’s disease affects 1 in every 500 people in Canada. Over 100,000 Canadians are living with Parkinson’s today and approximately 6,600 new cases of PD are diagnosed each year in Canada (based on annual incidence of 20 new cases per 100,000 people). Most are diagnosed over the age of 60; however, at least 10% of the Parkinson’s population develops symptoms before the age of 50. Approximately four million people worldwide are living with the condition.
Who is affected by Parkinson’s disease?
Parkinson’s disease affects both men and women. Statistically, however, men have a slightly higher chance of developing the disease. The risk of developing Parkinson’s disease also increases with age, with the average age of onset being 65 years old. Five to ten per cent of people develop the condition before the age of 40 years old. When symptoms appear in people aged 21-40, this is known as young-onset Parkinson’s disease. Juvenile Parkinson’s disease is the term used when symptoms appear before the age of 18 years old, although this is extremely rare.
To-date, no one knows exactly why people get Parkinson’s disease, but viral infection or environmental toxins may play a role. People with a parent, sibling or child with Parkinson’s disease, are twice as likely to get it as people in the general population.
What causes Parkinson’s disease?
Parkinson’s disease develops when there is a loss of nerve cells in the brain which produce a chemical called dopamine. Dopamine is a chemical messenger (neurotransmitter) that transmits impulses between nerve cells in the brain to control body movements. Without enough dopamine, nerves in the brain which control muscle action do not work properly. When the loss of nerve cells reaches 80%, Parkinson’s disease symptoms begin to appear. The disease progresses over time as dopamine levels in the brain gradually fall.
The reason for the nerve damage is currently unknown, although two areas currently being researched as possible causes are genetics and environmental factors.
What are the symptoms of Parkinson’s disease?
The symptoms of Parkinson’s disease develop gradually, as levels of dopamine fall. Early Parkinson’s disease symptoms usually affect one side of the body. The main symptoms of Parkinson’s disease include:
- Tremors: uncontrollable shaking, the symptom most associated with the disease, often beginning in the hands.
- Rigidity: stiffness or tensing of the muscles.
- Bradykinesia: slowness of movement, and loss of spontaneous movement.
- Postural instability: lack of balance and coordination which may lead to falling.
People with Parkinson’s disease may also experience other problems, including tiredness, depression, sleep problems, cognitive impairment and difficulties with handwriting. They can also find their speech and facial expression change and some people have difficulties eating and swallowing.
What are the stages of Parkinson’s disease?
Parkinson’s disease is often divided into two parts: early stage and advanced stage disease.
- Early stage: when symptoms appear and start to affect everyday activities, such as washing, getting dressed and walking.
- Advanced stage: when motor (movement) complications occur from the long term use of one of the main treatments for Parkinson’s disease, levodopa.
How is Parkinson’s disease diagnosed?
There is no laboratory test for Parkinson’s disease. Diagnosis is made by observing symptoms, reviewing medical history and conducting a neurological exam.
Please visit Parkinson Society Canada for further information about Parkinson’s disease.