Parkinson's disease - Causes 

Causes of Parkinson's disease 

Parkinson's disease is caused by a loss of nerve cells in the part of the brain called the substantia nigra.

Nerve cells in this part of the brain are responsible for producing a chemical called dopamine. Dopamine acts as a messenger between the parts of the brain and nervous system that help control and co-ordinate body movements.

If these nerve cells become damaged, the amount of dopamine in the brain is reduced. This means that the part of the brain controlling movement cannot work as well as normal, causing movements to become slow and abnormal.

The loss of nerve cells is a slow process. The symptoms of Parkinson's disease usually only start to develop when around 80% of the nerve cells in the substantia nigra have been lost.

What causes the loss of nerve cells?

It is not known why the loss of nerve cells associated with Parkinson's disease occurs, although research is ongoing to identify potential causes.

Currently, it is believed that a combination of genetic changes and environmental factors may be responsible for the condition.

Genetics

Several genetic changes (mutations) have been identified as increasing a person's risk of developing Parkinson's disease, although exactly how these make some people more susceptible to the condition is unclear.

Parkinson's disease can run in families as a result of faulty genes being passed to a child by their parents, however, inheriting the disease in this way is rare.

Environmental factors

Some researchers also feel that environmental factors may increase a person's risk of developing Parkinson's disease.

It has been suggested that pesticides and herbicides used in farming and traffic or industrial pollution may contribute to the condition.

However, the evidence linking environmental factors to Parkinson's disease is inconclusive.

Other causes of Parkinsonism

'Parkinsonism' is the umbrella term used to describe the symptoms of tremors, muscle rigidity and slowness of movement.

Parkinson's disease is the most common type of Parkinsonism, but there are also some rarer types where a specific cause can be identified.

These include Parkinsonism caused by:

  • medication ('drug-induced Parkinsonism') – where symptoms develop after taking certain medications, such as some types of antipsychotic medication, and usually improve once the medication is stopped
  • other progressive brain conditions, such as progressive supranuclear palsy, multiple systems atrophy and corticobasal degeneration
  • cerebral infarction – where a severe stroke causes several parts of the brain to die

You can read more about Parkinsonism on the Parkinson's UK website.


Page last reviewed: 02/04/2014

Next review due: 02/04/2016

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The 1 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Marylamb said on 15 March 2012

Not happy learning about part of brain dying - could be couched in a more gentle way perhaps? I have only just been diagnosed and therefore still in shock!

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