Causes of Parkinson’s disease

Parkinson’s disease is a progressive nervous system disorder that affects how the person moves, including how they speak and write. 

According to Medical News Today, approximately 127,000 people have Parkinson’s disease in the UK – around 1 in every 500 people. Around 10 million people around the world are estimated to be living with it. Parkinsons's Awareness Week aims to make people more aware of the condition. 

What causes it?

Although it is not known exactly why people get Parkinson’s, researchers think it’s a combination of genetic and environmental factors that cause the dopamine-producing nerve cells to die in the part of the brain called the substantia nigra.

Dopamine acts as a messenger between the parts of the brain and nervous system that help control and co-ordinate body movements. If these cells die, the part of the brain that controls movement can’t function as well as normal.

A male has a 50% higher risk of developing Parkinson’s disease than a female and in the majority of cases, symptoms start to appear after the age of 50. Young-onset Parkinson’s disease can develop in an individual under the age of 40 years however.

Many people with on-set Parkinson’s disease assume that their symptoms are a natural part of ageing, making early diagnosis sometimes difficult.

Although Parkinson’s disease can run in families, it is rare for it to be inherited this way. It has been suggested that environmental factors such as pesticides and herbicides used in farming and traffic or industrial pollution might be a factor, however the evidence is inconclusive.

What is Parkinsonism?

Parkinsonism is an umbrella term used to describe a neurological syndrome, usually characterised by symptoms of tremors, muscle rigidity and slowness of movement.

Although Parkinson’s is the most common type of parkinsonism, there are other types that have been identified, including:

• Idiopathic Parkinson’s disease is the most common type of parkinsonism, otherwise known as Parkinson’s. Idiopathic means that the cause is unknown.
• Drug induced parkinsonism – Around 7% of people diagnosed with parkinsonism develop symptoms after taking certain medications. Neuropletic drugs, such as those used to treat schizophrenia, are thought to be the biggest cause of drug-induced parkinsonism.
• Vascular parkinsonism, also known as arteriosclerotic parkinsonism, affects people with restricted blood supply to the brain. Having a stroke may lead to this type of parkinsonism, with the most common symptoms being walking difficulties, urinary incontinence and memory problems. 

Other progressive brain conditions, such as progressive supranuclear palsy, multiple systems atrophy, and corticobasal degeneration can cause symptoms similar to Parkinson’s.

How is it diagnosed?

Parkinson’s disease develops gradually and each person displays different symptoms. If you or someone you know is displaying signs, they will be referred to a Parkinson’s specialist for a formal diagnosis.

The specialist will look at medical history, carry out a detailed neurological interview and medical examination. From there, Parkinson’s drugs such as levodopa will likely be prescribed, with the specialist keeping a close eye on the effects.

Support available

Parkinsons UK runs a helpline and support groups across the country for people wanting to learn more about the condition and for those caring for those with Parkinson's. Further support and resources include NHS, Chartered Society of Physiotherapy and Nurseplus Homecare.