Parkinson's disease

Published by Bupa's Health Information Team, April 2011.

This factsheet is for people who have Parkinson's disease, or who would like information about it.

Parkinson’s disease affects the way the brain co-ordinates body movements. It happens when there is a shortage of a chemical called dopamine in the brain.

About Parkinson's disease

Parkinson’s disease is caused by the loss of brain cells that produce dopamine, which results in low levels of the chemical in your brain. Dopamine is a chemical messenger – or neurotransmitter – that makes other parts of your brain coordinate movement properly.

Parkinson’s disease affects around one to two out of 100 people over 65. It’s thought to be slightly more common in men than in women. Most people develop the condition around the age of 60, but around one in 12 people with Parkinson’s disease start having symptoms before the age of 50. 

Symptoms of Parkinson's disease

The symptoms of Parkinson’s disease often start on one side of your body first and then affect both sides. The main symptoms are listed below.

• Shaking (muscle tremor) is usually one of the first symptoms and affects most people with Parkinson’s disease. It often starts in your hand with circular movements – as if rolling a marble or pill between your thumb and forefinger. It usually affects your arms and legs, but sometimes also your jaw. The tremor will be most obvious when you’re at rest, and will be reduced when you’re moving or sleeping.
• Stiffness (rigidity) is a common symptom of Parkinson’s disease. This can make your limbs feel difficult to move.
• Slowness of movement is common in people with Parkinson’s disease.
• Walking problems. You may start to walk with a slow shuffle.

As different muscles become affected you may develop:

• problems with your posture and balance – you may have difficulty turning in bed or getting out of a chair and as the disease progresses you may have falls
• speech changes – your speech may become quiet or rapid and people may find it harder to understand you
• loss of facial expression – you may smile less, frown more and blink slowly
• small handwriting

You may also get other symptoms that aren’t related to movement. These can include:

• mental health problems, such as depression, memory loss, difficulty reasoning and increased anxiety
• bowel and bladder problems such as constipation and the need to urinate often
• problems with swallowing, which can lead to increased saliva and drooling
• weight loss
• impotence
• low blood pressure when you stand up
• increased sweat
• problems sleeping and tiredness

These symptoms aren’t always caused by Parkinson’s disease but if you have them, see your GP.

Causes of Parkinson's disease

Parkinson’s disease is caused by a loss of nerve cells in the part of your brain that produces dopamine. This can happen gradually and the level of dopamine in your brain can fall over time. Only when 60 to 80 percent of the nerve cells in your brain have been lost will the symptoms of Parkinson’s disease appear and become gradually worse. The exact reasons why the nerve cells die aren’t fully understood at present.

Rarely, Parkinson’s disease runs in families. How these inherited factors play a role isn’t currently known but research has shown a link between a number of different genes and the development of the disease.

Certain chemicals in the environment that may be harmful to the brain, called neurotoxins, have also been linked to Parkinson’s disease. It's possible that people who are exposed to more of these neurotoxins are more likely to develop the condition.

Research is ongoing to try and find the exact reasons why some people get Parkinson’s disease.

Diagnosis of Parkinson's disease

Your GP will ask about your symptoms and examine you. He or she may also ask you about your medical history.

Your GP may refer you to a neurologist (a doctor who specialises in conditions of the nervous system) or a geriatrician (a doctor who specialises in treating older people).

There is no single test for Parkinson’s disease. A diagnosis will be based on your symptoms and your doctor will rule out other conditions that cause similar symptoms.

You may need to have a blood test or scans, such as an MRI scan (this uses magnets and radiowaves to produce images of the inside of your body). You may need a further test called a SPECT (single photon emission computed tomography) scan to help your doctor distinguish between Parkinson’s disease and another condition called essential tremor.

If you’re diagnosed with Parkinson’s disease, your doctor will see you every six to 12 months to review your diagnosis and condition.

Treatment of Parkinson's disease

Treatment for Parkinson’s disease is aimed at restoring the levels of dopamine in your brain and controlling your symptoms. The symptoms and progression of Parkinson’s disease are different for each person. Your doctor will help you to decide which treatment is best for you depending on your symptoms and your individual needs.

Medicines

Several types of medicine are available.

Medicines that replace dopamine are the most effective treatment. These medicines are combinations of levodopa, which breaks down in your body to form dopamine, and another chemical that ensures that the levodopa reaches your brain. Dopamine replacement medicines can provide long-term improvement, although there are some side-effects such as feeling sick and tiredness. They can also cause long-term problems such as unwanted movements of your face and limbs (dyskinesia) and may become less reliable over time, with symptoms fluctuating suddenly – this is often called the ‘on-off syndrome’. Examples of medicines include co-beneldopa and co-careldopa.

Medicines that mimic the action of dopamine (dopamine agonists) are commonly taken alone or together with levodopa. Examples include pramipexole, ropinirole and rotigotine. These have side-effects such as feeling sick or sudden sleepiness, so your doctor will start you off at a low dose. If you have had Parkinson’s disease for a long time and have unpredictable ‘off periods’ you may be prescribed apomorphine, which is an injection.

Monoamine oxidase B inhibitors prevent the breakdown of dopamine. You can use these alone to delay the need for levodopa, or in combination with levodopa to reduce the on-off syndrome. Examples include selegiline and rasagiline.

Catechol O-methyl transferase (COMT) inhibitors are a type of medicine that stops the breakdown of dopamine. They are given alongside levodopa, usually if you have had Parkinson’s disease for some time and dopamine replacement medicines have started to lose their effectiveness. Examples include entacapone.

Amantadine acts like a dopamine replacement medicine but works on different sites in your brain. It has few side-effects, but is only used in the early stages of the disease and has a limited effect so isn’t a first choice drug.

Anticholinergic medicines block the action of the brain chemical acetylcholine. They help to correct the balance between dopamine and acetylcholine. These medicines only help with tremor and are less effective than the medicines that replace dopamine, so doctors don’t use them very often.

Always ask your doctor for advice and read the patient information leaflet that comes with your medicine.

Surgery

Sometimes, if medicines are no longer helping you, your doctor may recommend that you have surgery. Deep brain stimulation is the most common procedure. Electrodes will be placed in your brain in the areas that are important in controlling movement. The electrodes will be connected to a pulse generator, which will be placed under the skin in your chest. Tiny electrical currents will be sent from the pulse generator to your brain and this may help to reduce your symptoms of Parkinson’s disease.

Other therapies

Other therapies that are important for managing and living with Parkinson’s disease include physiotherapy, speech therapy and occupational therapy. If you have Parkinson’s disease, you will be cared for by health professionals with a range of different skills. They will make sure you have access to therapies that are right for your stage of the disease.

Future treatments

Research is ongoing to find new treatments for Parkinson’s disease. Examples include gene therapy, which involves delivering normal genes directly to your brain to help prevent the death of brain cells. Other research is looking at whether nerve cells that are lost in people with Parkinson’s disease can be replaced with new healthy cells from stem cells grown in the laboratory.

However, these therapies are still at an experimental stage and may not be available for some time.

Living with Parkinson's disease

Most people stay reasonably active and symptoms may progress no further than a slight tremor. However, some people do become debilitated and may need help with daily living, such as washing, eating and dressing. You may find it helpful to talk to other people who are affected by Parkinson’s disease.

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.