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Parkinson's disease

Page last reviewed: 13/07/2011

Parkinson's disease is a long-term (chronic) neurological condition that affects around 8,000 people in Ireland. It is named after Dr James Parkinson, who first identified it in 1817. Parkinson's disease affects the way the brain co-ordinates body movements, including walking, talking and writing.

Who is affected by Parkinson's disease?

Parkinson's disease affects men and women, although men are statistically slightly more likely to develop it than women.

The risk of getting Parkinson's disease increases with age. Symptoms usually appear in people who are over the age of 50. However, younger people can also be diagnosed with Parkinson's disease.

Young-onset Parkinson's disease

When the symptoms of Parkinson's disease occur in a person between 21 and 40 years of age, it is known as young-onset Parkinson's disease.

Juvenile Parkinson's disease

If a person is diagnosed with Parkinson's disease before the age of 18, it is known as juvenile Parkinson's disease. This is very rare.

Page last reviewed: 13/07/2011

The symptoms of Parkinson's disease usually begin slowly and develop gradually, in no particular order.

Parkinson's disease affects everybody differently. Each person with the condition will have a different collection of symptoms and will respond differently to treatment. The severity of the symptoms also varies between people.

There are three main symptoms of Parkinson's disease.

Slowness of movement (bradykinesia)

Parkinson's disease can make moving difficult, particularly when you try to start moving, and it can take you longer to perform tasks.

You may lack co-ordination in your movements. Often, this slowness of movement is attributed to old age. This means that some people are not diagnosed with Parkinson's disease until other symptoms develop.

Shaking (tremor)

Shaking usually begins in one of your hands or arms. It is more likely to occur when the particular part of your body is at rest. Shaking usually decreases when you are using the body part, and it can be more noticeable when you are stressed or anxious.

The presence of a tremor does not necessarily mean that you have Parkinson's disease. Tremor is also a symptom of other conditions and is most commonly due to a harmless condition called essential tremor.

Although most people associate Parkinson's disease with tremor, up to 30% of people with the condition do not have tremor.

Stiffness of muscles (rigidity)

If you have Parkinson's disease, your muscles may feel tense. Due to the stiffness, you may have trouble performing simple everyday tasks.

For example, you may find it difficult to turn around, get out of a chair and roll over in bed. Fine finger movements, facial expressions and body language may also become difficult.

Other symptoms associated with Parkinson's disease include:

  • tiredness
  • constipation and bladder weakness
  • depression
  • problems with handwriting, speech and balance
  • difficulty swallowing


When seen together, the three main symptoms associated with Parkinson's disease (slowness of movement, shaking and stiffness) are known as parkinsonism. Parkinsonism does not only happen in Parkinson's disease. This collection of symptoms can be caused by drugs or other conditions, including:

  • Multiple system atrophy (MSA). This neurodegenerative disorder affects your motor system (it causes the deterioration of brain signals to the muscles and limbs responsible for movement).
  • Progressive supranuclear palsy (PSP). This is another degenerative disorder that affects vision and movement.

Both of the above disorders have similar symptoms and effects as Parkinson's disease.

Page last reviewed: 13/07/2011

Parkinson's disease is caused by a loss of nerve cells in the part of the brain called the substantia nigra. The nerve cells in this part of the brain are responsible for producing a chemical called dopamine. Dopamine acts as a messenger between the brain and the nervous system, and helps control and co-ordinate body movements.

If these nerve cells become damaged or die, the amount of dopamine in the brain is reduced. This means that the part of the brain that controls movement cannot work so well, which causes movements to become slow and abnormal.

The loss of nerve cells is a slow process. The level of dopamine in the brain falls over time. Only when 80% of the nerve cells in the substantia nigra have been lost will the symptoms of Parkinson's disease appear and become gradually worse.

Why does Parkinson's disease occur?

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


Some research has shown that Parkinson's disease tends to run in families. The exact role that genetics plays in causing Parkinson's disease is unclear. Studies have shown a link between a number of different genes and the development of Parkinson's disease.

It is likely that having these genes makes people more vulnerable to developing the condition. However, having the genes does not necessarily mean that you will develop Parkinson's disease.

Environmental factors

Other research is being carried out into environmental factors, such as toxins and pesticides. It is thought these may directly damage the brain, causing nerve cells to die.

Page last reviewed: 13/07/2011

No tests can conclusively show that you have Parkinson's disease. Your doctor will base a diagnosis on your symptoms, your medical history and the results of a clinical examination.

Your GP will ask you some questions and may get you to perform a task or walk around. This will help with the diagnosis.

In the early stages of Parkinson's disease, your GP may find it difficult to say whether you definitely have the condition because symptoms are usually mild.

If your GP suspects that you have Parkinson's disease, you will be referred to a specialist (a neurologist or geriatrician). If your GP thinks that you may be in the early stages of Parkinson's disease, you should see a specialist within six weeks.

Diagnostic tests

Although no test can conclusively diagnose Parkinson's disease, your specialist may offer you a test that will allow them to look more closely at your brain.

SPECT (single photon emission computed tomography) scan

To help the specialist understand what is causing your tremor, you may be offered a scan of your brain called a SPECT scan (trade name DaT scan). This takes a series of pictures of your brain to find out whether there is any dopamine deficiency, which is seen in Parkinson's disease.

MRI scan

Your specialist may offer you an MRI scan.This can help them rule out other conditions that may have caused your symptoms.

Page last reviewed: 13/07/2011

Treatment overview

You may not need any treatment during the early stages of Parkinson's disease as symptoms are usually mild. However, you may need regular appointments with your specialist so that your condition can be monitored.

At the moment, there is no cure for Parkinson's disease. However, numerous treatments are available to help control your symptoms and maintain your quality of life. These may be supportive therapies that help you cope with everyday life or medication to control your symptoms. For some people with a particular pattern of symptoms, surgery may be an option.

You should agree a care plan with your healthcare professionals and your family or carers, and this should be reviewed regularly.

Supportive therapies

There are several therapies that can make living with Parkinson's disease easier and can help you deal with your symptoms on a day-to-day basis.


A physiotherapist can work with you to relieve muscle stiffness and joint pain through movement (manipulation) and exercise. The physiotherapist aims to make moving easier and improve your walking and flexibility. They also try to improve your fitness levels and your ability to manage things for yourself.

Occupational therapy

An occupational therapist can identify areas of difficulty in your everyday life, for example dressing yourself or getting to the local shops. They can help you to work out practical solutions and ensure that your home is safe and properly set up for you. This will help you carry on as normal for as long as possible.

Speech and language therapy

About half the people with Parkinson's disease have problems communicating, such as slurred speech or poor body language. If you have communication problems, a speech and language therapist can help you improve your speech and use of language. They may use vocal exercises or equipment to help you make yourself understood.

Diet advice

Some people with Parkinson's can experience constipation (difficulty passing stools). This can be helped by increasing the amount of fibre in your diet and making sure you are drinking enough fluid. Fibre is found in fruit, vegetables and cereals. You should be drinking six to eight glasses (1.2 litres) of fluid every day.

Another common problem is orthostatic or postural hypotension.This is low blood pressure when you change position, particularly after standing up too quickly. If you have orthostatic hypotension, your GP may advise that you increase the amount of salt and fluid in your diet.

Hypotension can also be helped by:

  • avoiding caffeine in the evenings
  • eating frequent, small meals, rather than large ones
  • avoiding alcohol

Around 50% of people with Parkinson's disease will experience some unintentional weight loss. Your GP may refer you to a dietitian (a healthcare professional trained to give diet advice) if you may benefit from changing your diet.


Medicines may be used to treat the symptoms of Parkinson's disease. Not all medicines are useful for everyone and the short- and long-term effects of each are different. Three main types of medication are commonly used. These are levodopa, dopamine agonists and monoamine oxidase-B inhibitors. Most people with Parkinson's disease will eventually need to have levodopa, which may be taken at the same time as other medicines to boost its effects.

Each medicine is prescribed to suit the individual needs of the person with Parkinson's disease. Factors that can influence which medicine is prescribed include:

  • your age
  • the severity of your symptoms
  • how well you respond to treatment
  • whether you experience any side effects

When people do not take their medication on time, or stop taking it completely,  they can become very ill. If you have to go into hospital, tell the hospital staff about your medication. If you have a stomach bug or are vomiting, tell your GP as this may affect the levels of medicine in your body.

Your specialist can explain your medication options and discuss which may be best for you. Regular reviews will be required as the disease progresses and your needs change.


Levodopa is absorbed by the nerve cells in your brain and turned into dopamine. It is usually taken as a tablet or liquid. Levodopa is often combined with other medication, such as benserazide or carbidopa. These drugs stop the levodopa from being broken down in the gut before it has a chance to get to the brain. They also reduce the side effects of levodopa, which include nausea, vomiting, tiredness and dizziness.

If you are prescribed levodopa, the initial dose will usually be very small. The dose will be gradually increased until it takes effect. At first, levodopa can cause a dramatic improvement in the symptoms of Parkinson's disease. However, it usually becomes less effective over time. This happens because as more nerve cells in the brain die, there are fewer of them to absorb the medicine. This means that the dose may need to be increased from time to time.

Long-term use of levodopa is linked to certain side effects. These include "on-off" effects, where you can suddenly switch between being able to move (on) and being immobile (off), and muscle problems that cause uncontrollable, jerky muscle movements (dyskinesias).


This is a specialist treatment used for patients with severe on-off swings. A tube is inserted through the abdominal wall into the gut.  Levodopa gel is continuously fed through the tube by a mini-pump, which is worn on your belt.

Dopamine agonists

Dopamine agonists act as a substitute for dopamine in the brain and have a similar effect to levodopa. They are used to treat early Parkinson's disease as they are less likely to cause muscle problems (dyskinesias) than levodopa. They are often taken as a tablet, but can also be injected into a vein (intravenously). Sometimes, dopamine agonists are taken at the same time as levodopa. This allows lower doses of levodopa to be used.

Possible side effects of dopamine agonists include nausea, vomiting, tiredness and dizziness. Dopamine agonists can cause episodes of confusion or hallucinations, so they need to be used with caution, particularly in elderly patients who are more susceptible to these symptoms.

For some people, dopamine agonists, especially at high doses, have been linked to the development of compulsive behaviours, including pathological gambling, increased libido and hypersexuality. These are very complex disorders you should talk to your healthcare specialist if you think that you may be experiencing them. As the person themselves may not realise that there is a problem, it is key that carers and family members note any abnormal behaviour and discuss it with the appropriate professional at the earliest possible stage.

If you are prescribed a course of dopamine agonists, the initial dose will usually be very small to prevent nausea. The dosage is gradually increased over a few weeks. If nausea becomes a problem, your GP may prescribe anti-sickness medication, such as domperidone. You may need blood tests and a chest X-ray before some types of dopamine agonist are prescribed.

Monoamine oxidase-B inhibitors

Monoamine oxidase-B (MAO-B) inhibitors, including selegiline and rasagiline, are another alternative to levodopa for treating early Parkinson's disease. They block the effects of a chemical called monoamine oxidase-B in the brain. This chemical destroys dopamine. By blocking it, MAO-B inhibitors allow dopamine to last longer in the brain.

Both selegiline and rasagiline can improve the symptoms of Parkinson's disease, although their effects are small compared with levodopa. They can be used alongside levodopa or dopamine agonists.

MAO-B inhibitors can cause a wide range of side effects, including nausea, headache and abdominal pain, though not everyone will experience them.

Catechol-O-methyltransferase inhibitors

Catechol-O-methyltransferase (COMT) inhibitors are prescribed for people in later stages of Parkinson's disease. They prevent levodopa from being broken down by the enzyme COMT.

Side effects of COMT inhibitors include nausea, vomiting, diarrhoea and abdominal pain. If the COMT inhibitor tolcapone is used, you will need liver tests every two weeks.


Most people with Parkinson's disease are treated with medication. However, surgery is sometimes used to treat people who have had Parkinson's disease for a long time. However, it is not suitable for everyone and your specialist will discuss with you the risks and benefits of this type of treatment.

Deep brain stimulation

Deep brain stimulation is a surgical technique that is sometimes used to treat Parkinson's disease. A pulse generator (similar to a heart pacemaker) is inserted in your chest wall and a fine wire is placed under the skin and attached to your brain. A tiny electric current is produced from the pulse generator, which runs through the wire and stimulates the part of your brain that is affected by Parkinson's disease.

Although surgery does not cure Parkinson's disease, it can ease the symptoms for some people.

Complementary therapies

Some people with Parkinson's disease find that complementary therapies help them feel better. Many complementary treatments and therapies claim to ease the symptoms of Parkinson's disease. However, there is no clinical evidence that they are effective in controlling the symptoms of Parkinson's disease.

Many people think that complementary treatments have no harmful effects. However, they can be harmful, and as such it is a bad idea to use them instead of the medicines prescribed by your doctor. If you decide to use an alternative treatment along with your prescribed medicines, it is important to let your doctor know.

Page last reviewed: 13/07/2011

Treating other symptoms

As well as the symptoms caused by the condition itself, people with Parkinson's disease may also experience other symptoms which need to be treated.


People with Parkinson's disease often have depression. This is caused by the changes in the levels of chemicals in the brain. There are many different treatment options for depression. Discuss which is the best for you with your healthcare team.


Psychosis is a mental condition where somebody is unable to distinguish between reality and their imagination. Sometimes, the medication you are taking to treat the symptoms of Parkinson's disease can cause psychosis. As with all medication for Parkinson's disease, do not stop taking it suddenly. If you have any concerns, talk to your healthcare team.


One in five people with Parkinson's disease will develop dementia as they get older. Any treatment of dementia should take into account your Parkinson's disease. Your healthcare team can discuss this with you.

Sleep problems

Many people with Parkinson's disease have problems with sleeping. You may be tired in the daytime, have difficulty moving at night or have problems with restless legs syndrome. If you have problems with sleep, talk to your healthcare team. They may suggest a change to the medicine you're taking or there may be practical changes that can help.


Loss of stability in later stages of Parkinson's disease can lead to falls.There are many ways to prevent falls. Your physiotherapist and occupational therapist may be able to help with this.

Relationships and support

Coming to terms with a long-term condition such as Parkinson's disease can put a strain on you, your family and your friends. It can be difficult to talk to people about your condition, even if they're close to you.

Dealing with the deterioration of symptoms, such as increasing difficulty with movement and tremor, can make people with Parkinson's disease feel very frustrated and depressed. Their spouse, partner or carer will inevitably feel anxious or frustrated too.

Be open about how you feel and let your family and friends know what they can do to help. Do not feel shy about telling them that you need some time to yourself, if that is what you want.


If you have questions, your GP or Parkinson's disease specialist nurse may be able to reassure you. You may find it helpful to talk to a trained counsellor or psychologist, or to someone at a specialist helpline. Your GP surgery will have details of these.

Some people find it helpful to talk to other people with Parkinson's disease, either at a local support group or in an internet chatroom. 


If you have Parkinson’s Disease, it could affect your ability to drive. It is important that you inform your doctor and the Road Safety Authority (RSA) about a medical condition that could have an impact on your driving ability.

Advanced Parkinson's disease

As Parkinson's disease progresses, you will be invited to discuss with your healthcare team the care you want as you near the end of your life.

What is palliative care?

Palliative care is the support and care of symptoms when no cure for the disease is possible, usually when the person is dying. Your doctor or nurse may suggest you see a specialist or nurse in palliative care, or a counsellor.

A palliative care team will focus on controlling your symptoms, keeping you as comfortable and as pain-free as possible, as well as offering physical, psychological, spiritual and social support for you and your family.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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