Parkinson’s disease

Parkinson's disease is a condition in which parts of the brain become damaged little by little over many years.

The three main symptoms are:

• involuntary shaking of particular parts of the body (tremor)
• slow movement
• stiff and inflexible muscles

A person with Parkinson's disease can also have many other physical and psychological symptoms, including:

• depression and anxiety
• balance problems (this may increase the chance of a fall)
• loss of sense of smell (anosmia)
• problems sleeping (insomnia)
• memory problems

If you're worried that you may have symptoms of Parkinson's disease, see your doctor. The doctor will ask about the problems you're having and may send you to a specialist for further tests.

Parkinson's disease happens when nerve cells are lost in a part of the brain called the substantia nigra. As these cells are lost, the amount of a chemical called dopamine in the brain falls.

Dopamine helps control how the body moves. So when there is less of it, many of the symptoms of Parkinson's disease appear.

Nobody knows exactly why the nerve cells are lost. Most experts think a mix of genetic and environmental factors is behind it.

Parkinson's disease is thought to affect around 1 in 500 people. That means an estimated 127,000 people in the UK live with the condition.

Most people with Parkinson's start to develop symptoms when they're over 50. Around 1 in 20 people with the condition first notice symptoms when they're under 40.

Men are slightly more likely to get Parkinson's disease than women.

There's no cure for Parkinson's disease at the moment. But treatments are available that can reduce the main symptoms and help you keep your quality of life for as long as possible.

These include:

• supportive treatments, such as physiotherapy and occupational therapy
• medicine
• in some cases, brain surgery

In the early stages of Parkinson's disease you may not need any treatment, because the symptoms are usually mild. Even so, you may need regular appointments with your specialist so your condition can be monitored.

As Parkinson's disease progresses, the symptoms can get worse, and everyday activities may become harder to manage without help. Many people respond well to treatment and have only mild to moderate disability. A minority may not respond as well and can, in time, become more severely disabled. Parkinson's disease doesn't directly cause death, but it can put great strain on the body, and that can make some people more vulnerable to serious, life-threatening infections. Even so, treatment has advanced, and most people with the condition now have a normal or near-normal life expectancy.

Parkinson's disease symptoms usually come on slowly, and they are mild at first. There are many different symptoms linked to the condition, and some of the more common ones are described below.

The order in which they appear, and how severe they become, differs from one person to another. It's unlikely that anyone with Parkinson's disease would have all of these symptoms, or even most of them.

Parkinson's disease has three main symptoms, and all of them affect how the body moves:

• tremor, which is shaking. It usually starts in the hand or arm and is more likely when the limb is relaxed and resting
• slowness of movement (bradykinesia), where physical movements are much slower than normal. This can make everyday tasks difficult, and it can lead to a slow, shuffling walk with very small steps
• muscle stiffness (rigidity), which means stiffness and tension in the muscles. It can make it hard to move around and to make facial expressions, and it can cause painful muscle cramps (dystonia)

Doctors sometimes call these main symptoms parkinsonism, because they can have causes other than Parkinson's disease.

Parkinson's disease can also bring other symptoms, both physical and mental.

• balance problems, which can make a person with Parkinson's disease more likely to fall and hurt themselves
• loss of sense of smell (anosmia), which sometimes happens several years before other symptoms develop
• nerve pain, which can cause unpleasant sensations such as burning, coldness or numbness
• problems with urination, such as having to get up often during the night to urinate or passing urine without meaning to (urinary incontinence)
• constipation
• an inability to get or keep an erection (erectile dysfunction) in men
• difficulty becoming sexually aroused and reaching an orgasm (sexual dysfunction) in women
• dizziness, blurred vision or fainting when moving from a sitting or lying position to a standing one, caused by a sudden drop in blood pressure
• excessive sweating (hyperhidrosis)
• swallowing difficulties (dysphagia), which can lead to malnutrition and dehydration
• excessive production of saliva (drooling)
• problems sleeping (insomnia), which can result in excessive sleepiness during the day

• depression and anxiety
• mild cognitive impairment, which means slight memory problems and trouble with activities that need planning and organisation
• dementia, a group of symptoms that includes more severe memory problems, personality changes, seeing things that aren't there (visual hallucinations) and believing things that aren't true (delusions)

If you're worried that you may have symptoms of Parkinson's disease, see your doctor. They will ask about your symptoms and your medical history, and that helps them decide whether you need to be referred to a specialist for further tests.

Parkinson's disease happens when nerve cells are lost in a part of the brain called the substantia nigra.

The nerve cells here make a chemical called dopamine. Dopamine works as a messenger between the parts of the brain and nervous system that help control and co-ordinate the movements of your body.

When these nerve cells die or get damaged, the amount of dopamine in the brain falls. The part of the brain that controls movement then can't work as well as it normally does, and movements become slow and abnormal.

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

Nobody knows yet why the nerve cells are lost in Parkinson's disease, though researchers are still working to find the possible causes.

At present, doctors believe the condition may come from a mix of genetic changes and environmental factors.

Researchers have found several genetic factors that raise a person's risk of developing Parkinson's disease. What isn't clear is exactly how these factors make some people more likely to get the condition than others.

Parkinson's disease can run in families when faulty genes are passed from parents to a child. But it's rare for the disease to be inherited this way.

Some researchers also think that things in a person's surroundings may raise the risk of developing Parkinson's disease. It's been suggested that pesticides and herbicides used in farming, along with traffic or industrial pollution, may play a part in the condition. But the evidence linking these environmental factors to Parkinson's disease is inconclusive.

"Parkinsonism" is the umbrella term for the symptoms of tremors, muscle rigidity and slowness of movement. Parkinson's disease is the most common type of parkinsonism. 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 medicines, such as some types of antipsychotic medicine, and usually improve once the medicine is stopped
• other progressive brain conditions, such as progressive supranuclear palsy, multiple systems atrophy, and corticobasal degeneration
• cerebrovascular disease, where a series of small strokes cause several parts of the brain to die

No test can show for certain that you have Parkinson's disease. Your doctor will base the diagnosis on your symptoms, your medical history and a detailed physical examination.

The doctor will talk with you about the problems you're having. They may also ask you to do some simple mental or physical tasks, such as moving or walking around, to help with the diagnosis.

In the early stages, it can be hard for the doctor to say whether you definitely have Parkinson's disease, because the symptoms are usually mild.

If your doctor suspects Parkinson's disease, you'll be referred to a specialist. This will usually be:

• a neurologist, a specialist in conditions affecting the brain and nervous system
• a geriatrician, a specialist in problems affecting elderly people

If your doctor thinks you may be in the early stages of Parkinson's disease, you should see a specialist within six weeks. If they think you may be in the later stages, you should see a specialist within two weeks.

The specialist will most likely ask you to do a number of physical exercises, so they can assess whether you have any problems with movement.

A diagnosis of Parkinson's disease is likely if you have at least two of these three symptoms:

• shaking or tremor in a part of your body that usually only occurs at rest
• slowness of movement (bradykinesia)
• muscle stiffness (rigidity)

If your symptoms get better after you take a medicine called levodopa, it's more likely that you have Parkinson's disease.

Special brain scans, such as a single photon emission computed tomography (SPECT) scan, may also be done in some cases to try to rule out other causes of your symptoms.

Parkinson's disease can be hard to live with from one day to the next. There are several therapies that can make life with it easier and help you deal with your symptoms on a day-to-day basis.

Your local authority may be able to advise and help you. You can ask them for a care and support needs assessment.

A physiotherapist can help with the muscle stiffness and joint pain that come with Parkinson's disease. They do this through movement (manipulation) and exercise.

The aim is to make moving easier and to improve your walking and flexibility. They also work on your fitness, and on how well you can manage things for yourself.

An occupational therapist can look at the areas of your everyday life where you struggle, such as dressing yourself or getting to the local shops. They can work with you to find practical solutions, and make sure your home is safe and properly set up for you. This helps you stay independent for as long as possible.

Many people with Parkinson's disease find it hard to swallow (this is called dysphagia), and many have problems with their speech. A speech and language therapist can often help with both. They may teach you exercises for speaking and swallowing, or give you assistive technology to use.

For some people with Parkinson's disease, a few changes to what they eat can ease some of the symptoms. These changes can include:

• increasing the amount of fibre in your diet and making sure you're drinking enough fluid to reduce constipation
• increasing the amount of salt in your diet and eating small, frequent meals to avoid problems with low blood pressure, such as dizziness when you stand up quickly
• making changes to your diet to avoid unintentional weight loss

If your care team thinks a change in diet may help you, you may be referred to a dietitian. This is a health professional trained to give diet advice.

Medicine can help with the main symptoms of Parkinson's disease, such as shaking (tremors) and problems with movement.

Not every medicine suits every person, though, and the short-term and long-term effects are different for each one. Three main types are commonly used:

• levodopa
• dopamine agonists
• monoamine oxidase-B inhibitors

Your specialist can explain the options to you, including the risks that come with each medicine, and talk through which may be best for you. You will need regular reviews as the condition progresses and your needs change.

The sections that follow describe the treatments you may be offered. There is also a summary of the pros and cons of each treatment, where you can compare your options.

Most people with Parkinson's disease eventually need a medicine called levodopa. Your brain's nerve cells absorb it and turn it into dopamine, a chemical that carries messages between the parts of the brain and the nerves that control movement. Raising the level of dopamine with levodopa usually improves movement problems.

Levodopa is usually taken as a tablet or a liquid. It is often combined with other medicines, such as benserazide or carbidopa. These stop the levodopa being broken down in the bloodstream before it can reach the brain. They also reduce the side effects of levodopa, which include:

• feeling sick (nausea) or vomiting
• tiredness
• dizziness

If your doctor prescribes levodopa, the first dose is usually very small. It is then increased bit by bit until the medicine takes effect.

At first, levodopa can bring a dramatic improvement in symptoms. Over the following years, though, its effects can become less long-lasting. As more nerve cells in the brain are lost, fewer of them are left to absorb the medicine, so the dose may need to be increased from time to time.

Long-term use of levodopa is also linked to other problems. One is uncontrollable, jerky muscle movements (dyskinesias). Another is "on-off" effects, where a person rapidly switches between being able to move (on) and being immobile (off).

Dopamine agonists act as a substitute for dopamine in the brain. Their effect is similar to levodopa, but milder, and they can often be given less frequently.

Most people take them as a tablet, but there is also a skin patch (rotigotine).

Sometimes dopamine agonists are taken at the same time as levodopa, because this allows lower doses of levodopa to be used.

Possible side effects of dopamine agonists include:

• nausea or vomiting
• tiredness and sleepiness
• dizziness

Dopamine agonists can also cause hallucinations and increased confusion, so they need to be used with caution, particularly in elderly patients, who are more susceptible.

For some people, dopamine agonists have been linked to compulsive behaviours, especially at high doses. These include addictive gambling and an excessively increased libido.

Talk to your doctor if you think you may be experiencing these problems.

The person themselves may not realise the problem, so it's key that carers and family members also note any abnormal behaviour and discuss it with an appropriate professional at the earliest opportunity.

If you're prescribed a course of dopamine agonists, the first dose is usually very small, to prevent nausea and other side effects.

The dose is then increased gradually over a few weeks. If nausea becomes a problem, your doctor may prescribe anti-sickness medicine.

A potentially serious but uncommon complication of dopamine agonist therapy is sudden onset of sleep.

This generally happens while the dose is being increased, and it tends to settle once the dose is stable.

People are usually advised to avoid driving while the dose is being increased, in case this complication occurs.

Monoamine oxidase-B (MAO-B) inhibitors, such as selegiline and rasagiline, are another option besides levodopa for treating early Parkinson's disease. They block an enzyme or brain substance called monoamine oxidase-B, which breaks down dopamine, so dopamine levels go up.

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

Most people tolerate MAO-B inhibitors very well, but they can occasionally cause side effects, including:

• nausea
• headache
• abdominal pain
• high blood pressure

Doctors prescribe catechol-O-methyltransferase (COMT) inhibitors for people who are in the later stages of Parkinson's disease. These medicines stop the enzyme COMT from breaking down levodopa.

COMT inhibitors can cause side effects, including:

• nausea or vomiting
• diarrhoea
• abdominal pain

Sometimes tablets alone can't keep Parkinson's disease symptoms under control. When that happens, there are several other treatments your doctor can consider.

Apomorphine is a dopamine agonist, and it's given as an injection under the skin (this is called a subcutaneous injection). There are two ways it can be given:

• a single injection, when required
• a continuous infusion using a small pump carried around on your belt, under your clothing, or in a bag

If you have severe on-off fluctuations, a type of levodopa called duodopa may be used. The medicine comes as a gel that's pumped continuously into your gut through a tube placed through the wall of your abdomen. An external pump is attached to the end of the tube, and you carry it around with you.

In the UK, about 25 specialist neuroscience centres offer this treatment. It's only available if you have very severe on-off fluctuations or involuntary movements.

Most people with Parkinson's disease are treated with medicine. In some cases, though, doctors use a type of surgery called deep brain stimulation.

This surgery isn't suitable for everyone. If it's being considered for you, your specialist will talk through the possible risks and benefits with you.

In deep brain stimulation, a surgeon places a pulse generator in your chest wall. It's similar to a heart pacemaker. The generator is connected to one or two fine wires that run under the skin, and these are inserted precisely into specific areas of your brain.

The pulse generator produces a tiny electric current. This runs through the wire and stimulates the part of your brain affected by Parkinson's disease. Surgery doesn't cure Parkinson's disease, but it can ease the symptoms for some people.

Besides the main movement problems, people with Parkinson's disease can have many other symptoms, and these may need to be treated separately. They include:

• depression and anxiety, which can be treated with self care measures such as exercise, psychological therapy or medication
• problems sleeping (insomnia), which can improve if you make changes to your normal bedtime routine
• erectile dysfunction, which can be treated with medication
• excessive sweating (hyperhidrosis), which can be reduced with a prescription antiperspirant, or with surgery in severe cases
• swallowing difficulties (dysphagia), which can improve by eating softened food, or by using a feeding tube in more severe cases
• excessive drooling, which can improve with swallowing exercises, or with surgery or medication in severe cases
• urinary incontinence, which can be treated with exercises to strengthen the pelvic floor muscles, with medication, or with surgery in severe cases
• dementia, which can be treated with cognitive therapies and, in some cases, medication

Some people with Parkinson's disease find that complementary therapies help them feel better. Many of these treatments and therapies claim to ease the symptoms of Parkinson's disease. But there's no clinical evidence that they work in controlling those symptoms.

Most people assume complementary treatments can't do any harm. That isn't always true. Some can be harmful, and they shouldn't be used in place of the medicines your doctor has prescribed.

Some herbal remedies, St John's wort for one, can interact unpredictably with certain medicines used to treat Parkinson's disease.

If you're thinking about using an alternative treatment alongside your prescribed medicines, check with your care team first.

If you have Parkinson's disease, you should do what you can to stay healthy, both in body and in mind.

If you have Parkinson's disease, regular exercise helps ease muscle stiffness, lifts your mood and relieves stress. You have plenty of choices for keeping fit. Some people prefer active sports like tennis and cycling, while others do better with gentler activities such as walking, gardening and yoga.

Try to eat a balanced diet that includes all the food groups, so your body gets the nutrition it needs to stay healthy.

If you have a long-term condition like Parkinson's disease, doctors encourage you to get a flu jab every year in the autumn.

The pneumococcal vaccine is usually recommended too. It's a one-off injection that protects against a serious chest infection called pneumococcal pneumonia.

A diagnosis of Parkinson's disease, like any long-term condition, can put a strain on you, your family and your friends. Talking about it isn't easy, even with people who are close to you.

As your symptoms get worse, and movement becomes harder, you may feel frustrated and low. Your spouse, partner or carer will feel anxious or frustrated too, and that can't be avoided.

Be open about how you feel, and tell your family and friends what they can do to help. If you want some time to yourself, don't feel shy about saying so.

Complex Parkinson's disease is the stage when treatment can no longer control symptoms consistently, or when a person has developed uncontrollable jerky movements (disabling dyskinesia). These problems can still be helped by adjusting some of the medicines used for Parkinson's disease, or by adding others. This should be done under the supervision of a doctor with a specialist interest in Parkinson's disease.

As Parkinson's disease progresses, you'll be invited to discuss the care you want from your care team as you near the end of your life. This is known as palliative care.

When there's no cure for an illness, palliative care tries to ease symptoms and make the end of a person's life as comfortable as possible. It does this by trying to relieve pain and other distressing symptoms, while giving psychological, social and spiritual support to you and your family.

Palliative care can be provided at home, in a hospice, in a residential home or in hospital. You may want to talk to your family and care team in advance about where you'd like to be treated and what care you wish to receive.