What is Parkinson's disease?

Parkinson's disease is a chronic, neurological condition that affects around 120,000 people in the UK. The condition was named after Dr James Parkinson, who first identified it in 1817. Parkinson's disease affects the way the brain coordinates body movements, including walking, talking and writing.

Parkinson’s is a disorder of body movement. It is a progressive disease that affects people of either sex and all ethnic groups. Parkinson's is not fatal. It is not infectious. and it cannot be transmitted to other members of the family.

Because the disease is progressive, it may ultimately become debilitating. Without adequate treatment and support, people with Parkinson’s may tend to become depressed and withdrawn. However, with modern drug treatment and community support, such isolation is unnecessary.


Who is affected?

Parkinson's affects 8000-10,000 new people in the UK each year: on average one person in every 500 is affected by Parkinson's disease.

Most patients are over 40 and it very rarely affects people below this age (only 5 per cent). However, some people have developed Parkinson's in their teens.

The risk rises so that by the age of 80 more than two people per 100 of the population have developed some signs of the condition. Both sexes and all races appear to be equally affected.


What causes Parkinson's disease?

Parkinson’s disease is caused by the failure of a group of nerve cells in the brain to produce adequate amounts of a chemical called dopamine. Dopamine is necessary for smooth, coordinated movement and muscle relaxation. It is not known why the cells cease producing dopamine. However, it is likely that research will soon provide the answer.


What are the symptoms of Parkinson's

The symptoms of Parkinson's disease usually begin slowly and develop gradually, in no particular order. It affects each individual differently and each person with the condition will have a different collection of symptoms and respond differently to treatment. The severity of symptoms also differs between individuals with the condition.

There are three main symptoms of Parkinson's disease which are outlined below:

Bradykinesia (slowness of movement)

If you have Parkinson's disease, initiating movement, such as starting to get out of a chair, can become difficult, and it can take you longer to perform tasks. You may also lack co-ordination in your movements. People often put this slowness of movement down to old age, and many do not have Parkinson's disease diagnosed until other symptoms occur.

Tremor (shaking)

Tremor (shaking) usually begins in one of your hands, or arms. It is more likely to occur when that part of your body is at rest, and usually decreases when you are using it. Shaking may become more noticeable when you are stressed, or anxious. Although most people associate the disease with tremor, up to 30% of people with the condition will not have this symptom.

Stiffness of muscles (rigidity)

If you have Parkinson's, your muscles may feel tense and, 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. Making fine finger movements, facial expressions and body language may also become difficult.

Other symtoms may include
- constipation and bladder weakness
- difficulty swallowing and drooling
- sleep problems
- tiredness
- depression
- problems with handwriting, speech and balance


Is Parkinson's inherited?

There is no conclusive evidence that Parkinson's is a hereditary condition that can be passed on within families apart from in exceptionally rare cases (up to 5%). It is rare to find more than one person in a family who has Parkinson's, although occasionally it does seem to run in particular families. In most cases, the development is sporadic.

It is thought that although Parkinson's is not directly inherited, some people may inherit a genetic susceptibility to develop Parkinson's. This means people with this genetic susceptibility may be more likely to develop Parkinson's when combined with other factors such as environmental toxins or viruses. There is currently no genetic test freely available for Parkinson's disease.


How does the disease progress?

The onset of symptoms is slow and may go unnoticed for several years. Early signs include stiffness of fingers or a stiff shoulder accompanied by stiffness of muscles. Pain may be a feature.

Symptoms usually only affect one side of the body for one to two years and then spread to the other. Tremor is often noticed first and usually provokes a visit to the doctor. However, up to 30 per cent of sufferers may not have tremor, which can lead to misdiagnosis.


How is Parkinson's disease diagnosed?

Parkinson's tends to develop gradually and it can be a number of months or even years before the symptoms become obvious enough for a person to consult a doctor.

The NICE Guideline for Parkinson's disease (which covers England and Wales) states that people with suspected Parkinson's should be referred quickly (within 6 weeks) and untreated to a specialist with expertise in the differential diagnosis of this condition. The Guideline also recommends that the diagnosis of Parkinson's should be reviewed regularly (every 6-12 months).


Treatment of Parkinson's disease

At the moment, there is no cure for Parkinson's disease, but there are a range of treatments available to help control your symptoms, and maintain your quality of life. Medication is the main treatment option and there are three main types that are commonly used - levodopa, dopamine agonist, and monoamine oxidase-B inhibitors. Each of these medicines has to be prescribed to suit the individual needs of each person who has Parkinson's disease.

Levodopa

Levodopa is a medication that is absorbed by the nerve cells in your brain, and turned into dopamine. It is usually taken by mouth, in tablet or liquid form, and is often combined with other medication, such as benserazide, or carbidopa. This prevents the levodopa from being destroyed by enzymes (proteins) in your gut. These medicines also reduce the side effects of levodopa, which include nausea, vomiting, tiredness, and dizziness.

The first effects of levodopa often show a dramatic improvement in the symptoms of Parkinson's disease. However, levodopa tends to be less effective over time. This is because as more nerve cells in the brain gradually die, there are less to absorb the medicine. This means that the dose may need to be increased from time to time.

Short-term side effects are uncommon but include nausea, hallucinations, tiredness and light-headedness. Virtually all patients suffer long-term complications, with about 50 to 75 per cent on the drug for 5 to 10 years developing abnormal excessive and involuntary movements called dyskinesias.

Dopamine agonists

Dopamine agonists have a similar effect to levodopa, but they work in a different way. They lock on to the dopamine receptors in your brain, which receive signals from the dopamine that tell your body to move. Therefore, dopamine agonists act as a substitute for dopamine.

The side effects of dopamine agonists are similar to levodopa although nausea and mental problems such as hallucinations usually occur more often.

Monoamine oxidase-B inhibitors

Monoamine oxidase-B inhibitors are another alternative to levodopa as a treatment for early Parkinson's disease. They include selegiline and rasagiline which work by blocking the effects of a chemical called monoamine oxidase-B in the brain. This chemical destroys dopamine, so by blocking it, dopamine is able to last longer in the brain. Both of these medicines improve the symptoms of Parkinson's disease, although their effects are small compared to levadopa. They can be used alongside levodopa or dopamine agonists.

In some patients, selegiline can cause confusion. Rasagiline is more powerful than selegiline and has few side effects. Rasagiline has been proven to improve symptoms of Parkinson's disease at all stages of the illness.
As with dopamine agonists, people using these monoamine oxidase-B inhibitors will eventually need to use levodopa. However, by using the inhibitors first, the need for levodopa can be delayed.

Other drugs used in the treatment of Parkinson's disease include :

Selegiline - Side effects include hallucinations, sleep disorder, agitation, postural hypotension (a drop in blood pressure on standing) and problems associated with the withdrawal of the medicine.

Amantadine - a mild antiviral agent and used in young patients to delay the need to use levodopa. In high doses, amantadine can act as an anti-dyskinetic drug. Amantadine side effects include visual hallucinations, confusion and agitation. It should be given as a single dose in the morning to prevent sleep problems. It can cause a specific discolouration of the legs (livido reticularis).

Anticholinergics - Used with levodopa therapy, they can help control resting tremor and dystonia (abnormalities of posture). In older patients they may cause confusion and aggravate dementia. Other side effects include difficulty in passing urine, constipation, blurred vision, dry mouth and the onset of narrow angle glaucoma. Anticholinergics are rarely used in the treatment of Parkinson's disease.

Surgery

Surgery is sometimes used to treat people who have had Parkinson's disease for many years. However, surgery is not suitable for everyone.

Chronic deep brain stimulation is a surgical technique that is sometimes used to treat Parkinson's disease. This is where a pulse generator (like a heart pacemaker) is inserted in your chest wall. A fine wire is placed under the skin that attaches 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 which is affected by Parkinson's disease.

Although surgery does not cure Parkinson's disease, it does ease the symptoms for many people, particularly if medication is not working well.

Other Therapies

Physiotherapists, Nutritionists, Speech and Occupational Therapists, and Counsellors can all help to maintain and improve the quality of life for people with Parkinson's.

There are all kinds of aids and equipment available to help people who have difficulties carrying out daily living activities. These might include smaller aids to help with washing, bathing, reaching, eating and drinking, or larger adaptations such as stair lifts and wheelchairs. Mobility aids that may help with Parkinson's Disease

Suitable exercise is good for everyone and is especially important for people with Parkinson's as their muscles and joints tend to get stiff and rigid. Exercise can also help relieve depression. Joining an exercise group or participating in a sporting activity can also offer opportunities to make new friends. Many people with Parkinson's are involved in active sports and activities such as racquet sports, bowling, sailing, skiing, swimming and dancing.


For more help and information please visit The Parkinson's Disease Society