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.
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 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.
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:
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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:
Both of the above disorders have similar symptoms and effects as Parkinson's disease.
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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. If they think you may be in the later stages of Parkinson’s disease, you should see a specialist within two weeks.
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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.
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.
Your specialist may offer you an MRI scan. This can help them rule out other conditions that may have caused your symptoms.
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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.
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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.
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.
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