AN INTRODUCTION TO PARKINSON'S DISEASE
WHAT IS PARKINSON'S DISEASE?
Parkinson’s disease (PD) is a ‘chronic’ and ‘progressive’ movement disorder. ‘Chronic’ means that it is a long-term condition that you will have to manage forever. ‘Progressive’ means that it will get worse over time. However, there are ways to manage the disease and all its symptoms. As PD is a movement disorder it will affect your body’s ability to move properly – these are called ‘motor’ symptoms. You will also experience other symptoms that are not associated with movement, these are called ‘non-motor’ symptoms, such as constipation or loss of sense of smell. Some of these non-motor symptoms cold have been present long before you noticed changes in your movement.
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Parkinson’s disease was first identified by a man called James Parkinson in the year 1817. PD happens because nerve cells in the brain (these are called ‘neurons’) die. Neurons produce a chemical called ‘dopamine’. Dopamine plays a role in our body’s movement or ‘motor’ function. So, when neurons die, it affects a person’s ability to move. As PD progresses, the number of neurons continues to decrease and so, the body produces less and less dopamine over time. Motor symptoms appear when the brain cannot make enough dopamine to control movement properly. This is why you need to take medication to increase the amount of dopamine produced in the brain and make sure you can move well for as long as possible.
WHAT CAUSES PARKINSON'S DISEASE?
Parkinson’s disease (PD) is a type of ‘parkinsonism’. ‘Parkinsonism’ is a term that covers several conditions, including PD, that have similar symptoms, such as slow movement, stiffness and problems walking. The most common type of Parkinsonism is ‘Idiopathic Parkinson’s disease’, which is what most of this guide refers to. ‘Idiopathic’ means that the cause is not known. A combination of genetic (in some cases) and exposure to environmental factors (for example, toxins or chemicals) might cause neurons in the brain to die.
Another type of parkinsonism is ‘Vascular parkinsonism’, which can happen after someone has a stroke. ‘Drug-induced parkinsonism’ is when drugs used to treat psychotic disorders cause symptoms like PD, but people can recover within weeks of stopping the drug. Other types of parkinsonism include: ‘Multiple System Atrophy’ (MSA) and ‘Progressive Supranuclear Palsy’ (PSP). These can be distinguished from PD by a neurologist. ‘Essential tremor’ can also often be confused with PD, your neurologist can determine the correct diagnosis.
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The cause of ‘Idiopathic Parkinson’s disease’ (PD) is still unknown, but it is a common and natural disease. We do know that PD is not caused by curses, spirits, jealousy or witchcraft. PD is a medical condition, you cannot get it because you, or someone you know, did something wrong in the past. Researchers across the world are working hard to discover possible causes for PD. Unfortunately, because no one knows what causes PD yet, it cannot be cured, but the medication you are prescribed will help manage symptoms.
HOW IS PARKINSON'S DISEASE DIAGNOSED?
Parkinson’s disease is currently diagnosed using a ‘clinical diagnosis’. This means that a doctor that specialises in neurology (someone who deals with disorders of the brain and nervous system) will assess your symptoms during a clinic appointment. They will look at the way that you walk and move, they will listen to how you speak, they might ask you to write your name repeatedly, they will ask you questions about symptoms and your medical history, they will do a physical examination and ask you to perform certain actions.
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Usually, this is enough to diagnose PD. There are no specific tests to diagnose PD. However, if the neurologist is not sure or they want to exclude another disease, they might conduct some further scans, such as an MRI or CT scan, but these cannot diagnose PD, they just tell you that it isn’t something else. Another way to confirm a diagnosis of Parkinson’s disease is to see how you respond to medication used to treat PD, such as Sinemet (levodopa). If your symptoms significantly improve, this confirms the diagnosis. The main ‘motor’ symptoms that confirm a diagnosis of PD are:
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Tremor in one hand or leg (70% of people with Parkinson’s disease have this)
Rigidity in the muscles (your muscles will be stiff)
Akinesia (this means that your movement is difficult or slow)
Postural instability (balance problems)
WHO GETS PARKINSON'S DISEASE?
It is thought that approximately 10 million people in the world have Parkinson’s disease. It is the second most common ‘neurodegenerative’ disease globally. ‘Neurodegenerative’ refers to the progressive death of nerve cells, or ‘neurons’, in the brain like we see in PD. There have been lots of studies in the world to estimate how many people have PD, but not many have been done in Africa. One study in Tanzania found that about 40 people per every 100,000 people have PD. That’s lower than in the USA, for example, but still quite high. Researchers think that the number of people getting PD and living with PD is going to continue to increase in the next few years as the world experiences a ‘Parkinson pandemic’.
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The likelihood of getting Parkinson’s disease increases as you get older and it is often thought of as a disease of older people. However, young people can get it too. Most people are diagnosed with PD after the age of 50 years old but people younger than 50 can also have PD. Men are also slightly more likely to get PD than women.
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In most cases, people get Parkinson’s disease because of environmental factors. However, about 20% of cases are inherited, meaning that someone in your family passed the ‘genes’ for Parkinson’s disease to you. ‘Genes’ are inherited from your parents and carry the information, or DNA, in your body that determines who you are and what characteristics you have. However, it is very rare for people to pass Parkinson’s disease on to their children.
HOW WILL PARKINSON'S DISEASE PROGRESS?
As Parkinson’s disease is ‘progressive’ and ‘degenerative’, you may only experience a few symptoms to start with, but the condition will get worse over time. Parkinson’s disease always begins as a ‘unilateral’ condition. This means that your symptoms will be worse on one side of your body than the other – you might find one arm is stiffer or if you have a tremor it might be worse in one hand. Over several years, your symptoms will get worse and they may affect your life a bit more. However, medication and exercise will help manage many of your symptoms - the amount of medication you take will have to increase every year. See the section on 'managing PD' for more information about medication.
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Parkinson’s disease is not fatal, you can live a long life with the disease if it is managed well. However, after many years of living with PD, your condition will have progressed significantly. At this stage you will need a lot of help and care and your movement will be very difficult. Support from your family is very important throughout your journey and particularly at later stages.
