Parkinson's disease

What is Parkinson’s disease?

Parkinson’s disease is a progressive neurological condition. This means that it causes damage to the brain and it gets worse over time. Over many years, the part of the brain responsible for movement (substantia nigra) becomes more and more damaged.

This can cause difficulties with movement, along with other physical and psychological symptoms. As the condition advances, symptoms can worsen. 

Parkinson’s disease is a common condition in elderly people. Most people start to develop symptoms over the age of 50, and men are more affected than women.

What are the symptoms of Parkinson’s disease?

The three main symptoms of Parkinson’s disease are related to movement:

• Slow movement

• Muscle stiffness, or rigidity

• Shaking of parts of the body when not using them, called tremor

Other motor symptoms include:

• Shuffling walk 

• Problems with balance which increase the chances of having falls

A person with Parkinson’s disease can also experience a wide range of symptoms that are not related to movement such as: 

• Depression

• Anxiety

• Memory problems

• Sleep disturbances

• Constipation

• Difficulty peeing (having to go frequently during the night or unintentionally passing urine)

What causes Parkinson’s disease?

Parkinson’s disease is caused by a loss of nerve cells in the part of the brain responsible for movement, called the substantia nigra. Nerve cells in the substantia nigra produce a chemical called dopamine which plays an important role in regulating body movement. 

As more of these nerve cells become damaged or die, the amount of dopamine in the brain drops. With less dopamine, the substantia nigra cannot control movement properly. As a result, the symptoms of Parkinson’s disease start to appear with movements becoming slow and abnormal. 

Most people with the disease have ‘idiopathic’ Parkinson’s disease. Idiopathic means the cause is unknown. Most experts believe that the combination of genetic and environmental factors contributes to the loss of nerve cells.

How is Parkinson’s disease diagnosed?

There’s no single test to diagnose Parkinson’s disease. A doctor will make a diagnosis based on symptoms, medical history and results of a physical examination. 

If you experience any of the symptoms listed above, talk to a doctor. In the early stages, it can be hard for your GP to diagnose Parkinson’s as the symptoms are usually mild. 

If your GP suspects Parkinson’s disease, they will refer you to a specialist (a neurologist or a doctor specialising in elderly care). The specialist will ask you to perform some physical tasks to work out whether you have any problems with movement.  

A Parkinson’s disease diagnosis is highly likely if you have at least 2 of the 3 main symptoms. If there is uncertainty about the diagnosis, a brain scan might be carried out to try to rule out other causes of your symptoms.

How to treat Parkinson’s disease

Although there's currently no cure for Parkinson's disease, treatments are available to help reduce the symptoms and maintain quality of life. These include supportive therapies that help you deal with everyday challenges and medications to manage symptoms. 

As Parkinson’s disease affects everyone differently, treatment can vary depending on your symptoms. Treating Parkinson’s disease can be very complex and to make sure your needs are met, your care will be provided by a team of different professionals (a multi-disciplinary team or MDT). 

You may not need any treatment during the early stages of Parkinson’s disease as symptoms are usually mild. However, you may have regular appointments with your specialist to closely monitor your condition. 

Therapies

Therapies that can help you better manage your day-to-day symptoms include:

• A physiotherapist who can advise on exercises to relieve muscle stiffness and improve range of movement and flexibility

• An occupational therapist who can advise on adaptations to help support you with day-to-day challenges

• Speech and language therapy (SALT) – many people with Parkinson’s disease have swallowing difficulties (dysphagia) and problems with speech. A speech and language therapist can teach you exercises to help improve these symptoms

• Dietary advice – making dietary changes such as increasing the amount of fibre in your diet and drinking enough water can help improve symptoms like constipation

Medication

Various medications can be used to improve the movement symptoms of Parkinson’s disease. 

The three main types of medication commonly used for Parkinson’s disease work to increase levels of dopamine in the brain:

• Levodopa – most people with Parkinson’s disease will eventually need this medication. Levodopa is absorbed by nerve cells in your brain and is turned into dopamine. Increasing the levels of dopamine in the brain usually improves movement problems. Levodopa is usually taken with other medications to boost its effects and reduce side effects

• Dopamine agonists – acts as a substitute for dopamine in the brain. Dopamine agonists have a similar but milder effect compared with levodopa. Sometimes both medications can be taken at the same time

• Monoamine oxidase-B (MAO-B) inhibitors – these medications block the enzyme in the brain which breaks down dopamine (monoamine oxidase-B) thereby increasing dopamine levels

Not all medications are useful for everyone. Your specialist can explain your medication options, the risks associated with each medication and help you decide which option may work best for you.

Surgery

Most people with Parkinson’s disease are treated with medication. However, a type of surgery called deep brain stimulation is used in some cases. A specialist will be able to discuss the possible benefits and risks of this option with you. This option is not suitable for everyone and is only available at specialist neuroscience centres.  

Treating additional symptoms

A person with Parkinson’s disease experiences a wide range of symptoms that are not related to movement. Your multi-disciplinary care team will be able to help you to manage these additional symptoms.

What is the difference between Alzheimer’s and Parkinson’s disease?

Although Alzheimer’s disease and Parkinson’s disease are both conditions caused by gradual damage to brain cells, the conditions are very different in terms of symptoms and management. 

Alzheimer’s disease is the leading cause of dementia. Dementia is an umbrella term used to describe symptoms associated with an ongoing decline in brain functioning. Alzheimer’s disease typically affects memory, concentration and decision-making. Memory loss is often the main symptom and as the condition develops, the symptoms become more severe. Parkinson’s disease specifically affects movement, Alzheimer’s disease does not present with movement symptoms. 

Parkinson’s disease can result in a specific type of dementia known as Parkinson’s dementia. These individuals can have problems with memory, concentration and decision making, symptoms which are shared with Alzheimer’s disease. These symptoms emerge many years after the initial motor symptoms of Parkinson’s disease have presented and a diagnosis of PD has been made.

What’s the outlook for Parkinson’s disease?

With advances in treatment, most people will have a normal or near-normal life expectancy. Parkinson’s disease is not a fatal condition. 

However, the condition does challenge the body making people more vulnerable to severe infections. Parkinson’s disease affects everyone differently - the speed at which the disease progresses, response to treatment and level of disability vary hugely between individuals.

Many people respond well to treatment experiencing mild to moderate disability, whilst others may not respond as well and can experience severe disability. As a progressive neurological condition, the symptoms of the disease can get worse over time.