How are Parkinson’s and dementia related?


Dementia is a comorbidity of Parkinson's, which means that the damage caused to the brain through Parkinson's, can cause dementia.

Parkinson's dementia

How are Parkinson’s and dementia related?

Parkinson’s and dementia are two of the most common degenerative neurological conditions in this country, affecting many thousands of people. However, there are a lot of myths and misunderstandings about the illnesses.

If you have been told that you have either condition, the future may seem bleak and bewildering. Whether you’ve found this blog having been recently been diagnosed, or are worried about a loved one, then read on, hopefully we can help you to gain some understanding.

What is dementia?

Dementia is defined in the dictionary as: A chronic or persistent disorder of the mental processes caused by brain disease or injury and marked by memory disorders, personality changes, and impaired reasoning. That does give a reasonable explanation, but it’s important to realise that dementia isn’t a specific disease with a single cause, it really is the term that is used to describe a group of symptoms that often exist together. These include forgetfulness, difficulties with thinking and problem solving, and issues with communication and behaviour. These changes can be hardly noticeable in the beginning but often increase until they affect the individual’s ability to live and function independently. Dementia is caused by damage and the death of brain cells. The most common cause of this is Alzheimer's disease, but it can also occur as a result of stroke, drug use or as a comorbidity. Comorbidities are separate illnesses that result from a primary illness. One primary illness that causes dementia is Parkinson’s Disease.

What is Parkinson’s?

Parkinson’s disease is a condition that affects the brain and nervous system. As many as one in five hundred people in the UK are affected, with the disease causing progressive problems with stiffness, shaking and slow movement. This is because nerve cells in the brain that produce an important chemical messenger called dopamine, steadily die off, leading to symptoms getting worse and worse with time.
For more information about Parkinson’s disease; the history, causes, treatments and more, see Parkinson’s: A Deeper Dive

Parkinson’s Dementia

As Parkinson’s disease develops, the brain changes can gradually spread so that they start to affect mental functions as well as movement. This may lead to memory loss, problems with concentration and difficulties with judgement and planning complex tasks. Communication can become challenging because it can be a struggle to remember words and names and to follow conversations. With time, the dementia can progress until it can affect the activities of everyday living like washing, dressing and cooking. As well as the practical and physical problems, Parkinson’s Dementia can affect mental and emotional wellbeing. Low energy, apathy and a lack of interest in things you used to love is common. Many people may also experience anxiety and depression, or find it difficult to control their feelings so that they may have angry or distressed outbursts. Some people can develop visual hallucinations or delusions, which can be upsetting for the individual and for those who love and care for them. This may sound frightening, but it’s important to remember that most people with Parkinson's disease do not get dementia. Although there is definitely an increased risk, the majority of people are unaffected. Usually, if dementia does develop, it happens fairly late on in the disease, typically after ten years or so, with dementia more likely in people who are older or who have had the disease for a long time.

Dementia with Lewy bodies

A less common type of dementia can also affect those with Parkinson’s. This is called Dementia with Lewy bodies. It is different from the classic Parkinson’s Dementia because the dementia comes on at the same time as the movement problems like tremor, stiffness and slowness. On occasion, the dementia can actually develop without any other symptoms or signs. Like Alzheimer’s and Parkinson’s Dementia, Dementia with Lewy bodies causes memory loss, problems with language and impaired concentration. It can also affect the ability to recognise faces, perform simple actions and to judge distances and movements. Vivid visual hallucinations, are particularly common in this type of dementia and can start fairly early on in the disease. Although there is still no cure for Parkinson’s or the dementia associated with the disease, the symptoms may be eased a little with medications and specialist therapies. So, it is important to get advice from your GP, specialist or Parkinson's nurse if you are worried, or if you are experiencing problems with your memory. Life with dementia can be challenging, but getting treatment and support early may improve symptoms and help you maintain your independence, function and wellbeing for longer. With the right care and disease control you really can continue to love, laugh and live with Parkinson’s. . If you are caring for someone with Parkinson's, or Parkinson's dementia, hometouch can help. Founded by an NHS dementia doctor and staffed by people with direct nursing and care experience, we’re dedicated to helping those in need of care to live safely in their own home for as long as possible.
hometouch care guide

Find out more:
  • How Parkinson's progresses
  • How does Parkinson's affect daily life?
  • What are Parkinson's symptoms?
  • How Parkinson's affects the body
  • Why do Parkinson's patients sleep so much?
  • The treatment of Parkinson's disease