Dementia with Lewy bodies 

  • Overview

Introduction 

What is dementia?

The term 'dementia' describes a loss of mental ability associated with gradual death of brain cells.

Dementia may affect:

  • memory
  • thinking speed
  • language
  • understanding
  • judgement

People with dementia may behave inappropriately in social situations and aspects of their personality may change – for example, they may seem uninterested, have problems controlling their emotions, or hold false beliefs.

Dementia is usually an age-related disease, and normally rare in anyone younger than 65.

'Dementia with Lewy bodies' is a common form of dementia, affecting over 100,000 people in the UK.

The term 'dementia' describes a loss of mental ability associated with gradual death of brain cells.

In dementia with Lewy bodies, tiny clumps of abnormal protein – called Lewy bodies – form in the brain. These are also present in the brains of people with Parkinson’s disease.

Symptoms usually develop gradually and become more severe over the course of many years. 

What are the symptoms?

People with this form of dementia not only experience problems with memory and judgement, like those with Alzheimer's disease, but are also likely to experience difficulty with concentration and visual perception (recognising objects and making judgements about where they are in space).

They may also have:

  • slowed movement, stiff limbs and tremors (as seen in Parkinson’s disease)
  • recurrent visual hallucinations (seeing things that aren't there)
  • sleep disturbances, including sleepiness during the day
  • fainting, unsteadiness and falls

They tend to swing from a state of alertness to drowsiness or staring into space. These extreme changes may be unpredictable and happen from hour to hour or day to day. 

It is these extra symptoms that distinguish dementia with Lewy bodies from other types of dementia.

Learn more about the symptoms of dementia with Lewy bodies.

Why do Lewy bodies form, and how do they cause damage?

It's not understood why Lewy bodies build up in people with dementia and Parkinson's disease. 

The protein deposits build up in certain areas of the brain. It is thought they disrupt the brain's normal functioning by interfering with chemical signals transmitted from one brain cell to another. For example, they affect the nerve cells responsible for initiating muscle movement.

Find out more about the causes of dementia with Lewy bodies.

How is dementia with Lewy bodies diagnosed?

If your GP thinks you may have dementia, you may be referred to a memory clinic or another specialist clinic, where you will be asked about your symptoms and have a physical check-up and memory test. You may also have blood tests and brain scans.

A diagnosis of dementia with Lewy bodies can be made if you have significant mental decline plus at at least two of the main features of the disease, such as fluctuating states of alertness, frequent visual hallucinations or slowed movements.

Learn more about the diagnosis of dementia with Lewy bodies.

How is it managed?

There is no cure for dementia with Lewy bodies, nor any drugs that will slow the disease.

However, a few different medications can be effective in controlling some of the symptoms. In particular, cholinesterase inhibitors (used to treat Alzheimer's disease) have been shown to improve the symptoms of mental decline and the hallucinations for some people.

Rehabilitative support such as physiotherapy, occupational therapy and speech therapy aim to help with regaining lost functions, and dementia activities such as 'memory cafes' and some psychological therapies can help with managing the symptoms.

If you have dementia, your future health and social care needs will need to be assessed and a care plan will be drawn up.

For more information, read about the treatment of dementia with Lewy bodies

What is the outlook?

The progression of symptoms will depend to an extent on the person's personality and general health. Home-based help will be needed, and some people will eventually need residential care in a nursing home.

The average survival after time of diagnosis is similar to that of Alzheimer's disease, about eight years. However, as with Alzheimer's disease, this can be highly variable in different people.

If you or a loved one has been diagnosed with dementia, remember that you are not alone. The NHS, social services and voluntary organisations will be able to provide advice and support to help you and your family.

More information

Living with dementia

Find dementia activities near you

Living well with dementia 

Staying independent with dementia 

Dementia activities 

Looking after someone with dementia 

Dementia and your relationships 

Communicating with people with dementia 

Coping with dementia behaviour changes 

Care and support

Sources of help and support 

Organising care at home 

Dementia and care homes 

Dementia, social services and the NHS 

Dementia and your money 

Managing legal affairs for someone with dementia 

End of life planning 

How you can help

Become a 'Dementia Friend'

Help make the UK a good place for dementia

Share your dementia experiences




Page last reviewed: 05/02/2013

Next review due: 05/02/2015

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