Dementia with Lewy bodies (DLB), also known as Lewy body dementia, is a common type of dementia estimated to affect more than 100,000 people in the UK.
"Dementia" is the name for problems with mental abilities caused by gradual changes and damage in the brain. It's rare in people under 65.
It tends to develop slowly and get gradually worse over several years.
This page covers:
Getting medical advice
Tests and diagnosis
Symptoms of dementia with Lewy bodies
People with dementia with Lewy bodies may have:
- problems with understanding, thinking, memory and judgement – this is similar to Alzheimer's disease, although memory may be less affected in people with dementia with Lewy bodies
- periods of fluctuating alertness alternating with periods of confusion or sleepiness – this can change over hours or days
- slow movement, stiff limbs and tremors (uncontrollable shaking)
- hallucinations (usually seeing or sometimes hearing things that aren't there)
- disturbed sleep, often with violent movements and shouting out
- fainting spells, unsteadiness and falls
These problems can make daily activities increasingly difficult and someone with the condition may eventually be unable to look after themselves.
Read more about the symptoms of dementia with Lewy bodies.
Getting medical advice
See your GP if you think you have early symptoms of dementia, especially if you're over 65 years of age.
If you're worried about someone else, encourage them to make an appointment with their GP and perhaps suggest that you go with them.
Your GP can do some simple checks to try to find the cause of your symptoms and they can refer you to a memory clinic or another specialist for further tests if needed.
Read more about getting a dementia diagnosis.
Tests for dementia with Lewy bodies
There's no single test for dementia with Lewy bodies.
The following may be needed to make a diagnosis:
- an assessment of symptoms – for example, whether there are typical symptoms of dementia with Lewy bodies
- an assessment of mental abilities – this will usually involve a number of tasks and questions
- blood tests to rule out conditions with similar symptoms
- brain scans, such as an MRI scan, CT scan or a single photon-emission computed tomography (SPECT) dopamine transporter scan – these can detect signs of dementia or other problems with the brain
Read more about the tests used to diagnose dementia.
Treatments for dementia with Lewy bodies
There's currently no cure for dementia with Lewy bodies or any treatment that will slow it down.
But there are treatments that can help control some of the symptoms, possibly for several years.
Read more about how dementia with Lewy bodies is treated.
Outlook for dementia with Lewy bodies
How quickly dementia with Lewy bodies gets worse varies from person to person.
Home-based help will usually be needed, and some people will eventually need care in a nursing home.
The average survival time after diagnosis is similar to that of Alzheimer's disease – around 6-12 years. But this is highly variable and some people live much longer than this.
If you or a loved one has been diagnosed with dementia, remember that you're not alone. The NHS and social services, as well as voluntary organisations, can provide advice and support for you and your family.
Causes of dementia with Lewy bodies
Dementia with Lewy bodies is caused by clumps of protein forming inside brain cells. These abnormal deposits are called Lewy bodies.
These deposits are also found in people with Parkinson's disease, and they build up in areas of the brain responsible for functions such as thinking, visual perception and muscle movement.
It's not clear why the deposits develop and how exactly they damage the brain. It's thought that part of the problem is the proteins affecting the brain's normal functions by interfering with signals sent between brain cells.
Dementia with Lewy bodies usually occurs in people with no family history of the condition, although there have been very rare cases that seem to run in families.