Overview

Dementia with Lewy bodies (DLB), also known as Lewy body dementia, is one of the most common types of dementia.

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.

Symptoms of dementia with Lewy bodies

People with dementia with Lewy bodies may have:

• hallucinations and hearing voices - seeing, hearing or smelling things that are not there
• 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
• confusion or sleepiness – this can change over minutes or hours
• slow movement, stiff limbs and tremors (uncontrollable shaking)
• disturbed sleep, often with violent movements and shouting out
• fainting spells, unsteadiness and falls
• depression and anxiety

These problems can make daily activities increasingly difficult and someone with the condition may eventually be unable to look after themselves.

Getting medical advice

See a 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 a GP and perhaps suggest that you go with them.

The 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 SPECT scan – these can detect signs of dementia or other problems with the brain

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.

Treatments include:

• medicines to reduce hallucinations, confusion, drowsiness, movement problems and disturbed sleep
• therapies such as physiotherapy, occupational therapy and speech and language therapy for problems with movement, everyday tasks, and communication
• psychological therapies, such as cognitive stimulation (activities and exercises designed to improve memory, problem-solving skills and language ability)
• dementia activities, such as memory cafés (drop-in sessions for people with memory problems and their carers to get support and advice)

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 care home.

The average survival time after diagnosis is around 5 to 7 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.

How you can help

• Share your dementia experiences on the Alzheimer's Society website

Symptoms

Dementia with Lewy bodies (DLB) causes problems with mental abilities and a number of other difficulties.

The symptoms tend to come on gradually and get slowly worse over several years, although treatment can help.

Problems with mental abilities

As with other types of dementia, dementia with Lewy bodies typically causes problems with:

• thinking speed
• understanding
• judgement
• visual perception
• language
• memory (but significant memory loss may not occur until later on)

These problems may be constant but typically tend to come and go.

Other symptoms

There are also other symptoms of dementia with Lewy bodies that can help distinguish it from other types of dementia, such as:

• seeing or sometimes hearing things that aren't there (hallucinations) – these can range from pleasant to distressing
• marked swings between alertness and confusion or sleepiness – this can happen unexpectedly and change over minutes or hours
• slow movement, stiff limbs, tremors (uncontrollable shaking) and shuffling when walking – similar to Parkinson's disease
• fainting, unsteadiness and falls 
• disturbed sleep – this could be talking in sleep, acting out dreams or sleepiness during the day
• dysphagia (swallowing problems)
• depression and anxiety

Daily activities become increasingly difficult and there may be further health problems, such as an injury after a fall or a chest infection caused by accidentally inhaling food.

Getting medical advice

See a 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 a GP and perhaps suggest that you go with them.

The GP can do some simple checks to try to find out the cause of your symptoms and may refer you to a specialist for further tests.

Treatment