Lewy body dementia


Lewy body dementia


Dementia with Lewy bodies is a common form of dementia estimated to affect more than 100,000 people in the UK.

The term "dementia" describes a loss of mental ability associated with gradual death of brain cells. It's rare in anyone younger than 65.

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

Signs and symptoms

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

They may experience:

slowed movement, stiff limbs, and tremors

recurrent visual hallucinations (seeing things that aren't there)

sleep disturbances, including sleepiness during the day

fainting, unsteadiness, and falls

People with the condition 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.

What causes dementia with Lewy bodies?

Dementia with Lewy bodies is caused by deposits of an abnormal protein called Lewy bodies inside brain cells. These deposits, which are also found in people with Parkinson’s disease, build up in areas of the brain responsible for things such as memory and muscle movement.

It's not clear why the deposits develop and how exactly they damage the brain, but it's thought they disrupt the brain's normal functions by interfering with chemical signals transmitted from one brain cell to another.

Dementia with Lewy bodies usually occurs in people with no family history of the condition, although there have been reports of rare cases that seem to run in families.

Diagnosing dementia with Lewy bodies

If you think you may have early symptoms of dementia, it's a good idea to see your GP. If you're worried about someone else, encourage them to make an appointment, and perhaps suggest that you go along with them.

Your GP can do some simple checks to see if there is chance you could have dementia, and they can refer you to a memory clinic or another specialist clinic if necessary.

At one of these clinics, 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.

The results of these checks and tests will give your doctor a good idea as to whether your symptoms are caused by dementia with Lewy bodies, another type of dementia, or something else entirely.

How dementia with Lewy bodies is managed

There is no cure for dementia with Lewy bodies or any medication that will slow it down.

However, a few different medicines can be effective in controlling some of the symptoms. In particular, acetylcholinesterase inhibitors (used to treat Alzheimer's disease) have been shown to improve symptoms such as hallucinations and confusion in some people.

Supportive treatments – such as physiotherapy, occupational therapy, and speech and language therapy – can help improve any problems with movement, everyday tasks, and communication.

Psychological therapies and specific dementia activities, such as memory cafés, can also help with memory loss, confusion, and feelings of disorientation.


How quick dementia with Lewy bodies progresses varies from person to person. Home-based help will be needed, and some people will eventually need residential care in a nursing home.

The average survival after the time of diagnosis is similar to that of Alzheimer's disease – around five to eight years. However, as with Alzheimer's disease, this can be highly variable.

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

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Communicating with people with dementia

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Care and support

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Dementia and your money

Managing legal affairs for someone with dementia

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How you can help

Share your dementia experiences

Symptoms of dementia with Lewy bodies 

The symptoms of dementia with Lewy bodies usually develop gradually and become more severe over the course of a few years.

Like other forms of dementia, the condition causes problems with:

thinking speed




memory (although significant memory loss may not occur until later on)

People with dementia with Lewy bodies may also have other symptoms that can help distinguish it from other types of dementia, such as:

extreme swings between alertness and confusion or drowsiness, which may happen unexpectedly and change from hour to hour or day to day

slow movement, stiff limbs, and tremors (as seen in Parkinson's disease), which cause shuffling when walking

seeing or hearing things that aren't real (hallucinations), which can range from pleasant to distressing

fainting, unsteadiness, and falls

sleep disturbances, which can cause talking in your sleep or acting out dreams

loss of facial expression

difficulty swallowing (dysphagia)


These symptoms can make daily activities very difficult and can lead to further health problems, such as injuries from falls, and chest infectionscaused by accidentally inhaling food instead of swallowing it. 

Seeking medical advice

If you think you may have early symptoms of dementia, it's a good idea to see your GP. If you're worried about someone else, encourage them to make an appointment and perhaps suggest that you go along with them.

Symptoms of dementia can have a number of different causes. Your GP will be able to carry out some simple checks to try to  what the cause may be, and they can refer you to a specialist for further tests if necessary.

Diagnosing dementia with Lewy bodies 

Confirming a diagnosis of dementia can be difficult, particularly when the condition is in its early stages. This is because many of the symptoms of dementia can also be caused by other conditions.

For dementia with Lewy bodies to be diagnosed correctly, you will have a number of tests and assessments, including:

an assessment of your symptoms – for example, whether you have typical symptoms of dementia with Lewy bodies

a full assessment of your mental abilities

a physical examination

a review of the medication you are taking

a range of tests, including blood tests, to rule out other possible causes of your symptoms, such as a vitamin B12 deficiency

brain scans, such as a computerised tomography (CT) scan or amagnetic resonance imaging (MRI) scan, which can check for signs of a stroke, brain tumour or brain shrinkage – a single photon emission CT (SPECT) scan, which looks at the dopamine system in the brain, can also sometimes help

Some of these tests can be carried out by your GP. Some will be carried out by other specialists, such as a neurologist (an expert in treating conditions that affect the brain and nervous system), an elderly care physician, or a psychiatrist with experience of treating dementia.

Assessing your mental abilities

The Mini Mental State Examination (MMSE) is widely used to help test mental ability.

The MMSE can be used to assess a number of different mental abilities, including:

short- and long-term memory

attention span


language and communication skills

ability to plan

ability to understand instructions

The MMSE involves a series of tasks, which together carry a maximum score of 30 points. Example tasks include:

memorising a short list of objects and then repeating the list back

correctly identifying the day of the week, the date, or the year

The MMSE is not a test to diagnose dementia, but it's useful for assessing the level of mental impairment a person with dementia may have.

Treating dementia with Lewy bodies 

There's currently no cure for dementia with Lewy bodies, but treatments can help manage the symptoms.

First of all, your future health and social care needs will need to be assessed and a care plan drawn up.

This is a way of ensuring you receive the right treatment for your needs. It involves identifying areas where you may need some assistance, such as:

what support you or your carer need for you to remain as independent as possible

whether there are any changes that need to be made to your home to make it easier to live in

whether you need any financial assistance


Medication cannot stop the progression of dementia with Lewy bodies, but it can sometimes help reduce the symptoms.

Acetylcholinesterase inhibitors

Acetylcholinesterase inhibitors, such as donepezil (Aricept), galantamine (Reminyl) or rivastigmine (Exelon), may help improvehallucinations, confusion, and drowsiness in some people.

These medicines work by increasing levels of the chemical acetylcholine in the brain, which improves the ability of the brain cells to send signals to each other.

Common side effects of acetylcholinesterase inhibitors include feeling and being sick, diarrhoea, headaches, fatigue (extreme tiredness), and muscle cramps.

Other medications

Other medications that may help control some of the symptoms of dementia with Lewy bodies include:

levodopa (a medication used to treat Parkinson's disease) can help reduce movement problems, although it can also worsen hallucinations and other psychotic symptoms, so it needs to be carefully monitored by your doctor

antidepressants may help you cope if you have depression

clonazepam can sometimes help improve your sleep if you experience sleep disturbances

Antipsychotics, such as haloperidol, should be avoided wherever possible, and should only be used to treat severely challenging behaviour that is putting you or others at risk of harm. This is because they can cause a range of serious side effects, including rigidity and immobility.

If antipsychotics are needed, they will be prescribed at the lowest possible dose, for the shortest possible time, by a specialist experienced in treating dementia with Lewy bodies. 

Supportive measures and treatments

In addition to medication, there are a number of therapies and practical measures that can help make everyday living easier for someone with dementia. These include:

occupational therapy to identify problem areas in everyday life, such as getting dressed, and help work out practical solutions

speech and language therapy to help improve any communication or swallowing problems

physiotherapy to help with movement difficulties

psychological treatments, such as cognitive stimulation, to help improve memory, problem-solving skills and language ability

relaxation techniques, such as massage, and music or dance therapy

home modifications, such as removing loose carpets and potential trip hazards, ensuring the home is well lit, and adding grab bars and handrails

checking for problems with vision and hearing that could be contributing to hallucinations

Legal matters

If you have been diagnosed with dementia, you will need to make arrangements for your care that take into account the gradual decline in your mental abilities. This should include ensuring that your wishes are upheld if you're not able to make decisions for yourself.

You may wish to draw up an advance decision after first receiving a diagnosis of dementia. This makes your treatment preferences known now, in case you are unable to do this in the future.

You may also want to consider giving a relative lasting power of attorney. This is the power to make decisions about you if you are unable to.

Advice for carers

If you care for someone with dementia, you may find it helpful.

respite care – this can allow you to take breaks from caring

legal issues for carers – such as what to do when someone can no longer make decisions for themselves

benefits for carers – such as allowances and tax credits that may be available

looking after someone with dementia