Dementia with Lewy Bodies

What is dementia with Lewy bodies and what causes it?

Causes of dementia with Lewy bodies 

Dementia with Lewy bodies is a type of dementia that shares characteristics with both Alzheimer’s disease and Parkinson’s disease. It accounts for 10-25% of dementia cases in Ireland. Like Alzheimer’s disease, symptoms progress gradually over several years. Dementia with Lewy bodies is caused by clusters of protein forming in the nerve cells of the brain.  These  deposits are called Lewy bodies. These deposits are also found in the brain cells of people with Parkinson’s disease. The area of the brain that is affected by these deposits affect moving, thinking and visual perception.

These deposits are also found in people with Parkinson’s disease. They build up in areas of the brain that affect thinking, visual perception and muscle movement. It’s not clear why the deposits develop and how exactly they damage the brain and cause dementia.

Dementia with Lewy bodies usually happens in people with no family history of the condition. There have been rare cases that seem to run in families.

Diagnosing dementia with Lewy bodies

There is no one test used to diagnose a type of dementia. Rather, the diagnosis involves a range of assessments and tests and this can mean that confirming a diagnosis can take time, particularly in the early stages.

A diagnosis of dementia usually begins with a General Practitioner, GP.  It can be helpful to make a note of the changes causing concern before your visit to help you to talk to the GP about them. Perhaps keep a diary to help you to do this.

The GP will generally begin an assessment by ruling out other possible causes of symptoms you are experiencing; this may involve running some tests including blood tests and memory tests as well as an overview of your general health. Some other possible causes of the symptoms you are experiencing include thyroid disorders, vitamin deficiency and side effects of some medication.

The GP may refer to a consultant who will conduct a full assessment to try to establish the cause of the symptoms.   Click here to find out who’s who in dementia care, as they can work with you to help you understand the diagnosis.

If you are under 65, you will be referred to a neurologist or a memory clinic. If you feel a referral to a specialist would be helpful you can discuss this with the GP.

The consultant will conduct a full assessment to try to establish the cause of the symptoms. They usually work with a specialist team and you may see a number of people from this team. This process usually includes

  • Blood tests,
  • A full history of family medical background,
  • A physical examination,
  • An assessment of memory, thinking and activities of daily living,
  • A brain scan (CT, MRI) to identify any changes taking place in the brain which may form part of the assessment, but this may not be required for every case.

The doctors will work directly with the person who is experiencing changes. The doctor may also ask family members to talk about any changes they see or any concerns they may have.

After the assessment, the consultant will draw together all the results and determine what is happening. It may be that the assessment is repeated at a later date in order to identify further changes and confirm a diagnosis.

What if a diagnosis is made?

A diagnosis of dementia can come as a shock, no matter how much it is expected. It is hard for everyone concerned and reassurance and support are vital. The most important thing is to try to be positive and to know that you are not alone. There are people you can talk to and supports and services that can help.

Your GP will be an important person to support you to live well with dementia. You can talk to them about your dementia, about any medications and treatments you may be prescribed, about areas such as driving and about any symptoms that may emerge.


Symptoms of dementia with Lewy Bodies

Dementia with Lewy bodies progresses over time. It affects everybody in different ways.There are a number of factors that determine how it progresses including a persons mood, their general health and mental and social interaction.

  • tremors and shuffling when walking – similar to Parkinson’s disease
  •  falls and being unsteady on the feet.
  •  depression
  • hallucinations (seeing things that are not there)
  • changing between alertness and confusion or sleepiness
  •  disturbed sleep – this could mean being sleepy during the day or believing your dreams are real.
  •  difficulty swallowing

Some of the symptoms of dementia with Lewy bodies may become more like those of Alzheimer’s disease. These include:
problems with day-to-day memory, changes in behaviour, and increased agitation and restlessness.




Treatment and Medication

There is currently no cure for dementia with Lewy bodies. There are methods that can help control some of the symptoms which include:

  • Physiotherapy, occupational therapy and speech and language therapy. These can help with communication, movement and every day tasks. You can speak to your GP or PHN for a referral to see any of these professionals.
  • Medication to improve movement and reduced hallucinations.
  • Social clubs, Alzheimer cafes to keep engaged socially and mentally. Visit our Supports and services page for information on what is available in your county.


There is certain medication that can help reduce some of the symptoms associated with dementia with Lewy body . They include

  • Donepezil (Aricept)
  • Rivastigmine (Exelon)
  • Galantamine (Reminyl)
  • Memantine

Anti- depressants  and medication to help with movement issues can also be prescribed. From time to time anti-psychotic drugs may be prescribed to deal with extremely distressing symptoms. These drugs are generally not recommended as they can be dangerous to people with Lewy body dementia and in general they should be avoided unless your doctor is fully aware of your diagnosis and the implications. With all medication, it is important to understand what drugs are being prescribed, why they are being prescribed, what benefits they are supposed to bring, and what side-effects may emerge. Where possible, it is important for the person with dementia and a trusted person to discuss this with the prescribing doctor. In 2019 the Department of Health launched a national clinical guideline for the “appropriate prescribing of psychotropic medication for non-cognitive symptoms in people with dementia”. A guide for people with dementia was published and is available HERE


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