Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Lewy body disease

7-minute read

What is Lewy body disease?

Lewy body disease is a disorder where round clumps of protein (called Lewy bodies) build up abnormally in the brain, causing the death of nerve cells. The Lewy bodies affect specific areas of the brain, which leads to symptoms affecting memory, thinking, movement and behaviour.

Lewy body disease is a feature of several conditions, including:

The term Lewy body dementia is used to describe the brain changes caused by Lewy bodies that is seen in all the conditions.

What are the symptoms of Lewy body disease?

The symptoms of Lewy body disease include:

  • difficulty concentrating and paying attention
  • extreme confusion
  • difficulty judging distances
  • visual hallucinations (seeing things that aren’t there)
  • Parkinsonism (slowness, stiffness and tremor)
  • a mental state that switches rapidly between thinking clearly and being confused
  • delusions
  • depression
  • disturbed sleep, acting out dreams
  • fainting spells, unsteadiness and falls
  • problems with understanding, thinking, memory and judgement

If you have any of the symptoms above, see your doctor.

In contrast with Alzheimer’s disease, Lewy body disease doesn’t cause short-term memory loss.

The 3 conditions that fall under the umbrella of Lewy body disease tend to overlap, but there are some differences in the mix of symptoms and the timing of when symptoms appear, that can help to distinguish the individual conditions.

Parkinson’s disease usually involves a person developing symptoms of movement disorder first, including stiffness, slowness of movement and tremor. When dementia develops in a person with Parkinson’s disease, it is usually 10-15 years after the other symptoms and is known as Parkinson’s disease dementia.

Dementia with Lewy bodies has symptoms similar to Alzheimer’s disease — including thinking problems and disorientation, but differs in that mental function fluctuates between good and poor in the early stages.

The problems with thinking and problems with movement usually appear within a year of each other in people with dementia with Lewy bodies. Usually the thinking problems come first. The movement problems include stiff muscles, shuffling when walking and stooping over (in common with people with Parkinson’s disease).

People may also have problems with sleep, including acting out their dreams, which may result in them shouting out or thrashing about in their sleep. This sleep disorder may happen years before the other symptoms of dementia with Lewy bodies.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes Lewy body disease?

Lewy body disease is caused by abnormal clumps of protein, called Lewy bodies, developing inside nerve cells in the brain. This leads to the degeneration and death of the nerve cells.

It is not known why Lewy bodies develop. No risk factors have been clearly identified so far, but dementia with Lewy bodies does seem to have a genetic component.

How is Lewy body disease diagnosed?

There is no specific test for Lewy body disease. A person with symptoms of Lewy body disease will usually be examined and assessed to see what mix of symptoms they have and the timing of the appearance of the symptoms. This can help make a diagnosis of Parkinson’s disease, Parkinson’s disease with dementia, or dementia with Lewy bodies.

To make a diagnosis, a neurologist, geriatrician or psychiatrist will assess a person’s thinking and alertness, whether they have hallucinations, Parkinson’s symptoms (stiffness, slowness of movement) and how they sleep.

They may want to ask the person and their family members about symptoms. They may ask a person to do a Mini-Mental State Examination — a short test to check for problems with thinking and memory.

The doctor may also look at blood pressure, heart rate, body temperature and sweating. They may do blood tests to rule out other conditions.

Scans can show degeneration in the brain, but there is no particular appearance that can diagnose Lewy bodies. However, doctors may suggest an MRI or CT scan of the brain to rule out other causes of dementia.

A SPECT (single-photon emission computerised tomography) or PET (positron emission tomography) scan may help to support a diagnosis of dementia with Lewy bodies, but at the moment Lewy bodies can only be confirmed by examining brain tissue after death.

A diagnosis of dementia with Lewy bodies is likely if, alongside dementia, a person has the characteristic symptoms of:

  • visual hallucinations
  • slowness, stiffness and tremors, as with Parkinson's disease
  • a fluctuating mental state
  • REM sleep disturbance with acting out of dreams (such as yelling out or thrashing about while asleep)

In Parkinson’s disease dementia, the muscle and movement symptoms are often more severe than the mental problems.

The sequence of symptoms can help to narrow down the Lewy body disease diagnosis to a specific condition:

  • If brain/thinking symptoms appear years after the muscle and movement problems, then it is more likely a person has Parkinson’s disease dementia.
  • If the movement problems start around the same time as a person’s mental function starts to decline, then dementia with Lewy bodies is more likely.

How is Lewy body disease treated?

There is no cure for Lewy body disease and it will progress. Although there are no specific medicines to slow or stop its progression, there are treatments that can help with some of the symptoms. Treatment is tailored specifically to the person, as symptoms vary so much in people with Lewy body disease.

Some of the medicines have unwanted side effects, and so a person needs to be monitored closely, as treating one symptom may worsen another symptom.

Some of the medicines that may be used to treat symptoms are:

  • Alzheimer's disease medications — to reduce hallucinations and help with thinking and behavioural problems
  • Parkinson's disease medications — to improve rigid muscles and slow movement
  • medicines to help with sleep and REM sleep behaviour disorder

Some medicines, such as first-generation antipsychotics, can cause severe reactions in people with dementia with Lewy bodies and may be dangerous. So, if antipsychotics are prescribed, they will be the newer medicines.

Other therapies and support that can help manage symptoms include:

  • physiotherapy, occupational therapy and speech and language therapy
  • providing cognitive stimulation, such as memory exercises
  • physical exercise, which can improve thinking, movement symptoms and mood
  • relaxation exercises, which can calm a person down
  • changing a person’s immediate environment to help them function (for example, reducing clutter and noise)
  • creating structure and daily routines

What is the outcome for a person with Lewy body disease?

People with Lewy body disease can often function fairly well in the early stages, but then usually need help at home as the disease progresses. How quickly the disease progresses varies from person to person.

As Lewy body disease progresses, the Lewy bodies become more widely spread in the brain. As more areas of the brain are involved, people with Parkinson’s disease and people with dementia with Lewy bodies tend to develop more similar symptoms. The people with Parkinson’s disease develop dementia symptoms and the people with dementia with Lewy bodies develop more movement problems.

As a person’s thinking and ability to move become more affected, they will need more support with daily living. Eventually, people may need residential care when they become dependent on others for help with everything.

Resources and support

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: March 2022

Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Lewy Body Disease | Dementia Australia

Lewy body disease  Lewy body disease is a term that incorporates both Parkinson’s disease and dementia with Lewy bodies, which share similarities in the ways by which they both damage the brain at the cellular level and in the symptoms a person may experience.

Read more on Dementia Australia website

Help sheets | Dementia Australia

Our dementia help sheets provide advice, common sense approaches and practical strategies on a wide range of subjects. These help sheets are available in more than 30 languages.

Read more on Dementia Australia website

Down syndrome and Alzheimer's disease | Dementia Australia

Research has established a link between Down syndrome and Alzheimer’s disease. This page explains what is currently known about this link, and discusses the diagnosis of Alzheimer’s disease in people with Down syndrome and some information about where to find additional support.

Read more on Dementia Australia website

Alzheimer's disease | Dementia Australia

Alzheimer’s disease is the most common form of dementia. Alzheimer’s disease is a physical brain condition resulting in impaired memory, thinking and behaviour. It disrupts the brain’s neurons, affecting how they work and communicate with each other.

Read more on Dementia Australia website

Types of dementia | Dementia Australia

Dementia is the umbrella term for a number of neurological conditions, of which the major symptom includes a global decline in brain function. It is a condition that has been noted in people for hundreds of years. Dementia was a relatively rare occurrence before the 20th century as fewer people lived to old age in pre-industrial society. It was not until the mid 1970s that dementia begun to be described as we know it today. We now know dementia is a disease symptom, and not a normal part of ageing.

Read more on Dementia Australia website

Chronic traumatic encephalopathy (CTE) dementia | Dementia Australia

Dementia describes a collection of symptoms caused by disorders affecting the brain. Chronic traumatic encephalopathy (CTE) is a type of dementia where many repeated head injuries can affect someone’s brain function over time, enough to interfere with the person’s normal or working life. Repeated head injuries can take the form of concussion, or even smaller head knocks without symptoms, which are called subconcussion.

Read more on Dementia Australia website

Vascular dementia | Dementia Australia

Vascular dementia is a form of dementia caused by brain damage resulting from restricted blood flow in the brain. It affects someone’s thinking skills: such as reasoning, planning, judgement and attention. Changes in skills and abilities are significant enough to interfere with daily social or work functioning. Often vascular damage occurs alongside Alzheimer’s disease or other brain disease. Causes of vascular dementia Vascular dementia can be caused by:

Read more on Dementia Australia website

Alcohol related dementia | Dementia Australia

What is alcohol related dementia? Alcohol related dementia, as the name suggests, is a form of dementia related to the excessive drinking of alcohol. This affects memory, learning and other mental functions. Korsakoff’s syndrome and Wernicke-Korsakoff syndrome are particular forms of alcohol related brain injury which may be related to alcohol related dementia.

Read more on Dementia Australia website

Frontotemporal dementia | Dementia Australia

Dementia describes a collection of symptoms caused by disorders affecting the brain. Frontotemporal dementia causes progressive damage to either or both the frontal or temporal lobes of the brain. Frontotemporal dementia can affect one or more of the following: behaviour, personality, language and movement. Memory often remains unaffected, especially in the early stages of the condition. Frontotemporal dementia is more commonly diagnosed in people under the age of 65. Signs and symptoms of frontotemporal dementia Ther

Read more on Dementia Australia website

HIV associated dementia | Dementia Australia

What is HIV associated dementia?  When someone has the human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) they may develop a complication to the disease which is known as HIV associated dementia, or as AIDS Dementia Complex (ADC).

Read more on Dementia Australia website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.