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Dementia With Lewy Bodies

Written by Ada’s Medical Knowledge Team

Updated on

What is Lewy Body Dementia?

Lewy Body Dementia is a type of dementia characterized by Lewy bodies, clumps of protein that form on brain nerve cells. Lewy Body Dementia is an umbrella term for two types of Dementia, Dementia with Lewy Bodies (DLB) and Parkinson’s Disease Dementia (PDD). 1 2 

Dementia with Lewy Bodies is one of the most common types of progressive dementia. The nerve cells that are affected control thinking, memory and movement. As such, the central features of DLB include progressive cognitive decline, “fluctuations” in alertness and attention, visual hallucinations, and parkinsonian symptoms, such as slowness of movement, difficulty walking, or rigidity. DLB most commonly affects the elderly and is rare in people under 65 years old. 3

Parkinson’s Disease Dementia can occur in those with Parkinson’s Disease, although it develops in later stages of the disease, approximately 10-15 years after onset. Not everyone with Parkinson’s Disease gets PDD. Around 30-40% of people with Parkinson’s develop PDD. Risk for developing Parkinson’s Disease Dementia is 6x greater with mild cognitive impairment. 4 Like in DLB, Parkinson’s Disease is caused by the presence of Lewy Bodies, however unlike in DLB, Parkinson’s Dementia starts with movement symptoms and tends to be consistent with a previous diagnosis of Parkinson’s Disease. 

Lewy Body Dementia life expectancy varies from on average 5-7 years after diagnosis for DLB and 9 years for PDD. 3 5

Because of their symptoms, people with Lewy Body Dementia may find daily activities difficult and require support. While there is no cure, many people learn to live with their symptoms.

What causes Lewy Body Dementia?

Lewy Body Dementia is caused by the formation of clumps of proteins called Lewy Bodies inside brain nerve cells. 2 These proteins build up in areas of the brain that control thinking, understanding, memory and muscle movement. It is unclear why Lewy Bodies form and how they cause symptoms, but current understanding suggests they interfere with brain signaling. 3

Lewy Body Dementia main risk factors include being older than 65, having a family history of the disease and being male. 1 6

What are the symptoms of Lewy Body Dementia?

Lewy body disease symptoms overlap between DLB and Parkinson’s Disease Dementia.

Lewy Body Dementia symptoms include difficulties with thinking, memory, judgment, visual perception, language, and reasoning. These symptoms are chronic, tending to get gradually worse with time. How fast symptoms develop is different for each individual. Symptoms can also include: 1 2 3

  • visual and auditory hallucinations
  • movement disorders e.g. tremors, stiff limbs and slowed movements
  • marked changes in alertness
  • dizziness, fainting, and falls
  • bowel issues and incontinence
  • difficulty swallowing
  • sleeping problems e.g. sleep walking or calling out during sleep
  • depression  

In Dementia with Lewy Bodies, difficulty with thinking and alertness, and hallucinations may develop in early stages. Issues with memory and movement may develop in later stages.

In Parkinson’s Disease Dementia, movement issues develop first and are often in line with a previous diagnosis of Parkinson’s Disease. 2

Because of these symptoms, further health problems may occur, such as injuries after falling. Daily activities may also get progressively more difficult and people with Lewy Body Dementia may require additional support and care.

Diagnosing Lewy Body Dementia

There is no single test for Lewy Body Dementia. Tests that may be performed include: 1 2 7

  • assessment of medical history and symptoms
  • physical examination
  • assessment of mental abilities e.g. memory testing
  • blood tests 
  • urine tests
  • brain scans

Through these, other conditions with similar symptoms can be ruled out and a diagnosis can be made.

How to treat Lewy Body Dementia

While there is currently no cure for Lewy Body Dementia, there are treatments that can help to manage symptoms. 8 A multidisciplinary care team of doctors, nurses, and allied-health professionals can help develop care plans to ease some of the everyday difficulties of living with DLB or PDD.

There is no single treatment that is best and as such, treatment is different for each individual. Treatments can include: 9

  • medicine to help to improve issues with thinking, memory, and confusion
  • medicine to help with movement problems like tremors and stiffness
  • medicine to improve sleep
  • antidepressants to help with depression
  • antipsychotics to help with hallucinations, agitation and aggression 
  • psychological therapies and activities to improve memory and problem solving skills
  • physiotherapy to help with movement problems
  • speech therapy to help with speech and swallowing problems
  • occupational therapy to help modify a patient’s environment to make it safer e.g. handrails in the home, removal of fall hazards
  • alternative therapies like massages, music or dance therapy to help with relaxation may be utilized, however further studies are needed to determine its clinical significance.

It is to be noted that all medications have side effects, and as such must be monitored.

Other considerations that those diagnosed with Lewy Body Dementia may wish to consider include making future arrangements for their personal care. This may take the form of ensuring their wishes for care can be upheld if they are ever unable to make decisions for themselves on account of progressive cognitive decline. 

Support groups also exist that may provide support for people with Lewy Body Dementia, for example The Lewy Body Society and Parkinson’s UK.

DLB vs PDD vs Alzheimer's?

Lewy bodies can be found in other types of dementia, including Alzheimer's dementia. These diseases have similar processes and many overlapping symptoms. Dementia with Lewy Bodies (DLB) shares mental symptoms like confusion and memory loss with Alzheimer’s disease, and motor symptoms such as gait and slow movement with Parkinson’s Disease Dementia. Early memory loss is seen more commonly in Alzheimer’s compared to Dementia with Lewy Bodies. Both conditions can result in problems with movement, but hallucinations, sleep disorders, and dizziness/fainting are more common in early DLB.  Parkinson’s Disease Dementia differs from DLB as movement symptoms start first and are consistent with a diagnosis of Parkinson’s Disease.

Dementia with Lewy Bodies FAQs

Q: How is Lewy Body Dementia diagnosed?

A: There is no single test for Lewy Body Dementia. Tests that may be performed include assessments of symptoms and mental abilities, blood tests and brain scans. Together, a doctor can use these to make a diagnosis and rule out similar conditions. 

Q: What are the first signs of Dementia with Lewy Bodies?

A: In Dementia with Lewy Bodies, difficulty with thinking, alertness, and hallucinations may develop first.

Q: What are the first signs of Parkinson’s Dementia?

A: Parkinson’s Disease Dementia starts with movement symptoms and tends to be consistent with a previous diagnosis of Parkinson’s Disease.