Lewy body dementia (LBD) is a common, under-recognized and often misdiagnosed brain disease that affects more than 1 million people in the United States.
1. What is Lewy body dementia?
Lewy body dementia is a progressive brain disease that causes changes in memory, thinking, movement and behavior. Memory and thinking changes typically involve difficulties planning, making decisions and understanding visual information (seeing and interpreting where objects are in space). Movement problems -- tremor, slowness, stiffness, and walking/balance problems -- are similar to those in Parkinson's disease. People with LBD may experience visual hallucinations (seeing things that aren't there); fluctuations in attention and alertness; and changes in behavior, personality and mood (depression or anxiety). Acting out dreams (REM sleep behavior disorder) also is a common symptom. Lewy body dementia is a progressive disease, meaning it gradually worsens over time.
Lewy body dementia often is used as an umbrella term for two related conditions: Parkinson's disease dementia and dementia with Lewy bodies. These diseases share symptoms and brain changes (clumps of abnormal alpha-synuclein protein in clusters called Lewy bodies).
2. How are Lewy body dementia and Parkinson's disease related?
Lewy body dementia and Parkinson's disease (PD) are both progressive diseases involving loss of brain cells and abnormal alpha-synuclein protein clusters called Lewy bodies. LBD and PD also share symptoms, including movement problems (tremor, slowness, stiffness, and walking/balance problems) and, for some people with Parkinson's, memory and thinking changes.
In PD, memory and thinking changes, ranging from mild to significant, can occur at any time in the disease. Not everyone develops memory/thinking changes or dementia. But if dementia does occur, it's typically in later stages, after living with the disease for many years, often decades. In some people with Parkinson's, dementia can come with hallucinations and behavior changes as well. In these ways, the symptoms of Parkinson's disease dementia are similar to LBD and the main difference is in timing. In Lewy body dementia, memory and thinking changes typically come on early in the disease, at the same time or within a year of the movement symptoms.
3. What is the difference between Lewy body dementia and Alzheimer's disease?
Lewy body dementia and Alzheimer's disease (AD) are both types of dementia. Dementia is a broad term that describes a significant change in memory and thinking that interferes with a person's everyday activities. Dementia has many different potential causes. The most common is Alzheimer's, but LBD is the second most common type of progressive dementia.
Some symptoms of Alzheimer's and LBD overlap. But Alzheimer's typically affects memory more considerably, especially early in the disease, whereas LBD commonly causes hallucinations during earlier stages. AD causes short-term memory loss and forgetfulness: a person with AD may ask the same question repeatedly and be unable to learn new information. LBD leads to difficulty processing information, paying attention, and making judgments and decisions: someone with LBD might get confused with directions and have trouble with previously simple tasks. LBD also shows movement problems early in the disease, typically at the same time or with a year of memory and thinking changes. Movement problems sometimes develop in AD, but if these do occur, it's later in the disease.
4. How is Lewy body dementia diagnosed?
There is no test (brain scan or blood test, for example) to diagnose LBD. The lack of a diagnostic test and shared symptoms with Parkinson's and Alzheimer's lead to LBD's common misdiagnosis.
Doctors use your medical history, physical examination and memory tests to make the diagnosis. Oftentimes blood tests and brain imaging scans such as CT or MRI are done to rule out other medical conditions. Doctors also may order detailed neuropsychological testing to formally evaluate all aspects of memory and thinking.
Movement disorder specialists (the same physicians who treat Parkinson's) or cognitive/memory specialists (doctors who treat dementia) typically evaluate and treat people with LBD.
5. How is Lewy body dementia treated?
While no current treatments can slow or stop the progression of disease, there are therapies to ease the symptoms of LBD.
For memory and thinking problems, medications that were originally developed for Alzheimer's disease, including Aricept (donepezil), Razadyne (galantamine) and Exelon (rivastigmine), are commonly prescribed. These drugs won't bring back memory and thinking, but they can boost what functions remain and help with behavioral problems and hallucinations.
In some people with hallucinations (when hallucinations are frightening or threaten safety, for example), additional treatment may be necessary. Doctors may consider antipsychotic medications such as Seroquel (quetiapine), Clozaril (clozapine) or a newer medication called Nuplazid (pimavanserin). These drugs are used cautiously because they can potentially worsen certain LBD symptoms.
For movement symptoms, physicians may prescribe the Parkinson's medication levodopa, using low doses to avoid worsening hallucinations (a potential side effect). Physical and occupational therapists may be helpful for movement problems as well.
For sleep changes (acting out dreams, or REM sleep behavior disorder), treatment often is melatonin (an over-the-counter hormone) or clonazepam.
6. What causes Lewy body dementia?
Scientists do not yet know the exact cause of Lewy body dementia, but the brains of people with LBD show changes in brain chemicals and cells that are responsible for memory/thinking and movement. Clumps of abnormal alpha-synuclein clusters called Lewy bodies are seen in certain brain cells, and researchers believe these cause cell damage or death.
As in other progressive brain diseases (such as Alzheimer's and Parkinson's), the cause is likely to be a complex mix of environmental, lifestyle and genetic factors.
Risks include aging, certain genetic mutations and Parkinson's disease. (But not everyone with Parkinson's will develop dementia, and not everyone with PD who gets dementia has LBD as there are other forms of dementia.)
7. Can Lewy body dementia be prevented?
While no therapy has yet been proven to prevent Lewy body dementia, some strategies may promote brain health, reduce dementia risk and improve general well-being. Recommendations include:
- Eat a healthy, well-balanced diet
- Exercise regularly
- Interact with others socially
- Stimulate your mind (read, do crossword puzzles, learn a new language)
- Decrease stress
- Keep a regular sleep schedule
- Don't smoke (or consider quitting)
- Drink alcohol in moderation
- Work with your doctor to ensure all health conditions (diabetes, high blood pressure, etc.) are controlled
8. What research is ongoing?
Scientists are looking into causes and risks of LBD, as well as ways to diagnose, treat symptoms, and slow and stop progression. Much work surrounds alpha-synuclein and Lewy bodies (also a focus of Parkinson's research) since these clusters are thought to be responsible for brain cell damage and death. Researchers are working to visualize Lewy bodies in the living brain (they can currently only be seen in autopsied tissue) to diagnose and track disease. And in the absence of imaging scans, scientists are looking to measure alpha-synuclein outside the brain (in body fluids and tissues) as an indirect assessment of Lewy bodies. The Michael J. Fox Foundation is funding several teams working to develop alpha-synuclein tests and imaging scans.
Other studies are following people with LBD over time to look for objective measures of disease (biomarkers) that could help diagnose and track disease. Still others, such as Biomarkers Across Neurodegenerative Diseases (BAND) -- a global funding initiative between The Michael J. Fox Foundation and three other leading brain organizations -- investigate existing disease datasets to uncover differences that could lead to tests to diagnose and track these conditions.
At the same time, researchers are working to understand causes and develop better treatments for symptoms and therapies that could slow or stop progression. Recently uncovered genetic mutations that increase LBD risk, some of which overlap with Parkinson's and Alzheimer's, are helping deepen knowledge and open new potential treatment pathways.
9. What resources are available for people with Lewy body dementia and their families?
The Lewy Body Dementia Association has an abundance of educational materials, care partner resources and information about ongoing clinical trials. Your doctor also can connect you to local support groups and staff such as social workers, physical and occupational therapists, and palliative care physicians (who can help with managing symptoms and coordinating care at any point in the disease).
For more on Lewy Body dementia and cognitive changes in Parkinson’s disease, download The Michael J. Fox Foundation’s guide to “Navigating Cognitive Changes in Parkinson’s Disease.”