The terms Lewy body dementia and Dementia with Lewy bodies are used interchangeably, as are the abbreviations LBD and DLB.
What is Lewy Body Dementia
Lewy body dementia (LBD) is a form of dementia, which is a broad term for a disease of memory, thinking and/or social abilities that are severe enough to interfere with everyday activities. LBD is also a form of Parkinsonism, meaning that it causes some or all of the motor symptoms of Parkinson’s disease (tremor, stiffness, slowness, and walking/balance problems). Additionally, LBD causes visual hallucinations (seeing things that aren’t there) and unpredictable fluctuations in a person’s level of attention or alertness. Many people will also exhibit changes in mood (such as depression) and alterations in behavior or personality (including agitation or aggression). REM sleep behavior disorder (a condition in which people act out their dreams), fainting spells and low blood pressure can also be associated. Symptoms of LBD may seem to arise in the course of several months or may be more gradual in onset. The symptoms do, unfortunately, worsen and people with LBD will require progressively more assistance over time.
What is the difference between Lewy body dementia and Alzheimer’s?
Lewy body dementia (LBD) and Alzheimer’s dementia (AD) are both types of dementia, meaning that they cause problems with memory, thinking and/or social abilities that are severe enough to interfere with everyday activities. Both of them affect “cognition” or thinking capabilities. In general, AD affects memory more significantly (causing forgetfulness) whereas LBD impacts executive function (planning and processing information) and the ability to understand visual information. LBD also causes some or all of the motor symptoms of Parkinson’s (tremor, slowness, stiffness, and walking/balance problems). People with AD may develop these symptoms too but if so, it’s typically much later in the disease course. Visual hallucinations (seeing things that aren’t there) and fluctuating levels of alertness and attention are more characteristic of LBD than AD. While every individual’s course is different, AD usually progresses a bit slower than LBD.
What is the difference between Parkinson’s disease and Lewy body dementia?
Parkinson’s disease (PD) is characterized by motor symptoms, including resting tremor, stiffness, slowness, and walking/balance problems. The diagnosis of PD relies on the presence of slowness plus tremor and/or stiffness. Many people with PD will experience cognitive (memory or thinking) problems, which can range from mild — “mild cognitive impairment” — to severe — “dementia.” However, not everyone with PD will have memory problems; not everyone with memory problems will have dementia; and not everyone with dementia will be classified as having Lewy body dementia (LBD). Even in people with PD, other types of dementia (Alzheimer’s dementia, vascular dementia — that due to multiple strokes, etc.) can occur. Lewy body dementia typically causes some or all of the motor symptoms of PD, memory/thinking problems, visual hallucinations, and fluctuating levels of attention or alertness.
I have Parkinson’s disease. Am I more likely to get Lewy body dementia?
Some studies suggest that having Parkinson’s disease increases your risk of developing Lewy body dementia but having Parkinson’s certainly isn’t a guarantee that you will develop the condition.
Is there a test to diagnose Lewy body dementia?
There is no test that can diagnose Lewy body dementia (LBD). Imaging studies (brain PET, SPECT, DaT scans) are being researched to determine if they might be able to accurately diagnose LBD. At the present time, doctors make the diagnosis based on your medical history and their physical examination. Blood work and standard imaging tests (MRI or CT scans) may be done to exclude other medical conditions. Detailed memory testing is sometimes performed to support a doctor’s diagnosis or establish a baseline for comparison to future testing. Movement disorders specialists (the same physicians who treat Parkinson’s) or cognitive specialists (doctors who treat dementia) typically manage LBD.
Are there any treatments for Lewy body dementia?
There is currently no medication that slows or stops the progression of Lewy body dementia (LBD). However, there are many medications that can help with the symptoms.
For memory and thinking problems, medications called acetylcholinesterase inhibitors (e.g., donepezil, galantamine and rivastigmine), which are also used for Alzheimer’s dementia, are commonly prescribed. These drugs sometimes help control behavior problems and hallucinations as well.
The motor symptoms that are similar to those of Parkinson’s disease (tremor, slowness and stiffness) can be treated with levodopa. Because people with LBD are usually a little more sensitive to the side effects of this medication, doctors use the lowest dosage possible.
If visual hallucinations are frightening or disturbing, or if delusions (false beliefs) or paranoia occur, medications called atypical antipsychotics (e.g., quetiapine or clozapine) may be prescribed. These are used cautiously in select cases because they can potentially worsen the symptoms of LBD. Medication might be avoided, at least for a while, if hallucinations aren’t severe and a person can be reassured regarding them. A visual examination should also be performed as vision problems (the need for corrective lenses, for example) can trigger or worsen hallucinations.
If REM sleep behavior disorder (a sleep disorder in which a person acts out their dreams) is present, melatonin or clonazepam may be helpful.
Is there anything that can be done to prevent Lewy body dementia?
No therapies or behavioral changes have been identified that can prevent Lewy body dementia (LBD). However, some strategies have been suggested to help stave off memory problems in general, and since these don’t have side effects and are good for overall well-being and quality of life, they are worth a try. Recommendations include eating a healthy, balanced diet; exercising regularly; interacting with others socially; and doing activities to stimulate memory and thinking (e.g., reading, completing crossword puzzles, playing a musical instrument, etc.). Decreasing stress and getting enough sleep — easier said than done! — are also beneficial for everyone, of course.
Are there genetic risks for Lewy body dementia?
There are no clear genetic factors that increase one’s risk for Lewy body dementia (LBD). It is worth mentioning, though, that several genetic risk factors do exist that increase risk for Parkinson’s disease, and Parkinson’s may increase risk for LBD.
Do all people with Parkinson’s have Lewy bodies? Do Lewy bodies always cause dementia? How do you know if you have Lewy bodies?
The vast majority of people with Parkinson’s disease (other than a rare subset with a certain genetic mutation) have Lewy bodies — clusters of abnormally folded proteins, including alpha-synuclein, which are found in the nerve cells in the brain. Not everyone with Parkinson’s disease who has Lewy bodies gets dementia.
There is no way to know if you have Lewy bodies because the only way we can see them at the current time is to study the brain at autopsy (although some imaging tests are being done in research settings). We are also working on ways to measure alpha-synuclein (which could indirectly tell us about Lewy bodies) with brain imaging and other testing.