Dementia with Lewy Bodies: Causes, Symptoms & Suggestions for Caregivers

Last Updated: June 11, 2021


Introduction: What is Lewy Body Dementia?

People with Lewy Body Dementia (LBD), experience a progressive decline in their memory and ability to think, similar to Alzheimer’s disease. What is different about LBD is that the cognitive ability or alertness of a person with Lewy body dementia is more likely to fluctuate from one moment to the next, unlike Alzheimer’s and related diseases like vascular dementia. Individuals with LBD also often have visual hallucinations (seeing things that aren’t there) and delusions (believing something that is not true). On the surface, people with LBD often have movement problems resembling Parkinson’s disease. This is because the same structures of the brain are affected in Lewy body dementia as in Parkinson’s disease.

There are actually several subtypes and different names for Lewy body dementia, because LBD is a term for any brain disease caused by the buildup of the destructive protein alpha-synuclein. Types of LBD include:

● Diffuse Lewy body disease
● Cortical Lewy body disease
● Senile dementia of Lewy type
● Lewy body variant of Alzheimer’s
● Parkinson’s disease dementia (PDD)


How Common Is Lewy Body Dementia?

Dementia with Lewy bodies is the third most common type of dementia after Alzheimer’s disease and vascular dementia. According to the Lewy Body Dementia Association (LBDA), it affects about 1.4 million individuals and families in the United States. The average age of onset is after 50, and studies indicate the disease is slightly more common in men than women.

Lewy body dementia is progressive, like Alzheimer’s disease. This means that even with current treatments, individuals who have it get worse, in terms of function and ability, over time. On average, a person diagnosed with LBD lives approximately 5 to 8 more years, although one can live as long as 20 years with the disease.

Approximately 50-80% of individuals with Parkinson’s disease go on to develop Parkinson’s disease dementia.


Causes of Lewy Body Dementia

Lewy body dementia is caused by the build-up of a protein called alpha-synuclein, which forms abnormal deposits called Lewy bodies within the brain. Lewy bodies (named for the physician who discovered them, Friedrich H. Lewy) are also found in the brains of those with Parkinson’s disease dementia and Alzheimer’s disease. Lewy bodies interrupt the normal function of brain cells by making it harder for them to communicate and by leading to cell death. Currently, the cause for the Lewy body protein buildup is not known. However, it is believed that environmental and genetic risk factors combined with aging play a role in the development of LBD.

It is also important to note that plaques and tangles in the brains of people with Alzheimer’s disease are similar to the Lewy-body clumps that form between cells in brains with LBD, but come from a different type of protein: Alzheimer’s is linked to amyloid-beta, while LBD’s biological marker is the abnormal protein alpha-synuclein.

LBD is not necessarily inherited. Having an immediate family member who had Lewy body dementia may increase your risk of getting this form of dementia, but it often develops in persons who have no family history of the disease. Individuals may develop Lewy body dementia in combination with Alzheimer’s disease and/or Parkinson’s disease.


Symptoms of Lewy Body Dementia

Most forms of dementia initially affect specific parts of the brain, but Lewy bodies may develop in several different areas of the brain and can cause a wider range of physical and behavioral symptoms.

Common symptoms include: difficulty with thinking, movement, sleep, memory, and depth perception. There may be changes in mood and behavior, such as depression, anxiety, and agitation. In addition, bodily functions are affected as the disease progresses, including the ability to regulate body temperature, bladder and bowel control, and blood pressure control. The range of possible symptoms includes many of the same ones seen in persons with Alzheimer’s disease and Parkinson’s disease.

Symptoms Similar to Parkinson’s Disease
● Moving slowly and shuffling or shaking as the individual walks
● Walking or standing very stiffly, with arms and legs flexed
● Having a blank expression / staring into space
● Balance issues / regular falls

Symptoms Similar to Alzheimer’s Disease
● Problems making new memories or recalling past memories
● Becoming easily confused
● Making odd or inappropriate decisions and actions

Symptoms Relatively Unique to Lewy Body Dementia
● Symptoms improve or worsen from moment to moment or hour to hour
● Hallucinating, especially visually
● Delusions
● Becoming active and violent at night, acting out dreams due to a condition that develops called rapid eye movement (REM) sleep disorder

 Did You Know? REM sleep behavior disorder affects as many as ⅔ of people with LBD. It causes someone to act out their dreams, sometimes flailing arms or legs and crying out in fear.


Diagnosis of Lewy Body Dementia

It is often difficult for physicians to diagnose Lewy body dementia because it is so similar to Alzheimer’s and Parkinson’s diseases. Further complicating the process is that a patient may actually have mixed dementia, which is a combination of these diseases. Someone with Lewy body dementia may be diagnosed as having Alzheimer’s disease or vascular dementia when symptoms first appear.

Early diagnosis is important, because treatments can make symptoms easier to live with and it’s best to get started as soon as possible. It’s also important to diagnose LBD as soon as possible because certain medications that might be prescribed for Alzheimer’s or Parkinson’s (for example, anticholinergics) are not appropriate for someone with LBD and might worsen symptoms. For more on medications and treatment, see below.

There are no specific tests for Lewy body dementia, but doctors can make a diagnosis based on symptoms and behaviors. The diagnosis process usually begins when symptoms related to memory or movement become so severe that they affect how someone functions in daily life. The first step is scheduling an appointment with a primary care physician. The next step is usually a referral to a psychiatrist, neurologist, and/or a geriatrician.

Medical professionals will consider a combination of symptoms and test results (including questionnaires and possibly brain scans). Someone with LBD may either be diagnosed as having “probable” Lewy body dementia or “possible” Lewy body dementia.

Is it “Probable” or “Possible” LBD?
According to the LBDA, diagnosis of probable Lewy body dementia requires that 2 of the 3 following characteristics be present, in addition to dementia symptoms. A diagnosis of possible Lewy body dementia only requires that 1 of the 3 are present, in addition to presenting with dementia.

1) Fluctuating cognition: Has trouble with his or her memory or abilities to stay alert and attentive. However, these symptoms may seem to get better or worse at times.
2) Visual hallucinations: Experiences and reacts to hallucinations that seem very real to him or her. This usually means seeing something that is not actually present.
3) Parkinsonisms: Has some of the problems with movement and action similar to those associated with Parkinson’s disease. Examples include tremors and muscle stiffness.

Apart from the differences already noted, approaches to diagnosis and treatment of Lewy body dementia are similar to those of other forms of dementia. To learn more about diagnosing dementia (general), click here.


Treatment of Lewy Body Dementia

There is no cure available for Lewy body dementia at this time. Currently, there are also no medications approved by the FDA that specifically target this form of dementia. However, many individuals with the disease seem to benefit from the use of cholinesterase inhibitors.

Cholinesterase Inhibitors

Cholinesterase inhibitors are a group of drugs commonly prescribed to individuals with Alzheimer’s disease and other forms of dementia in order to slow the progression of the disease. For individuals with dementia, brain function decreases in part because their brain cells are no longer able to communicate with one another as well as previously. Cholinesterase inhibitors act to increase levels of a neurotransmitter called acetylcholine. This is a chemical that helps brain cells (neurons) communicate and function better, and acetylcholine also plays a significant role in memory and learning. In practical terms, one may find that their loved one can remember names and details or perform activities with fewer problems when taking these medications.

There are four main cholinesterase inhibitors on the market:
1) Aricept® (generic name: donepezil)
2) Razadyne®, formerly known as Reminyl (generic name: galantamine)
3) Exelon® (generic name: rivastigmine)
4) Cognex® (generic name: tacrine) is another option, but is less commonly prescribed due to its serious potential side effects including nausea, weight loss and skin rash.

These medications are typically prescribed to individuals in the early to middle stages of dementia (though Aricept® has been approved to treat severe dementia as well). It is important to remember that they only slow the progression of dementia and Alzheimer’s disease; they do not stop or reverse their course. Additionally, as an individual’s dementia advances, these medications are not able to balance out the damage that has already occurred. These medications typically help for only months to a few years.

In general, individuals who use cholinesterase inhibitors experience few side effects. The most commonly experienced side effects are gastrointestinal problems, such as nausea, diarrhea, vomiting, and loss of appetite.

These drugs, originally developed for persons with Alzheimer’s disease, help improve the brain’s ability to function. In fact, these drugs may even be more effective for Lewy body patients than for Alzheimer’s patients. Parkinson’s disease medications, such as Sinemet®, Parcopa®, and Stalevo®, may also be prescribed in the event that the person has increasing trouble with movement.

 Aducanumab for Lewy Body Dementia? A drug recently FDA-approved for the treatment of Alzheimer’s disease may help those with other dementias, including Lewy body dementia. Aducanumab (brand name Aduhelm) has been shown in studies to reduce amyloid-beta plaques in the brains of people with Alzheimer’s, and while LBD presents different types of protein clumps, alpha-synuclein rather than amyloid-beta, some patients have a mix of both and could see benefits.

Be Careful with Medications
One of the reasons it’s important to get an accurate diagnosis is that people with Lewy body dementia can have particularly bad reactions to medications normally prescribed to help with psychiatric conditions. Antianxiety drugs affect the brain in a way that causes severe side effects for people with LBD. Anticholinergics (including Benadryl) should also be avoided by those with LBD because those drugs, often prescribed for urinary incontinence, affect bodily function in a way that can cause disorientation and confusion.

Persons with Lewy body dementia should not take antipsychotic drugs unless otherwise directed by a physician. Even though these medications can help manage hallucinations, in Lewy body patients they can make movement problems worse.

Because side effects from medications are stronger, and even more dangerous, for people with LBD, doctors will often start these prescriptions at a very low dose and carefully monitor the response. Learn more about how dementia is treated in general.


Suggestions for Caregivers

The most important thing to realize when caring for someone with Lewy body dementia is there is a need for flexibility. A person with LBD’s symptoms may change from day to day, becoming better or worse, and this can be difficult for caregivers to explain and handle. People with Alzheimer’s tend to become confused and agitated at night, a condition called “sundowning”; with LBD, those sundowning behaviors can strike at any time of day. Remind yourself and others that your loved one is not simply “acting up.” Maintaining a consistent day-to-day routine will help make agitation and confusion less frequent and easier to manage. It’s also a good idea to keep your loved one with LBD away from large crowds and noisy environments. At home, use a calm voice and play soothing music.

As Lewy body dementia progresses, afflicted individuals will also have an increasingly difficult time maintaining balance and moving about safely. Some caregivers find that suggesting the use of a cane or a walker is helpful. Additionally, there are several things you can do around the house to make sure that your loved one is able to move about safely and easily in order to prevent future accidents.

As with Alzheimer’s disease, Lewy body dementia will continue to progress and reduce your loved one’s ability to make appropriate decisions. Be sure to review our pages on legal and financial issues to learn what can be done before your loved one reaches the later stages of the disease.