What is Lewy body dementia?

Lewy body dementia (LBD) is a progressive disease involving abnormal deposits of a protein called alpha-synuclein in the brain. The deposits are called Lewy bodies and are named after Friedrich H. Lewy, the scientist who discovered them.

LBD is a term that covers two conditions that have similar symptoms. One is dementia with Lewy bodies, and the other is Parkinson’s disease dementia.

Lewy bodies grow in nerve cells in the brain that affect motor control and thinking.

When you think of dementia, the first thing that comes to mind might be Alzheimer’s disease. The two conditions differ in that Alzheimer’s involves extreme memory problems, and LBD is more likely to affect how you process information. In addition, LBD causes physical symptoms such as tremor and muscle stiffness.

It’s estimated that LBD affects 1.4 million people in the United States, but that may be an underestimate. It’s likely underdiagnosed because early symptoms are so similar to those of Parkinson’s disease and Alzheimer’s disease.

The cause of LBD isn’t clear, so there’s no known method of prevention. Treatment primarily focuses on symptom management. Keep reading to learn more.

There are four patterns in which symptoms typically begin. They are:

  • physical symptoms such as tremor, motor problems, and balance issues
  • cognitive issues and memory problems
  • neuropsychiatric symptoms such as hallucinations, behavioral problems, and difficulty with complex mental tasks
  • variations in alertness and attention

Cognitive symptoms tend to present earlier in dementia with Lewy bodies than in Parkinson’s disease dementia.

No matter how it starts, LBD eventually leads to a similar set of physical, cognitive, and behavioral symptoms.

These include:

  • cognitive issues, such as trouble processing information and planning

  • visual and spatial problems
  • tremors and other movement problems, such as muscle stiffness, that make it harder to walk
  • irritability or agitation
  • hallucinations that are very well formed and detailed, or delusions
  • depression or apathy
  • anxiety or paranoia
  • sleep disorders, including acting out dreams while asleep
  • daytime sleepiness or the need to nap
  • staring, inability to pay attention, or fluctuating attention span
  • disorganized speech

LBD can also affect the autonomic nervous system. This can lead to poor regulation of:

  • blood pressure, pulse, and heart rate
  • perspiration and body temperature
  • digestive functions

This can lead to:

  • excessive sweating
  • bowel and bladder problems
  • dizziness, which can increase the risk of falling

Research has yet to uncover the root cause of LBD.

What is clear is that people with LBD have abnormal clusters of proteins, called Lewy bodies, in their brains. Lewy bodies disrupt brain function.

Most people who have dementia with Lewy bodies don’t have a family history of the disease. To date, there’s no known genetic cause.

Between 50 and 80 percent of people with Parkinson’s disease later develop Parkinson’s disease dementia. It’s not apparent why some people do and others don’t.

Scientists aren’t certain what prompts the proteins to build up in the first place.

Not everyone with Parkinson’s disease will develop LBD, but having Parkinson’s may increase your risk of LBD.

Your risk may be higher if someone else in your family had LBD or Parkinson’s disease. It’s more likely to be diagnosed in people older than 60 and in men more often than women.

LBD may be associated with depression.

Learn more: What’s the difference between dementia and Alzheimer’s disease? »

Early diagnosis is important, because some drugs used to treat Parkinson’s and Alzheimer’s can make LBD worse. However, that’s not easy because there’s no single test that can accurately diagnose LBD.

Here are some of the exams and tests that can help your doctor arrive at the correct diagnosis.

Physical examination may include testing of:

  • heart rate and blood pressure
  • muscle tone and strength
  • reflexes
  • balance and coordination
  • sense of touch
  • eye movements

Your doctor will look for signs of Parkinson’s disease, stroke, or tumors.

Blood tests can pick up on things such as thyroid problems and vitamin B-12 deficiency, which can affect brain function. This may help rule out LBD.

An assessment of mental abilities, such as memory and thinking skills, can indicate signs of dementia.

Imaging tests, such as MRI, CT, or PET scans can help diagnose brain bleeding, stroke, and tumors.

Sleep evaluation can reveal REM sleep behavior disorder.

Autonomic function testing looks for signs of heart rate and blood pressure instability.

For a diagnosis of LBD, you must have at least two of these:

  • fluctuation in cognitive function
  • visual hallucinations
  • signs and symptoms of Parkinson’s disease, such as tremor and muscle stiffness

These symptoms also support the diagnosis of LBD:

LBD is a progressive disorder, so signs and symptoms will get worse over time.

This can lead to:

  • aggressive behavior
  • increasingly severe tremors and balance issues
  • high risk of injury from falls due to confusion or balance problems
  • depression
  • severe dementia

There’s no treatment to slow or stop disease progression. Treatment is designed to make symptoms more manageable.


People with LBD tend to be very sensitive to drugs. Medications must be prescribed with great caution and careful monitoring. Here are some of the drugs that may be considered.

For thinking and memory problems, as well as behavior problems and hallucinations:

  • donepezil (Namzaric)
  • galantamine (Razadine)
  • rivastigmine (Exelon)

For tremor, slowness, and stiffness:

  • levodopa with carbidopa (Sinemet)

For sleep disturbances:

  • low-dose clonazepam (Klonopin)
  • melatonin, a natural hormone

In some cases, antipsychotics may be prescribed for hallucinations, delusions, or paranoia, but with extreme caution. Antipsychotics can worsen symptoms of LBD. Severe side effects can be life threatening.

Other medications may be used to treat blood pressure or other symptoms as they arise.


A typical treatment plan may include one or more of the following:

  • Physical therapy: This can help improve gait, strength, flexibility, and promote overall health.
  • Occupational therapy: This can help make everyday tasks such as eating and bathing easier, requiring less assistance from others.
  • Speech therapy: This can help improve problems with swallowing and speaking.
  • Mental health counseling: This can help both the person with LBD and their family learn to cope with their emotions and behaviors.

Complementary therapies

This can include:

  • Vitamins and supplements: Studies of vitamins and supplements in people with LBD are lacking. And because they can interact with medications, you should consult your doctor before using them.
  • Art and music therapy: This may help ease anxiety and improve mood.
  • Pet therapy: A pet can provide companionship and boost mood.
  • Aromatherapy: This can help calm and soothe.

Learn more: Animal-assisted therapy for depression »

There’s no way to stop the progression of LBD. It will continue to affect cognitive abilities and motor functions and require lifelong medical care. Some symptoms can be managed, but medications must be monitored and adjusted as needed.

A person with LBD will need assistance provided by family and professional caregivers. Average life expectancy is eight years after onset of symptoms.

The role of the caregiver is likely to grow as the disease progresses. The situation is different for everyone, but here are some general tips for caregivers of people with LBD:

Communicate effectively

Speak slowly and in a clear voice. Use simple sentences and supplement with hand gestures and pointing.

Keep it simple. Throwing in extra information or providing too many choices can be confusing, so stick to one streamlined topic at a time. Then allow ample time for the response. Rushing a person with LBD can lead to frustration for both of you.

LBD can cause an array of emotions. It’s understandable if the person you’re caring for seems irritated, fearful, or depressed. Be respectful and nonjudgmental. Offer reassurance that they will have the support they need.

Provide stimulation

Physical movement is good for people with LBD. Encourage simple exercises and stretching routines. Daytime exercises can also make it easier to sleep at night.

Stimulate mental functioning with puzzles and games that require thinking skills.

Promote good sleep

People with LBD have sleep disorders, including sleep behavioral problems.

Don’t offer caffeinated beverages to them, and try to prevent daytime napping. Provide a calming atmosphere before bed, which should be at the same time every night. Leave nightlights on throughout the house to prevent nighttime confusion, tripping, and falling.


People with LBD have to deal with tremors, balance issues, and trouble getting around. They also tend to get confused and may experience hallucinations or delusions.

Lower the risk of injury by eliminating clutter, loose rugs, and other tripping hazards. Arrange furniture so that it’s easy to get around and keep the home well lit.

Care for the caregiver

It’s easy to get lost in caregiving to the detriment of your own health and well-being. But you can’t do your best for someone else if you don’t take care of yourself.

Try to follow these self-care tips:

  • Ask for help. Enlist family, friends, neighbors, or in-home healthcare providers.
  • Take time off to do something for yourself. Socialize with your friends, schedule a massage, or plop on the sofa and stream a movie. “Me time” matters.
  • Get regular exercise, even if it’s just a walk around the neighborhood.
  • Maintain a healthy diet so your own health doesn’t get derailed.
  • Take a periodic time out for deep breathing and quiet meditation or soothing music.
  • See your own doctor when you start to feel out of whack.

Caregiver burnout is all too real. It doesn’t mean you’ve failed, it only means you’re stretching yourself too thin. You might find it helpful to join a caregiver support group so you can interact with people who get it. If you start to feel emotionally or physically drained, consider speaking to a therapist.