Lewy Body Dementia

Medically Reviewed By William C. Lloyd III, MD, FACS

What is Lewy body dementia?

Lewy body dementia (LBD) is a type of progressive dementia. Lewy bodies are microscopic clumps of a protein, alpha-synuclein, in the brain. The name comes from the doctor, Frederich H. Lewy, who discovered the abnormal deposits. LBD affects about 1.4 million Americans. It accounts for up to 25% of dementia cases. Other common forms of dementia include Alzheimer’s disease and vascular dementia.

Lewy bodies build up in areas of the brain that affect memory, thinking, and motor skills. This leads to problems with reasoning, behavior and cognition. It also causes movement and autonomic body function problems. Autonomic functions are things you don’t have to think about—they happen automatically. They include things like blood pressure, digestion, and temperature control. These physical symptoms of LBD overlap with another closely related condition, Parkinson’s disease. Making matters more complicated, Parkinson’s disease can also lead to dementia. In fact, many experts consider LBD to be an umbrella diagnosis that includes Parkinson’s dementia and dementia with Lewy bodies.

LBD typically starts after age 50 and tends to affect men more often than women. Most people who develop LBD do not have a family history of the disease. However, your risk increases if you have a family member with LBD or Parkinson’s disease.

There is no cure for LBD. Instead, treatment focuses on relieving symptoms and managing behaviors. Doctors use a combination of medications, therapy, and other strategies. See your doctor if you, or a loved one, are having symptoms consistent with dementia. LBD is a progressive disease that will eventually be fatal. However, you can improve quality of life by seeking an early diagnosis and treatment.

What are the symptoms of Lewy body dementia?

Lewy body dementia symptoms affect cognition, memory, movement, and autonomic body functions.

Common symptoms of Lewy body dementia

The most common symptom of LBD is progressive deficits in attention and executive functions, such as planning and processing information. Additional core features include recurrent visual hallucinations and fluctuations in thinking and alertness. These variations can change day to day or throughout the day. This can lead to episodes of confusion, drowsiness, vacant staring, and disorganized speech.

Other LBD symptoms and features include:

  • Delusions and hallucinations involving touch, smell or hearing

  • Difficulty interpreting visual and spatial information

  • Loss of autonomic body function control leading to such problems as sweating, dizziness, falls, constipation, and bowel or bladder incontinence

  • Memory loss that becomes more noticeable later in the disease and is not as prominent as in Alzheimer’s disease

  • Movement problems, including tremors, rigid muscles, stiffness, slowness, balance problems, hunched posture, and difficulty walking or shuffling walk

  • REM (rapid eye movement) sleep behavior disorder, which causes people to act out physically, and sometimes violently, in their dreams

It’s important to establish an accurate diagnosis and exclude other types of dementia—especially treatable forms of dementia, such as alcoholism. It can be challenging for doctors to tell the difference between LBD and related disorders. However, it is essential to get the right diagnosis from an experienced neurologist or neuropsychologist. Some treatments for other conditions, including Alzheimer’s and Parkinson’s disease, can worsen LBD symptoms. Seeking the advice of a dementia specialist with LBD experience is the best way to avoid a misdiagnosis.

To diagnose LBD, doctors use a combination of the patient’s symptoms, family history, and a variety of tests to diagnose or exclude other potential causes of the patient’s symptoms. It can take up to a year to establish the diagnosis with reasonable certainty. Brain imaging can help narrow the diagnosis. MRI can show loss of brain cells (atrophy), but this occurs with other types of dementia too. Certain nuclear scans of the brain, including positron emission tomography (PET) can be more specific for diagnosing LBD. This type of technology is available at some medical centers and may be covered by insurance. Some scans are only for studying LBD and its treatment. Your doctor is the best person to ask about the latest diagnostic tools for Lewy body dementia. 

What causes Lewy body dementia?

Scientists do not know what causes Lewy bodies to form. The protein in Lewy bodies, alpha-synuclein, is normally present in the brain. It is involved in several brain functions, including communication between nerve cells (neurons). In LBD, alpha-synuclein forms into Lewy bodies, which are microscopic deposits inside neurons. Lewy bodies interfere with the neurons’ ability to communicate and function. Eventually, the neurons die.

What are the risk factors for Lewy body dementia?

There are only a few Lewy body dementia risk factors. Growing older is the main one. The disease typically develops after age 50. There have been cases of LBD in younger people, although this is rare. Other risk factors include being male and having a family history of LBD or Parkinson’s disease. LBD occurs slightly more frequently in men compared to women. And while most people who get it have no family history, the risk is higher if they do.

Reducing your risk of Lewy body dementia

Reducing your risk of a condition focuses on changing risk factors that are under your control. This is not possible with LBD. However, experts believe that adopting a healthy lifestyle can help decrease your risk of dementia in general. This includes eating a balanced diet, exercising regularly, and providing mental stimulation for your brain on a regular basis and as you age. Many people enjoy working puzzles, playing brain games, or reading to “exercise” their brain.

If you are concerned about dementia, talk with your doctor about your risk factors. Find out what you can do to keep your brain healthy.

How is Lewy body dementia treated?

Currently, scientists have not found a cure for LBD. Lewy body dementia treatment aims to treat the symptoms of the disease and manage behaviors. The two main types of treatment are medications and various forms of therapy. It is very important to see a doctor with plenty of experience treating LBD. Some medications doctors commonly use to treat other dementias and related conditions affect LBD differently. They can actually worsen LBD symptoms and cause severe side effects.

Medications for LBD include:

  • Cholinesterase inhibitors, such as donepezil (Aricept), galantamine (Reminyl), and rivastigmine (Exelon). These are Alzheimer’s drugs that can help improve cognitive symptoms, alertness, and possibly behavioral problems and hallucinations.

  • Carbidopa/levodopa (Sinemet), which is a Parkinson’s drug. It can help improve movement problems, such as rigid muscles and difficulty walking.

  • Sleep medicines, such as clonazepam (Klonopin) or the supplement melatonin, to treat REM sleep behavior disorder

Doctors sometimes use antidepressants and antipsychotics to manage depression, behavioral problems, and hallucinations. However, many of the drugs in these classes can cause problems for people with LBD. An experienced dementia specialist will know when to use these medicines and which ones are safe.

Non-medical therapies for LBD include:

  • Behavioral therapy to help manage negative behaviors, hallucinations and emotions

  • Caregiver education to help with offering soothing responses to the person with LBD and avoid aggravating unwanted behaviors

  • Occupational therapy to help improve functioning and independence by creating daily routines and breaking tasks into small steps

  • Physical therapy to help with walking gait and muscular problems

  • Speech therapy to help with swallowing and speaking control

  • Support groups for both the person with LBD and the caregiver

What are the potential complications of Lewy body dementia?

Lewy body dementia is a progressive and irreversible disease. As the disease worsens, dementia can become severe and behavior can become aggressive. Depression can also develop. Worsening motor symptoms can lead to falls and other injuries. Eventually, LBD is fatal. The average time from diagnosis to death ranges from 5 to 8 years. However, it can progress as quickly as 2 years or last as long as 20 years. How fast the disease advances and how long it lasts depends on a person’s age at diagnosis, their overall health, and the severity of symptoms.

Was this helpful?
  1. Dementia with Lewy Bodies. Alzheimer’s Association. https://www.alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia/dementia-with-lewy-bodies
  2. Learn About LBD. Lewy Body Dementia Association. https://www.lbda.org/go/what-lbd-0
  3. Lewy Body Dementia. Mayo Foundation for Medical Education and Research. https://www.mayoclinic.org/diseases-conditions/lewy-body-dementia/symptoms-causes/syc-20352025
  4. What Is Lewy Body Dementia? National Institute on Aging. https://www.nia.nih.gov/health/what-lewy-body-dementia

Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Dec 9
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