What Is Lewy Body Dementia?

Lewy body dementia (LBD) is a type of dementia caused by abnormal protein deposits in the brain, called Lewy bodies. The deposits cause chemical changes in the brain, leading to problems with thinking, movement, balance, behavior, and mood. 

LBD is one of the most common causes of dementia, affecting an estimated 1.4 million people in the U.S.

Symptoms of Lewy Body Dementia

Lewy body dementia symptoms include:

• Memory impairment and confusion
• Difficulty solving problems
• Dizziness and falls
• Erratic body movements
• Sleep disorders such as REM sleep behavior disorder
• Hallucinations and delusions

As many as 80% of people with Lewy body dementia experience vivid, well-formed visual hallucinations. They may, for example, see people who aren't there or witness the transformation of an object into something entirely different.

About 30% also have auditory hallucinations.

Complications

Lewy body dementia can affect the autonomic nervous system, which regulates how the heart, lungs, and other organs function. This can lead to symptoms such as:

• Sensitivity to temperature extremes
• Blood pressure changes
• Dizziness
• Fainting
• Falls
• Constipation
• Urinary incontinence
• Sexual dysfunction
• Diminished ability to smell
  

Other Forms of Dementia

Lewy body dementia symptoms are so similar to those of other forms of dementia that LBD can be misdiagnosed. This might make more sense when you consider that there are many types of dementia.

It may help to think of dementia as one large (and cruel) "umbrella" that slowly robs people of their ability to think, talk, remember, and use their bodies. Many diseases crowd underneath this umbrella, including:

• Alzheimer’s disease
• Frontotemporal dementia (FTD)
• Huntington’s disease
• Lewy body dementia
• Mixed dementia
• Parkinson’s disease dementia
• Vascular dementia

Of these, Alzheimer's is the most common. And it shares many symptoms with LBD, which adds to the confusion.

What Are the Stages of Lewy Body Dementia?

Lewy body dementia usually takes five to eight years to progress from diagnosis to death. Some cases may progress faster, while others may progress much more slowly. Regardless of the speed of progression, the timeline of Lewy body dementia is usually distinguished by early, middle, and late stages.

Early Stages

In general, the earlier stages of Lewy body dementia may involve hallucinations or other distortions of reality such as delusions, restlessness, acting out dreams during sleep (called REM sleep disorder), and some movement difficulties.

Some people may appear to "freeze" or get stuck as they move about. Others may develop urinary urgency and incontinence. Unlike Alzheimer's disease, memory is usually still fairly intact in the early stages. But confusion and some mild cognitive changes may be present.

Middle Stages

As Lewy body dementia progresses, symptoms develop that more strongly resemble Parkinson's disease. These symptoms include falls, increased problems with motor functions, difficulty with speech, swallowing problems, and greater paranoia and delusions.

Cognition also continues to decline, with shorter attention and significant periods of confusion. 

Later Stages

In the later stages of Lewy body dementia, extreme muscle rigidity and sensitivity to touch develop. People need assistance with almost all activities of daily living. Speech is often very difficult and may be whispered. Some people stop talking altogether.

Lewy body dementia typically causes the individual to become very susceptible to pneumonia and other infections because of weakness.

It is impossible to predict how long it will take to progress through any stage of Lewy body dementia. According to one study, end-stage Lewy body dementia could last between two months and one year. For some people, however, death may occur quickly and unexpectedly.

Causes of Lewy Body Dementia

The exact cause of LBD is unknown, but scientists are learning more about its biology and genetics. The accumulation of Lewy bodies in the brain interferes with the production of the neurotransmitters dopamine and acetylcholine, which leads to problems with muscle movements, memory, thinking, and processing information.

Risk Factors

Factors that increase the risk of developing LBD include:

• Age (typically 50 and older)
• Having a family member with LBD
• Having certain health conditions, including Parkinson's disease or REM sleep behavior disorder

Diagnosing Lewy Body Dementia

Lewy body dementia is hard to diagnose because the early symptoms can resemble those of Alzheimer's disease, Parkinson's disease, or a psychiatric illness. It may involve a team of healthcare specialists, including your primary care provider, a neurologist, and a geriatric psychiatrist.

The diagnosis is based on your symptoms and ruling out other conditions. Tests may include:

• Physical and neurological exam
• Cognitive assessment to assess memory and thinking skills
• Blood tests to rule out other health conditions
• Brain imaging tests
• Sleep study

How Is Lewy Body Dementia Treated?

There's no cure for Lewy body dementia, but some symptoms may improve for a period of time with treatment. An LBD treatment plan may involve medications, physical or other types of therapy, and counseling. 

The healthcare team may make suggestions for home safety updates and identify any equipment that might make everyday tasks easier.

What Is the Prognosis for Lewy Body Dementia?

Lewy body dementia cannot be prevented or cured. The life expectancy of people with LBD varies, but people typically live about five to seven years after diagnosis.

Tips for Caregivers

As a caregiver for someone with LBD, you will take on many responsibilities, but you don't have to do them alone. There are many sources of help available, such as adult day centers, respite care, and online and in-person support groups.

Some actions you can take include:

Advocate for your loved one. Inform healthcare staff of the LBD diagnosis and medication sensitivities; request that the person's neurologist be consulted before giving any drugs to control behavior problems.

Be prepared. Keep a list of the person's medications and dosages, health conditions, and allergies to medications. Keep copies of insurance cards, healthcare advance directives, and contact information for doctors, family members, and friends handy.

Adjust expectations. The biggest thing to expect is the unexpected. The unpredictability of Lewy body dementia is one of its characteristics. Knowing this can be reassuring to both the individual living with the disease as well as family and caregivers.

Take time for yourself. All caregivers need time away from caregiving responsibilities to maintain their own health and well-being. Learn to accept help when it's offered, and learn to ask family, friends, and agencies—such as home care and adult day care—for support.

Summary

Lewy body dementia is one of many types of dementia (with Alzheimer's being the most common). A major difference with Lewy body dementia is that its symptoms can fluctuate significantly from day to day. It is marked by early, middle, and late stages. A team of healthcare providers can diagnose LBD, but there is no cure. Life expectancy varies but is typically five to seven years after diagnosis.