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A B C D E F G H I J K LM N O P Q R S T U V W X Y Z 0-9
(A-Z listing includes diseases, conditions, tests and procedures)

Dementia with Lewy Bodies (DLB)

Lewy Body Dementia: What You Need to Know

  • Lewy body dementia is a form of progressive dementia that affects a person’s ability to think, reason, and process information.

  • Diagnosing Lewy body dementia can be challenging; an estimated 1.4 million Americans are living with the disease.

  • The condition has three features that distinguish it from other forms of dementia:

    1. Fluctuating effects on mental functioning, particularly alertness and attention, which may resemble delirium

    2. Recurrent visual hallucinations

    3. Parkinson-like movement symptoms, such as rigidity and lack of spontaneous movement.

  • Interventions used in other forms of dementia may help people living with Lewy body dementia. It’s important to work with a specialist familiar with the many aspects of the disease.

What is Lewy body dementia?

Lewy body dementia is a form of progressive dementia caused by degeneration of the tissues in the brain.

More than a million people in the U.S. are affected by Lewy body dementia, according to the Lewy Body Dementia Association.

People with Lewy body dementia have a buildup of abnormal protein particles called Lewy bodies in their brain tissue. Lewy bodies are also found in the brain tissue of people with Parkinson disease (PD) and Alzheimer disease (AD). However, in these conditions, the Lewy bodies are generally found in different parts of the brain.

The presence of Lewy bodies in Lewy body dementia, PD, and AD suggests a connection among these conditions. But scientists haven’t yet figured out what the connection is.

Lewy body dementia affects a person’s ability to think, reason, and process information. It can also affect personality and memory. Lewy body dementia becomes more prevalent with age, and typically first presents when a person is in his or her 60s and 70s.  Lewy body dementia is progressive, which means it continues to develop over time. There are several types of dementia with different causes.

What causes Lewy body dementia?

Lewy body dementia is caused by degeneration or deterioration of brain tissue. Lewy body dementia may be genetic, but it is not always clear why someone develops Lewy body dementia. Lewy bodies in the brain affect substances called neurotransmitters. A neurotransmitter is a chemical that helps to transmit signals from one nerve cell to another.

One type of neurotransmitter is dopamine, which helps transmit signals that cause muscle movement. Lewy bodies interfere with the production of dopamine. A lack of dopamine causes movement problems, such as those seen in  Parkinson disease.

Acetylcholine is another type of neurotransmitter found in the parts of the brain responsible for memory, thinking, and processing information. When Lewy bodies build up in these areas, they use up the acetylcholine, causing symptoms of dementia.

What are the symptoms of Lewy body dementia?

According to the National Institute of Neurological Disorders and Stroke, Lewy body dementia has 3 features that distinguish it from other forms of dementia:

  • Fluctuating effects on mental functioning, particularly alertness and attention, which may resemble delirium

  • Recurrent visual hallucinations

  • Parkinson-like movement symptoms, such as rigidity and lack of spontaneous movement

In Lewy body dementia, memory problems often occur later in the progression of the disease.

Lewy body dementia can be confused with other forms of dementia, but it also has unique features, such as hallucinations and delirium.

The primary sign of Lewy body dementia is a progressive decline in cognitive functions, such as memory, thinking, and problem-solving. The decline in cognitive function is enough to affect the ability to work and perform normal daily activities. Although memory may be affected, it isn’t usually as impaired as in someone with Alzheimer disease.

Lewy body dementia is generally diagnosed when at least 2 of the following features are also present with dementia:

  • Fluctuations in attention and alertness. These fluctuations may last for hours or days. Signs of these fluctuations include staring into space, lethargy, drowsiness, and disorganized speech. These fluctuations have been referred to as “pseudo delirium” because they are a lot like delirium.

  • Visual hallucinations. These hallucinations recur and are very detailed. While the hallucinations may be upsetting to someone observing them, they generally don’t bother the person having them. Many people with Lewy body dementia have detailed visual hallucinations.

  • Movement symptoms consistent with Parkinson disease (PD). Such movement symptoms include slow movement, shuffling gait, rigidity, and falls. Tremors may also be present, but not as pronounced as in a person with PD with dementia.

Additional signs and symptoms seen in Lewy body dementia include:

  • Depression

  • Sleep disorder that affects REM sleep, causing vivid dreams with body movement

  • Dizziness, feeling lightheaded, fainting, or falling

  • Urinary incontinence

The symptoms of Lewy body dementia may resemble other conditions. Always see a health care provider for a diagnosis.

How is Lewy body dementia diagnosed?

Diagram of a man receiving a CT scan

The only definite way to diagnose Lewy body dementia is by doing an autopsy – there are tests that show the presence of Lewy bodies. So, Lewy body dementia is diagnosed based on medical history, a physical exam, and symptoms.

In addition to a complete medical history and physical exam, the health care provider may order some of the following:

  • Blood tests. These are to rule out conditions such as vitamin B12 deficiency and hypothyroidism (a lack of thyroid hormones).

  • Computed tomography (CT) scan. This imaging test uses X-rays to create pictures of cross-sections of the brain.

  • Electroencephalogram (EEG). An EEG measures the electrical activity of the brain.

  • Magnetic resonance imaging (MRI). This imaging test uses a large magnet and radio waves to look at organs and structures inside your body. MRIs are very useful for examining the brain.

  • Positron emission tomography (PET). PET may detect biochemical changes in an organ or tissue that can show the onset of a disease process before physical changes related to the disease can be seen with other imaging tests.

  • Neuropsychological assessments. These tests assess mental functioning and include attention span, memory, language and math skills, and problem-solving skills.

  • Psychiatric evaluation. This may be done to rule out a psychiatric condition that may resemble dementia.

How is Lewy body dementia treated?

Dementia with Lewy bodies has no cure. Treatment for Lewy body dementia involves addressing the symptoms.

Medications used to treat Alzheimer disease (AD) and Parkinson disease (PD) are often used to treat Lewy body dementia. Other treatments, such as supportive care, physical therapy, psychotherapy, and behavioral interventions, may be used, too.

It’s important that the health care provider treating Lewy body dementia is familiar with all aspects of the disease, because other specialists are often involved. Because Lewy body dementia shares features with AD and PD, those features will need to be treated. Many people with Lewy body dementia, however, can’t tolerate some of the medications for AD or PD. Caution must be used when prescribing certain medications for Lewy body dementia.

Living with Lewy body dementia

Interventions used in other forms of dementia may also help people living with Lewy body dementia. These include using glasses or hearing aids as needed, educating the patient and family, providing a structured environment, and teaching behavioral interventions. The interventions depend on the specific needs of each patient and his or her caregivers. Needed interventions will change over time as the disease progresses.

Hallucinations may be managed by simply ignoring them and educating the caregiver(s) about them. Improving lighting and keeping the patient around other people also helps.

It’s important to work with a health care provider familiar with Lewy body dementia and the many aspects of the disease. Other specialists are often involved, too.

When should I call my health care provider?

If you are diagnosed with FTD, you and your caregivers should talk with your health care providers about when to call them. Your health care providers will likely advise calling if your symptoms become worse, or if you have obvious and/or sudden changes in

Next steps

Tips to help you get the most from a visit to your health care provider:

  • Before your visit, write down questions you want answered.

  • Bring someone with you to help you ask questions and remember what your provider tells you.

  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.

  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.

  • Know how you can contact your provider if you have questions.

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