Lewy Bodies Disease

Dementia with Lewy bodies (DLB) is a form of progressive dementia. It's caused by the decay of the tissues in the brain.

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

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

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

The decay or deterioration of brain tissue causes dementia with Lewy bodies. DLB may be genetic. But it is not always clear why someone develops DLB. Lewy bodies in the brain affect substances called neurotransmitters. A neurotransmitter is a chemical that helps send signals from one nerve cell to another.

One type of neurotransmitter is dopamine. It helps send signals that cause muscle movement. Lewy bodies interfere with the making of dopamine. A lack of dopamine causes movement problems, such as those seen in PD.

Acetylcholine is another type of neurotransmitter. It is 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.

The main sign of DLB is a worsening decline in things like memory, thinking, and problem solving. This decline is enough to affect the ability to work and do normal daily activities. Memory may be affected. But it isn’t usually as impaired as in someone with AD.

DLB is generally diagnosed when at least 2 of the following features also occur with dementia:

• Changes in attention and alertness. These changes may last for hours or days. Signs of these changes include staring into space, being lethargic or drowsy, and having speech problems. 
• Visual hallucinations. These hallucinations recur and are very detailed. They generally don’t bother the person having them. 
• Movement symptoms consistent with PD. These include slow movement, shuffling gait, rigidity, and falls. The person may also have tremors. But they are not as pronounced as in a person with PD with dementia.

Other signs and symptoms seen in DLB include:

• Depression.
• Sleep disorder that affects REM sleep, causing vivid dreams with body movement.
• Dizziness, feeling lightheaded, fainting, or falling.
• Urinary incontinence.

In DLB, memory problems often occur later in the disease.

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

The symptoms of DLB may look like other conditions. Always see a healthcare provider for a diagnosis.

Your healthcare provider will ask about your medical history and symptoms. He or she will do a physical exam. You may also need these tests:

• Blood tests. These are to rule out conditions such as vitamin B12 deficiency and hypothyroidism (low levels of thyroid hormone).
• CT scan. This imaging test uses X-rays to create pictures of the brain.
• Electroencephalogram (EEG). An EEG measures the electrical activity of the brain.
• 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 find chemical changes in an organ or tissue. These changes can show the start of a disease before physical changes can be seen with other imaging tests.
• Neuropsychological assessments. These tests assess things such as 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 look like dementia.

DLB has no cure. Treatment involves managing symptoms. It may include:

• Supportive care.
• Physical therapy.
• Psychotherapy.
• Behavioral interventions or strategies to manage the disease.

Medicines used to treat AD and PD may also be used to treat DLB. But many people with DLB can’t tolerate these medicines. Talk with your healthcare provider if you have problems taking any medicine.

Interventions used in other forms of dementia may also help people living with DLB. These include:

• Using glasses or hearing aids as needed.
• Having a structured environment.
• Learning behavioral strategies to manage the disease. These will change over time as the disease worsens.
• Improving lighting and staying around other people to help with hallucinations.
• Using assistive devices or physical therapy to help prevent falls.

It’s important to work with a healthcare provider familiar with DLB and the many aspects of the disease. Other specialists are often involved, too.

Talk with your healthcare providers about when it's important to call them. Your healthcare providers will likely advise calling if your symptoms become worse, or if you have obvious or sudden changes in behavior, personality, or speech. This includes mood changes, such as increasing depression or feeling suicidal.