Lewy Body Dementia

What Is Lewy Body Dementia (LBD)?

LBD is a kind of dementia that happens when abnormal deposits of protein (alpha-synuclein) build up in the brain.

The protein deposits, called Lewy bodies, affect certain chemicals in the brain that are vital for:

• Memory
• Conduct
• Thinking
• Sleep
• Movement

LBD is the second most common type of dementia, after Alzheimer's disease. More than 1 million people in the U.S. have Lewy body dementia.

People with LBD often have:

• Issues with thinking and reasoning.
• Distinct movements, such as a hunched posture and a shuffling gait.
• Delusions.

LDB symptoms mostly affect people after age 50. Symptoms start out slow and get worse over time.

The disease is slightly more common in men than women.

Types of Lewy body dementia

LBD is an umbrella term for two related types of brain disorders:

• Dementia with Lewy bodies, where thinking ability declines before physical problems occur. For this reason, people can easily mistake LBD for Alzheimer's disease. And sometimes a person has both.
• Parkinson's disease dementia starts as a movement disorder, with tremors or shaking. Most people with Parkinson's have Lewy bodies in their brain. Dementia symptoms start more than a year after other symptoms, though not all people with Parkinson's will have dementia.

In time, most people with LBD suffer both mental and physical symptoms.

Lewy body dementia causes

Doctors don't know the exact cause of LBD.

But they do know that Lewy bodies are in the brains of people with this type of dementia.

LBD risk factors and complications

The following may increase your risk for LBD:

• Age. LBD almost always occurs in people over 50.
• Sex. LBD affects more men than women.
• Parkinson's disease. This degenerative nerve disease is often a forerunner of LBD.
• REM sleep behavior disorder. People with LBD may also have this disorder, where they physically act out their dreams. They may shout, punch, or kick in their sleep.
• Family history. Having a family member with the disease increases your chances of getting it.

Complications of LBD include:

• A decline in thinking and reasoning ability.
• Depression.
• Worsening of tremors.
• Balance problems.
• Risk of falls.
• Death.

How does Lewy body dementia differ from Alzheimer's?

Though the two disorders have some symptoms in common, LBD differs from Alzheimer's in a few ways:

• Memory problems tend to surface later in LBD. Loss of memory is often one of the first clear symptoms of Alzheimer's.
• There may be movement problems earlier in LBD.
• Delusions aren't a common symptom of Alzheimer's disease. Having visual hallucinations are common in people with LBD (up to 80% have them), even in the early stages. People with LBD may also hear and smell things that aren't there.
• Sudden changes in mood or behavior are more common with LBD. People with LBD may be alert and attentive one minute, confused and drowsy a short time later. Their behavior may change from day to day, not following any routine or pattern.
• Disruption of the autonomic nervous system is more common in LBD. This can cause a sudden drop in blood pressure leading to falls and dizziness. It may also cause bladder control issues.