Aug 21, 2016

Lewy Body Dementia or Alzheimer’s Disease?

If the Lewy bodies are found in the neurons that make up the cerebral cortex, the gray outside covering of the brain, then the person has Lewy body dementia.

Lewy Body Dementia shares characteristics with both Alzheimer's and Parkinson's diseases.
By Rita Jablonski-Jaudon
Alzheimer's Reading Room

First, let me address the word “dementia.” Dementia is a general word that describes a person who is losing his or her memory over time. Alzheimer’s Disease and Lewy Body are TYPES of dementia, just like Labrador or beagle are types of dogs.

Alzheimer’s disease can occur in people younger than 60, and this type of AD is labelled as early onset AD.

Persons who have AD have PROGRESSIVE difficulty with short-term memory, orientation to time (days and dates), judging distances, calculation, and abstract thinking. The decline is consistent - there are no “ups and downs.”

Depression or lack of sleep can make thinking temporarily worse, so that if depression or sleep issues are addressed, the person seems to “improve.” But the improvement is relatively minor.

Lewy Body Dementia is trickier to diagnose.

What are Lewy bodies?

Lewy bodies are very tiny, abnormal protein structures that show up in brain cells—neurons. They do not belong in these cells. If the Lewy bodies are found in the neurons that make up the cerebral cortex, the gray outside covering of the brain, then the person has Lewy body dementia.

When Lewy bodies affect neurons found in the substantia nigra, a place deep near the brain stem, the person will show the signs of Parkinson’s Disease. When Lewy bodies are found in both the cerebral cortex and the substantia nigra, the person has Parkinson’s Disease Dementia.

Usually, person who has LBD will start with symptoms like with short-term memory loss that seems to literally come and go. This is known as “fluctuating dementia.”

Other symptoms include very vivid dreams, acting out dreams (this is also called a REM behavior sleep disorder or “parasomnia”), and hallucinations.

The REM behavior sleep disorder sometimes occurs for years before any other symptom. The hallucinations are usually visual but can sometimes be auditory. The person with LBD will start to have Parkinson’s disease-types of symptoms, such as a mechanical, shuffling walk and tremors of the hands or arms. Problems with judging distances occur, and delusions (false beliefs), aggression, and depression can also be present.

To make things even more confusing, there is an abrupt and temporary confusional state known as “delirium.”

Delirium is often observed in older adults who are hospitalized, and is usually caused by infections and some medications. It may take up to 3 months for a delirium to resolve in an older adult. A person suffering from delirium may seem “normal” at times and “confused” at other times.

A person with delirium may be incorrectly diagnosed with some form of dementia.

Also, some people who have Parkinson’s Disease for a couple of years can develop dementia, which is called Parkinson’s Disease Dementia.

Likewise, persons with AD can have movement problems, like shuffling when they walk, as the disease worsens.

Some people with AD may experience visual or auditory hallucinations, too. This is why a person may be given one diagnosis early when symptoms show, only to have the diagnose change as new symptoms show up.

How to Get Answers To Your Questions About Alzheimer's and Dementia

What is the relationship between Parkinson’s Disease and Lewy body dementia?

There is disagreement about the relationship between the two diseases, but more neurologists are embracing the idea that Parkinson’s Disease, Parkinson’s Disease dementia, and LBD are all pieces of the same disease.

The only 100% absolute way to diagnose LBD is through a brain autopsy. Neurologists make the diagnosis after a thorough clinical examination that includes a detailed history and may possibly include an MRI of the brain.

Subscribe to the Alzheimer's Reading Room

Anticholinesterase inhibitors like donepezil (Aricept™) or rivastigmine (Exelen™) can help with many of the symptoms, including the hallucinations.

Over-the-counter melatonin can help with the REM behavior sleep disorders.

Rita Jablonski-Jaudon, PhD, CRNP, FAAN is an internationally recognized researcher and expert on non-drug ways to handle dementia-related behaviors. She is an Associate Professor at the School of Nursing at the University of Alabama at Birmingham and a nurse practitioner in The Memory Disorders Clinic at the Kirklin Clinic, UABMC, Birmingham, Alabama. She can be reached at

Related Articles

What Is LBD? | Lewy Body Dementia Association

9 Types of Dementia

What is the Difference Between Alzheimer's and Dementia

Memory Tests

Alzheimer's Care

We help caregivers live a better life! The Alzheimer's Reading Room operates for the benefit of society.

The Alzheimer's Reading Room contains more than 5,000 searchable articles, and has been published daily since July, 2009.

You are reading original content the Alzheimer's Reading Room