Dementia with Lewy bodies (DLB) is a type of progressive dementia that leads to a decline in thinking, reasoning, and independent function because of abnormal microscopic deposits that damage brain cells over time. These deposits consist mainly of alpha-synuclein, a protein that is found widely in the brain but whose normal function is not yet known. The deposits are named Lewy bodies after Frederick H. Lewy, M.D., the neurologist who discovered them while working in Dr. Alois Alzheimer’s laboratory during the early 1900s.
Dementia with Lewy bodies is the third most common cause of dementia after Alzheimer’s disease and vascular dementia, accounting for 10 to 25 percent of dementia cases.
Lewy bodies are also found in other brain disorders, including Alzheimer’s disease and Parkinson’s disease dementia. Many people with Parkinson’s eventually develop problems with thinking and reasoning, and many people with DLB experience movement symptoms, such as hunched posture, rigid muscles, a shuffling walk, and trouble initiating movement.
Symptoms of Dementia with Lewy Bodies:
This overlap in symptoms and other evidence suggest that DLB, Parkinson’s disease, and Parkinson’s disease dementia may be linked to the same underlying abnormalities in how the brain processes the protein alpha-synuclein. Many people with both DLB and Parkinson’s dementia also have plaques and tangles-” hallmark brain changes linked to Alzheimer’s disease.
Common DLB Symptoms Include:
- Changes in thinking and reasoning
- Confusion and alertness that varies significantly from one time of day to another or from one day to the next
- Parkinson’s symptoms, such as a hunched posture, balance problems, and rigid muscles
- Visual hallucinations
- Trouble interpreting visual information
- Acting out dreams, sometimes violently, a problem known as rapid eye movement (REM) sleep disorder
- Malfunctions of the “automatic” (autonomic) nervous system
- Memory loss that may be significant but less prominent than in Alzheimer’s
Diagnosis of Dementia with Lewy bodies:
The only way to confirm a diagnosis of dementia with Lewy bodies (DLB) is through a postmortem autopsy. Researchers currently believe that DLB and Parkinson’s disease dementia are two different expressions of the same underlying problems with brain processing of the protein alpha-synuclein. Despite this, doctors recommend continuing to diagnose DLB and Parkinson’s dementia as separate disorders.
The Diagnosis is DLB when:
- Dementia symptoms consistent with DLB develop first
- When both dementia symptoms and movement symptoms are present at the time of diagnosis
- When movement symptoms develop within a year after DLB diagnosis
However, the diagnosis is Parkinson’s disease dementia when a person is originally diagnosed with Parkinson’s based on movement symptoms, and dementia symptoms do not appear until a year or later.
Causes of DLB:
Researchers have not yet identified any specific causes of dementia with Lewy bodies. Most people diagnosed with DLB have no family history of the disorder, and no genes linked to DLB have been conclusively identified yet.
Treatment for DLB:
As of now, there are no treatments that can slow or stop the brain cell damage caused by dementia with Lewy bodies. Instead, current strategies focus on helping symptoms.
Current Medication Treatments for DLB may Include:
- Cholinesterase inhibitor drugs are the current mainstay for treating thinking changes in Alzheimer’s. They also may help certain DLB symptoms.
- Antipsychotic drugs should be used with extreme caution in DLB patients. Although physicians sometimes prescribe these drugs for behavioral symptoms that can occur in Alzheimer’s, they may cause serious side effects in as many as 50 percent of those with DLB. Side effects may include sudden changes in consciousness, impaired swallowing, acute confusion, episodes of delusions or hallucinations, or appearance or worsening of Parkinson’s symptoms.
- Antidepressants may be used to treat depression, which is common with DLB, Parkinson’s disease dementia, and Alzheimer’s. The most commonly used antidepressants are selective serotonin reuptake inhibitors (SSRIs).
- Clonazepam may be prescribed to treat REM sleep disorder.
Unfortunately, DLB gets worse over time and shortens oneâ€™s lifespan.
- Dementia with Lewy Bodies. A.M.A.D. Encyclopedia. n.d. Web. 31 January 2013.