Dementia with Lewy Bodies (DLB)
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Also known as:
- Lewy-Body Dementia (LBD)
- Diffuse Lewy-Body Dementia
- Cortical Lewy-Bodies
Introduction
Dementia with Lewy-Bodies sometimes occurs alone as the presenting illness
and sometimes it occurs simultaneously with Alzheimer’s or Parkinson’s
disease. Dementia with Lewy-Body is the second most frequent cause of dementia
in elderly adults. It is a neurodegenerative disorder associated with abnormal
structures (Lewy-Bodies) found in certain areas of the brain. Lewy-bodies
are named after smooth round protein lumps, which are found in the nerve
cells of affected brains. The Lewy-Bodies are found throughout the outer
layer of the brain (the cerebral cortex) and deep inside the midbrain and
brainstem.
Frederich Lewy, a neurologist and contemporary
of Alois Alzheimer, first described these abnormal protein structures
in 1912. Because these structures and many of the symptoms of
dementia with Lewy bodies are associated with Parkinson’s
and Alzheimer’s disease, researchers do not yet understand
whether dementia with Lewy bodies is a distinct clinical entity
or perhaps a variant of Alzheimer’s or Parkinson’s
disease. Symptoms can range from traditional parkinsonian effects,
such as loss of spontaneous movement (bradykinesia), rigidity
(muscles feel stiff and resist movement), tremor, and shuffling
gait, to effects similar to those of Alzheimer’s disease,
such as acute confusion, loss of memory, and loss of, or fluctuating,
cognition.
Visual hallucinations may be one of the first symptoms
noted, and patients may suffer from other psychiatric disturbances
such as delusion and depression. Onset of the disorder usually
occurs in older adults, although younger people can be affected
as well.
Symptoms
- Progressive cognitive decline, memory loss, confusion
- Fluctuating cognition with pronounced variation in attention
- Recurrent visual hallucination that are typically well formed and detailed
- Spontaneous motor features of parkinsonism
Features supportive of the diagnosis are:
- Repeated falls
- Syncope
- Transient loss of consciousness
- Neuroleptic sensitivity
- Systematized delusion
- Hallucinations in other modalities
An extensive neurological and neuropsychological evaluation including brain
image are essential for a diagnoses. Dementia with Lewy-Bodies is difficult
to diagnose because it resembles and overlaps with other dementias like Alzheimer’s
disease and Vascular dementia and Parkinson’s disease.
As in most dementias, a definitive diagnosis in
only available after an autopsy.
Treatment
Caution must be used in treating a person whom are suspected of having DLB.
Medications must be monitored closely for proper balance because some patients
are very sensitive to medication changes and are adversely affected. Neuroleptic
(tranquilizing) anti-psychotic drugs such as haloperidol or thioridazine
that are sometimes given to Alzheimer's patients to help lessen symptoms
such as agitation or hallucinations can cause extreme adverse reactions in
many DLB patients and can bring on motor-related symptoms. A patient treated
with these drugs could become catatonic, lose cognitive function and/or develop
more muscle rigidity, results that could threaten life. Levodopa is usually
given to treat the parkinsonian features of the DLB and Aricept and Cholinesterase
inhibitors, is given to treat the hallucinations.
Caregiving
DLB patients can live at home with frequent reassessment and careful monitoring
and supervision. Caregivers must watch them closely because of the tendency
to fall or lose consciousness. Dementia prevents patients from learning new
actions that might help them overcome movement problems. They may need more
assistance some days than others, and can be reassured by a caregiver's help
in turning attention away from hallucinations.
Links & Resources
For more information, go to our Dementia with Lewy Bodies section of our Links
and Resources page where we list some other helpful websites on the topic.
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