Dementia with Lewy bodies
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Dementia with Lewy bodies is the second most frequent cause of hospitalization for dementia, after Alzheimer's disease. It consists of a set of disorders characterized by the development of abnormal proteinaceous cytoplasmic inclusions, called Lewy bodies, inside neurons and the degeneration of brain stem cells responsible for the manufacture of the neurotransmitter dopamine. The cerebral cortex also degenerates. While Alzheimer's disease results in a pathological loss of cholinergic neurons and the formation of amyloid plaques primarily the hippocampus, Lewy Bodies patients develop these same plaques along with an even more profound loss of cholinergic activity in the hippocampus, in cotical areas, as well as in the basal nuclei.
Dementia with Lewy bodies is similar in some ways to the dementia resulting from Alzheimer's disease or Parkinson's Disease dementia (PDD). It manifests symptoms similar to those of Parkinson's disease as well as in early development of hallucinations (although this can also be due to the treatment of the Parkinsoninian symptoms) and pronounced variation in intellectual function, attention, and alertness. Lewy Bodies Dementia is not a DSM-IV recognized diagnosis. Generally, it is diagnosed when dementia type symptoms develop within a year or two of movement disorder/Parkinsoninian symptoms.
It is often confused in its early stages with Alzheimer's disease and vascular dementia (multi-infarct dementia). No cause has been identified.
The treatment of Lewy Bodies disease, as with Parkison's Dementia, involves stricking a balance between treating the motor and emotive symptoms. Treatment of the movement portion of the disease can typically result in worsening hallucinations and psychosis, treatment of the hallucinations and psychosis can result in worsening movement symptoms. The use of atypical antipsychotics (especially quetiapine) and cholinesterase inhibitors (especially rivastagmine)represent the treatments of choice, but these are all aimed at palliation as there is no cure. The use of memantine may be recommended, and may represent a means to slow or prevent the decline of cognitive function, although strong evidence to support or disprove this is lacking.
Dementia with Lewy bodies is also known under a variety of other names for example, senile dementia of Lewy type. All incorporate the name Lewy.
External link
- NINDS Dementia With Lewy Bodies Information Page (http://www.ninds.nih.gov/health_and_medical/disorders/dementiawithlewybodies_doc.htm)