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14 Cards in this Set
- Front
- Back
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Three requirements for dementia?
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Persistent
Decline Two or more areas of cognitive functioning |
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What are some different forms of generic dementia?
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brain tumors
nutritional disorders (Korsakoff's syndrome) prion diseases vascular dementia (problems with supply of blood to the brain) - saw-tooth variability; 25% overlap with Alzheimer's disease frontal temporal dementia - Pick's disease Lewy body dementia - in conjunction with Parkinson's Disease Alzheimer's Disease (50-70%) |
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Idiopathic disease
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don't understand the underlying causes of a certain disease
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Greatest risk factor for Alzheimer's Disease?
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age (but AD is not a normal condition of aging)
65: 0.5% prevalence 85: 50% prevalence |
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Does AD shorten lifespan?
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yes - survival average is 8-10 years after diagnosis; some patients live for 20 years
death typically occurs as a result of wasting, bladder or respiratory infections, accidents |
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Who has a higher prevalence of AD - women or men?
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WOMEN
also, higher prevalence if the parent with AD was the mother instead of the father |
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Is AD genetic?
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Yes - particularly in aggressive, early-onset dementia
tends to be familial rather than sporadic and the onset can occur in 40's or 50's. Perhaps an autosomal dominant pattern |
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Genes for early onset AD?
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S182 gene, chromosome 14. 40 variations, accounts for about 80% of familial form of early-onset DAT - encodes for presinilin 1. Individuals with the S182 gene = larger amounts of beta-amyloid protein
STM2 gene (similar) - chromosome 1. 2 variations; accounts for most of the rest of the familial form of earl onset DAT - encodes for presinilin 2 Amyloid precursor protein (APP) leads to beta-amyloid protein. gene encoding for APP is on chromosome 21; 10 variations linked to AD; accounts for 2-3% of early-onset AD |
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Gene for late-onset AD?
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apoE gene on chromosome 19
three alleles: epsilon 2 (10%) - protective? epsilon 3 (75%) - normal epsilon 4 (15%) - associated with AD; apoE binds tau protein |
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apoE?
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protein associated with late-onset AD; chromosome 19
apolipoprotein E is the main protein that transports cholesterol into the blood and is involved in fatty acid metabolism in brain and peripheral nervous system. The form of apoE protein formed by the epsilon 4 allele binds to tau protein. |
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How is AD diagnosed in living
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mri scans and repeated neuropsychological testing can diagnose 80%
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Two principal morphological changes used to diagnose AD post-mortem
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neuritic plaques and neurofibrillary tangles
1. both are found in normal elderly persons but in much larger numbers in AD patients 2. both are abundant in areas such as the hippocampus, neocortex and damygdala --areas one would expect given the cognitive symptoms of AD 3. both are correlated with extent of dementia prior to the patient's death; better correlation for tangles than for plaques |
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neuritic plaques
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extracellular masses consisting of a core of amyloid protein surrounded by what is probably neuritic debris and an outer margin of astrocytes
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neurofibrillary tangles
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masses of neurofibers occuring in the cytoplasm of neurons - often extending through the cell membrane to the outside of the cell; composed of paired helical filaments containing a lot of tau protein
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