Behav. Sci. Dementia Flashcards
what are age-associated cognitive changes?
- difficulty retrieving words and names
- slower processing speed
- difficulty sustaining attention when faced with competing environmental stimuli
- learning something new takes a bigger effort
- no functional impairment
how does dementia occur?
on a continuum (normal aging, followed by mild cognitive impairment, followed by dementia)
mild cognitive impairment definition
- memory complaint corroborated by an informant
- objective memory impairment for age and education
- preserved general cognition
- normal activities of daily living can still be done
- not demented
amnestic MCI
- memory loss not meeting the criteria for dementia
- progresses to AD at rate of 10%-15% per year vs. 1%-3% incidence in the general population
- may be the earliest phase of AD
- clinical diagnosis because no “MCI test”
DSM-IV diagnostic criteria for dementia
memory decline/impairment and at least one of the following:
aphasia (language decline)
impaired executive function
apraxia (inability to do certain actions)
agnosia (inability to interpret sensations)
-cognitive deficits must impact social/occupational function
early-onset AD
occurs btw 30-60
rare; familial in most cases
what are the gene mutations present in early-onset AD?
1,14,21
1 - presenilin 2 mutation
14- presenilin 1 mutation
21 - abnormal amyloid precursor protein
late-onset AD
MC
develops after 60
combination of factors
which gene is implicated in late-onset AD?
chromosome 19 - apolipoprotein E4 gene
what is present in the brain of someone with AD?
amyloid plaques (alpha beta) both extracellular and in arteries (amyloid angiopathy) neurofibrillary tangles (intracellular inclusions of tau)
what is disproportionately atrophied in AD?
hippocampus (memory!)
what does silver stain show?
neuritic plaques and neurofibrillary tangles in AD brain
congo red shows what?!
amyloid in plaques
what are the cleave sites on APP?
40 and 42 - 42 is worse
mutations in which gene is responsible for the large majority of cases of autosomal dominant alzheimer’s?
presenilin
how does a neuritic plaque appear?
dense central core of compact amyloid surrounded by a clear zone and a peripheral corona or halo
what is the patient at risk for when they have amyloid angiopathy?
hemorrhage
why does the body have difficulty clearing neurofibrillary tangles?
insoluble - body can’t clear
how do neurofibrillary tangles appear?
flame shape (form shape of neuron)