Old age cognitive disorders Flashcards
Which memory is maintained in old age?
Semantic memory (world knowledge)
What memory is lost with old age?
Episodic long term memory, working memory and processing speed
What happens to brain usage as we age?
Hemispheric asymmetry reduction in older adults
Compensation - i.e. additional recruitment of neural activity to maintain performance
De-differentiation - loss of regional specificity
Alzheimer’s pathology
Amyloid plaques, tau tangles
Alzheimer’s site
MTL, parietal lobes to frontal lobes
FTD pathology
Several, tau, FUS, TDP-43
FTD site
Frontal (behavioural), temporal (semantic aphasia)
Vascular dementia pathology
Vascular
Dementia with LB pathology
Lewy bodies
Dementia with LB features
Motor symptoms and sleep disturbances
What is Delirium?
Delirium is an abrupt change in the brain that causes mental confusion, changed consciousness and emotional disruption
Dementia diagnosis requires
Multiple cognitive deficits (including amnesia) Functional impairment Clear consciousness Change from previous level Long duration (> 6 months)
Which of the following best discriminates between dementia and delirium?
Fluctuation over time
What neuropsychological disorder is associated with Ribot’s Law?
Retrograde amnesia
AD primarily what type of memory deficit?
Episodic
FDT primarily what type of memory deficit?
Semantic
AD prevalence?
60-80%
FTD prevalence?
5-20%
VD prevalence?
5-15%
DWLB prevalence?
2-8%
Delirium contributing factors
Older age (> 65yo)
Male sex
Cognitive impairment / dementia
Physical comorbidity (biventricular failure, cancer, cerebrovascular disease)
Psychiatric comorbidity (e.g., depression)
Sensory impairment (vision, hearing)
Functional dependence (e.g., requiring assistance for self-care or mobility)
Dehydration/malnutrition
Drugs and drug-dependence
Alcohol dependence
What can distinguish delirium?
Changes in consciousness not seen in dementia or psychosis
Social treatments
Family, friends, and other caregivers can offer frequent reassurance, tactile and verbal orientation, cognitive stimulation (e.g. regular visits, familiar objects, clocks, calendars, etc.), and means to stay engaged (e.g. making hearing aids and eyeglasses readily available).
What drugs can help and worsen delirium?
Haloperidol help
Benzodiazepines worsen
Late Onset Alzheimer’s Disease (LOAD)
> 65 years
Vast majority of AD cases
Early Onset Alzheimer’s Disease (EOAD)
<65 years
Mendelian single gene cause
More aggressive than LOAD
EOAD accounts for
1% of all cases
What a beta is more amyloidogenic?
Abeta 42
What mutations are common in EOAD?
Presenilin I: chromosome 14 mutations are the most common cause of EOAD
Presenilin 2: chromosome 1
Presenilin encodes
Gamma secretase component
Presenilin mutations …
Increase ratio of Aβ42 : Aβ40 produced by γ-secretase
Gene risk for LOAD?
APOE e4
