Aging & dementia Flashcards
Aging depends on the interaction of which 3 variables
Time, genetic background, stochastic encounters with diverse events (e.g., HTN, stress, oxidation, trauma)
Correlates of successful aging
Educ achievement, early educ experiences, physical health status, exercise, perception of health & control, emotional state/life satisfaction
Brain changes associated with aging
Loss of synapses, neurons, neurochemical input, neuronal networks
In aging, atrophy due to neuronal loss (or cell shrinkage) is most/least pronounced in
Most - hippocampus & anterior dorsal frontal lobe
Least - occipital lobes
In aging, progressive decline in CBG is greatest/least in which brain areas?
Greatest - prefrontal & inferior temporal cortex
Least - occipital areas
Memory changes associated with normal aging
Reduction in amount of info that can be processesd at once
Decline affects recent > immediate or remote
Less efficient encoding due to reduced use of learning strategies, more difficulty retrieving info that has been encoded
Language changes associated with normal aging
Strengths: linguistic knowledge, lexical knowledge, expressive vs. receptive
Weaknesses: naming, precision of verbal description, drawing abstract inferences, drawing unstated principles from facts
Visuospatial changes associated with normal aging
Small changes in simple perception, slowed visual processing
Complex visual tasks produce large age effects (visual closure, integration, construction)
Executive functioning changes associated with normal aging
Decline in cognitive flexibility, application of abstract concepts
6 factors that should be taken into account when examining the geriatric population (Potter & Attix)
VIsion, hearing, motor fx, fatigue, literacy, rapport & motivation
DSM-IV definition of dementia
Deficit in memory AND 1+ of apraxia, agnosia, aphasia, exec fx
Decline from previous level of functioning
Interference w/ work, school, ADLs, or other social activities
Not delirium
Probable AD (NINCDS-ADRDA criteria)
Dementia established by clinical exam & cognitive tests
Deficits in 2+ areas of cognition
Progressive worsening of memory & other cog fx
No disturbance of consciousness
Onset between ages 40-90
Absence of systemic disorders/other disease that could account for symptoms
Pathological progression of Alzheimer’s
1) Medial temporal lobes
2) Basal temporal cortex extending over lateral posterior temporal cortex, parieto-occipital cortex, posterior cingulate gyrus
3) Frontal lobes
Anatomical changes associated with Alzheimer’s disease
Cerebral atrophy
Neuronal loss
Amyloid plaques
Neurofibrillary tangles
Where is cerebral atrophy most prominent in Alzheimer’s disease?
Parietal, inferior temporal, limbic cortex
Widespread cause of atrophy appears to be loss of dendritic arborization
Neuronal loss in Alzheimer’s disease is most prominent in
Nucleus basalis, septal nuclei, nucleus of the diagnoal band where cholinergic projections arise
Lesser extent in locus ceruleus (NE) & raphe nuclei (serotonin)
Amyloid plaques
Insoluble protein core containing beta-amyloid and ApoE surrounded by abnormal axons & dendrites called dystrophic neuritis
Neurofibrillary tangles
Intracellular accumulations of tau proteins
Cognitive decline accounts for only ____% of functional decline in Alzheimer’s disease
40
Declines in advanced IADLs predict
Frequency of hospital contact, nursing home placement, mortality
Basic ADLs rely on
Procedural memory skills & basic motor programming
Instrumental ADLs require
Controlled processing & executive function
What age group are at the highest risk of driving accidents?
Over 85
Performance in what cognitive domains is highly correlated with driving status & performance?
Visual search, selective attention, visuospatial perception & construction, exec fx
Alzheimer’s patients have an increase of _____x the normal concentration of aluminum in their brains
10-30x
Baseline tests that predict later cognitive decline in AD
Verbal tests of naming, verbal memory, fluency, abstraction
Baseline tests that predict later functional decline in AD
Nonverbal measures of visuospatial functioning & visual memory
What are some conditions or comorbidities that should be considered when making a diagnosis of AD?
Thyroid, B12 or folate levels, CVD, stroke & other neuron conditions; kidney, liver, endocrine fx
Diagnostic criteria for probable vascular dementia (NINDS-AIREN)
Evidence of dementia
Evidence of cerebrovascular disease
Relationship b/t dementia & CVD
Other features that support include gait disturbance, falls, incontinence, pseudobulbar palsy, mood changes
Neary et al. diagnostic criteria for frontotemporal dementia
Insidious onset & gradual progression, early decline in social interpersonal fx, early impairment in regulating personal conduct, early emotional blunting, early loss of insight
What are some features that support a diagnosis of frontotemporal dementia?
Behavioral disorder, speech/language disorder, physical signs, diagnostic procedures
Lund & Manchester groups diagnostic criteria for frontotemporal dementia
Behavioral symptoms (loss of personal awareness, disinhibition, mental inflexibility, perseverations, impulsivity) Affective symptoms (indifference, depression, aspontaneity) Speech symptoms (repetition of phrases, echolalia, mutism)
Histopathological subtypes of frontotemporal dementia
1) Microvacuolar subtype: spongiform degeneration, loss of large cortical neurons in frontal & temporal cortices
2) Pick body subtype
Primary progressive aphasia
Early difficulties in word retrieval, decreased fluency, anomia; comprehension generally intact in early stages; later in disease, other aspects of cognition are impaired
Semantic dementia
Fluent speech but substantial impairments in word comprehension & word-finding; difficulty on semantic memory tests
Pick’s disease
Atrophy of frontal & temporal lobes
See personality changes, stereotyped verbal output, Kluver-Bucy symptoms
Diagnostic criteria for dementia with Lewy Bodies
Fluctuating levels of consciousness/cognition with pronounced variations in arousal level/attention; spontaneous parkinsonian motor features; visual hallucinations that are typically well-formed & recurring
Neuropathology of dementia with Lewy bodies
Diffuse & widespread Lewy bodies across cortex, nucleus basalis of Meynert, & substantia nigra; most case also show senile plaques & possibly NFTs
Creutzfeldt-Jakob’s disease
Caused by rapidly progressive viral infection (prion) of nervous system which usually leads to death w/i 6 mos of onset
Clinical triad of Creutzfeldt-Jakob
Dementia, involuntary movements, periodic EEG sharp wave activity
Name 3 other prion related dementias
Kuru, fatal familial insomnia, bovine spongioform encephalopathy
Criteria for MCI
Subjective memory complaints & objective evidence of mild memory impairment (<1.5 SD), normal intellectual fx & normal ADLs
Predictors of progression from MCI to dementia
Hippocampal atrophy, genetic susceptibility (ApoE-4)
7 conditions that are potentially reversible causes of dementia
NPH, hypothyroidism, B12 deficiency, thiamine deficiency, depression-related, sleep-disordered breathing, medication effects
Depression vs. AD
Recognition memory is relatively intact, fewer false-positive errors, more DK errors Poorer effort, more variability across tasks of similar difficulty Better performance with semantic organization & prompting Intact awareness (complaint of memory problems)
Risk factors for Alzheimer’s disease
Age, female gender, lower education, family hx, Apoe4, Down’s syndrome, head injury, psychiatric illness, alcohol abuse, risk factors of heart disease
Neuropathology of progressive nonfluent aphasia
Greater degeneration of left posterior frontal cortex, anterior insula, basal ganglia
Neuropathology of semantic dementia
Polar & inferolateral temporal cortex
Neuropsychological profile of NPH
Gait instability (shuffling apraxic gait), urinary incontinence, bradyphrenia, confusion & disorientation
Early deficits in attention & exec fx, memory encoding (recognition improves recall), visuoconstructional deficits
What are the cardinal features of Alzheimer’s disease?
Social withdrawal, poor memory w/ rapid forgetting, dysnomia, constructional apraxia
What are the cardinal features of frontotemporal dementia
Onset typically in 50s, personality changes early with ‘frontal’ signs, language deficits in PPA
What are the cardinal features of dementia with Lewy bodies?
Variable MS, parkinsonian motor symptoms (tremor not predominant), visual hallucinations
What are the cardinal features of vascular dementia?
Motor/sensory abnormalities, poor attention, recognition cues improve recall, apraxias common
What are the cardinal features of dementia in Parkinson’s disease?
Slowed processing speed, attention deficits, constructional apraxia, learning slow but retention can be normal, parkinsonian motor features
What are the cardinal features of progressive supranuclear palsy
Vertical gaze palsy, falling backwards, ‘applause sign’, frontal/subcortical cognitive deficits
What are the cardinal features of corticobasal dengeneration?
Ideomotor apraxia, asymmetric parkinsonian rigidity & bradykinesia, alien hand sign, later dementia
What are the cardinal features of depression-related cognitive impairment?
Complaints of memory problems, good description of perceived difficulties, withdrawn, speech fluent & articulate, no apraxias
Alcoholic dementia
Frontal lobe signs including apathy, poor hygiene, poor judgment, lower cog. efficiency, attention, & recent memory, flattened affect
Clinically similar to neurosyphilis
Assoc. w/ enlarged cerebral ventricles, frontal atrophy, thinning of cortex
Dementia pugilistica
Characterized by forgetfulness, slowness in thought, dysarthria, wide-based unsteady gait
Flattened affect & parkinsonian extrapyramidal features also common
Mattis Dementia Rating Scale (DRS)
Assesses 5 cognitive domains - attention, construction, initiation/perseveration, conceptualization, memory
Mayo Older Age Normative Study (MOANS)
Normative data for a # of NP measures for individuals aged 55-97
How do older non-demented individuals perform on list learning tasks?
Reduced learning, particularly as the length of the list increases
Recall, however, is as good as younger patients (in contrast to clear impairment in AD)
What is the most likely syndrome associated with the visual spatial type of dementia?
AD
Clinical features that suggest something other than AD
Sudden onset
Focal neurological findings
Seizures & gait disturbance @ onset
DLB vs AD on neuropsych testing
Hard to distinguish, but DLB has slightly better memory & slightly worse exec fx
What is the annual incidence of HIV dementia after the diagnosis of HIV?
7% per year
Neuropsychological profile of HIV dementia
Prominent psychomotor slowing, memory (in early stages worse recall than recognition), visual constructional skills w/o other parietal signs like anomia or dyscalculia
Carphologia
Lint picking or aimless plucking at clothing as if picking off thread, frequently accompanied by chewing movements; ST seen in patients with AD
Approximately what percent of dementias are reversible?
5% (others say 10-15%)
Functional neuroimaging in late-life depression
Bilateral frontal lobe hypometabolism
Prevalence of dementia across lifespan
Age 65 = 1.5%, doubles every 4 years afterward, 30% by age 80
Neuropsychological profile of early Lewy Body dementia
Marked deficits in attention & exec fx, visuospatial impairments, constructional difficulties
Behavioral deficits in Lewy Body dementia (compared to AD)
> apathetic, > distractible, greater tendency toward perseveration, confabulations, intrusions, more environmentally triggered errors (suggestibility)
In aging, _____ intelligence increases, while _____ intelligence decreases.
Crystallized, fluid
Areas of cognitive that are relatively preserved with aging
Simple attention, primary & tertiary memory, everyday language communication
What area of the cortex shows the most cell loss in AD?
Entorhinal cortex
Differences between Pick’s disease & AD
Less memory, calculation, & visuospatial impairments; more extravagant personality alterations; greater tendency to produce stereotyped verbal output; Kluver-Bucy symptoms
Clinical triad of Creutzfeldt-Jakob
Dementia, involuntary mvmts (esp. myoclonus), periodic EEG
Atrophy associated with normal aging generally reflects a loss of
Myelin
