Dementias Flashcards
Diagnostic goal
whether or not cognitive changes are above and beyond what we expect from normal aging
Dementia
a collection of cognitive/personality/behavioral changes associated with disease progression
Atrophy
neuronal loss leading to loss of brain volume
cortical dementia
affects behavior, personality, and memory.
-alzheimers, FTD
Subcortical dementia
affects motor, processing speed, and attention
-Parkinson’s, Huntington’s
Mixed dementia
affects cortical and subcortical areas
-lewy body, vascular dementia
Alzheimer’s Disease
most common dementia, 50%
-majority dev after 65
-risk increases with age
-onset can happen as early as 40
Alzheimer’s pathology
characterized with abnormal protein deposits (amyloid plaques and tau tangles)
-initial degeneration occurs in the medial temporal lobe (memory), the hippocampus, and the entorhinal cortex
-later spreads to the parietal and frontal cortexes (perceptual, visual, and exec. funtioning)
Alzheimer’s MRI finding
temporal and parietal lobe atrophy, enlargement of the ventricles
Mild Alzheimer’s
memory lapses, word finding problems, trouble with planning and organizing
Moderate Alzheimer’s
more pronounced memory and word finding problems, increased executive concerns, personality changes, changes in sleep patterns
Severe Alzheimer’s
brain tissue shrink significantly, severe cog impairments, withdrawl
Alzheimer’s early deficits
memory impairment (amnesia), rapid forgetting, impaired learning, semantic memory deficits
Alzheimer’s later deficits
global cognitive impairment, visual agnosia, aphasia
Vascular dementia
2nd most common (10% pure 15%mixed)
-onset b/t 60-75
VD risk factors
stroke, high bp, diabetes, high cholesterol, smoking, obesity
VD course
depends on when/where ischemic event occurs in the brain
-often a stepwise pattern (periods of stability followed by rapid deterioration due to additional strokes)
VD pathology
cause; cerebrovascular disease or impaired cerebral blood flow
-frontal subcortical profile (slow processing, attention, concentration, exec functioning)
-impaired memory as a consequence of impaired attention/concentration
-spec deficits due to lesion location
Frontal temporal dementia
4th most common
-onset b/t 50-60 (earlier than most)
-Risk: genetics and presence of ubiquitin
FTD pathology
inclusion bodies and pick bodies
-regional cortical atrophy, predom in frontal or temporal lobes
-degeneration of some aspect of frontal or temporal lobes
inclusion bodies
accumulation of protein inside cells that are markers of disease
Pick bodies
tau inclusions and ubiquitin inclusions
Behavioral variant FTD
atrophy, neuronal loss of the frontal cortex
- tauopathy with tau positive inclusions
PPA variants
nonfluent/agrammatic, semantic, logopenic
Nonfluent/agrammatic PPA
frontal and basal ganglia atrophy
-Intact: meaning of words
-Impaired: grammar and speech production
Semantic PPA
temporal atrophy
-intact: fluent speech
-impaired: meaning of words
Logopenic PPA
temporal and parietal atrophy
-intact: comprehension
-impaired: word finding
PPA vs aphasia from stroke
Aphasia from stroke appears suddenly and does not worsen
PPA is a neruodegen disorder and develops gradually and worsens over time
FTD behavioral presentation
personality changes consistent with frontal systems dysfunction
-loss of social awareness, apathy, social withdrawal, decreased personal hygiene, etc.
FTD neruopsych presentation
exec dysfunction, memory dysfunction, language deficits, intact visuospatial and orientation
AD vs FTD: AD
(memory, rapid forgetting, exec dysfunction, personality change)
memory: early
rapid forgetting: present
Exec dysfunction: later on
Personality change: later on
AD vs FTD: FTD
(memory, rapid forgetting, exec dysfunction, personality change)
Memory: later
rapid forgetting: absent
Exec dysfunction: early on
Personality change: early on
Parkinson’s disease/dementia
motor symptoms related to dysfunction w/in nigrostriatal dopaminergic pathways
non-motor associated with progressive impairment in other dopaminergic pathways
-hypokinetic (loss of muscle movement)
PD epidemiology
peak onset around 60
-7-8 years after diagnosis become wheelchair bound
-neuropsych involvement predictor of progression rate
PD causes
dopamine involved in control and coordination of body movement
- loss of dopaminergic neurons in substantria nigra (of basal ganglia)
-reduction of dopamine leads to dif with controlling movement
neuronal loss is slow, so symptoms become noticeable after 80% of cells in sub. nigra are gone
PD symptoms
Motor: tremors, slow movements (bradykinesia), involuntary muscle contractions, shuffling gait
non-motor: depression, anxiety, apathy, pain, fatigue
cog: processing speed, working mem, language
PD treatments
L-DOPA: precursor to dopamine that can pass BBB, mod doses decrease motor
Deep brain stim: implants electrodes w/in spec brain regions
Lewy body
12-27%
b/t 50-70
-slow, 5-7 years
-cognitive deficits present before motor
-punctuated by periods of fluctuation of mental status/orientation
LB pathology
lewy bodies that are diffusely spread
-brainstem, cortical areas, hippo, midbrain, basal ganglia
-
LB behavior
fluctuating attention/mental status
-parkinsonian symptoms
-hallucinations
-sleep problems
Huntington’s disease
hyperkinetic movement disorder
-inherited caused by mutations in HTT gene
-leads to degeneration of neurons in basal ganglia
-30-50
progresses 15 days after onset
HD pathology
loss of some neurons in the caudate
-indirect b. ganglia thalamocortical circuitry affected
-at death, brain volume can be decreased by as much as 25%
HD symptoms
chorea (involuntary dance), bradykinesia (slow movement), dystonia (involuntary muscle contractions, parkinsonian, exec function, mem loss
ALS (amyotrophic lateral sclerosis)
neruodegen disease that causes progressive loss of motor neurons w/in spinal cord and cranial nerves
-results in continual difficulties with controlling voluntary movements
-initial presentation can be either limb or bulbar onset
ALS early symptoms
limb: muscle twitching, cramps, weakness, stiffness
Bulbar: muscle twitches in tongue, slurred speech, chewing and swallowing diff
ALS epidemiology
58-80
survival for 3-4 years
ALS cog& behavorial
exec dysfunction
depression, apathy, low motivation
ALS treatment
no cure, slow progression
