Week Six - Dementia & Alzheimer's Flashcards
What is dementia?
An overarching term defining a wide range of memory problems.
What are progressive dementias?
A condition that has a continuous/step-wise decline over time
3 forms of progressive dementias?
Cortical
Subcortical
Mixed
What are examples of cortical dementia?
Alzheimer’s
Pick’s disease
FTD
What are some examples of subcortical dementias?
PD
Huntington’s
Who diagnoses dementia?
Usually by a geriatrician or neurologist - CNP opinion is essential however as behaviour observation help define type of dementia
What do we need to make a diagnosis?
past/present history family history psych assessment/evaluation brain imaging other medical testing
What is important for dementia?
Early diagnosis
Why is early diagnosis important in dementia for every case?
It provides a diagnostic answer and education
Why is early diagnosis important in for patients with reversible or static dementia?
To:
Relieve the fear of irreversibility
Treatment
Initiate prevention/rehab
Why is early diagnosis important in for patients with irreversible or progressive dementia?
To:
Treat cognitive and behavioural symptoms
Plan legal and financial future while patient still can
Initiate management strategies to postpone dependence
How is dementia reflected in the DSM-5?
It is defined as a Neurocognitive Disorder
can be:
- mild or major
Diagnostic criteria for major NCD in dsm-v?
A) Evidence of decline from previous level in one + cog domains (must be noted by others and with testing)
B) Deficits must be substantial enough to require assistance (decline in everyday functioning)
C) Deficits do not occur in the context of delirium
D) Deficits are not better explained by another disorder
What diagnosing someone with major CND, you need to do what?
Specify what type/cause Specify with/without behavioural disturbance and to what extent Specify severity (mild/moderate)
What is cortical dementia characterised by and what is the progression to subcortical (if any)?
It is characterised by preferential neuronal loss to cortical regions of the brain. Involvement in subcortical regions is rare but if it does occur, it won’t be until later stages of the disease course
What is AD?
An irreversible cortical progressive dementia
What is the strongest predictor of AD?
Age (incidence increases with age) - but there is no identifiable cause
What is the average duration of AD?
8-10 years after diagnosis - rarely survive past 15 years
Why might AD symptoms go unnoticed until later?
Because the brain is so good at using cognitive reserve to compensate for losses until a certain point
Sporadic Vs Familial AD
Sporadic is most common and has a mean age of onset of 80 yrs.
Familial is rare but has an early onset <50 yrs
Where does preferential cell loss occur in AD?
In the cortical grey matter of the brain and also in the limbic structures (hippo and amygdala)
What are the 2 key features of AD?
- Targets specific brain regions
2. Targeted structures sustain massive cell loss
What lobes experience the most cortical atrophy in AD? What % of neurons/cells are lost in these areas and why?
Frontal, temporal and parietal
50% of neuronal loss due to loss of dendritic arborisation
What does cortical thinning of the brain result in?
Ventricular enlargement
What are the 2 primary markers of AD?
Amyloid/senile plaques
Neurofibrillary tangles
What are Amyloid/senile plaques?
Clump like deposits, round aggregates of cellular trash.
What two proteins do Amyloid/senile plaques contain?
b-amyloid protein and apolipoprotein (ApoE)
What do neurofibrillary tangles resemble?
Resemble entwined and twisted pairs of rope
Where are neurofibrillary tangles located?
Throughout the brain (temporal and parietal), within the cytoplasm of swollen cell bodies
What are neurofibrillary tangles made of?
Tau proteins (they become dislodged causing the twists)
Where are senile plaques located?
In the frontal and temporal regions of the brain and in the hippocampal complex
In AD what part of brain is affected initially?
The temporal lobe
Signs and symptoms associated with AD onset are? (5)
Memory problems (recent) Depression/irritability Seizures (occasionally) Language problems Disorientation/confusion (due to sudden disruptions eg work, life)
What functions are affected in AD?
Memory deficits - LT declarative (episodic/semantic, anterograde, increasing retrograde, WM/STM)
Attention deficits
Slowed info processing
Impaired abstract reasoning
Impaired visuospatial skills
Impaired language
Fluent aphasia/apraxia/agnosia
In late AD, what happens to speech?
Becomes non-fluent, repetitive and largely non-communicative. Many display partial or complete mutism.
What can no longer be measured in the end stages of AD and may reemerge?
Can no longer measure neuropsychological functions Primitive reflexes such as sucking, grasping
What does the progression of AD resemble?
A reversal of development from infancy to childhood with high level skills being lost, returning to a reflexive state
What are some behavioural and personality changes associated with AD? (7)
clinging to caregiver easily distracted disinterest/passive poor self care agitation bursts of violence (decreases with disease progression) paranoia/suspicious
What parts of the brain are affected in FTD?
Mostly affects frontal lobe
Atrophy in frontal and temporal lobes with some change in parietal.
What parts of the brain are unaffected in FTD?
subcortical structures and cerebellum and brain stem
What happens in the initial stages of FTD?
Silliness, socially disinhibited behavior and poor judgement.
What happens in the middle stages of FTD?
Characterised by progressive apathy, blunted affect and significant cognitive dysfunction
What happens in the late stages of FTD?
Patients become more muste and display motor rigidity, ending in a terminal vegetative state
What is the disease durations of FTD?
2-17 years
What % of dementia is FTD
12%
What are some of the cognitive deficits in those with FTD? (5)
empty speech dysnomia dysfluency executive dysfunction hyperorality
What is Huntington’s Disease?
A progressive subcortical dementia that is always fatal
HD prevalence and age of onset
5-10 in 100,000
onset of symptoms 30-40 yrs
What is HD linked to?
Gene ITI5 on chromosome 4
Is there is cure for HD
no known cure or treatment
Describe the heritability of HD
It is a hereditary condition and is the only known autosomal dominant condition (affecting 50% of all children with one parent with the disorder)
Chorea is a symptom of HD, what is it?
involuntary, spasmodic and torturous movements that become disabling
The primary neuropathological change in HD is what?
Bilateral deterioration of the caudate nucleus
What neuropathology occurs with disease progression in HD?
There is a deterioration of multiple systems involving white matter structures and areas of the cerebellum
What is the caudate nucleus?
A component of the BG involved in timing, ordering, and sequencing of movement
What are some cognitive profiles of HD? (8)
eye movement deficits (delayed) decreased attention span memory difficulties language stays in tact deteriorating speech production visuo-spatial orientation impaired impaired behaviour regulation depression
What is the second largest type of dementia?
Multi-infarct vascular dementia
MIVD is a result of what?
Multiple infarction of brain tissue, from repeated strokes or blockages to blood vessels
is MIVD cortical or subcortical?
can present with both or combination of the two
How is MIVD different from AD?
It is acute and rapid cog deficits proceed personality changes people tend to be aware of deficits frontal lobe compromise is early deteriorating is step-wise, AD is slow/insidious
Example of dementia from infection?
Creutzfeldt-Jakob Disease (CJD)
What is CJD?
A rapidly progressive subcortical dementia
What does CJD result in?
Spongiform encephalopathy (SE) in which sponge-like holes appear throughout the brain
CJD is related to what other forms?
Minks in sheep
Cows - mad cows disease
What are the 4 types of CJD and what are their characteristics?
- Sporadic: most common - occurs with no risk factors
- Variant (mad cow disease): cross species infection via consumption of meat containing neural tissue
- Familial: GSSS - found in handful of families result in fatal insomnia
- Iatrogenic: transmission through affected neuronal tissue, contamination via medical procedures
Why is it hard to identify CJD?
As it’s a transmissible agent which does not produce usual symptoms of acute infection as it is camouflaged in cells and therefore is not recognised by the immune system
CJD produces SE targeting what areas of the brain?
cerebellum and cerebrum
What is found in human and sheep brains with kuru and CJD but not AD?
scrapie-associated fibrils (SAF) which is the disease agent
Hallmark features of CJD are what?
Motor symptoms deficits such as uncoordination, slurred speech, tremors
What are some emotional/cognitive symptoms of CJD?
mood disorders
fatigue
sleep problems
attention
what is the progression of CJD like?
Very rapid - usually less than a year (approx 3-4 months)
