Lecture 39: Aging, MCI and Non-Alzheimer's Disease Dementia Syndromes Flashcards
What is the unifying hypothesis for cognitive aging?
Localization to the premotor frontal cortex
- deficit of executive control - evidence shown in imaging of atrophy in prefrontal brain regions
What are normal cognitive problems?
Relative preservation of vocab and world knowledge (semantic memory)
- however, there is forgetfulness
- decreased information retrieval, word-finding difficulty (with names)
- slower info processing
What is mild cognitive impairment?
More cognitive decline than memory but DAILY ACTIVITIES ARE NORMAL
- so more like mild cognitive unimpairment lol
- does not meet criteria for dementia
What must you exclude when you see somebody with MCI or dementia?
Impairment from depression
- anxiety - medications - B12 deficiency - vascular disease
What are two types of MCI? And what is the significance?
A. Amnestic MCI
-single domain
-multiple domain
Significance: leads to AD
B. Non-amnestic MCI
-single domain
-multiple domain
Significance: leads to non-AD dementia
What are risk factors for MCI progression?
- increasing age
- amnestic component
- APOE genotype
- vascular risk factors (clotting)
- Amyloid imaging (Pittsburgh Compound B elevated = PiB)
What is treatment for MCI?
AChE inhibitor but there no treatment shown to definitively improve MCI outcome
- stay physically and mentally active
- treat vascular risk factors
What are the three general types of Non-AD dementias (that we have to know for this test lol)
- Frontotemporal Dementia
- Dementia with Lewy Bodies
- Vascular Dementia
What is Frontotemporal dementia? And what impairments are to be expected in general?
Focal degeneration of the frontal and temporal lobes (with cognitive and behavioral disturbances)
Young onset (45-65)
a. Behavioral/emotional disinhibition (anterior cingulate/orbitofrontal cortex degeneration)
b. Decreased executive function (prefrontal motor cortex)
c. Broca’s aphasia
d. Loss of semantic knowledge
-words/concepts on left
-emotions/faces on right
-associated with temporal lobe degeneration
What are the three types of frontotemporal dementias (FTD)?
- Behavioral Variant FTD
- Progressive nonfluent aphasia (PNFA)
- Semantic dementia
Delineating factor for behavioral variant FTD
Think of Phineas Gage Loss of empathy Personality change -socially inappropriate behavior -overeating/preference for sweet foods Poor executive function
Delineating factor of Progressive nonfluent aphasia (PNFA)
Broca’s aphasia
- agrammatic, language apraxia, decreased total verbal output for words
- they can find the CORRECT label for an object…just can say it
What is semantic memory?
General knowledge of objects, word meanings, facts WITHOUT connection to any particular time or place
Delineating factor of Semantic dementia
Loss of semantic memory (words lose their meaning)
Example: forget how to spell a word, the fact that Cows make a “moo” sound, that milk is consumed by humans, etc.
Localized on the temporal lobe
What are the two types of proteins involved in pathology of FTDs?
- Tauopathy (Pick bodies)
PNFA is majority Pick bodies while BehavioralFTD is 50/50 - TDP-43 proteinopathy
Semantic dementia is majority TDP-43
Delineating factor of dementia with Lewy bodies (DLB)
Benign hallucinations (kitten on the couch or kids running around)
PD like motor symptoms (shuffling steps when turning)
-autonomic dysfunction
-REM sleep behavior disorder (RBD)
What is REM sleep behavior disorder (RBD)? And what is its significance?
When you are acting out your dream
-your muscles should be paralyzed during sleep…but not so in these patients
Predictor for DLB/Parkinson’s disease with dementia
How do you treat dementia with lewy bodies (DLB)?
- Acetylcholinesterase improves cognition
2. Low levels of levodopa (too much can worsen hallucinations)
What are the three types of vascular dementia?
- Multi-infarct dementia
- Subcortical vascular dementia
- Strategic infarct dementia
Delineating factors for multi-infarct dementia:
Person has vascular risk factors and stepwise declien
Corresponds with arterial territories
anterior cerebral artery: apathy, abulia (loss of initiative), kinetic features, akinetic mutism
MCA: aphasia, neglect (right and left respectively)
PCA: amnesia, agnosia (cant interpret sensation), anomia (cant name shit)
Delineating factors for Subcortical vascular dementia
-psycho-motor slowing
-impaired concentration
-forgetfulness
Absence of focal cortical deficits (like no aphasia, no apraxia)
Delineation of strategic infarct dementia
Impairs a critical frontal-subcortical connection by lesioning a key relay pathway
Example:
1. Thalamic dementia from dorsomedial nucleus lesion
-thiamine deficiency
-loss of memory
-stroke from paramedian artery (branch of PCA)
2. infarct to anterior thalamic nuclei
-amnesia with apathy and reduced emotional expression (loss of Papez circuit)
-loss of tuberothalamic artery (from PCOMM)
- Infarct of genu of internal capsule
How do you treat?
Prevent stroke
-vascular dementia cant be treated once don
Primary prevention: managing risk factor
Secondary prevention: management of risk factors after initial episode of vascular brain injury
Tertiary amelioration of symptoms: neurostimulants
