Alzhiemer's and sleep Flashcards
What is a typical macroscopic clinical feature of Alzhiemer’s Disease?
Gross cerebral atrophy
What are the presences of Alzhiemer’s in the pop. at different ages?
Dementia affects 1 in 17,000 below 65; 1 in 50
jobetween 65 and 70 an 1 in 5 over 80.
What are the histopathological features that are diagnostic of Alzhiemer’s Disease?
Senile plaques
neurofibrillary tangles
neurone loss
What are the different neuronal cell types?
Spiny neurons - pyramidal cells and stellate cells
Non-spiny neurons - types of GABAergic and peptide-containing cells
Neurofibrillary tangles and AD?
- tangles (NFT) correlate with dementia
- found first in entorhinal cortex
- composed of paired helical filaments (PHF)
- PHF composed of highly phosphorylated tau
- tau normally stabilises microtubules
- tau mutated in FTD‐P 17
(Disturbance of enzymes which add and remove phosphate
Tau in normally as phosphate protein)
What is tau?
- 6 isoforms in CNS
- 1 gene
- phosphoprotein
What are the stages of degeneration in Alzhiemer’s?
Transentorinhal - stage I and II
Iimbic - stage III and IV
Neocortical changes - stages V+VI
(3-5 - dementia onset)
See pages 15-16 of neuropathology of Alzhiemer’s for diagrams
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Is Alzheimer’s genetic?
A small percentage of people with Alzheimer’s have autosomal dominant mutations on these chromosomes 1, 14, 21
Mutations in tau known to cause Alzhiemer’s
Apoe genotype e4 increases risk and makes onset earlier
What is the role of Amyloid Precursor Protein in Alzheimer’s?
Deposited in plaques
Beta-secretase
Fibrillisation
Which NTs are particularly deficient in Alzhiemer’s Disease?
Ach
5HT
NA
(Glutamate)
2 important nuclei in the major cholinergic pathways?
Septal nuclei
Nucleus basalis
What happens with hippocampal pyramidal neurones in AD?
• Normal human brain
‐ stain for glutamate and glutaminase.
• Alzheimer’s disease
‐ decreased numbers stain for glutamate and glutaminase.
‐ neurones have disorganised and shortened dendrites
‐ glutamate and glutaminase stained neurones contain tangles.
Why is the hippocampus important in AD?
Memory formation requires activation of hippocampal circuitry
Signalling between cortical areas and hippocampus is dysfunctional in AD
What drug treatment is available for Alzheimer’s and how effective is it?
• Based on the Acetylcholine deficiency model
(Aricept, Exelon and Remenyl) or glutamate (Ebixa).
- 60% of suffers gain some benefit.
- Improve over 6/12 then begin to decline again.
- Many more in the pipeline.