Alzheimer's

Question 1

What is the definition of Dementia and the relationship between Alzheimers and Dementia

Answer 1

Cognitive or behavioural symptoms that interfere with function, represent decline, which are not caused by delirium and other psychiatric disorders. 2+ domains of cognitive impairments

Alzheimers is the most common disease that will lead to Dementia as a symptom

Question 2

Explain the types of Alzheimer

Answer 2

Proteinopathy
Amyloid tauopathy

Sporadic (late onset, most common)
Caused by the failure to clear AB protein
due to the carriage of the APOE e4 gene on chromosome 19, which is the only known genetic risk
not that has this gene = must develop Alzheimer

Familial (early onset, very rare)
Caused by the overgeneration of AB protein
due to the mutation of the Amyloid Precursor Protein (APP) 1/2

Environmental factors can moderate the symptoms

Question 3

Explain the biology of Alzheimer and where does the tauopathy occur

Answer 3

AB (beta-amyloid)
made up of 40-42 Amino acid peptides
formed by larger protein (Amyloid Precursor Protein)
If the B and Y secretases (scissors) cut in a particular way = AB oligomers
AB oligomers = stick to the neurones in the brain > causes a cascade of events > causes them to self degenerate (the Amyloid Hypothesis)

Tau:
stablise microtubules of the axons and feed nutrients to the axon from the cell body
However, when tau goes wrong, they hyperphosphorylate and become neurofibrillary tangles that cause the neurones to destruct
neurofibrillary happens in the MT = Alzheimer’s
seems like one of the cascade events caused by the accumulation of beta-amyloid = tau’s hyperphosphorylation (not sure about the cause)

Question 4

Methods that are used to diagnose Alzheimers

Answer 4

PET scanners
inject molecules that travel to the brain and stick to the AB oligomers
PET scanner can see the AB oligomers in orange and red
Hypothesis = younger people on the trajectory = higher chance of developing Alzheimer

CSF test
higher AB in CSF = lower AB in the brain
Hypothesis = the CSF takes away the AB in the brain

Blood test
~80% accuracy
flaws
protein can be highly affected by external factors
Cardiovascular and CNS = different

Question 5

What are the three stages of Tau hyperphosphorylation

Answer 5

1. entorhinal stage
2. limbic stage
3. neocortical stage

Question 6

Stages of amyloid development

Answer 6

12 years from no amyloid > amyloid level at risk
19 years from at risk > clearly seen in AD

Question 7

Simple development of AD overview

Answer 7

Tau and beta-amyloid > synaptic dysfunction > cell loss > cognitive and functional impairment (dementia)