Alzheimer's Disease Flashcards
What needs to be done to confirm the definite diagnosis of AD?
Autopsy - looking for plaques and tangles in the brain
What is Alzheimer’s Disease?
It is a progressive neurodegenerative disease.
How much does AD contribute to dementia?
60-70%
What are the risk factors for developing AD?
- AD is poorly understood
- 70% - genetic
- Head injuries
- Depression
- Hypertension
What is the treatment of AD?
- There is no current treatment for reversing progression.
2. Some medication are used to improve symptoms.
What is the pathophysiology of AD?
Currently there is very limited knowledge however hypotheses have been developed to explain the condition.
What are the 3 main hypotheses?
- Cholinergic hypothesis
- Amyloid hypothesis
- Tau hypothesis
What is the cholinergic hypothesis?
- oldest hypothesis
- based on current drug treatment
- reduced synthesis of acetylcholine neurotransmitter
- not much support for hypothesis
What is the amyloid hypothesis?
1, Mutation in the chromosome 21 causes deposits of misfolded amyloid in the brain.
- These destroy neuronal connections. resulting in decline in cognitive funciton
Who are at most risk of developing AD and why?
Down Syndrome as the extra chromosome may cause extra deposits in of amyloid (trisomy 21) in the brain, causing dementia as soon as the age of 40.
What is the tau hypothesis?
- Abnormalities in th tau protiens trigger a cascade
- they become hyperphosphorylated
- This causes them to aggregate with other tau causing the formation of neurofibrillary tangles
- this cuases the microtubules to degenerate
- That causes the cell to collapse as the cytoskeleton is broken.
- This results into cell death.
What is a tau protein?
Are used to stabilise microtubules in the neurons in the CNS.
What is the NEUROpathophysiology?
1. AD characterised by loss of neurons and synapses in the cerebral cortex 2, This causes gross atrophy of regions 3. Such as -temporal lobe -frontal cortex -cingulate gyrus -parietal lobe
What is the cerebral cortex?
Most developed part of the human brain, known as the grey matter it is the outside layer of the brain.
What is the function of the cerebral cortex
Memory Attention Cognition Perception Language Conciousness