9 Memory and Disease Flashcards
What is Alzheimer’s Disease? And what are it’s symptoms?
The most common form of dementia.
Dementia is the term used when a person experiences aa gradual loss of brain function due to physical change in their brain.
Symptoms
- Loss of memory
- Impaired reasoning
- Reduced language skills
- Loss of daily living skills
Alzheimer’s mild symptoms.
- Confusion and memory loss
- Disorientation, getting lost in familiar surroundings
- problems with routine tasks
- change in personality and judgement.
Alzheimer’s moderate symptoms
- Difficulty with activities of daily living, such as feeding and bathing
- Anxiety, suspiciousness, agitation.
- Sleep disturbances
- Wandering, pacing
- Difficulty recognising famliy and friends.
Alzheimer’s severe symptoms
- loss of speech
- loss of appetite, weight loss
- loss of bladder and bowel control
- total dependence on caregiver
A test used to diagnose Alzheimer’s disease. Hint… (SVF)
Phonemic and semantic verbal fluency (SVF)
Patients are asked to generate as many words as they can either starting with a certain letter of the alphabet (phonemic fluency) or belonging to a certain semantic category e.g. animals (semantic fluency)
Primary risk factor of Alzheimer’s?
Age.
The likelihood of developing the condition doubles every five years after you reach 65 years of age.
New Zealand’s population of 85+ is going to be very large by the time we are old, and the prevalence at 85 is around 20%
What part of the brain changes happen in Alzheimer’s?
- Shrinkage of the hippocampus
- Shrinkage of cerebral cortex
- Ventricles are enlarged.
What to look for when determining if a brain has had Alzheimer’s?
- Plaques, are clusters that sit outside of the neurons
- Neurofibrillary Tangles, are occurring inside the neuron the cause them to degenerate.
What neurotransmitter is reduced during Alzheimer’s?
Acetylcholine, (ACH). Involved in the transmission of information from neurons to muscles.
Treatment for Alzheimer’s
Drugs that increase the time acetylcholine has to send messages.
Therefore, it prolongs the development of alzheimer’s.
The effects of the drug are not particularly good.
What is Amyloid Precursor Protein (APP), and how does it affect Beta-Amyloid (AB)? + What is its relation to Alzheimer’s?
Amyloid Precursor Protein (APP) is a protein that has an important role in synaptic plasticity. (forming memory and learning).
The compound that forms in plaques is Beta Amyloid.
In Alzheimer’s, Beta Amyloid is overproduced. It forms a fibrillar plaque on the outside of surface cells. These plaques are distributed through the cortex.
However, there are issues with this. Some people have lots of plaques and are fine. Clinical trials of the drug have not been successful.
Controversy with Alzheimer’s research?
Faked data.
What does the Tau Protein do in Alzheimer’s?
Tau protient stablise neruons. During Alzheimer’s Tau protein loose the ability to keep together and they create neurofibrillary tangles (NFTs).
What do these neurofibrillary tangles (NFTs) correlate to?
Symptoms of Alzheimer’s disease.
Stage of tangle impairment are well correlated with cognitive decline.
Known major risk factors for Alzheimer’s?
age: early-onset (5% < 65 years), vs late onset
Family history/genetic disposition.
Familial (early onset) AD - 3-5% of cases. 50% chance linked to genes.
Late-onset (sporadic) AD - 97% of cases.
Role gene APOE4 plays in Alzheimers?
Having one E4 variant is 2-3 x higher
Having two E4 genes is 5-8x higher risk
APOE4 caused impaired Amalid beta generation.
Increased cholesterol
what is the chemical APOE4
BBB separates the circulation of the brain from the rest of the body. Protects the brain from bad chemicals.
APOE4 is associated with the disruption of tight junctions that opens the BBB.
Overtime people who had injuries BBB has their cognitive ability decrease.
What is the Nun Study?
A longitudinal study of aging and Alzheimer’s disease. Have the same diet and procedure.
They were asked to write an autobiography at the start.
Categorise into two groups, complex autobiography and simple autobiography.
Those with a simple autobiography are more likely to generate Alzheimer’s and neruofiblitary tangles.
Suggests those with education and thinking (intact cognition) are less likely to gain AD.
Modifiable risk factors for dementia.
- Poor education
- Midlife hearing loss
- obesity and hypertension
- late-life depression
- smoking
- physical inactivity
- diabetes
- social isolation
