Beth-dementia Flashcards
Intro to Alzheimer’s
It is a from of dementia, loss of brain cells with shrinkage of the brain, gets more and more. Lasts 3-20 years avg 7-8, no cure, around 60% of dementia cases. Risk increases after 65, ppl living longer, overtook cardiovascular disease as leading cause of death, 42% have family or friend AD, annual cost is a lot
What are some other forms of dementia
Vascular, focal dementias including posterior cortical atrophy, semantic dementia , parkinsons and huntingtons
Symptoms of AD
- Mild dementia: memory loss (episodic and semantic) impaired thinking and decision making but still independent 2. Moderate: confusion, disorientation, apathy, personality changes (withdrawn, paranoid, neglect), sundowning, hallucinations 3. Severe: forget self, don’t recognise anyone, loss of mobility and bodily functions
Assessment for Ad
Mini mental state exam: repeat and recall object names, the date, where are you, name common object, following 3 step instructions, writing grammatical sentence
Copying an image of intersecting pentagons- as can’t compute complex visual motor mappings
AD effects on the brain
Reduced levels of glucose and NTs (ach. Dopamine, glutamate). Pet uses radioactive G to measure metabolism. Beta amyloid plaques- fragments of beta amyloid protein released from neurone membrane and clump, become insoluble and interfere. Neurofibrillary tangles: neurones have microtubules and transport materials held by tau (protein), tau becomes separated causing Microtub to disintegrate, tau forms tangles which stop transport, cell death. Plaques AD spec, tau depositions in others-causes neuronal loss:brain shrinks and gaps expand
History of AD
Alzheimer German psychiatrist studied changes post-mortem, August (patient) admitted for loss of memory, disorientated, hallucinations, incontinent- examined piece dead and found nuerofibrillary tangles and plaques. In 1910-60 called senile dementia in elderly and pre senile in younger but 60s onwards, realised the same. In 80s, plaques and tau id, in 90s, genetic risks from genome, 2000 used neuroimahine and 2010 brain connectivity
AD and default mode network
Abnormal associated w memory retrieval, emyloid deposition may explain memory problems early on. May spread within functional networks, dmn at greater risk at greater metabolic rate
Genetic risks to AD -familial AD
Form called familial AD, rare but common for early onset, clear genetic basis. AD is an autosomal recessive disease but familial AD is autosomal dominant, on 3 diff chromies, presenilin 1 on 14, 2 on 1 and amyloid beta precursor protein on 21-each causes plaques. Can use genetic testing
Late onset AD genetic risks
Having other family W disease increases prob but only small. Gene APOE on 19 has 3 alleles, one copy of allele 4 increases risk by 4 times, 2 copies by 10-20 times but some don’t develop the disease
Environmental risk factors for dementia
Saturated fats, red meat increase, med diet decrease. Gu 2010 analysed diets of 65 years old and 4 years alter. Those without dementia had med diet, moderate alc and smoking increased risk in apoe4 carriers. Bad gut microbes trigger inflammatory response, releases cytokines that cross blood brain barrier and damage cells
Diagnosis
Happens slowly, starts with mild cog impairment: forgetting appointments and recent events, train of thought, misplacing. Need increasing deficits in at least 2 areas of function and severe problems that interfere W daily life. Mci when deficits milder, early, could be due to depression, heave to repeat every 6motnhs to id. Only 12% with mci over 65 have dementia after 1 year, after 5 it’s 50%
Mci and brain images
Whitwell: degeneration of hippocampus in mci patients 3 years before diagnosis, brain vol diffs (reduced in temp and anterior lobes). Mci important as new treatments effective at this point. Chandler 2019: wellness training shows biggest effect on qual of life (habit training, writing things down) brain games less effective
Cognitive reserve
High levels of intelligence and education allows ppl to function normally in early stages. The nun study Kemper 2001: nuns did annual assessment of physical and cog function and donated brains. Also analysed thier autobiographies and found those W dementia had lower scores in early autobiographies. Nuns W college degree lived longer and more mentally healthy. Eclipse study brain study- no effect of years of education but more educated ps less likely to be diagnosed
Treatments for dementia -therapies and vitamin D
Brain training, better nutrition, reminiscence therapy (promote interactions). Ppl W alcoholism have vit b1 deficiency as poor absorption which causes brain damage and wernicke korsakoff syndrome (like dementia). Those W mci found 30% less atrophy in fit b group (small sample, only mci, atrophy may not be related).
Treatments for dementia- AcH, inhibitors and recent trials
Cholinesterase inhibitors boost AcH by inhibiting enzyme that breaks it down, half AD ps showed benefits for milder AD. For more moderate: nmda inhibitors block glutamate as it’s released in large amounts and becomes toxic. But don’t stop progression, only work for some, spenny, only prescribed in moderate ps. 2022 trial with early ad had anti amyloid antibody infusions -reduced amyloid plaques supports amyloid hyp, showed improved cognition