Term
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Definition
| caused by beta-methylamino l-alanine |
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Term
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Definition
a frontotemporal dementia
2-3% of all dementias
20-25% of all frontotemporal dementias |
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Term
| What is the onset and duration of Pick's disease? |
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Definition
onset 56-58 years (but wide range)
duration 8-11 years |
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Term
| Is Pick's disease genetic? |
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Definition
no known genetic factor
45% of patients have first degree relative with frontotemporal dementia |
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Term
| What are the symptoms of Pick's disease? |
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Definition
- personality changes
- speech
- emotional changes
- can develop voracious appetite |
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Term
| Describe Pick's pathology |
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Definition
- frontotemporal atrophy
- neuronal cell loss
- asrtogliosis (astrocytic scar tissue where neurones have been lost)
- swollen neurones contain 'Pick bodies' |
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Term
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Definition
| intracellular inclusion bodies made of cellular proteins |
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Term
| What causes Picks Disease? |
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Definition
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Term
| What changes are seen/not seen in Picks disease? What does this mean? |
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Definition
- decreases in 5-HT receptors and in 5-HT levels
- ChAT unchanged
- CSF and brain DA unchanged
- CSF and brain somatostatin decreased
Therefore distinct and separate from Alzheimers, however over confused due to symptoms |
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Term
| What is the most common form of dementia? |
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Definition
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Term
| When does Alzheimers occur? |
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Definition
senile and presenile dementia (either side of 65 years)
there used to be a distinction however it is now redundant as they both show identical symptoms and pathologies |
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Term
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Definition
| no, sporadic form predominated however familial forms do exist |
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Term
| Describe the onset and progression of Alzheimers |
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Definition
onset usually >60 years
death 5-10 years from onset |
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Term
| What is the cause of death in Alzheimers? |
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Definition
| the individual becomes completely bedridden and could get an infection (bronchopneumonia), sepsis from bedsore and much more susceptible to haemorrhagic stroke. Additionally, inanition, as they often require someone to feed them. |
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Term
| Describe the pathology of Alzheimer's disease |
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Definition
- amyloid plaques in hippocampus
- tangles
- neurone loss |
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Term
| Describe the plaques you can see in Alzheimers |
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Definition
deposits of amyloid beta protein (mainly)
surrounded by dystrophic neurites (axonal or dendritic)
they show a reactive gliosis in the area, macrophages will attack (unsuccessfully) but will produce everything necessary to produce toxicity |
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Term
| Describe the tangles you can see in Alzheimers |
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Definition
'flame-like' structures within the brain
neurones that have aggregations of hyperphosphorylated Tau-proteins that form tangles within the cells |
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Term
| Describe the neurone loss in Alzheimers |
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Definition
| distinct progression of mainly cholinergic pathways resulting in massive reductions in nAChR and ChAT levels |
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Term
| How does the brain physically change in Alzheimers? |
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Definition
- cortical atrophy
- smaller brain due to shrinking grey matter
- narrower gyri and wider sulci
- wider ventricles
- degenerated hippocampus |
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Term
| What are the earliest symptoms of Alzheimers? |
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Definition
- Short term memory
- Disorientation - time then place
- Aphasia, anomia acalculia
- Apraxia
- Visuospatial orientation (gets lost) |
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Term
| What are the later symptoms of Alzheimers? |
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Definition
- Loss of social skills
- psychosis + paranoia/hallucinations/delusions
- bradykinesia/rigidity |
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Term
| What are the latest symptoms of Alzheimers? |
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Definition
- Mutism
- Incontinence
- Bedridden |
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Term
| How is Alzheimers assessed? |
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Definition
Mini Mental State Examination
Normal score - 30
mild AD: MMSE 21 to 26
moderate AD: MMSE 10 to 20
moderately severe AD: MMSE 10 to 14
severe AD: MMSE less than 10. |
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Term
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Definition
- Genetics
- Amyloid
- Trauma |
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Term
| Describe the genetic causes of Alzheimers |
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Definition
- not as common
- trisomy 21 (Down's syndrome) because they have 3 copies of gene 21 and the protein that encodes amyloid beta protein resides on chromosome 21. Causes early Alzheimers and build up of plaque.
- mutations to amyloid precursor proteins (APP) and PS-1 and PS-2 (proteins that cleave APP)
- ApoE4 is a risk factor for AD. Its an allelic variant. I you have ApoE4 you are 50% more likely to develop Alzheimers (ApoE2 makes you less likely) |
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Term
| Describe the amyloid hypothesis of Alzheimers |
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Definition
| The amyloid beta protein that forms plaques is neurotoxic ad therefore build up of the protein kills neurones in the brain and that gives rise to the symptoms of Alzheimers. |
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Term
| Describe the traumatic causes of Alzheimers |
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Definition
- risk with head injury
- risk with hypoxic/anoxic episodes |
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