Dementia and degenerative disorders Flashcards
What are the two major gray matter areas in the brain?
- Cerebral hemispheres
- BG
What is the basic pathogenesis of dementia?
Loss of neurons within the gray matter
Degeneration of what large area of the brain leads to dementia?
Cortex
Degeneration of the brainstem and BG leads to what?
Movement disorders
What is the most common cause of dementia?
Alzheimers
What is the pathogenesis of Alzheimer’s disease?
Disruption of the degradation of APP into beta amyloid, leading to A-beta-amyloid deposition
Is the memory loss with Alzheimer’s fast or slow?
- Slow memory loss
- Progressive disorientation
- Loss of learned motor skills
- Behavior and personality changes
- Mute and bedridden
Are there focal neurological deficits with Alzheimer’s?
No
True or false: most cases of Alzheimer’s are inherited
False–sporadic
What is the most important risk factor for the development of sporadic AD?
Age
What are the most important risk factors for the development of early AD? (2)
- Presenilin 1 or 2 gene
- Down Syndrome
What is the protein that carries an INcreased risk of developing AD? Why?
- Epsilon-4-ApoE
- Increases APP conversion to the beta form
What is the protein that carries a DEcreased risk of developing AD?
-Epsilon-2-ApoE
What are the genes that increase the risk for early Alzheimer’s disease?
Presenilin 1 or 2
Why is it that patients with Down syndrome develop Alzheimer’s?
Chromosome 21 is where APP is—thus they express more of it
What are the genes that increase the risk for later Alzheimer’s disease?
Epsilon-ApoE4
What are the gross characteristics of brains with AD?
Diffuse cerebral atrophy:
- Narrowing of gyri
- Widening of the sulci
What, generally, is hydrocephalus ex vacuo?
The appearance of enlarged ventricles 2/2 loss of cerebral matter
What are the neuritic plaques seen in AD?
Pink extracellular AB amyloid, surrounded by entrapped neuritic processes
What is cerebral amyloid angiopathy?
A-beta amyloid in AD deposits around blood vessels, weakening them and leading to hemorrhage
What are the neurofibrillary tangles seen in AD?
Hyperphosphorylated Tau protein in cells
What is normal role of Tau protein in neurons?
Helps to organize microtubules
True or false: AD is a diagnosis of exclusion
True–confirmed with pathology at autopsy
What is the second most common cause of dementia?
Vascular dementia
What generally causes vascular dementia?
HTN, atherosclerosis, or vasculitis
What is the natural h/o vascular dementia?
Stepwise deterioration of mental functioning
What is Pick’s disease (aka frontotemporal dementia)?
Degenerative disease of the frontal and temporal cortex, that spares the parietal and occipital lobes