Neurodegenerative Diseases

Question 1

What is the most common neurodegenerative disease of the cortex?

Answer 1

Alzheimers

Question 2

What is the prognosis for AD?

Answer 2

3-20 years

Question 3

What is the incidence of AD among 85 year olds?

Answer 3

40%

Question 4

What do AD patients usually die from?

Answer 4

infection - often pneumonia

Question 5

What are the grossa and macroscopic findings in AD?

Answer 5

gross = brain atrophy
microscopic = tangles and plaques

Question 6

Where in the cortex does AD usually start? Progresses?

Answer 6

starts in the hippocampus, then to the frontal lobe, then to the rest of the cortex

Question 7

What are the plaques made of in AD?

Answer 7

AB amyloid

Question 8

What are the tangles made of and where are they located?

Answer 8

tau protein

located in the neuron

Question 9

What are some other pathological changes you see with AD?

Answer 9

1. neuronal loss and gliosis
2. cerebral amyloid angiopathy
3. granulovacuolar degeneration
4. hirano bodies

Question 10

How can you stain for amyloid?

Answer 10

Congo red will stain is slightly redder, but when you turn the slide to a certain angle, it will look green

Question 11

What does the AB peptide come from in AD?

Answer 11

It’s an alternate cleaving of amyloid precursor protein.

it’s usually cleaved by alpha secretase and gamma secretase into dissolvable parts. But in AD, it’s cleaved by gamma and beta secretase. This forms an AB segment that is not soluble and will form aggregates

Question 12

What forms first in AD, the amyloid plaques or the tangles?

Answer 12

the plaques are first and the tau tangles are secondary - maybe directly caused by the plaques damaging the microtubules

Question 13

What parts of the brain are affected in Pick Disease?

Answer 13

It’s a distinctive dementia that affects the frontal lobe and temporal lobes only

Question 14

What do you see on pathology in Pick Disease?

Answer 14

you get severe atrophy of the frontal and temporal lobes with neuronal loss, swolen neurons (pick cells) with cytoplasmic neuronal inclusions (pick bodies)

Question 15

True or false: Parkinsons’s disease diminishes life expectancy.

Answer 15

false

Question 16

What will you see on pathology in PD?

Answer 16

loss of pigemented neurons causing pallor of substantia nigra

Lewy body formation in the remaining neurons

Question 17

What protein is contained in Lewy Bodies (but we don’t really know what it does?

Answer 17

alpha-synuclein

Question 18

What degenerates in amyotrophic lateral sclerosis?

Answer 18

motor neurons

Question 19

Is cognition and sensation affected in ALS?

Answer 19

Nope - just motor

Question 20

What is usually the cause of death in ALS?

Answer 20

Death occurs usually witnin 2-3 years due to the respiratory compromise

Question 21

“Progressive musclar artophy” is a subtype of ALS that is characterized by what?

Answer 21

loss of upper motor neurons only - not LMNs

Question 22

Progressive bulbar palsy is a subtype of ALS that is characterized by what?

Answer 22

cranial nerve signs - especially difficulty swallowing and speaking

Question 23

What proteins are potentially mutated in ALS?

Answer 23

superoxide dismutase
ubiquilin 2 (a housekeeping protein)

Question 24

What will you see on pathology in ALS?

Answer 24

thin anterior roots of spinal cord
reduction in anterior horne neurons
skeletal muscles atrophies
degeneration of corticospinal tracts