Alzheimer's and Lewy Body Dementia

Question 1

What is the most common cause of adult dementia?

Answer 1

Alzheimer’s disease

Question 2

What are the two pathological hallmarks of AD? What is a better predictor of outcome?

Answer 2

Amyloid beta plaques and hyperphosphorylated tau protein called neurofibrillary tangles. NFTs are a better predictor of clinical symptoms

Question 3

In what gene does a polymorphism confer greater risk of AD?

Answer 3

Apolipprotein E, age of onset in 6th and 7th decades

Question 4

What is the earliest signs of AD?

Answer 4

Episodic autobiographical memory deficits.

Question 5

In what area do NFTs hit first?

Answer 5

Entorhinal cortex and hippocampus (two key nodes in the limbic/memory network)

Question 6

To what areas of the cortex do NFTs spread after hippocampal and related regions?

Answer 6

To the heteromodal cortices and unimodal cortices associated with different functions like language and visuospatial reasoning.

Question 7

What is spared in AD until much later?

Answer 7

Primary motor visual and auditory regions.

Question 8

What percentage of cases are autosomal dominant, and what are they related to functionally?

Answer 8

Autosomal dominant AD is less than 5% of cases and all the genes are related to amyloid protein processing

Question 9

What is the source of amyloid plaques?

Answer 9

The source is the amyloid precursor protein (APP) which is cleaved by alpha, gamma and beta secretases. Gamma and beta promote plaque formation

Question 10

What is the involvement of acetylcholine in AD?

Answer 10

Loss of central cortical cholinergic cells in the nucleus basilis of Meynert is involved in AD pathology.

Question 11

What drug developed in response to the knowledge of the role of acetylcholine in AD?

Answer 11

Donepezil, modest slowing of progression

Question 12

What is an important radiological finding in AD?

Answer 12

Hippocampal and medial parietal atrophy on MRI

Question 13

What is mild cognitive impairment?

Answer 13

Beginning stages of AD, with some short term memory loss. Pathology is limited to entorhinal cortex and hippocampus

Question 14

What is the prevalence of MCI in people over the age of 65, and what is the annual rate of progression to dementia?

Answer 14

Prevalence is between 10-20%. With MCI, annual rate of progression to dementia is between 5-10%

Question 15

What is the 2nd most common adult onset neurodegenerative dementia?

Answer 15

Dementia with Lewy body

Question 16

What other characteristics distinguish DLB from AD?

Answer 16

Association with parkinsonism and early visual hallucinations.

Question 17

What is the pathological hallmark of DLB?

Answer 17

Deposits of alpha-synuclein, is a synucleinopathy.

Question 18

What other symptoms are associated with DLB?

Answer 18

REM sleep associated sleep disorder as well as neuroleptic sensitivity (eg typical antipsychotics)