Neuropathology 3: Dementia and Demyelinating Disorders

Question 1

how do oligodendrocytes facilitate saltatory conduction?

Answer 1

by forming nodes of ranvier

Question 2

demyelination causes defects in the __ and ___ of neuroconduction

Answer 2

rate

consistency

Question 3

axons are preserved in demyelinating disorders T or F

Answer 3

T

Question 4

multiple sclerosis is a primary cause of demyelination T or F

Answer 4

T

Question 5

name secondary causes of demyelination

Answer 5

viral eg leukoencephalopathy
metabolic eg central pontine myelinosis
toxic eg CO, solvents

Question 6

primary causes of demyelination

Answer 6

MS
acute disseminated encephalomyelitis (ADEM)
acute haemorrhagic leukoencephalomyelitis

Question 7

patient with hyponatraemia that is overly corrected can cause…

Answer 7

central pontine myelinosis

Question 8

lesions in MS occur in the __ matter; why?

Answer 8

white

this is the area of the brain with myelinated axons

Question 9

what is found in CSF in an MS patient?

Answer 9

IgG oligoclonal bands

Question 10

visual impairment is __lateral in optic neuritis?

Answer 10

uni

Question 11

MS is primarily a disease of the __ matter

Answer 11

white

Question 12

the lesions are mainly on the outside of the brain in MS T or F

Answer 12

F, in middle

Question 13

what do the lesions in MS look like?

Answer 13

glassy, thin

non symmetrical

Question 14

where are MS plaques found?

Answer 14

periventricular white matter
corpus callosum
optic nerves and chiasm
brainstem
spinal cord

Question 15

active plaques show evidence of…

Answer 15

inflammatory cells
microglia
active demyelination

Question 16

what do demyelinating plaques look like?

Answer 16

yellow/brown with an ill defined edge that blends into the surrounding white matter

Question 17

chronic plaques show evidence of..

Answer 17

gliosis
loss of myelin
less oligodendrocytes and axons

Question 18

what do inactive plaques look like?

Answer 18

well demarcated grey brown lesions located around the lateral ventricles

Question 19

does MS have a genetic component?

Answer 19

yes, 15x risk if 1st degree relative

Question 20

MS has genetic linkage to what gene complex?

Answer 20

HLA DR2

Question 21

what degenerative diseases affect the cerebral cortex?

Answer 21

alzheimers
CJD
pick disease

Question 22

main pathological process in degenerative disease?

Answer 22

simple neuronal atophy

subsequent gliosis

Question 23

what degenerative diseases affect the brainstem and basal ganglia

Answer 23

parkinsons

huntingtons

Question 24

define dementia

Answer 24

acquired and persistence generalised disturbance of higher mental functions in an otherwise fully alert person

Question 25

dementia is part of the normal ageing process T or F

Answer 25

F, always pathological

Question 26

dementias tend to present symmetrically T or F

Answer 26

T

Question 27

name primary dementias

Answer 27

alzheimers lewy body vascular frontotemporal

Question 28

alzheimers tends to present after age __

Answer 28

60

Question 29

is alzheimers familial?

Answer 29

not really, only about 1%

Question 30

what gene is said to be implicated in alzheimes?

Answer 30

amyloid precursor protein

Question 31

how does alzheimers progress?

Answer 31

onset is subtle but once symptoms begin the patient deteriorates quickly with disorientation and memory loss

Question 32

what happens to the appearance of the brain in alzheimers?

Answer 32

cortical atrophy widening of sulci and narrowing of gyri frontal, temporal and parietal lobe atrophy

Question 33

what parts of the brain are NOT affected in alzheimers?

Answer 33

brainstem | cerebellum

Question 34

classic microscopic appearance of alzheimers

Answer 34

neuronal loss -> gliosis neurofibrillary tangles (aggregates of tau protein) are characteristic amyloid plaques

Question 35

what genetic condition is associated with early onset of alzheimers?

Answer 35

down syndrome

Question 36

name the protein responsible for creating neurofibrillary tangles

Answer 36

tau protein

Question 37

main component of amyloid plaques? how do they kill neurons

Answer 37

amyloid beta | promote excitotoxicity

Question 38

what amyloid disease are alzheimers patients at risk of?

Answer 38

amyloid angiopathy (disrupts BBB)

Question 39

describe lewy body dementia; how is it different from alzheimers?

Answer 39

``` progressive dementia WITH: hallucinations fluctuating attention and cognition REM sleep disorder (acting out dreams) parkinsonism ``` NB memory loss occurs much later

Question 40

why do you get parkinsonism in lewy body dementia?

Answer 40

lewy body affects the nigro striatal dopaminergic pathways

Question 41

main pathological process in lewy body dementia

Answer 41

degeneration of the substantia nigra due to gliosis of dopaminergic neurons

Question 42

microscopic appearance of lewy body dementia

Answer 42

lewy bodies (discrete eosinophilic lesions surrounded by a pale halo) reactive gliosis loss of pigmented neurons

Question 43

main age of onset in huntingtons?

Answer 43

35-50

Question 44

name the triad of symptoms in huntingtons?

Answer 44

triad of emotional, cognitive and motor disturbance

Question 45

symptoms in huntingtons?

Answer 45

``` chorea myoclonus clumsiness slurred speech depression irritability dementia develops MUCH LATER ```

Question 46

what chromosome carries the huntington gene?

Answer 46

4

Question 47

dementia is an early feature of huntingtons T or F

Answer 47

F, occurs much later

Question 48

main pathological process in huntingtons - be specific

Answer 48

atrophy of the caudate nucleus in the basal ganglia | frontal and parietal atrophy

Question 49

microscopic appearance of huntingtons

Answer 49

degenerations of striatal neurons in the caudate nucleus | gliosis

Question 50

frontotemporal dementia is also called...

Answer 50

picks disease

Question 51

what dementia is known to begin early (in middle life)

Answer 51

fronto-temporal

Question 52

fronto-temporal dementia macroscopic appearance?

Answer 52

extreme atrophy of cerebral cortex starting in frontal and later affecting the temporal lobesp

Question 53

what are picks cells? what do they present in?

Answer 53

swollen neurons | fronto-temporal dementia

Question 54

cerebrovascular dementia occurs due to what pathological process

Answer 54

hypoxia or anoxia

Question 55

you need to lose ___mls of brain before the dementia begins in CV dementia

Answer 55

50-100

Question 56

how does CV dementia differ from alzheimers?

Answer 56

abrupt onset rather than insidious stepwise progression rather than smoothly progressive history of CV problems eg HT/stroke

Question 57

classic macroscopic appearance of CV dementia

Answer 57

large vessel infarcts scattered through hemispheres with atheroma of large cerebral arteries