Prion Disease

Question 1

what are prions

Answer 1

misfolded forms of the normal protein, can transform other proteins into prion proteins - domino effect

Question 2

what pathological changes do prion proteins cause in the brain

Answer 2

spongiform changes

also neuronal loss, astrocytosis and amyloid plaque formation

Question 3

are prion diseases progressive

Answer 3

rapidly

Question 4

age of onset of sCJD

Answer 4

60s

Question 5

duration of sCJD illness

Answer 5

4 months

Question 6

clinical features of sCJD

Answer 6

Rapid onset dementia + neurological signs + myoclonus

Urinary incontinence and gait abnormalities

Question 7

how is sCJD caused

Answer 7

production of prion proteins

Question 8

age of onset of vCJD

Answer 8

20s

Question 9

how does vCJD present

Answer 9

Painful sensory disturbance + neuropsychiatric decline

Question 10

how long does vCJD last

Answer 10

14 months

Question 11

aetiology of vCJD

Answer 11

Found outside CNS in gut, liver, salivary glands, kidney, lung and bone marrow

Exposure to BSE (mad cow) via contaminated meat (beef) or blood

Question 12

is vCJD common

Answer 12

no <1% frequency

Question 13

imaging of vCJD

Answer 13

hockey stick sign on MRI - thalamuc nuclei

Question 14

how does iCJD present

Answer 14

Cerebellar/visual onset. Multifocal neurological decline.

Question 15

how long does iCJD last for

Answer 15

<2 years

Question 16

aetiology of iCJD

Answer 16

transmission of prion proteins through medical procedures

eg pituitary hormone replacement, surgical instruments, dura mater grafts, corneal transplants

Question 17

which part of the brain can be grafted and can transmit iCJD

Answer 17

dura mater

Question 18

which type of CJD may genetic CJD mimic

Answer 18

sporadic

Question 19

age of onset of gCJD

Answer 19

any

Question 20

what are teh 2 subtypes of gCJD

Answer 20

Gerstmann-Straussler-Scheinker disease and fatal familial insomnia

Question 21

how does Gerstmann-Straussler-Scheinker disease present

Answer 21

progressive ataxia - progressive degeneration of the cerebellum and differnet degreres of dementia

Question 22

which gene is mutated in gCJD

Answer 22

PRNP - there are more than 30 mutations and each produces its own phenotype

Question 23

what is the best inital test

Answer 23

EEG

Question 24

what other tests are performed

Answer 24

MRI and LP

Question 25

what is seen on LP

Answer 25

elevated 14-3-3 protein

Question 26

management

Answer 26

currently there is none, focus on supportive care, genetic counselling in familial forms

main aim is to prevent transmission!!!