Infections of the CNS and Prion Disease

Question 1

Name some types of infections in the CNS

Answer 1

Cerebral abscess

Meningitis

Chronic meningitis

Encephalitis

Question 2

Name some symptoms of meningitis

Answer 2

Non-specific symptoms, e.g. fever, tired, nausea

Headache

Non-blanching rash

Stiff neck

Photophobia

Drowsiness

Question 3

Name some causes of meningitis

Answer 3

Neonates - E. coli, L. monocytogenes

2-5yrs - H. influenzae type B

5-30yrs - N. meningitidis

>30yrs - S. pnuemoniae

Question 4

Name a cause of chronic meningitis

Answer 4

M. tuberculosis

Question 5

What pathological features are seen in chronic meningitis

Answer 5

Granulomatous inflammtion and caseous-like material which undergoes fibrosis to cause fibrosis of the meninges

Can have nerve entrapment

Question 6

Name some symptoms of chronic meningitis

Answer 6

Symptoms are similar to acute meningitis but are more subtle

Headache

Fever

Vomiting

Mental cloudiness

Question 7

Name some symptoms of encephalitis

Answer 7

Fever, headache, nausea, aching muscle

Confusion/disorientation

Drowsiness

Seizures

Changes in personality and behaviour

Weakness of body movement

Loss of sensation

Question 8

Name some causes of encephalitis and where they affect

Answer 8

Herpes virus - temporal lobe

Polio - spinal cord motor neurones

Rabies - brain stem

Question 9

Name some complications of meningitis

Answer 9

Death due to raisd ICP

Cerebral infarction

Cerebral abscess

Neurological deficit

Subdural empyema

Epilepsy - in either acute stages or will remain throughout

Question 10

Describe what prion disease is and what causes it

Answer 10

Prion disease is the aggregation of mutated prion proteins in the brain causing neuronal death and holes in grey matter

When mutated, prion proteins interact with normal proteins causing the normal proteins to undergo a post-translational conformational change into the mutated prion protein

These mutated prion proteins are extremely stable and are not detected or broken down by the immune system

Mutation can be sporadic, inherited or ingested

Question 11

What is the name given to the group of conditions that mutated prion proteins cause

Answer 11

Spongiform encephalopathies

Question 12

Name some forms of spongiform encephalopathies

Answer 12

Scrapie in sheep

Bovine spongiform encephalopathy in cows

Kuru disease

Varient creutzfeldt jacob disease (vCJD)

CJD

Question 13

What are the differences between vCJD and CJD

Answer 13

CJD - age of death around 68yrs, 4-5mth duration of illness. Signs are dementia and early neurological signs

vCJD - age of death around 28yrs, 12-13mth duration of illness. Signs are psychiatric or behavioural symptoms, painful dysesthesias, delayed neurological signs