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Flashcards in Meningitis Deck (16):
1

What morbidity does meningitis cause?

deafness
paralysis
speech
epilepsy
neuro-psychiatric disorders

2

What is meningitis?

Inflammation of the lepto - meningeal membranes

3

What are the 4 types of meningitis?

Infection
Inflammation
Para - meningeal foci
Neoplastic or paraneoplastic

4

What 4 infectious agents cause meningitis?

Virus - enterovirus, mumps
Bacteria - meningococcus, H. influenzae
Fungus - cryptococcus
Parasite - naegleria

5

What prevents infection reaching the brain?

BBB

6

How to organisms reach the CNS?

Bacteraemia/ Parasitaemia / viraemia - BBB most vulnerable in the capillaries of choroid plexus (leaky so pathogens get through)
Direct spread - chronic infections in cranial bones, ears, sinus, oral cavity, Upper Resp tract
Indirect spread - infection of peripheral neurones, axonal transport, cell - cell spread of infection to connecting neurones in CNS

7

How does meningitis develop?

Mucosal colonisation
Intravascular survival
Meningeal invasion
Subarachnoid survival
BBB more permeable, blocked blood vessels,
Oedema, CSF flow disturbances
Intercranial pressure increase, cerebral flow decreases
Cerebrovascular autoregulation lost
Coma
Death

8

What factors influence the cause of meningitis?

Age - extremes - week BBB in 75 yrs
Geography - overcrowding, high temp, tropical
Immunity - chemo, steroids, transplant
Trauma - base of skull fracture

9

How will someone with meningitis present?

Non specifically:
Stiff neck, fever, altered mental stability, headache
Clinically, if they show these signs then 95% meningitis but only 5% meningitis will show these signs (95% specific, 5% sensitive)

10

How do you collect CSF?

lumbar puncture to test CNS

11

How does normal CSF present?

sterile, low protein, 60%blood glucose, lymphocytes

12

How does CSF present in bacterial infection?

+ve gram stain, high protein, low glucose, lots neutrophils

13

How do you exclude other pathologies?

MRI / CT scan

14

What are the 5 complications with bacterial meningitis?

1) SEIZURES
2) INFARCTS
3) SCARRING - epilepsy
4) HYDROCEPHALUS - CSF in ventricles builds up. Ventricles swell and brain is compressed
5) TRANSENTONIAL HEMIATION - increase intercranial pressure. Brain expands inwards, compressing brain stem, compressing vasomotor and resp centres, coma/death

15

What is the management for meningitis?

-Supportive care
-Antimicrobial therapy -
-Antibiotics - penicillin, chloramphenicol, vancomycin
-Steroids - good before antibiotics because their efficiency at decreasing inflammation is better
-Surgical intervention
-Prophylaxis - antibiotics (prevent spread) and vaccines

16

What must you do if you see/suspect meningitis?

It is a notifyable disease.
Legally bound to do something