cns infections

Question 1

how is menigitis spread

Answer 1

Sneezing, coughing, kissing
Meningitis isusually caught from people who carry these viruses or bacteria in their nose or throat but are not ill themselves.
It can also be caught from someone with meningitis, but this is less common.
Infection spreads from mucosal surfaces via the bloodstream and causes infection in the meninges

Question 2

how do organisms reach the brain and spinal cord

Answer 2

sinuses
ear infections
head trauma
infective endocarditis

Question 3

what organisms cause menigitis

Answer 3

Neisseria meningitidis (meningococcus) - most common* cause of bacterial meningitis and septicaemia in UK.
streptococcus pneumoniae
listeria menigitis

Question 4

what is the pathophysiology

Answer 4

Infection results in what can be a massive inflammatory response
Albumin enters in the CSF; toxins from bacteria and neutrophils; together with reduced O2 and nutrients to brain cells - oedema and brain swelling – stops CSF entering brain
Circulatory failure, intractable seizures etc
Can get septicaemia - bacterial toxins - cause damage to blood vessels and organs.
Blood leaks into tissues, often causing a skin rash
Clotting factors released – tissues starved of oxygen
Damage and death in a matter of hours

Question 5

symptoms of menigitis

Answer 5

stiff neck/back, altered mental state; photophobia; convulsions/seizures; pale blotchy skin, spots, non- blanching rash;* cold hands and feet etc

Question 6

what is menigitis usually common with

Answer 6

septicaemia

Question 7

what happens when you press a glass on the menigitis rash?

Answer 7

rash wont go away

Question 8

prognostic factors of menigitis

Answer 8

ABM is a medical emergency
Urgent hospitalisation
Early treatment – rapidly fatal

In hospital start empiric AB therapy:
Likely causes & antibiotic sensitivities
Consider age of patient
CSF penetration of ABs
Bactericidal ABs
High doses
Parenteral
Modify therapy, as necessary

Question 9

how diagnosis menigitis

Answer 9

Investigations must not delay treatment
Signs & symptoms
Lumbar puncture for CSF analysis
Critical - CSF: often turbid, with low glucose, elevated protein and WBC count
Organisms – often seen in Gram stain of CSF
CSF & Blood cultures etc
CT scan etc

Question 10

what are the antibiotic effects with menigitis

Answer 10

Penetrate even when meninges are not inflamed: e.g. chloramphenicol, metronidazole, isoniazid, pyrazinamide
Penetrate inflamed meninges & used in high doses: e.g.most ß-lactams, quinolones, rifampicin
Penetrate poorly but better when inflamed : vancomycin
Penetrate poorly: gentamicin (synergy with amoxicillin)

Question 11

prevention of abm

Answer 11

Pool of healthy carriers – hard to eradicate
Vaccination
Prophylaxis on significant exposure
Local guidelines for treatment and prophylaxis (resistant strains)