meningitis W4

Question 1

what is bacterial meningitis

Answer 1

bacterial infection of the meningeal space

Question 2

pathophysiology of bacterial meningitis?

Answer 2

bacteria invade meningeal space, multiply. leads to inflammation, neutrophils form pus causing elevated ICP and inflammation and thrombosis in the arteries. can cause damage in cranial nerves

Question 3

what can inflammation and thrombosis in arteries cause (in bacterial meningitis)

Answer 3

ischaemia/stroke

Question 4

what can damage to cranial nerves cause?

Answer 4

deficits eg deafness

Question 5

3 organisms that cause meningitis?

Answer 5

neisseria meningitidis (‘meningococcus’)
streptococcus pneumonia (‘pneumococcus’)
haemophilus influenza

Question 6

infection pattern in bacterial meningitis due to neisseria meningitidis?

Answer 6

epidemic outbreaks

Question 7

other cause of bacterial meningitis?

Answer 7

listeria monocytogenes

Question 8

what groups is listeria monocytogenes cause of meningitis common in?

Answer 8

older adults
diabetic patients
pregnancy

Question 9

example of meningitis where infection seeds from other sites?

Answer 9

eg staphylococcus aureas where infection comes through skin (skull fractures)

Question 10

clinical features of meningitis?

Answer 10

acute headache (onset in hours)
meningism (neck stiffness, photophobia)
fever
non-blanching rash (meningococcus)
confusion
reduced consciousness/coma
seizures

Question 11

clinical features of meningitis on examination?

Answer 11

stiff neck
kernings and brudzinskis tests (these lack sensitivity)

Question 12

when should you consider meningitis? (generally)

Answer 12

think meningitis in anyone with fever and headache

Question 13

diagnosis of meningitis - key test?

Answer 13

CSF sampling via LP

Question 14

CSF tests?

Answer 14

microscopy, culture and sensitivity testing
glucose levels compared to serum, protein

Question 15

additional tests for meningitis?

Answer 15

PCR
virology
other infections (TB)

Question 16

when should a LP not be performed before a CT scan? why?

Answer 16

reduced consciousness
focal signs (look for mass lesion eg empyema, abscess)
if these are present then risk of brain herniation

Question 17

pressure of CSF in:
bacterial meningitis
viral meningitis
TB

Answer 17

bacterial meningitis - high
viral meningitis - normal
TB - high

Question 18

appearance of CSF in:
bacterial meningitis
viral meningitis
TB

Answer 18

bacterial meningitis - cloudy/turbid or pus
viral meningitis - clear
TB - sometimes cloudy

Question 19

white cell count in CSF (x10^6 / L) in:
bacterial meningitis
viral meningitis
TB

Answer 19

bacterial meningitis - 1000-5000 polymorphs
viral meningitis - 10-2000 lymphocytes
TB - 50-5000 lymphocytes

Question 20

glucose levels in CSF in:
bacterial meningitis
viral meningitis
TB

Answer 20

bacterial meningitis - low
viral meningitis - normal
TB - low

Question 21

protein levels in CSF in:
bacterial meningitis
viral meningitis
TB

Answer 21

bacterial meningitis - high
viral meningitis - normal, sometimes high
TB - high

Question 22

CSF microbiology in:
bacterial meningitis
viral meningitis
TBL

Answer 22

bacterial meningitis - bacteria on gram stain culture
viral meningitis - sometimes virus on PCR
TB - myobacteria on ZN stain and culture

Question 23

management of bacterial meningitis?

Answer 23

antibiotics
supportive treatment
management of complications
meningococcus prophylaxis in contacts - give single dose ciprofloxacin

Question 24

when should antibiotics ideally be taken? when are they often actually taken? (for bacterial meningitis)

Answer 24

ideally after LP and blood cultures
often started early to prevent delay

Question 25

supportive treatment for meningitis?

Answer 25

manage shock (fluids for hypotension)
may require intensive care for organ support/ventilation

Question 26

management of complications in bacterial meningitis?

Answer 26

surgical input for abscess/empyema
anti-seizure medications

Question 27

complications of bacterial meningitis among survivors?

Answer 27

weakness/paralysis
cranial nerve deficits (especially deafness)
recurrent seizures (epilepsy)