CNS infections

Question 1

CSF analysis: low WBC, slightly raised protein, normal glucose

Answer 1

acute aseptic (viral) meningitis = non-pyogenic bacterial meningitis

Question 2

Examples of focal suppurative infections?

Answer 2

brain abscess, subdural and extradural empyema

Question 3

What is acute encephalitis?

Answer 3

infection of the brain parenchyma

Question 4

Thick layer of suppurative exudate covering the leptomeninges and microscopically: neutrophils in subarachnoid space…?

Answer 4

pyogenic meningitis

Question 5

Child presents with neck stiffness, photophobia and general malaise. Parent is unsure if vaccines have been completed.
Gram film shows gram positive cocci in chains which shows partial/green haemolysis.
Diagnosis and causative organism?

Answer 5

community acquired pneumococcal meningitis

streptococcus pneumoniae (gram positive cocci in chains that is alpha haemolytic)

Question 6

Young child presents with neck stiffness, general malaise and photophobia. Gram film shows gram positive cocci in chains that show full haemolysis.
Pathogen?

Answer 6

neisseria meningitis (neonatal meningitis)
Group B streptococcus - beta haemolysis in gram positive cocci in chains.

Question 7

Patient with CSF skull fracture presents with meningitis symptoms - likely pathogen and treatment?

Answer 7

streptococcus pneumonia (pneumococcal meningitis)
10 days ceftriaxone + 4 days dexamethasone

Question 8

A patient with pneumococcal meningitis is found to be cephalosporin/penicillin resistant… treatment options?

Answer 8

14 days ceftriazone + vancomycin + 4 days dexamethasone

vancomycin mono therapy not recommended due to concerns re. CSF penetratioN

Question 9

70 y/o patient with advanced leukaemia develops meningitis symptoms. Gram film shows gram positive bacilli and doctor suspects bacteraemia.
What is the pathogen and what treatment would you choose?

Answer 9

listeria monocytogenes
AT LEAST 21 days amoxicillin + stop dexamethasone

(ceftriaxone no value as intrinsically resistant)

Question 10

Patient presents with sudden onset confusion, aphasia and seizure. Meningitis is ruled out.
What other investigations do you want to do and what do you think is happening?

Answer 10

LP, EEG and MRI
likely encephalitis - could start pre-emptive acyclovir if any delay in investigations since they would improve outcomes.

Question 11

What are the likely pathogens in neonatal meningitis?

Answer 11

listeria, group B strep, E.coli

Question 12

Most likely meningitis pathogen(s) in children?

Answer 12

Haemophilus influenza - requires blood factors for growth; type b is most common cause in kids <4

Question 13

most common meningitis pathogen in 10-21 y/o?

Answer 13

neisseria meningitidis

Question 14

most common meningitis pathogen in >21?

Answer 14

strep pneumoniae > neisseria meningitidis

Question 15

most common meningitis pathogen in >65?

Answer 15

strep pneumonia > listeria

Question 16

CSF findings in community acquired bacterial meningitis?

Answer 16

glucose decreased
protein increased
+++ polymorphs