CNS infection and meningitis

Question 1

Which broad category of organisms is most commonly responsible for acute meningitis?

Answer 1

Bacteria

Question 2

How does chronic meningitis present and which organisms are more likely to be the cause?

Answer 2

Headaches for months

Likely to be TB or cryptococcus

Question 3

Which broad category of organisms is most commonly responsible for aseptic meningitis?

Answer 3

Viruses

Question 4

What is the most common Gram -ve cause of bacterial meningitis in otherwise healthy adults?

Answer 4

Neisseria meningitidis

Question 5

What is the most common Gram +ve cause of bacterial meningitis in otherwise healthy adults?

Answer 5

Strep pneumoniae

Question 6

List 3 causes of bacterial meningitis in neonates

Answer 6

Group B strep
Listeria monocytogenes
E coli

(All GI flora)

Question 7

List 3 causes of bacterial meningitis in the elderly

Answer 7

Group B strep
Listeria monocytogenes
Mycobacterium tuberculosis (subacute)

Question 8

List 4 viral causes of meningitis

Answer 8

Coxsackie
Mumps
HSV2
Echovirus (in children

Question 9

Name a fungal cause of chronic meningitis

Answer 9

Cryptococcus neoformans

Question 10

Describe the aetiology of bacterial meningitis?

Answer 10

Spread of infection either systemically (eg from mucosa) or locally (eg from skull fracture)

Question 11

List 3 risk factors for Neisseria meningitidis meningitis

Answer 11

Complement deficiency
Hyposplenism (susceptible to encapsulated organisms)
Hypogammaglobulinaemia

Question 12

List 6 risk factors for Strep pneumoniae meningitis

Answer 12

Complement deficiency
Hyposplenism
Immune defect (eg alcoholics)
Infection (ie pneumonia)
Entry fracture
Previous head trauma w/CSF leak

Question 13

How does acute bacterial meningitis present?

Answer 13

Headache
Vomiting
Photophobia
Irritability
Fever
Focal neuro signs
Rash

Question 14

How is bacterial meningitis diagnosed?

Answer 14

Clinical features
Blood cultures
Serum-Ag
EDTA-PCR
Throat swab
CSF - WCC (polymorphs)↑
Protein ↑
Glucose ↓

Question 15

What is the treatment for bacterial meningitis?

Answer 15

Resuscitate (ABC)
Ceftriaxone
Corticosteroids

*If listeria suspected cover with ampicillin

Question 16

Which scoring system is used to predict the need for intensive care in children with bacterial meningitis?

Answer 16

Glasgow Meningococcal Septicaemia Prognostic Score

>8 usually fatal

Question 17

How can viral meningitis be distinguished from viral encephalitis?

Answer 17

In viral meningitis there is no change in consciousness or focal neurology

Question 18

What are the normal ranges for WCC, protein and glucose in adult CSF?

Answer 18

WCC: 0-5
Protein: 0.15-0.4
Glucose: 2.2-3.3 (>50% serum)

Question 19

What is the most likely type of infection in a patient with the following CSF results: -

Glucose: low
WCC: high with polymorphs

Answer 19

Bacterial infection

?turbid

Question 20

What is the most likely type of infection in a patient with the following CSF results: -

Glucose: normal
WCC: high with polymorphs

Answer 20

Partially treated bacterial infection

Question 21

What is the most likely type of infection in a patient with the following CSF results: -

Glucose: normal
WCC: high with mononuclear cells

Answer 21

Viral meningitis/encephalitis

Question 22

What is the most likely type of infection in a patient with the following CSF results: -

Protein: high
WCC: high with mononuclear cells

Answer 22

Mycobacterium TB or cryptococcus

Question 23

Name 2 CNS infections in which the CSF results can be normal

Answer 23

Cerebral abscess (Streptococci)
Viral encephalitis (Herpes)

Question 24

What is the treatment for meningoencephalitis?

Answer 24

Acyclovir and ceftriaxone