Microbio - CNS Infections

Question 1

Meningitis

Answer 1

Inflammation of the meninges (layer surrounding brain)

Question 2

Most common causes of bacterial meningitis overall

Answer 2

Neisseria meningitidis (meningococcus), Streptococcus pneumoniae

Question 3

*Most common cause of bacterial meningitis in neonates

Answer 3

Group B strep, Listeria monocytogenes, E. Coli

up to 3/12 then N men

Question 4

*Most common cause of bacterial meningitis in elderly

Answer 4

Group B strep, Listeria monocytogenes

Question 5

*Most common cause of viral meningitis

Answer 5

*Enterovirus (coxsackie, echovirus), mumps, HSV2

Question 6

Most common cause of fungal meningitis

Answer 6

Cryptococcus neoformans (chronic)

Question 7

Presentation of acute meningitis

Answer 7

Headache, photophobia, neck stiffness, fever, non-blanching rash (meningococcal septicaemia)

Question 8

Presentation of bacterial v viral meningitis

Answer 8

Bacterial presentation is more severe

Question 9

Presentation of subacute/chronic meningitis

Answer 9

Headache for months, confusion

Question 10

Investigations for meninigits

Answer 10

• A to E approach (incl observations, bloods - VBG, cultures, FBC, CRP)
• CT head
  (must do before lumbar puncture if concern about raised ICP - vom, personality change, decr consciousness)
• Lumbar puncture

Question 11

LP results for bacterial meningitis

Answer 11

Appearance: turbid
Glucose: low
White cells: high - polymorphs

Question 12

*LP results for viral meningitis

Answer 12

Appearance: clear
Glucose: normal
White cells: high - lymphocytes

Question 13

LP results for TB meningitis

Answer 13

Appearance: clear/turbid
Glucose: low
White cells: high - mononuclear

Question 14

*Treatment for bacterial meningitis

Answer 14

IV ceftriaxone + corticosteroids

If Listeria suspected -> add ampicillin – e.g., neonate/elderly

Question 15

Treatment for viral meningitis

Answer 15

Definitive: Supportive (self-limiting)

In practice: start Abx to cover bacterial

Question 16

Encephalitis

Answer 16

Inflammation of the brain parenchyma (brain itself)

Question 17

Usual type of pathogen responsible for encephalitis

Answer 17

Viral - HSV1

Question 18

Presentation for encephalitis

Answer 18

Confusion, fluctuating consciousness

Question 19

Investigations for Encephalitis

Answer 19

• A to E approach
• CT head
• LP (same result as viral meningitis)

Question 20

Management for Encephalitis

Answer 20

IV acyclovir

Question 21

Which causative organism is responsible for meningitis post eating unpasteurised cheese?

Answer 21

Listeria monocytogenes

Question 22

Meningitis mx at GP

Answer 22

IM benpen + call 999