CNS infections

Question 1

What is the difference between meningitis and encephalitis?

Answer 1

meningitis - infection of the meninges

encephalitis - infection of the brain itself

Question 2

Bacterial meningitis - what is it also known as

Answer 2

Pyogenic meningitis

Question 3

Bacterial meningitis - where is the inflammation

Answer 3

Inflammation of the leptomeninges and CSF within the subarachnoid space

Question 4

Bacterial meningitis. Thick layer of suppurative exudate covers the surface of the brain. True or false?

Answer 4

True

- think of injecting pus into the CSF and the pus gets everywhere and gets matted

Question 5

Bacterial meningitis - patient with CNS devices (e.g. cochlear implants) - what is the likely causative organism?

Answer 5

Strep pneumoniae (pneumococcal meningitis)

Question 6

Where is strep pneumoniae commonly found?

Answer 6

Nasopharynx

Question 7

Bacterial meningitis - patient with CSF skull fracture - what is the likely causative organism?

Answer 7

Strep pneumoniae

Question 8

Bacterial meningitis - what is the likely causative organism in adolescents?

Answer 8

Neisseria meningitidies (meningococcal meningitis)

Question 9

Neisseria meningitides is intracellular/extracellular?

Answer 9

Intracellular

Question 10

Neisseria meningitides likely gains access to the meninges through _______

Answer 10

The bloodstream

Question 11

Bacterial meningitis - in the past what was the likely causative organism in childhood but incidence has decreased now due to introduction of vaccine?

Answer 11

Haemophilus influenzae

Question 12

Bacterial meningitis - extremes of age (over 60 and neonates) - what is the likely causative organism?

Answer 12

Listeria monocytogenes

Question 13

Bacterial meningitis - immunocompromised patients - what is the likely causative organism?

Answer 13

Listeria monocytogenes

Question 14

Bacterial meningitis - E coli affects

Answer 14

Neonates

Question 15

Bacterial meningitis - H influenzae affects

Answer 15

Infants and children

Question 16

Bacterial meningitis - neisseria meningitides affects

Answer 16

Young adults

Question 17

Bacterial meningitis - listeria monocytogenes affects

Answer 17

Elderly

and neonates

Question 18

Bacterial meningitis - strep pneumoniae affects

Answer 18

Over 21 year olds (roughly)

Question 19

Bacterial meningitis - from head trauma/neurosurgery - what is the likely causative organism (2)

Answer 19

Staph aureus

Staph epidermidis

Question 20

Bacterial meningitis - microscopically, there will be an abundance of _____ in the subarachnoid space?

Answer 20

Polymorphs (neutrophils)

Question 21

Bacterial meningitis - clinical features

Answer 21

Crescendo headache 
Fever 
Change in mental state 
Neck stiffness 
N+V
Photophobia
Confusion
Slowness in responding to questions 
Non blanching ash

Question 22

Bacterial meningitis - what are the 5 warning features

Answer 22

Marked decline in conscious level 
Focal neurology 
Seizure before or at presentation
Bradycardia + hypertension
Papilloedema

Question 23

Bacterial meningitis - investigations

Answer 23

Bloods
Throat swab
CSF lumbar puncture

Question 24

What is the best way to determine aetiology (viral vs bacterial) meningitis?

Answer 24

CSF lumbar puncture

Question 25

Bacterial meningitis - CSF lumbar puncture findings

Answer 25

Increased neutrophils (abundant polymorphs) Low CSF glucose

Question 26

Bacterial meningitis - antibiotics should not be given until CSF lumbar puncture has been carried out. True or false?

Answer 26

False | - antibiotics should be given before lumbar puncture

Question 27

Bacterial meningitis - which patients should undergo CT prior to lumbar puncture?

Answer 27

``` Immunocompromised patients Pts with Hx of CNS disease Papilloedema Focal neurological deficit New onset seizure ```

Question 28

Management of suspected bacterial meningitis

Answer 28

High doses of antibiotics because you need to get into the CNS which is matted with pus

Question 29

Bacterial meningitis - which antibiotics are used?

Answer 29

Ceftriaxone IV 2g bd | Cefotaxime 2g qds

Question 30

Bacterial meningitis - which antibiotics are used if penicilin allergic ?

Answer 30

Chloraphenicol IV 25mg/kg qds | + Vancomycin

Question 31

Bacterial meningitis - aside from antibiotics, what is also administered to the patient

Answer 31

Dexamethasone IV 10mg qds

Question 32

Bacterial meningitis - when is dexamethasone given in relation to antibiotics?

Answer 32

This is started with or just before first dose of antibiotics

Question 33

Bacterial meningitis - why is dexamethasone administered?

Answer 33

Required if the causative organism is strep pneumonia. If the causative organism is strep pneumoniae, dexamethasone should be continues for 4 days If the causative organism is not strep pneumoniae, dexamethasone should be stopped

Question 34

Bacterial meningitis management - if patient is over 60 which additional antibiotic should be administered

Answer 34

2mg amoxicillin

Question 35

Why is amoxicillin given in over 60 year olds?

Answer 35

As the likely organism may be listeria

Question 36

Bacterial meningitis - when organism is confirmed to be listeria, what is the management?

Answer 36

Ceftriaxone + Dexamethasone + Amoxicillin

Question 37

Bacterial meningitis - if the patient has recently travelled to a country with high rates of penicillin resistant pneumococci then what should be added to management?

Answer 37

Rifampicin

Question 38

If a patient has suspected meningitis, public health must be informed. True or false?

Answer 38

True

Question 39

What are the prophylactic regimes if you have been in contact with a patient with meningitis?

Answer 39

600mg rifampicin

Question 40

Bacterial meningitis - complications

Answer 40

Cerebral oedema | Hydrocephalus

Question 41

Bacterial meningitis - vaccinations

Answer 41

Haemophilus influenzae B Neisseria meningitides Pneumococcal vaccines

Question 42

Aseptic meningitis - definition

Answer 42

In patients where there is no bacteria found on investigation but you think there is some form of meningococcal infection

Question 43

Aseptic meningitis - CSF results

Answer 43

Low number of WBC Normal glucose No bacteria

Question 44

Aseptic meningitis - causes

Answer 44

Viruses (most common) Fungi Spirochetes

Question 45

Viral meningitis - cause

Answer 45

Enterovirus (ECHO virus) | Travel related viruses

Question 46

Viral meningitis - investigations

Answer 46

Viral stool culture Throat swab CSF PCR Lumbar puncture

Question 47

Viral meningitis - lumbar puncture findings

Answer 47

Lots of lymphocytes

Question 48

Viral meningitis - management

Answer 48

Self limiting

Question 49

Encephalitis - causative organism

Answer 49

Herpes simplex virus (HSV)

Question 50

Encephalitis has a sudden onset. True or false?

Answer 50

False | - gradual onset

Question 51

Encephalitis - clinical features

Answer 51

``` Mental state change Seizures Partial paralysis Confusion Speech problems Behavioural disturbances Meningismus - stiffness in the head ```

Question 52

Encephalitis - always do a lumbar puncture. True or false?

Answer 52

False | - try to do a lumbar puncture but if unsafe then do a CT scan

Question 53

Encephalitis - most useful investigation

Answer 53

MRI scan

Question 54

Encephalitis - management

Answer 54

IV aciclovir

Question 55

``` Which antibiotic is first line for most cases of meningitis? IV vancomycin IV amoxicillin IV ceftriaxone IV chloramphenicol IV co-trimoxazole ```

Answer 55

IV ceftriaxone