CNS Infections

Question 1

Why are infections in the cranial cavity so dangerous?

Answer 1

Infection leads to inflammation which in an enclosed space like the skull leads to compression herniation and necrosis.

Question 2

If you have pyogenic meningitis in a non immunosuppressed patient caused by a gram +ve what is it likely to be?

Answer 2

Streptococci Pneumonia

Question 3

If you have pyogenic meningitis in a non immunosuppressed patient caused by gram -ve rods what is it likely to be?

Answer 3

Neisseria Meningitidis

Question 4

If you have pyogenic meningitis in an immunosuppressed patient caused by gram +ve rods what is it likely to be?

Answer 4

Listeria Monocytogene

Question 5

If you have a pyogenic meningitis in an immunosuppressed patient caused by gram -ve what is it likely to be?

Answer 5

H.Influenzae

Question 6

Someone presents with pyogenic meningitis what is the treatment?

Answer 6

IV Ceftriaxone 2g

IV Dexamethasone

Question 7

What organisms would IV Ceftriaxone be effective for?

Answer 7

Pneumococcus
Meningococcal
H.Influenzae

Question 8

If someone is Penicillin allergic what is the alternative to Ceftriaxone?

Answer 8

Chloramphenicol IV 25mg

Question 9

When is Listeria considered a suspected cause of meningitis?

Answer 9

Over 60’s

Immunosuppressed diabetes Alcohol

Question 10

If Listeria is the suspected cause of the meningitis what is the treatment?

Answer 10

IV Ceftriaxone
IV Dexamethasone
IV Amoxicillin 2g 4 hourly

Question 11

If someone has recently travelled and presents with meningitis what is the treatment?

Answer 11

IV Ceftriaxone
IV Dexamethasone
IV Vancomycin - increased risk of Penicillin resistance

Question 12

For all cases of Pyogenic Meningitis what is the baseline length of treatment ?

Answer 12

5 days

Question 13

A Purpuric non blanching rash is only present in one form of meningitis. Which organism is responsible?

Answer 13

Meningocococcal Menigitis

Question 14

What is the presentation of viral meningitis?

Answer 14

Headache Fever Neck Stiffness

Question 15

When is a common time for people to contract Viral Meningitis ?

Answer 15

Late Summer Autumn

Question 16

What are two common causes of viral meningitis ?

Answer 16

Enterovirus

HSV - Most severe infection

Question 17

What is the treatment for viral meningitis?

Answer 17

Usually supportive due to its self limiting nature.

Question 18

What is used to diagnose viral meningitis ?

Answer 18

CSF

PCR

Question 19

What are the clinical signs of encephalitis ?

Answer 19

Confusion
Coma
Behavioural Changes - due to cerebral cortex involved

Question 20

What signs can show up on MRI that might indicate a encephalitis?

Answer 20

Temporal lobe and adjacent parahippocampal gyrus are bright white on MRI

Question 21

What gives the definitive diagnosis of encephalitis ?

Answer 21

Lumbar puncture

Question 22

What are the clinical signs of a CNS infection?

Answer 22

Headache
Vomiting
Pyrexia
Neck Stiffness
Photophobia
Lethargy
Confusion
Rash

Question 23

What nerves are at risk in a very purulent meningitis?

Answer 23

III Oculomotor

VI Abducens

Question 24

What routes can an infection take to cause a meningitis ?

Answer 24

Direct route - Invasion through bone into the cranial cavity e.g. mastoiditis from middle ear
Remote focus - Endocarditis Myocarditis blood

Question 25

If there is a suspicion of a raised ICP what should be undertaken before a Lumbar Puncture ?

Answer 25

CT

Question 26

What region are you trying to hit in a lumbar puncture?

Answer 26

Sub Arachnoid Space

Question 27

How may vials should be taken and where should they be sent to?

Answer 27

1 Haematology Cell Count and differentiation 2 Microbiology - Gram stain and culture 3 Chemistry - Glucose Protein 4 Haematology - Cell count

Question 28

What is normal for a CSF sample?

Answer 28

Protein - 0.15 to 0.45 Glucose - 40 to 60% of blood No RBC WBC 5mm³

Question 29

Bacterial Meningitis

Answer 29

WBC >2000mm³ Neutrophils >1180 High Protein >220 Low Glucose

Question 30

Viral Meningitis

Answer 30

Less WBC Lymphocytes > Neutrophils Normal Glucose Slightly High or normal protein

Question 31

If someone presents with Neisseria Meningitis what should you do?

Answer 31

Alert Public Health | Close relatives given vaccine or prophylaxis

Question 32

Where is Neisseria Meningitis found in healthy individuals?

Answer 32

Throat

Question 33

What is it that causes the most serious symptoms in a Neisseria Meningitis infection?

Answer 33

Endotoxins

Question 34

What are some of the more severe symptoms due to Neisseria Meningitis?

Answer 34

Non Blanching Rash Necrosis of the extremities High Morbidity

Question 35

What else is required in order diagnose H.Influenzae?

Answer 35

Blood factors are required for cultures

Question 36

When is a S.Pneumonia infection more likely?

Answer 36

CSF leaking Skull fractures Cochlear Implant

Question 37

What does someone with TB meningitis present like?

Answer 37

Non specific generally ill health | High Morbidity

Question 38

When is a meningitis considered Aseptic?

Answer 38

No bacteria are found in the lumbar puncture

Question 39

What does the CSF look like in Aseptic Meningitis?

Answer 39

Low WBC Normal Glucose Minimally Elevated protein

Question 40

Treatment for HSV I and II is what?

Answer 40

Acyclovir

Question 41

What is one way other than the severity to differentiate between HSV and Enterovirus?

Answer 41

Enterovirus has no confusion

Question 42

List some non infectious causes of Meningitis?

Answer 42

Sarcoidosis | Carcinoid