CNS infection

Question 1

What are the complications of steroids?

Answer 1

• Peptic ulcers ( + GI discomfort)
• Osteoporosis
• Impaired healing ability
• Increased risk of infection
• Weight gain - esp trunkal
• Electrolyte imbalance + fluid retention
• Sleep disorder
• Mood alterations
• Hirsutism

Question 2

What are the S+S of meningitis

Answer 2

Symptom
	- Stiff neck 
	- Headache 
	- Photophobia
	- Vomiting 
	- Rash 
Sign 
	- Photophobia
	- Confusion, -Reduced GCS
	- Rash - non blanching 
	- Fever
	- Seizure
        - Kernig's sign 
          Flex hip, pain on knee extension

Question 3

What are the common causes of meningitis?

Answer 3

Bacterial or viral infection 
Aetiology varies between age groups 
- Neisseria at any age except babies
- Group b strep in kids + babies
- babies < month, also consider e coli and listeria
- toddlers - haemophilis, e coli
- teens + adults - strep pneumoniae
- over 65 - also listeria

Question 4

How would you treat a meningitis?

Answer 4

blood Cx +S or PCR
For adults - give dexamethasone before antibiotics
then empiric antibx, varies for age
cefotaxime for all + vanc to cover strep pneumonia ( also covers resistant Neisseria?
± amoxicillin to cover listeria in babies + over 65, pregnant
± Acyclovir if HSV cannot be ruled out

DO A HEAD CT
to rule out any possible intracranial pressure that would put the patient at risk of herniation from a Lumbar puncture.
then lumbar puncture ( b/t L3 + L4)
CSF analysis Culture + sensitivity or PCR

if gram stain comes back negative, continue with the treatment
If it looks like a duck and quacks like a duck , treat it like bacterial meningitis

Question 5

What is the role of the steroids given for meningitis?

Answer 5

To stop inflammation and fibrosis early to avoid possible complications of neurological deficits

Question 6

What are you checking in the CSF analysis for suspected meningitis?

Answer 6

• Glucose, proteins and white cells
• low glucose = bacterial ( not viral)
  look at it - cloudy = bacterial, viral = clear
  WCC - neutrophilic over 1000 = bacterial, lymphocytic over 100 = viral

Question 7

Why are proteins present in CSF in meningitis?

Answer 7

Because of disruption to the BBB.

If extremely elevated + CSF is turbid => TB

Question 8

Why is haemophilus seen as a cause of meningitis is kids only?

Answer 8

May become infected before they get their Hib vaccine at 6months + 6 yrs

Question 9

What strains of neisseria are pathogenic?

Answer 9

A,B,C,Y, W135

Question 10

What is an aseptic meningitis?

Answer 10

Bacterial cultures negative + lymphocytic CSF

- cause could be Viral, TB or 3 possible bacterial causes; leptospirosis, syphilis, Lyme disease

Question 11

What tests would decide you didn’t need to give acyclovir ?

Answer 11

• CSF PCR showing no HSV

* MRI looking for medial temporal lobe inflammatory or necrotic lesions of HSV encephalitis

Question 12

What is the most common cause of endemic encephalitis? Management?
What is always a symptom of this? What would be seen in CSF?

Answer 12

HSV
early acyclovir
always will have a fever
proteins, ± RBCs, lymphocytes

Question 13

What is deficient / low in a patient with purpura fulminant?

Answer 13

Protein C and S

Question 14

What proportion of meningitis cases are caused by meningococcal vs other bacteria?

Answer 14

meningococcal 80%