CNS Infections

Question 1

Which virus is the cause of viral meningitis?

Answer 1

Enteroviruses, especially ECHO virus

Question 2

What is the diagnosis and treatment for viral meningitis?

Answer 2

• Viral stool culture, throat swab and CSF PCR

- Generally supportive (paracetamol) as it is self limiting

Question 3

What is the causative virus in viral encephalitis in:

1. The young
2. Adults

Answer 3

1. Herpes simplex

2. Varicella zoster

Question 4

How is viral encephalitis treated?

Answer 4

Immediate high dose IV aciclovir

Question 5

What are some clinical features of encephalitis?

Answer 5

• Insidious onset
• Behaviour changes
• Headache, fever
• Seizures
• Speech/memory issues
• Coma

Question 6

What makes H. influenzae difficult to treat and also gives it subtypes?

Answer 6

Its viral capsule

- vaccines are directed against the capsule antigen

Question 7

Which bacteria causes meningitis at the extremes of ages and is a gram positive bacilli?

Answer 7

Listeria monocytogenes

Question 8

How do you treat meningitis caused by listeria monocytogenes?

Answer 8

• IV Ampicillin/Amoxicillin

Ceftriaxone has NO value due to resistance

Question 9

What are the three clinical signs of bacterial meningitis?

Answer 9

1. Fever/Headache
2. Stiff neck
3. Alteration in consciousness

Question 10

What should be checked for in patients with bacterial meningitis?

Answer 10

A purpura fulminanes rash - can lead to widespread vessel coagulation and tissue necrosis

Question 11

What ratio of CSF glucose to blood glucose is suggestive of infection?

Answer 11

Less than 0.5 (bacteria remove sugar from the CSF)

Question 12

What could cause a negative culture in a patient with strong symptoms for bacterial meningitis?

Answer 12

Previous antibiotic use (probably given to the patient by their GP prior to admission)

Question 13

What can not be checked for using PCR?

Answer 13

Listeria monocytogenes (you have to wait for culture to diagnose this)

Question 14

What is the empirical antibiotic therapy for bacterial meningitis?

Answer 14

1. IV Ceftriaxone 2g bd
2. Add IV Ampicillin/Amoxicillin 2g bd IF LISTERIA SUSPECTED
   (If penicilin allergic give chloramphenicol and vancomycin IV)

Question 15

What should be given to all patients with suspected bacterial meningitis along with antibiotics?

Answer 15

Steroids (10mg IV shortly before or with first dose of Ab)

- DO NOT GIVE in post-surgical meningitis, severe immunocompromise or those in septic shock