CNS Infections Acute Meningitis

Question 1

Most common supporative infection of the CNS

Answer 1

Acute Bacterial Meningitis

Question 2

Most common causative organism of acute bacterial meningitis?

Answer 2

Strep Pneumoniae - 50% of cases

N. Meningitidis - 25%
GBStrep - 15%
Listeria Mening - 10%
H. Influenzae - <10%

Question 3

This organism is the cuasative agent in recurring epidemics of meningitis q 8-12 years

Answer 3

N meningitidis

Question 4

This organisms are commonly found to complicate neurosurgical procedures, head trauma, CSF rhinorrhea, otorrhea?

Answer 4

Gram negative organisms

Question 5

Classic Triad of Meningitis?

Answer 5

Fever
Headache
Nuchal rigidity

Question 6

Patients with acute bacterial meningitis rarely present with depressed level of consciousness?

True or False?

Answer 6

False

> 75% present with a depressed level of consciousness

Question 7

Pathognomonic sign of meningeal irritation?

Answer 7

Nuchal rigidity

• which is defined as the resistance of the neck to passive flexion

Question 8

This classic sign of meningitis is present when you notice the patient flex his knee and hip when passive neck flexion is performed?

Answer 8

Brudzinksi

Kernig - hip flexed to abdomen, knee flexed. Straighten the knee. Positive when pain is present when straightening the knee

Question 9

Rash of meningococcemia is an important clinical finding to help with the diagnosis. What are the characteristics of this rash?

Answer 9

Initially maculopapular —> rapidly evolves to petechial pattern.

areas of predicliction
Trunk
Lower extremities
Mucous membranes
Conjuctiva
Occ palms and soles

Question 10

neuroimaging studies should be done in all cases of acute bacterial meningitis prior to lumbar puncture?

Answer 10

No

Stable patients with no signs and symptoms of increased ICP can be immediately LPd

Question 11

Antibiotics can be given a few hours prior to LP since it will not alter CSF findings.

True or false?

Answer 11

True

Antibiotics given a few hours prior to LP will not significantly alter the expected findings.

Question 12

A postive CSF LA test is virtually diagnostic of N. Meningitidis infection?

Answer 12

TRue

CSF LA is used for Strep pneumoe and N. Meningitidis infection
95-100% specific 70-100% sensitive

Question 13

This diagnostic test is used for rapid detection of gram-negative endotoxin for the diagnosis of gram negative bacterial meingitis?

Answer 13

Limulus amebocyte lysate assay

Question 14

This is the preferred neuroimaging tool for patients with acute bacterial menigits?

Answer 14

MRI

Question 15

This form of CNS infection can mimic bacterial meningitis?

Answer 15

Viral enceph

Specifically HSV enceph

Question 16

This findings are consistent with HSV enceph rather than bacterial meningitis?

Answer 16

Orbitofrontal, anterior, and medial temporal lobes within 48 hours of symptom onset.

Question 17

Periodic pattern in a patient with acute bacterial meningitis is consistent with the diagnosis

Answer 17

No

This is consistent with HSV enceph

Question 18

Lumbar tap was done in a patient and it revealed
Glucose - 36 mg/dl
Protein - 100
WBC - 12,000
Opening pressure of 18.5

Diagnosis?

Answer 18

Bacterial meningitis
Low glucose
High protein
> 10,000 wbc
Increased opening pressure

Question 19

Major non infectious differential for acute bacterial meningitis

Answer 19

SAH

Question 20

When should antimicrobial therapy for bacterial meningitis be initiated?

Answer 20

Within 60 min

Question 21

Included in the emperical treatment of acute bacterial meningitis?

Answer 21

Dexamethasone
3rd/4th gen cephalosporins
Vanco
Acyclovir

DVAC

Question 22

This antimicrobial is added to the emperical regimen for suspected casees of L monocytogenes especially those who are immuno-compromised and those who are preganant?

Answer 22

Ampicillin

Question 23

Foro cases with otitis media, sinusitis, or mastoiditis this antimicrobial is added to the emeprical regimen?

Answer 23

Metronidazole

Question 24

Patients who are post neurosurgical procedure need coverage for what organisms

Answer 24

Staph

P. Aeroginosa

Question 25

For susceptible strains what is the antimicrobial of choice for Meningococcal Meningitis?

Answer 25

Pen-G x 7 days if uncomplicated

Question 26

An outbreak of Meningococemia occured. A friend of the victim was concerned if he needed prophylaxis. What is a close contatct case?

Answer 26

Individual who had contatc with oropharyngeal secretions through kissing sharing toys beverages or cigar

Question 27

Recommended prophylaxis for Meningococcemia?

Answer 27

Rifampin 600 mg q12 x 2 days

Alternatives

Azith 500 one dose

Ceftriaxone 250 IM one dose

Question 28

For pneumococcal meningitis how long is the recommended treatment duration?

Answer 28

2 Weeks

Question 29

When should repeat LP be done in pneumoccal meningits?

Answer 29

24-36 hours to document sterilization of the CSF

Failure to sterilize is presumptive of antibiotic resitance

Question 30

What is the treatment for L meningitides?

Answer 30

Ampicillin x 3 weeks

+ gentamycin for critically ill patients

Question 31

Treatment duration for gram negative meningitis?

Answer 31

3 weeks

Question 32

When should dexamethasone be initiated?

Answer 32

20 minutes before antimicrobial therapy

Role is to decrease CSF outflow resistance and to stableize the BBB

Not beneficial if started > 6 hours after antibiotic therapy

Question 33

For methicillin sensitive staph what is the treatment of choice?

Answer 33

Naf is enough

Nafcillin

Question 34

Antimicrobial of choice for P. Aerogenosa?

Answer 34

Ceftazidime or meropenem

Question 35

The following are risk factors for increased death except?

1. Decreased sens
2. Seizure within 48 hours
3. Infants
4. > 50
5. Shock/ ARF

Answer 35

2. Seizure wihin 24 hours not 48 hours