Acute Meningitis

Question 1

organisms most often responsible for community-acquired bacterial meningitis

Answer 1

Streptococcus pneumoniae (~50%), Neisseria meningitidis (~25%), group B streptococci (~15%), and Listeria monocytogenes (~10%)

Question 2

causative organism of recurring epidemics of meningitis every 8–12 years.

Answer 2

N. meningitidis

Question 3

most common cause of meningitis in adults >20 years of age,

Answer 3

S. pneumoniae

Question 4

Most important risk factor to develop pneumococcal meningitis

Answer 4

Pneumococcal pneumonia

Question 5

Additional risk factors to develop pneumococcal meningitis

Answer 5

coexisting acute or chronic pneumococcal sinusitis or otitis media, alcoholism, diabetes, splenectomy, hypogammaglobulinemia, complement deficiency, and head trauma with basilar skull fracture and CSF rhinorrhea.

Question 6

Most common form of suppurative CNS infection

Answer 6

Bacterial Meningtis

Question 7

True or False. Mortality rate remains around 20% despite antibiotic therapy in pneumococcal meningitis.

Answer 7

True

Question 8

Demographic profile of L.monocytogenes

Answer 8

Neonates (<1 month of age), pregnant women, individuals >60 years, and iimmmunocompromised individuals of all ages.

Question 9

Food borne human listerial infection may cause meningtis. What foods?

Answer 9

Coleslaw, milk, soft cheeses, and several types of ready to eat foods including delicatessen meat and uncooked hotdogs.

Question 10

In the pathophysiology of meningitis, these two factors prevent effective opsonization of bacteria.

Answer 10

In CSF, relatively small amounts of complement protein and immunoglobulins.

Question 11

Signs of increased ICP

Answer 11

1. Deteriorating/reduced ICP 2. Papilledema 3. Dilated poorly reactive pupils 4. Sixth nerve palsies 5. Decerebrate posturing 6. Cushing reflex (bradycardia, hypertension, irregular respirations)

Question 12

Classic CSF abnormalities of bacterial meningitis

Answer 12

(1) polymorphonuclear (PMN) leukocytosis (>100 cells/μL in 90%), (2) decreased glucose concentration (<2.2 mmol/L [<40 mg/dL] and/ or CSF/serum glucose ratio of <0.4 in ~60%), (3) increased protein concentration (>0.45 g/L [>45 mg/dL] in 90%), and (4) increased opening pressure (>180 mmH2O in 90%).

Question 13

CSF Abnormalities in Bacterial Meningitis

Answer 13

Question 14

What is the typical CSF profile with viral CNS infections?

Answer 14

Lymphocytic pleocytosis with a normal glucose concentration.

Question 15

Noninfectious disorders which can mimic bacterial meningitis

Answer 15

Subarachnoid hemorrhage ( major consideration)

medication-induced hypersensitivity meningitis

chemical meningitis due to rupture of tumor contents into the CSF (e.g., from a cystic glioma or craniopharyngioma epidermoid or dermoid cyst);

carcinomatous or lymphomatous meningitis; meningitis associated with inflammatory disorders such as sarcoid, systemic lupus erythematosus (SLE), and Behçet’s syndrome;

pituitary apoplexy;

uveomeningitic syndromes (Vogt- Koyanagi-Harada syndrome).

Question 16

Empirical therapy of community acquired bacterial meningitis

Answer 16

Dexamethasone

3rd/4th gen cephalosporin (Ceftriaxone, Cefotaxime, Cefepime)

Vancomycin

Acyclovir ( HSV encephalitis is the leading disease in the differential diagnosis)

Doxycycline (during tick season)

Question 17

Antibiotic of choice for meningococcal meningitis caused by susceptible strains

Answer 17

Penicillin G

Question 18

Chemoprophylaxis in Meningococcal Meningitis

Answer 18

2 day regimen of rifampin (600 mg every 12 h for 2 days in adults and 10 mg/kg every 12 h for 2 days in children >1 year)

azithromycin (500 mg) or one intramuscular dose of ceftriaxone (250 mg).

Question 19

Antimicrobial therapy Of CNS Bacterial Infections based on pathogen

for Streptococcus Pneumonia

Answer 19

Penicillin-sensitive (PenG)

Penicillin-intermediate (Ceftriaxone or cefotaxime or cefepime)

Penicillin-resistant (Ceftriaxone (or cefotaxime or Cefepime) + Vancomycin)

Question 20

Antimicrobial therapy of Gram-negative bacilli (except Pseudomonas)

Answer 20

Ceftriaxone or Cefotaxime

Question 21

Antimicrobial therapy of Pseudomonas aeruginosa

Answer 21

Ceftazidime or Meropenem

Question 22

Antimicrobial therapy of staphylococci spp.

Methicillin-sensitive

Methicillin-resistant

Answer 22

Methicillin-sensitive (NAFCILLIN)

Methicillin-resistant (VANCOMYCIN)

Question 23

Antimicrobial therapy of Listeria monocytogenes

Answer 23

AMPICILLIN + GENTAMICIN

Question 24

Antimicrobial therapy of Haemophilus influenzae

Answer 24

Ceftriaxone or Cefotaxime or Cefepime

Question 25

Antimicrobial therapy Streptococcus agalactiae

Answer 25

Penicillin G or ampicillin

Question 26

Antimicrobial therapy for

Bacteroides fragilis

Fusobacterium spp.

Answer 26

Metronidazole

Question 27

Beneficial effect of Dexamethasone in Meningitis

Answer 27

-Exerts its beneficial effect by inhibiting the synthesis of IL-1B and TNF-alpha at the level of mRNA, decreasing CSF outflow resistance, stabilizing the blood-brain barrier.

Question 28

What is the emergency treatment of increased ICP?

Answer 28

1. Elevation of the patient’s head to 30-45 deg
2. Intubation and hyperventilation (PaCo2 25-30 mmHg_
3. Mannitol