Meningitis

Question 1

Bacterial causes of pyogenic meningitis:

Answer 1

Group B streptococcus
H. flu, type B
Strep pneumoniae
Neisseria meningiditis

Question 2

Fungal causes of pyogenic meningitis:

Answer 2

Histoplasma capsulatum
Coccidiodomyces immitus
Cryptococcus neoformans

Question 3

Amoebic causes of pyogenic meningitis:

Answer 3

Naegleria

Question 4

Infectious causes of aseptic meningitis:

Answer 4

Enteroviruses, arboviruses, mumps virus, HSV, VSV, adenovirus, EBV, parvovirus, cryptococcus, tuberculosis, syphilis, Lyme disease

Question 5

Non-infectious causes of aseptic meningitis:

Answer 5

IVIg, bactrim, carcinomatous meningitis, leukemia, lymphoma, Kawasaki disease.

Question 6

Bacterial meningitis in the immunocompromised:

Answer 6

Listeria monocytogenes

Cryptococcus neoformans

Question 7

Bacterial meningitis in those younger than 2 months:

Answer 7

Group B streptococcus
E. coli
Listeria monocytogenes

Question 8

Pathophysiology of meningitis:

Answer 8

1) Carriage, transmission, or colonization by encapsulated pathogenic bacteria.
2) Bacteremia (children don’t produce anti-capsular antibodies well)
3) Penetration of BBB
4) Diminished cerebral blood flow (vasculitis, cerebral edema)

Question 9

Major viral causes of aseptic meningitis:

Answer 9

Group B coxsackievirus, echoviruses. Aseptic meningitis occurs in the seasonal pattern observed with enterovirus infections (marked SUMMER-FALL predominance).

Question 10

Pathophysiology of enterovirus aseptic meningitis:

Answer 10

1. Transmission (direct and indirect fecal-oral transmission)
2. Minor viremia
3. Systemic lymphoid involvement
4. Major viremia
5. Involvement of CNS, myocardium, etc.

Question 11

Signs/symptoms of meningitis in neonates:

Answer 11

Irritability, lethargy, poor feeding, vomiting, seizures, temperature instability, tense fontanelles, cranial nerve palsy, FEVER AND NUCHAL RIGIDITY MAY BE ABSENT

Question 12

Signs/symptoms of meningitis in children/adults:

Answer 12

Headache, vomiting, lethargy, mental confusion, stiff neck, fever, nuchal rigidity, Kernig’s sign, Brudzinski’s sign

Question 13

CSF analysis in meningitis:

Answer 13

Opening pressure
WBC count/differential
Glucose/protein
Gram stain/culture

Question 14

CSF results in bacterial meningitis:

Answer 14

CSF white cell count >200.
CSF WBC differential, usually >90% polys
CSF glucose decreased (<40)
CSF protein elevated

Question 15

CSF results in viral meningitis:

Answer 15

CSF white cell count usually 10-500 cells
CSF WBC differential initially predominance of polys, but drops to <50% polys within 24 hours
CSF glucose normal to slightly low
CSF protein normal to slightly increased

Question 16

Diagnosis of viral meningitis:

Answer 16

PCR to detect enterovirus RNA
Cell culture (only in 30-40% of cases). Likelihood of a positive viral culture correlates directly with CSF WBC count.

Question 17

Sequellae of meningitis:

Answer 17

Usually none
Deafness (10%)
Bilateral/profound deafness (5%)
Mental retardation (4%)

Question 18

Acute complications of meningitis:

Answer 18

Seizures, SIADH, hydrocephalus, subdural effusion, hearing loss, hemiparesis, stroke.

Question 19

Meningitis prognosis:

Answer 19

For bacterial meningitis: Mortality is lower for children (<5%) than for adults (20-30%).
For viral meningitis: Most infants and children recover completely within 3-7 days of onset. Adults may experience more severe and more prolonged symptoms.

Question 20

Chronic viral meningitis in immunocompromised patients:

Answer 20

Patients with agammaglobulinemia and CVID are susceptible to persistent or recurrent meningoencephalitis with enteroviruses. CNS manifestations include: weakness, lethargy, headache, cognitive and intellectual decline, hearing loss, ataxia, seizures, and sensory abnormalities.

Question 21

Treatment of bacterial meningitis:

Answer 21

Vancomycin and ceftriaxone until susceptibility is known with adjunctive steroid therapy.

Question 22

Treatment of viral meningitis:

Answer 22

Antibiotics until CSF and blood cultures are reported negative at 48-72 hours.
Enterovirus PCR assay may assist in immediate management decisions.
PLECONARIL reduces the duration of headache and other symptoms by 50%.

Question 23

Post-exposure prophylaxis:

Answer 23

Four doses of rifampin over 2 days, or a single dose of ciprofloxacin.

Question 24

Immunization:

Answer 24

Routine immunization of all infants and children with HiB, and 13-valent pneumococcal conjugate (PCV13).
Selective immunization for individuals at risk for meningococcal disease and pneumococcal disease is recommended with quadrivalent meningococcal conjugate (MCV4) and 23-valent pneumococcal polysaccharide (PPV23).