Meningitis

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Background

Microbiology

Pathophysiology

Risk Factors

Classification

  • Acute (<24hr)
    • Usually bacterial in origin (25%)
  • Subacute (1-7d)
    • Viral or bacterial
  • Chronic (>7d)

Clinical Features

Almost all adults present with at least 2 of the following:[1]

Other nonspecific symptoms include:

  • Photophobia
  • Vomiting
  • Prodromal URI
  • Focal neuro symptoms (e.g. CN deficit)
  • Seizures

Differential Diagnosis

Headache

Common

Killers

Maimers

Others

Aseptic Meningitis

Altered mental status and fever

Evaluation

Physical Exam

Clinical Tests for Meningitis
Finding Description Sensitivity Specificity
Nuchal rigidity
  • Rigidity of neck muscles with flexion
 13%[2] 80% [2]
Kernig's sign
  • With flexed hip at 90°, extension of knee produces pain
 2%[2] 97%[2]
Brudzinski's sign
  • Involuntary lifting of legs with passive flexion of the neck
 2%[2] 98%[2]
Jolt Test
  • Horizontal rotation of the head at frequency of 2 rotations/second
  • Exacerbation of pre-existing headache is positive test.
 100%?^

^Although a 1991 study[3] showed high sensitivity with this test, multiple newer studies have cast doubt on its sensitivity.[4][5] Although it may be clinically useful in the right subset of patients, it should not be considered to be 100% sensitive.

Work-Up

  1. CBC
  2. Chem
  3. Blood culture
  4. ?CT head: See CT Before Lumbar Puncture
  5. CXR (50% of patients with pneumoccocal meningitis have evidence of pneumonia on CXR)
  6. Lumbar Puncture

Lumbar Puncture Diagnosis

Measure Normal Bacterial Aseptic (Viral) Fungal Tuberculosis Subarachnoid hemorrhage Neoplastic
Appearance Clear Clear, cloudy, or purulent Clear Clear or opaque Clear or opaque Xanthochromia, bloody, or clear Clear or opaque
Opening Pressure (cm H2O) 10-20 >25 Normal or elevated >25 >25 >25 Normal or elevated
WBC Count^ (cells/µL) 0-5^ >100^ 5-1000 <500 50-500 0-5 (see correction section) <500
% PMNs >80-90% 1-50%^^ 1-50% Early PMN then lymph 1-50%
Glucose >60% of serum glucose Low Normal Low Low Normal Normal
Protein^^^ (mg/dL) < 45 Elevated Elevated Elevated Elevated Elevated >200
Gram Stain Neg Pos Neg India ink Tb stain Blood
  • ^Normal or lower WBC results may be found in immunocompromised, early, or partially treated (e.g. with oral antibiotics) bacterial menintigis, and those with tuberculosis meningitis
  • ^^Lymph predominance may be found in patients with early bacterial meningitis or those that have been partially treated (e.g. with oral antibiotics)
  • ^^^For unexplained elevations of protein, consider encephalitis, MS, Guillian Barre

Corrections

  • WBC correction (for bloody tap)
    • Simplified version (if peripheral WBC and RBC counts are within normal limits):
      • Subtract 1 WBC for every 750 RBC in CSF
    • Complex version (WBC and/or RBC not within normal limits):
      • "WBCs added" = WBC(blood) x [RBC(CSF) / RBC(blood)]
      • WBC counted/resulted - "WBCs added" = actual WBC
  • Protein correction (for bloody tap)
    • For each 1000 RBC decrease protein value by 1mg/dl

Delay in LP

  • CSF cultures are become sterile in 2 hrs after parenteral antibiotics in meningococcal meningitis and 6 hrs in pneumococcal meningitis[6][7]
  • 12 hrs after antibiotics: CSF glucose levels increase and protein levels decrease. CSF WBC and neutrophils are not affected[8]

Antibiotics

  • Give as soon as possible (if LP performed within 2hr of antibiotics, CSF culture will not be affected)

Neonates (up to 1 month of age)[9]

MRSA is uncommon in the neonate

> 1 month old[10]

Adult < 50 yr[11]

Adult > 50 yr and Immunocompromised[12]

Post Procedural (or penetrating trauma)[14]

Cryptococcosis Meningitis

Options

  • Amphotericin B 1mg/kg IV once daily AND Flucytosine 25mg/kg PO q6hrs daily
  • Amphotericin B 5mg/kg IV once daily AND Flucytosine 25mg/kg PO q6hrs daily


Meningitis with severe PCN allergy

Meningitis with VP shunt

  • Coverage for skin contaminants (S. epidermis, S. aureus)
  • Vancomycin plus ceftriaxone plus shunt removal

Neisseria meningitidis Prophylaxis

  • Ceftriaxone 250mg IM once (if less than 15yr then 125mg IM)
  • Ciprofloxacin 500mg PO once
  • Rifampin 600 mg PO BID x 2 days
    • if < 1 month old then 5mg/kg PO BID x 2 days
    • if ≥ 1 month old then 10mg/kg (max at 600mg) PO BID x 2 days

Steroids

  • Dexamethasone in adults
    • Only give 15 min prior to or with first dose of antibiotics
    • 10mg IV q6hr x4d
  • Dexamethasone in children and infants
    • There has been no mortality benefit found with steroid use in children[15]
    • Neurologic sequelae was reduced only in high income coutries

The only benefit is shown in patients with meningitis from Streptococcus pneumoniae with a possible mortality benefit and a decrease in hearing loss[16]

AntiVirals

  • Acyclovir
    • Consider for patients with suspected viral meningitis who present with neurologic deficits
    • 10mg/kg IV q8hr (Obese patients should be dosed using ideal body weight)

Prophylaxis

Only for meningococcus exposure

Indications

  • Household contacts
  • School or day care contacts in previous 7d
  • Direct exposure to pt's secretions (kissing, shared utensils or toothbrush)
  • Intubation without facemark

Prophylaxis regimen

Either of the options are acceptable

  • Rifampin 600mg PO BID x2d
    • 5mg/kg PO if < 1 month old
    • 10mg/kg PO ≥ 1 month old
  • Ceftriaxone 250mg IM x1
    • 125mg IM if ≤ 15 years old
    • Ceftriaxone should be used for pregnant patients
  • Ciprofloxacin 500mg PO x1

Disposition

Bacterial meningitis

Viral meningitis

  • Admit for empiric antibiotics until culture results return OR
  • Discharge with 24hr follow up

See Also

References

  1. ↑ van de Beek D. et al. Clinical features and prognostic factors in adults with bacterial meningitis. N Engl J Med. 2004 Oct 28. 351(18):1849-59.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Nakao JH, et al. Jolt accentuation of headache and other clinical signs: poor predictors of meningitis in adults. Am J Emerg Med. 2014;32(1):24-28.
  3. ↑ Jolt accentuation of headache: the most sensitive sign of CSF pleocytosis. Headache. 1991 Mar;31(3):167-71.
  4. ↑ Absence of jolt accentuation of headache cannot accurately rule out meningitis in adults. Am J Emerg Med. 2013 Nov;31(11):1601-4
  5. ↑ Jolt accentuation of headache and other clinical signs: poor predictors of meningitis in adults. Am J Emerg Med. 2014 Jan;32(1):24-8
  6. ↑ Kanegaye JT, Soliemanzadeh P, Bradley JS. Lumbar puncture in pediatric bacterial meningitis: defining the time interval for recovery of cerebrospinal fluid pathogens after parenteral antibotic pretreatment. Pediatrics2001;108:1169–74
  7. ↑ Michael B1, Menezes BF, Cunniffe J, Miller A, Kneen R, Francis G, Beeching NJ, Solomon T. Effect of delayed lumbar punctures on the diagnosis of acute bacterial meningitis in adults. Emerg Med J 2010;27:6 433-438. PMID 20360497
  8. ↑ Lise E. Nigrovic, Richard Malley, Charles G. Macias, John T. Kanegaye, Donna M. Moro-Sutherland, Robert D. Schremmer, Sandra H. Schwab, Dewesh Agrawal, Karim M. Mansour, Jonathan E. Bennett, Yiannis L. Katsogridakis, Michael M. Mohseni, Blake Bulloch, Dale W. Steele, Ron L. Kaplan, Martin I. Herman, Subhankar Bandyopadhyay, Peter Dayan, Uyen T. Truong, Vince J. Wang, Bema K. Bonsu, Jennifer L. Chapman, Nathan Kuppermann. Effect of Antibiotic Pretreatment on Cerebrospinal Fluid Profiles of Children With Bacterial Meningitis. Pediatrics Oct 2008, 122 (4) 726-730. PMID 18829794
  9. ↑ van de Beek D. et al. Advances in treatment of bacterial meningitis. Lancet. Nov 10 2012;380(9854):1693-702
  10. ↑ van de Beek D. et al. Advances in treatment of bacterial meningitis. Lancet. Nov 10 2012;380(9854):1693-702
  11. ↑ van de Beek D. et al. Advances in treatment of bacterial meningitis. Lancet. Nov 10 2012;380(9854):1693-702
  12. ↑ van de Beek D. et al. Advances in treatment of bacterial meningitis. Lancet. Nov 10 2012;380(9854):1693-702
  13. ↑ [Guideline] Chaudhuri A, Martinez-Martin P, Kennedy PG, et al. EFNS guideline on the management of community-acquired bacterial meningitis: report of an EFNS Task Force on acute bacterial meningitis in older children and adults. Eur J Neurol. 2008 Jul. 15(7):649-59.
  14. ↑ van de Beek D. et al. Advances in treatment of bacterial meningitis. Lancet. Nov 10 2012;380(9854):1693-702
  15. ↑ Mongelluzzo J, Mohamad Z, Ten Have TR, et al. Corticosteroids and mortality in children with bacterial meningitis. JAMA. 2008. 299(17):2048-2055.
  16. ↑ Brouwer MC, McIntyre P, de Gans J, Prasad K, van de Beek D. Corticosteroids for Acute Bacterial Meningitis. Cochrane Database of Systematic Reviews 2010, Issue 9.
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