Meningitis: Difference between revisions

(Add Herpes B for meningitis)
(Herpes b-> Herpes B)
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*Viral meningitis
*Viral meningitis
**Echo, coxsackie, entero (85%)
**Echo, coxsackie, entero (85%)
**[[HSV]], [[CMV]], [[Herpes b]]
**[[HSV]], [[CMV]], [[Herpes B]]


===Pathophysiology===
===Pathophysiology===

Revision as of 19:51, 11 September 2015

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 sx (e.g. CN deficit)
  • Seizures

Differential Diagnosis

Headache

Common

Killers

Maimers

Others

Aseptic Meningitis

Altered mental status and fever

Diagnosis

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 cx
  4. ?CT head: See CT Before Lumbar Puncture
  5. CXR (50% of pts w/ pneumoccocal meningitis have e/o pna 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

Management

Antibiotics

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

Neonates (up to 1 month of age)[6]

MRSA is uncommon in the neonate

> 1 month old[8]

Adult < 50 yr[9]

Adult > 50 yr and Immunocompromised[10]

Post Procedural (or penetrating trauma)[12]

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

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

The only benefit is shown in patients with meningitis from Streptococcus pneumoniae with a possible mortality benefit and a decrease in hearing loss[13]

AntiVirals

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

Osmotics

  • Mannitol
    • Rarely used
    • Only for marked cerebral edema

Prophylaxis

  • 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 facemask
    • Meds

Disposition

Bacterial meningitis

Viral meningitis

  • Admit for empiric antibiotics until culture results return OR
  • Discharge w/ 24hr f/u

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. van de Beek D. et al. Advances in treatment of bacterial meningitis. Lancet. Nov 10 2012;380(9854):1693-702
  7. https://www.aappublications.org/content/early/2015/02/25/aapnews.20150225-1
  8. van de Beek D. et al. Advances in treatment of bacterial meningitis. Lancet. Nov 10 2012;380(9854):1693-702
  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. [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.
  12. van de Beek D. et al. Advances in treatment of bacterial meningitis. Lancet. Nov 10 2012;380(9854):1693-702
  13. 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.