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meningitis

Inflammation of the membranes of the brain or spinal cord. Etiology: 1) aseptic a) viral - enteroviruses* (70%) (* most common viral) [9] - Coxsackievirus - echovirus - Herpes-simplex virus*, Herpes zoster - HIV1 infection, acute retroviral syndrome - mumps virus - arbovirus - Epstein-Barr virus - adenoviruses b) fungal (most common in immunocompromised patients) - Candida albicans - Coccidioides immitis - Cryptococcus neoformans c) Mycobacterium tuberculosis d) spirochetes - syphilis (Treponema pallidum) - Lyme disease (Borrelia burgdorferi) - Leptospirosis e) drug-induced - NSAIDs - pyridium - quinolones 2) Bacterial* a) neonates - group B streptococcus - Escherichia coli - Listeria monocytogenes - Gm- rods vs Gm+ cocci associated with antepartum antibiotics [7] b) Infants & toddlers (3 months - 2 years, the highest incidence of meningitis is in this age-group) - Streptococcus pneumonia (most common) [16] - Neisseria meningitidis - Haemophilus influenzae uncommon since introduction of HiB vaccine [16] c) older children & adolescents - Streptococcus pneumonia - Neisseria meningitis - Haemophilus influenzae d) adults - Streptococcus pneumonia - Listeria monocytogenes - Neisseria meningitis - Haemophilus influenzae e) hospital-acquired - gram negative rods 3) fungal - Coccidioides immitis - candida - Cryptococcus neoformans 4) complication of surgical procedures or trauma - craniotomy - external lumbar catheters - head trauma (basilar skull fracture) - infection rates may be as high as 25% [11] * bacterial meningitis is most urgent & likely in HIV1 patients on antiretroviral therapy Clinical manifestations: 1) headache 2) fever 3) nausea/vomiting 4) photophobia 5) stiff neck, nuchal rigidity 6) seizures 7) Kernig's sign 8) Brudzinski's sign 9) purpura or petechiae 10) tachycardia 11) altered mental status - irritability, lethargy 12) recent infection may be noted - otitis, sinusitis, URI Laboratory: 1) cerebrospinal fluid (CT of head prudent prior to lumbar puncture) a) aseptic or viral - no growth on cultures (1/2 of cultures) [10] - negative gram stain - latex agglutination for bacterial antigens is negative - WBC < 1000/mm3, generally < 100/mm3, predominantly lymphocytes - CSF protein normal to slightly elevated - 130-180 mg/dL is not uncommon - < 200 mg/dL [10] - CSF glucose normal to slightly decreased (> 45 mg/dL) - opening pressure - normal: 100-150 mm H20 - viral meningitis: < 250 mm Hg - bacterial meningitis: 200-500 mm Hg - values > 600 mm Hg suggest cerebral edema, cerebral abscess, or communicating hydrocephalus [10] b) bacterial* - increased opening pressure of 200-500 mm Hg [10] - decreased CSF glucose (< 40 mg/dL) - increased CSF protein (100-500 mg/dL) [10] - WBC count 1000-10,000/mm3, predominantly neutrophils - neoates (median) 1217/mm3 gram-negative rods vs 167/mm3 gram-positive cocci [7] - gram stain positive for organisms 60-90% of time - culture positive in 70-85% of cases [10] - latex agglutination: - indications: - CSF findings consistent with bacterial meningitis - gram stain is negative - organisms detected - Streptococcus pneumonia - Haemophilus influenzae - Neisseria meningitidis - heparin-binding protein c) tuberculosis - WBC < 300/mm3, predominantly lymphocytes - CSF protein < 300 mg/dL [10] - CSF glucose < 40 mg/dL d) cryptococcus - WBC < 300/mm3, predominantly lymphocytes - CSF protein > 100 mg/dL [10] - CSF glucose < 40 mg/dL 2) Blood culture*: - positive in 50% of bacterial meningitis cases - prior to head CT & lumbar puncture for bacterial meningitis 3) Herpes simplex virus DNA 4) CH50 for repeated episodes of Neisseria meningitidis 5) serum CRP > 20 mg/L, serum procalcitonin > 0.5 mg/mL, CSF protein > 0.5 g/L, positive CSF gram stain best predicators of bacterial meningitis [8] 6) screening for HIV1 [15] 7) see ARUP consult [14] * blood cultures & administration of antibiotics prior to head CT & lumbar puncture for bacterial meningitis Radiology: - computed tomography (CT) of the head - after blood cultures & administration of antibiotics for bacterial meningitis - prior to lumbar puncture* if signs/symptoms of increased intracranial pressure - may identify site(s) of CSF leakage [11] * see lumbar puncture for indications for head CT [10] * absence of papilledema on fundoscopic examination insufficient to skip head CT prior to lumbar puncture [10] Differential diagnosis: 1) brain abscess 2) subarachnoid hemorrhage 3) epidural abscess 4) viral encephalitis 5) migraine 6) CNS symptoms may occur with connective tissue disease, including lupus erythematosus & polyarteritis nodosa Management: 1) aseptic: - see aseptic meningitis - see viral meningitis 2) bacterial - see bacterial meningitis - see tuberculous meningitis 3) fungal: see fungal meningitis Follow-up: 1) adults do not need follow-up because neurologic sequellae are rare with appropriate therapy 2) test hearing in children

Interactions

disease interactions

Related

meningococcal polysaccharide vaccine (Menomune-A/C/Y/W-135, MenACWY-CRM, Menactra, MenACYW-D) meningococcal serogroup B vaccine (Bexsero, Trumenba, 4CMenB)

Specific

arachnoiditis aseptic meningitis bacterial meningitis carcinomatous meningitis (leptomeningeal metastases) choriomeningitis fungal meningitis lymphomatous meningitis meningoencephalitis pachymeningitis viral meningitis

General

inflammation meningeal disease

References

  1. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 1063-64
  2. Contributions from Robert Libke, MD, Dept of Medicine, UCSF Fresno
  3. Journal Watch 22(24):179, 2002 de Gans J & van de Beek D Dexamethasone in adults with bacterial meningitis. N Engl J Med 347:1549, 2002 PMID: 12432041 Tunkel AR & Scheld WM N Engl J Med 347:1613, 2002 (commentary)
  4. Journal Watch 24(24):184, 2004 van de Beek D, de Gans J, Spanjaard L, Weisfelt M, Reitsma JB, Vermeulen M. Clinical features and prognostic factors in adults with bacterial meningitis. N Engl J Med. 2004 Oct 28;351(18):1849-59. PMID: 15509818
    1. Swartz MN Bacterial meningitis--a view of the past 90 years. N Engl J Med. 2004 Oct 28;351(18):1826-8. No abstract. PMID: 15509815
  5. Journal Watch 24(24):185, 2004 Thwaites GE, Nguyen DB, Nguyen HD, Hoang TQ, Do TT, Nguyen TC, Nguyen QH, Nguyen TT, Nguyen NH, Nguyen TN, Nguyen NL, Nguyen HD, Vu NT, Cao HH, Tran TH, Pham PM, Nguyen TD, Stepniewska K, White NJ, Tran TH, Farrar JJ. Dexamethasone for the treatment of tuberculous meningitis in adolescents and adults. N Engl J Med. 2004 Oct 21;351(17):1741-51. PMID: 15496623
  6. Kupila L, Vuorinen T, Vainionpaa R, Hukkanen V, Marttila RJ, Kotilainen P. Etiology of aseptic meningitis and encephalitis in an adult population. Neurology. 2006 Jan 10;66(1):75-80. PMID: 16401850
  7. Smith PB et al, A comparison of neonatal gram-negative rod and gram-positive cocci meningitis. J Perinatol 2006; 26:111 PMID: 16435007
  8. Dubos F et al, Serum procalcitonin and other biologic markers to distinguish between bacterial and aseptic meningitis J Pediatr 2006, 149:71 PMID: 16860131
  9. Logan SAE and MacMahon E, Viral meningitis BMJ 2008, 336:36 PMID: 18174598
  10. Medical Knowledge Self Assessment Program (MKSAP) 14, 15, 16, 17, 18. American College of Physicians, Philadelphia 2006, 2009, 2012, 2015, 2018. - Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022
  11. van de Beek D et al Nosocomial bacterial meningitis. N Engl J Med 2010 Jan 14; 362:146. PMID: 20071704
  12. Linder A et al. Heparin-binding protein: A diagnostic marker of acute bacterial meningitis. Crit Care Med 2011 Apr; 39:812. PMID: 21200320
  13. Thigpen MC et al. Bacterial meningitis in the United States, 1998-2007. N Engl J Med 2011, May 26; 364:2016. PMID: 21612470
  14. ARUP Consult: Acute Meningitis The Physician's Guide to Laboratory Test Selection & Interpretation https://www.arupconsult.com/content/meningitis-acute
  15. Hanson KE, Reckleff J, Hicks L, Castellano C, Hicks CB. Unsuspected HIV infection in patients presenting with acute meningitis. Clin Infect Dis. 2008 Aug 1;47(3):433-4. PMID: 18605915 Free Article
  16. NEJM Knowledge+ Question of the Week. Dec 17, 2019 https://knowledgeplus.nejm.org/question-of-week/4763/
  17. National Institute of Neurological Disorders and Stroke (NINDS) NINDS Encephalitis and Meningitis Information Page https://www.ninds.nih.gov/Disorders/All-Disorders/Meningitis-and-Encephalitis-Information-Page