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Viral Meningitis

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Viral Meningitis, HSV2 Meningitis, Mollaret Meningitis, Herpes Meningitis, Enterovirus Meningitis, Arbovirus Meningitis

  • Epidemiology
  1. Age: under 30 years (90%)
  2. Peaks in late summer
  • Etiology
  • Common
  1. Coxsackie virus
  2. Echovirus
  • Causes
  1. Most common in children
    1. Enterovirus or Arbovirus (summer, fall)
    2. Herpes Simplex Virus (HSV)
  2. Most common in adults
    1. Enterovirus
    2. Herpes Simplex Virus (HSV, typically HSV 2)
    3. Varicella-Zoster Virus (VZV)
  3. Common viral infections causing Aseptic Meningitis
    1. Enterovirus (85% of Viral Meningitis)
      1. Echovirus (esp. children)
      2. Coxsackievirus (type A which causes hand, foot and mouth, and Type B)
      3. Polio Virus
    2. Arbovirus (Arthopod-borne viruses such as St. Louis Encephalitis virus, West Nile Virus)
    3. Herpes Viruses
      1. HSV1 (typically causes HSV Encephalitis instead of Meningitis)
      2. HSV2 Meningitis (Mollaret Meningitis) - most common of herpes virus Meningitis
        1. Causes primary and secondary recurrent lymphocytic Meningitis
      3. Epstein Barr Virus (Mononucleosis)
      4. Cytomegalovirus
      5. Varicella Zoster Virus
    4. Acute Retroviral Syndrome (HIV Infection)
    5. Lymphocytic choriomeningitis virus (rodent-borne arena virus)
    6. Mumps
    7. Less common causes include Adenovirus, Measles, Rubella
  • Symptoms
  1. Flu-like Prodrome
  2. Intense Onset of symptoms
    1. Headache
    2. Malaise
    3. Nausea
    4. Vomiting
    5. Photophobia
    6. Stupor (rarely)
    7. Neck stiffness
  • Signs
  1. Fever (maximum 38-40 degrees Celsius)
  2. Meningeal Irritation
    1. Nuchal Rigidity
    2. Spinal Rigidity
    3. Kernig's Sign
    4. Brudzinski's Sign
  3. Rash (Coxsackie or Echovirus)
  4. Herpangina (Coxsackie Virus)
    1. Painful Vesicles at posterior third of oropharynx
  • Differential Diagnosis
  1. Aseptic Meningitis
    1. Includes Viral Meningitis, fungal Meningitis, malignancy, Autoimmune Conditions, medications
  2. Bacterial Meningitis
    1. Often indistinguishable without Lumbar Puncture and CSF Culture
    2. Additional findings (e.g. Parotitis in mumps) may suggest cause
  3. Encephalitis (e.g. HSV Encephalitis, West Nile Virus, St. Louis Encephalitis)
    1. Abnormal brain function distinguishes Encephalitis from Meningitis
    2. Altered behavior, personality, Level of Consciousness, speech, movement or weakness
    3. Seizures may occur with either Meningitis or Encephalitis
  • Labs
  • Cerebrospinal Fluid (CSF)
  1. CSF White Blood Cells: 10-100 (75% Lymphs)
  2. CSF Protein Normal
  3. CSF Glucose Normal
    1. May be reduced in Mumps and HSV
  4. CSF Culture Negative
  • Course
  1. Fever typically resolves in 3-5 days
  2. CSF Leukocytes increased for weeks
  • Management
  1. Symptomatic Therapy
  2. See Meningitis
  3. See Bacterial Meningitis Management
    1. Empiric antibiotics for Meningitis if diagnosis unclear
  • References
  1. Johnson in Hirsch (2012) Aseptic Meningitis, UpToDate, Wolters-Kluwer, accessed 4/9/2016
  2. Wan in Roos (2015) Viral Meningitis, EMedicine, Medscape, accessed 4/9/2016
  3. Bamberger (2010) Am Fam Physician 82(12): 1491-8 [PubMed]
  4. Mount (2017) Am Fam Physician 96(5): 314-22 [PubMed]