CSF Analysis

Lumbar Puncture (LP) is performed to examine the cerebrospinal fluid

CSF Analysis

Meningitis

  • Infective
    • Bacterial
    • Aseptic - Viral, TB, Fungi, Parasites
  • Non-infective
    • Malignancy
    • Auto-immune

Age-related Causes of Meningitis

  • Bacterial:
    • Neonatal (<3/12)
      • Gram negative (E coli)(Pseudomonas), Listeria, Group B strep, Coag –ve staphylococcus
    • 3/12 to 15 years
      • Neiserria meningitidis, Pneumococcus (strep pneumonia), Haemophilus pneumonia
    • Adult > 15 years
      • N meningitidis, s. pneumonia, listeria, klebsiella, s. aureus
    • Elderly
      • Gram negatives predominate
    • Immunocompromised
      • Complement deficiency – Neiserria
      • Humoral or asplenic - Neiserria, enterovirus
      • Sickle cell disease - Capsulated organisms
  • Aseptic meningitis (Generally accepted as mainly viral meningitis)
    • Lymphocytosis, variable protein elevation and normal glucose
    • Viral
      • Echovirus, Enterovirus, Mumps
      • HSV 1 + 2, CMV, VZV, EBV
    • Other
      • TB, Nocardia, Leptospira, Treponema
      • Fungi, rickettsia, parasites
      • Malignancy, auto-immune

Specific Risk Factors

  • Pneumococcus: (40%) – Otitis media, head injury, pneumonia, immunocompromised
  • N meningitidis: (30%) – Children and adolescents
  • Staphylococcus: Penetrating skull injury, ear or neuro operations
  • Fungal: HIV and organ transplant
  • Listeria: Extremes of age
  • H Influenzae: (3%)  - Head trauma with CSF leak, otitis, sinusitis, anatomical defects such as dermal sinus tracts
  • Anaerobes: Consider brain abscess, elderly
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