Template: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/┬ÁL) 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


  • 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