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/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
- Simplified version (if peripheral WBC and RBC counts are within normal limits):
- Protein correction (for bloody tap)
- For each 1000 RBC decrease protein value by 1mg/dl