Table 1.
Typical CSF characteristics in the immunocompetent patient with meningitis and encephalitis.
| Investigation | Normal | Bacterial | Viral | Tuberculosis | Fungal |
|---|---|---|---|---|---|
| Opening pressure | 10–20 cm | Increased | Normal/mildly increased | Increased | Increased |
| Colour | Clear | Cloudy | Clear | Cloudy/yellow | Clear/cloudy |
| White cell count (× 106 L−1) | <5 | 100–50,000 | 5–1,000 | <500 | 0–1,000 |
| Differential | Lymphocytes | Neutrophils | Lymphocytes | Lymphocytes | Lymphocytes |
| CSF/plasma glucose | 50–65% | <40% | Normal | <30% | Normal or low |
| Protein (g dl−1) | <0.45 | Increased | Mildly increased | Significantly increased | Increased |