Spinal Tap!

No, not the parody English heavy metal band, but the procedure to help identify infectious and auto-immune diseases effecting the central nervous system. Below is a summary of the expected CSF findings in a variety of conditions:

Routine CSF constituents in different CNS disorders
  Normal Viral infection Bacterial infection Fungal infection TB infection GBS Multiple sclerosis
Appearance Clear Clear or opaque Turbid Clear Clear/opaque Clear Clear
White cells (per mm3) 0–5 10–2,000 100–60,000 20–500 50–5,000 Normal >15 atypical (>50 very rare)
Protein (g/l) <0.5 0.5–0.9 >0.9 >0.5 >1.0 >1.0 Normal
Glucose (% serum glucose) >60–75% Normal <40% <80% <50% Normal Normal

Adapted from Clarke et al.