result interpretation

Question 1

Normal CSF

Answer 1

Appearance: Clear and colourless
• White blood cells (WBC): 0 – 5 cells/µL
• No neutrophils present, primarily lymphocytes
• Normal cell counts do not rule out meningitis or any other pathology
• Red blood cells (RBC): 0 – 10/mm³
• Protein: 0.15 – 0.45 g/L (or <1% of the serum protein concentration)
• Glucose: 2.8 – 4.2 mmol/L (or ≥ 60% plasma glucose concentration)
• Opening pressure: 10 – 20 cm H2O

Question 2

bacterial meningitis

Answer 2

• Appearance: Cloudy and turbid
• Opening pressure: Elevated (>25 cm H₂O)
• WBC: Elevated >100 cell/µL (primarily polymorphonuclear leukocytes
(>90%))
• Glucose level: Low (<40% of serum glucose)
• Protein level: Elevated (>50 mg/dL)

Question 3

further investigations that can be done

Answer 3

• CSF gram stain and cultures
• CSF bacterial antigens
• CSF PCR
• Blood cultures
• Imaging to rule out other intracranial pathology – CT / MRI head

Question 4

viral meningitis

Answer 4

Appearance: Clear
• Opening pressure: Normal or elevated
• WBC: Elevated (50 – 1000 cells/µL, primarily lymphocytes, can be
PMN early on)
• Glucose level: Normal (>60% serum glucose however may be low in
HSV infection)
• Protein level: Elevated (>50 mg/dL)

Question 5

TB meningitis

Answer 5

Appearance: Opaque, if left to settle it forms a fibrin web
• Opening pressure: Elevated
• WBC: Elevated (10 – 1000 cells/µL, Early PMNs then mononuclears)
• Glucose level: Low
• Protein level: Elevated (1-5 g/L)

Question 6

subarachnoid haemorrhage

Answer 6

Appearance: Blood stained initially, then xanthochromia (yellowish)
>12 hours later
• Opening pressure: Elevated
• WBC: Elevated (WBC to RBC ratio of approx 1:1000)
• RBC: Elevated
• Glucose level: Normal
• Protein level: Elevated

Question 7

Guillain barre syndrome

Answer 7

Appearance: Clear or xanthochromia
• Opening pressure: Normal or elevated
• WBC: Normal
• Glucose level: Normal
• Protein level: Elevated (>5.5 g/L)

Question 8

Multiple sclerosis

Answer 8

Appearance: Clear
• Opening pressure: Normal
• WBC: 0 – 20 cells/µL (primarily lymphocytes)
• Glucose level: Normal
• Protein level: Mildly elevated (0.45 – 0.75 g/L)

Question 9

further investigations for MS

Answer 9

MRI head
Oligoclonal bands of IgG on electrophoresis (CSF and Serum)
• Evoked potential tests (visual/somatosensory)