Common Laboratory (LAB) Values – [CSF Analysis]

Cerebrospinal fluid (CSF) analysis - Meningitis

Normal values (CSF):
CSF opening pressure: 50–180 mmH2O
Glucose: 40–85 mg/dL.
Protein (total): 15–45 mg/dL.
Lactate dehyrogenase: 1/10 of serum level.
Lactate: less than 35 mg/dL.
Leukocytes (WBC): 0–5/µL (adults / children); up to 30/µL (newborns).
Gram stain: negative.
Culture: sterile.
Specific gravity: 1.006–1.009.
Syphilis serology: negative.
Gross appearance: Normal CSF is clear and colorless.
Differential: 60–70% lymphocytes; up to 30% monocytes
and macrophages; other cells 2% or less.

Bacterial Meningitis

Glucose (mg/dL): Normal to marked decrease.  <40 mg/dL.
Protein (mg/dL) (Marked increase)  > 250 mg/dL.
WBCs (cells/µL) >500 (usually > 1000).  Early: May be < 100.
Cell differential: Predominance of Neutrophils (PMNs)
Culture: Positive
Opening Pressure Elevated

Fungal Meningitis

Glucose (mg/dL): <40 mg/dL (Low)
Protein (mg/dL) (moderate to marked increase) 25 -500 mg/dL
WBCs (cells/µL) Variable (10 -1000 cells/µL) <500cells/µL.
Cell differential: Predominance of Lymphocytes
Culture: Positive (fungal)
Opening Pressure Variable

Tubercular Meningitis

Glucose (mg/dL): <40 mg/dL (Low)
Protein (mg/dL) (moderate to marked increase) 50 -500 mg/dL
WBCs (cells/µL) Variable (10 -1000 cells/µL) <500cells/µL.
Cell differential: Predominance of Lymphocytes
Culture: Positive for AFB
Opening Pressure Variable

Viral Meningitis

Glucose (mg/dL): Normal   (> 40 mg/dL.)
Protein (mg/dL) <100 mg/dL (moderate increase)
WBCs (cells/µL) < 100 cells/µL.
Cell differential: Early: neutrophils. Late: lymphocytes.
Culture: Negative
Opening Pressure Usually normal

Important Notes
>Unless noted, all values are for adults.
Common Laboratory (LAB) Values – [CSF Analysis]