Cerebrospinal Fluid Analysis

Reference Range

Characteristics of normal spinal fluid are below:

Total volume: 150 mL                                     

Color: Colorless, clear, like water

Opening pressure – 90-180 mm H
₂O (with patient lying in lateral position)                 

Osmolarity at 37°C: 281 mOsm/L

Specific gravity: 1.006 to 1.008

Acid-base balance:                                                            

pH: 7.28-7.32                                                

Pco₂: 47.9 mm Hg                                          

HCO₃-: 22.9 mEq/L                                         

Sodium: 135-150 mmol/L                                                

Potassium: 2.7-3.9 mmol/L                                                       

Chloride: 116-127 mmol/L                                                         

Calcium: 2.0-2.5 mEq/L (4.0 to 5.0 mg/dL)                                  

Magnesium: 2.0-2.5 mEq/L (2.4 to 3.1 mg/dL)                              

Lactic acid: 1.1-2.8 mmol/L                                                       

Lactate dehydrogenase: Absolute activity depends on testing method; approximately 10% of serum value                                      

Glucose: 45-80 mg/dL                                                    

Glutamine – 8-18 mg/dL

Lactate dehydrogenase (LDH) – <2.0-7.2 U/mL

Proteins: 20-40 mg/dL

At different levels of spinal tap:     

Lumbar: 20-40 mg/dL                

Cisternal: 15-25 mg/dL

Ventricular: 15-45 mg/dL  

Normal CSF proteins concentration in children:

Up to 6 days of age: 70 mg/dL

Up to 4 years of age: 24 mg/dL

Electrophoretic separation of spinal fluid proteins (% of total protein concentrations)

Prealbumin: 2-7%

Albumin: 56-76%

a₁-Globulin: 2-7%

a ₂-Globulin: 3.5-12%

b-and g-globulin: 8-18%

g-Globulin: 7-12%

Oligoclonal bands – absent

Immunoglobulins

IgG: 10-40 mg/L

IgA: 0-0.2 mg/L

IgM: 0-0.6 mg/L

k/l ratio: 1

Erythrocyte count:

Newborn: 0-675/mm³

Adult: 0-10/mm³

Leukocyte count:

Children: 

Younger than 1 year: 0-30/mm³

Age 1-4 years: 0-20/mm³

Age 5 years to puberty: 0-10/mm³

Adult: 0-5/mm
³

Antibodies, viral DNA – None

Bacteria (Gram stain, culture, VDRL) – Negative

Cancerous cells – None

Cryptococcal antigen – None