Composition and functions of CSF

Composition

Clear fluid

Slightly alkaline

Specific gravity : 1.005 - approximately isotonic solution

Consists of

water

mineral salts

glucose

plasma proteins : small amounts of albumin and globulin

creatinine

urea

Functions

Supports and protects the brain and the spinal cord - a basic mechanical and immunological protection to the brain inside the skull.

Maintains a uniform pressure in the brain

Cushions and absorbs shock

Maintains moisture

Carries nutrients to the nerve cells

Carries away wastes

Prevention of brain ischemia

Normal values

Normal values vary from lab to lab but typically range as follows :-

Pressure: 50 - 180 mm H20

Appearance: clear, colorless

CSF total protein: 15 - 45 mg/100 mL

Gamma globulin: 3 - 12% of the total protein

CSF glucose: 50 - 80 mg/100 mL (or approximately 2/3 of blood sugar level)

CSF cell count: 0 - 5 white blood cells, no red blood cells

Chloride: 110 - 125 mEq per liter