CSF collection
Alternative names:
cisternal puncture; collecting a spinal fluid specimen; lumbar puncture; spinal tap; ventricular puncture
Normal values:
Pressure: 50 to 180 mm H20
Appearance: clear, colorless
CSF total protein: 15 to 45 mg/100 ml
Gamma globulin: 3 to 12% of the total protein
CSF glucose: 50 to 80 mg/100 ml (or approximately 2/3 of serum glucose level)
CSF cell count: 0 to 5 WBC's, no RBC's
chloride: 110 to 125 mEq per liter
Note: mg/ml = milligrams per milliliter; mEq/L = milliequivalent per liter
(See also CSF coccidioides complement fixation, CSF culture, CSF oligoclonal banding, CSF smear, CSF VDRL test.)
What abnormal results mean:
- Pressure, increased: increased intracranial pressure (pressure within the skull) from trauma or infection
- Pressure, decreased: obstruction to the flow of CSF above the puncture site (spinal cord tumor), shock, fainting, diabetic coma
- Appearance
- cloudy: infection, white blood cells in the CSF, protein in the CSF, microorganisms
- bloody or reddish colored: bleeding within the brain or subarachnoid space, spinal cord obstruction, traumatic lumbar puncture (first specimen bloody, rest clear)
- brown, orange, yellow color: elevated protein in the CSF, old (greater than 3 days) blood in the CSF
- Protein, increased: blood in the CSF, diabetes mellitus, polyneuritis, tumors, trauma
- Protein, decreased: rapid CSF production
- Gamma globulin, increased: demyelinating disease (e.g. multiple sclerosis), neurosyphilis, Guillain-Barre syndrome
- Glucose, increased: systemic hyperglycemia (elevated blood sugar)
- Glucose, decreased: systemic hypoglycemia (low blood sugar), bacterial or fungal infection (such as meningitis), mumps, old subarachnoid hemorrhage
- WBC, increased: active meningitis, acute infection, beginning of a chronic illness, tumor, abscess, brain infarction (stroke), demyelinating disease (such as MS)
- RBC: bleeding into the spinal fluid, traumatic lumbar puncture
Note: Chloride and other chemical tests help to differentiate disorders that affect the nerves (such as poliomyelitis) from meningeal disorders (meningitis, tuberculosis).
Additional conditions under which the test may be performed:
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