How the Test is Performed

A sample of CSF is needed. A lumbar puncture (spinal tap) is the most common way to collect this sample. For information on this procedure, see the article on lumbar puncture.

Other methods for collecting CSF are rarely used, by may be recommended in some cases. They include:

• Cisternal puncture
• Ventricular puncture
• Removal of CSF from a tube that is already in the CSF, such as a shunt or ventricular drain.

After the sample is taken, it is sent to a laboratory for evaluation.

How to Prepare for the Test

See: Lumbar puncture

How the Test Will Feel

See: Lumbar puncture

Why the Test is Performed

Your doctor may order this test to help diagnose tumors, infection, inflammation of several groups of nerve cells, vasculitis, blood in the spinal fluid, or injury.

Normal Results

The normal protein range varies from lab to lab, but is typically about 15 to 60 mg/dL.

Note: mg/dL = milligrams per deciliter

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

What Abnormal Results Mean

An abnormal protein level in the CSF suggests that there is an abnormal process occurring in the central nervous system.

When the protein level increases, it may be a sign of a tumor, bleeding, nerve inflammation, or injury. Protein can rapidly build up in the lower spinal area where the lumbar puncture is done, if something is blocking the flow of spinal fluid.

When the protein level in decreases, it can mean your body is rapidly producing spinal fluid.

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Additional conditions under which the test may be performed:

• Hemorrhage - subarachnoid
• Neuropathy, including chronic inflammatory polyneuropathy

Risks

See: Lumbar puncture

References

Griggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 418.

Rosenberg GA. Brain edema and disorders of cerebrospinal fluid circulation. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Bradley: Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 63.

Update Date: 4/30/2012

Reviewed by: Kevin Sheth, MD, Department of Neurology, University of Maryland School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine;David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.