CSF myelin basic protein is a test to measure the level of myelin basic protein (MBP) in the cerebrospinal fluid (CSF), the clear liquid that surrounds the brain and spinal cord.

MBP is found in the material that covers your nerves.

A sample of CSF is needed. The most common way to collect this sample is with a lumbar puncture, also called a spinal tap. See the article on lumbar puncture for details about this procedure.

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

• Cisternal puncture
• Ventricular puncture
• Removing CSF from a tube already in place in the CSF, such as a shunt or ventricular drain

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

How the Test is Performed

See: Lumbar puncture.

How the Test Will Feel

For detailed information, see the article on lumbar puncture.

Why the Test is Performed

This test is done to see if myelin, the substance covering your nerves, is breaking down. Myelin breakdown is called demyelination. Multiple sclerosis is the most common cause for this, but other causes may include:

• Bleeding of the central nervous system
• Central nervous system trauma
• Certain brain diseases (encephalopathies)
• Infection of the central nervous system
• Stroke

Normal Results

In general there should be less than 4 ng/mL of myelin basic protein in the CSF.

Note: ng/mL = nanogram per milliliter

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

What Abnormal Results Mean

Myelin basic protein levels between 4 and 8 ng/mL may be a sign of a chronic breakdown of myelin, or recovery from an acute episode of myelin breakdown.

If the myelin basic protein levels are greater than 9 ng/mL, myelin is actively breaking down.

Risks

For information on the risks of spinal tap, see: Lumbar puncture and CSF collection.