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 many of your nerves.

A sample of spinal fluid is needed. For information on how this is done, see: Lumbar puncture

For detailed information, see the article on lumbar puncture.

This test is done to see if myelin is breaking down. 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

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.

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

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 level is greater than 9 ng/mL, myelin is actively breaking down.

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

Lublin FD, Miller AE. Multiple sclerosis and other inflammatory demyelinating diseases of the central nervous system. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Bradley: Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 58.