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.

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

See: Lumbar puncture.

For detailed information, see the article on lumbar puncture.