CSF oligoclonal banding is a test to look for inflammation-related substances in the cerebrospinal fluid (CSF), the clear fluid that flows in the space surrounding the spinal cord and brain.

Oligoclonal bands are substances called immunoglobulins, which suggest inflammation of the central nervous system. The presence of oligoclonal bands may be a sign of multiple sclerosis.

A lumbar puncture (spinal tap) is performed and the fluid is sent to the laboratory for analysis.

Patients will be asked to either sit up or lie down on their side with back parallel to the bed and chin tucked under and legs curled in the fetal position. The healthcare provider will use the bony protrusions of the hip to determine the most appropriate location to remove fluid. This is usually at the lower lumbar area.

A germ-killing solution is used to clean off the area and a sterile sheet is draped over the surrounding area. In infants and small children, a local numbing cream is applied to the skin about 1 hour prior to the procedure. In adults, numbing medicine is injected under the skin.

A thin needle is inserted into the space between the vertebra. You may hear a popping sound when the needle goes through the tissue surrounding the spinal cord and fluid.

The fluid flows out of the needle and into a plastic container. The spinal fluid is sent to a laboratory for examination under a microscope.

Under experienced hands there should not be any pain. There may be a feeling of pressure when the needle is inserted but with appropriate anesthetic, this should not hurt. Occasionally, some people may feel numbness shooting down the leg. This may be due to irritation of a nerve root and subsides when the needle is withdrawn.

Following the procedure, the patient is advised to remain lying down for a short time to prevent low-pressure headache. The entire procedure takes approximately 20 minutes.