Definition: A procedure used to extract cerebral spinal fluid (CSF) to test for the presence of substances that indicate MS. In this procedure, a needle is inserted between spinal vertebrae and a small amount of CSF is extracted into a tube. Also called a spinal tap, lumbar punctures used to be a standard part of the diagnosis of MS. MRI scans are now considered more authoritative for diagnosing MS.
Also Known As: spinal tap
