Is a lumbar puncture (also called a spinal tap) necessary to diagnose MS?
No, a lumbar puncture (LP) is not always necessary to confirm the diagnosis of MS. The LP is a relatively painless and simple procedure that can be done in the doctor’s office in about 15 minutes. It involves inserting a small needle into the lower back (local anesthesia is used to minimize discomfort) to obtain a small amount of fluid. This fluid, called cerebral spinal fluid or CSF, bathes the spinal cord and the nerves coming out of it. Almost 70-80 percent of MS patients have immunological changes in the spinal fluid. This means that 20-30 percent of MS patients do not have these changes.
