Skin on back is cleansed with anantiseptic solution. Local anesthetic is injected. It causes temporary, stinging pain. Remain still, and breathe normally through the test. The spinal needle passes through the skin into the spinal canal to collect spinal fluid.
Spinal fluid is removed.
Pressure of the spinal fluid is measured before and after collection. During the test, tell the doctor if you experience any pain after the needle is in place to collect fluid. He may be able to reposition the needle if necessary. Spinal needle is removed. Fluid is sent to the laboratory for analysis.