What Happens During the Spinal Tap?

• The doctor and possibly a nurse or a technologist will be in the room with you during a spinal tap.
• Pre-medication may be given to help you relax.
• You will wear a hospital gown during the test.
• You will either: Lie on your side with your knees drawn as close to your chest as possible and your chin toward your chest; or lie on your stomach with a small pillow beneath your lower abdomen.
• After cleaning your back with an antiseptic, sterile cloths will be placed around the area.
• A local anesthetic (pain-relieving medication) will be injected into the area of your back that the fluid will be drawn from. You may feel a slight burning sensation.
• When the area is numb, a hollow needle is inserted in the lower back between the two lumbar vertebrae. This sometimes causes pressure.
• The spinal canal is penetrated, and fluid is collected (the spinal cord is not touched by the needle during the test).
• The needle is removed after the fluid is removed. The area will be cleaned with an antiseptic and covered with a small bandage.
• A blood sample may be taken from a vein in your arm and tested, along with the spinal fluid, in the laboratory.

SOURCE: WebMD Medical Reference