What is a lumbar puncture?

A lumbar puncture is a procedure in which the doctor inserts a needle between two bones (vertebrae) of the spine. The doctor then either withdraws a small amount of spinal fluid for examination or injects medication or dye.

The term lumbar refers to the lower back between the pelvis and the ribs.

When is it used?

This procedure is used to help diagnose diseases that affect your brain and spinal cord (for example, multiple sclerosis and meningitis). It is also used to inject anticancer drugs to treat leukemia and other diseases of the central nervous system. Dye is injected when you need special x-rays to diagnose a disease affecting your spine. In addition, a lumbar puncture can be used to inject an anesthetic to numb your lower body for surgery without putting you to sleep.

How do I prepare for a lumbar puncture?

No preparation is needed unless the doctor gives you special instructions.

What happens during the procedure?

This procedure can be done in your doctor's office or in a hospital. It takes less than 20 minutes. It may cause a headache.

Usually, the doctor will have you lie on one side with your knees bent and pulled up with your chin touching your chest. This position allows the bones or vertebrae in the spine to separate so that the needle can pass between the vertebrae and into the spinal canal. A local anesthetic is used to numb the skin before the needle is inserted.

What happens after the procedure?

Sterile tape is applied to your skin where the needle was inserted. You will need to lie down for a while.

Ask your doctor what steps you should take and when you should come back for a checkup.

What are the benefits of this procedure?

A lumbar puncture can help the doctor make a more accurate diagnosis. When it is used to give an anesthetic, you won't feel any pain during surgery, but you can be fully alert, if you wish.

What are the risks associated with this procedure?

• A local anesthesia may not numb the area quite enough and you may feel some minor discomfort. Also, in rare cases, you may have an allergic reaction to the drug used in this type of anesthesia.

• You may have a headache for several days that is worse when you sit or stand up.

• You may have internal bleeding, which means bleeding inside the body.

• Infection may develop internally or in the skin where the needle was inserted.

Ask your doctor how these risks apply to you.

When should I call the doctor?

Call the doctor immediately if:

• You notice any unusual drainage, including bloody discharge, where the needle was inserted.

• You develop a fever.

• Your pain or symptoms worsen.

Call the doctor during office hours if:

• You have questions about the procedure or its result.

• You want to make another appointment.