Lumbar Puncture & Intrathecal Chemotherapy
A lumbar puncture is a procedure to collect and look at the fluid (cerebrospinal fluid, or CSF) surrounding the brain and spinal cord. During a lumbar puncture, a needle is carefully inserted into the spinal canal low in the back (lumbar area). Samples of CSF are collected.
Why It Is Done
A lumbar puncture is done to:
- Find a cause for symptoms possibly caused by an infection (such as meningitis), inflammation, cancer, or bleeding in the area around the brain or spinal cord (such as subarachnoid hemorrhage).
A lumbar puncture may also be done to:
- Put medicines into the CSF. Medicines may be injected to treat leukemia and other types of cancer of the central nervous system-Intrathecal Chemotherapy.
How To Prepare
Before you have a lumbar puncture, tell your doctor if you:
- Are taking any medicines. If you take medicines every day, ask your doctor whether you should take these medicines on the day of the lumbar puncture.
- Are allergic to any medicines, such as those used to numb the skin (anesthetics).
- Have had bleeding problems or take blood-thinners, such as aspirin or warfarin (Coumadin).
- Are or might be pregnant.
- Take any herbal remedies. Some of these remedies may thin the blood.
You will empty your bladder before the procedure.
For a lumbar puncture, you will be asked to sign a consent form.
How It Is Done
A lumbar puncture may be done in your doctor’s office, in an emergency room, or at your bedside in the hospital. You will lie on a bed on your side with your knees drawn up toward your chest. Or you may sit on the edge of a chair or bed and lean forward over a table with your head and chest bent toward your knees. These positions help widen the spaces between the bones of the lower spine so that the needle can be inserted more easily. The area is cleaned with a special soap and draped with sterile towels. A numbing medicine (local anesthetic) is put in the skin.Then a long, thin needle is put in the spinal canal. When the needle is in place, the solid central core of the needle (stylet) is removed. If the needle is in the right spot in the spinal canal, a small amount of cerebrospinal fluid (CSF) will drip from the end of the needle. If not, the stylet will be put back in and the needle will be moved in a little farther or at a different angle to get to the fluid. Your doctor may need to move to another area of your spine if it is hard to get to the spinal fluid.The entire procedure takes about 30 minutes.To lower your chance of getting a headache following a lumbar puncture, you may be told to lie flat in bed or with your head slightly raised for 1 to 4 hours. Since your brain makes new CSF all the time and replaces it 2 to 3 times a day, the small amount of fluid that is removed will be quickly replaced. You may be told to drink extra fluids after the procedure to help prevent or to reduce the severity of a headache.
How It Feels
Some people find it uncomfortable to lie curled up on their side. The soap may feel cold on your back. You will probably feel a brief pinch or sting when the numbing medicine is given. You may feel a brief pain when the spinal needle is inserted or repositioned.
During the procedure, the needle may touch one of your spinal nerves and cause a tingling feeling, like a light electrical shock, running down one of your legs. The needle will not touch or damage the spinal cord. Some people (10% to 25%) develop a headache after having a lumbar puncture. Of those who do get headaches, only about half report that they are severe. These headaches last 24 to 48 hours and go away on their own. Pain medicine does not help control the headache, but lying flat in bed for several hours after the procedure may help the headache.
You may feel tired and have a mild backache the day after the procedure. Some people have trouble sleeping for 1 to 2 days.
A lumbar puncture is generally a safe procedure. In some cases, a leak of cerebrospinal fluid (CSF) may develop after a lumbar puncture. Symptoms of this problem are a headache that does not go away after 1 to 2 days. A CSF leak can be treated with a blood “patch,” in which the person’s own blood is injected into the area where the leak is occurring in order to seal the leak.
About 1 in 1,000 people who have a lumbar puncture have a minor nerve injury. This heals on its own with time. There is also a small chance of infection of the CSF (meningitis), bleeding inside the spinal canal, or damage to the cartilage between the vertebrae. Your doctor will talk with you about these risks. People who have bleeding problems and those who are taking blood-thinning medicine (such as warfarin or heparin) have a higher chance of bleeding after the procedure. A lumbar puncture may not be done unless it is needed for a life-threatening illness.
A lumbar puncture may cause serious problems for people who have high pressure in the brain caused by a tumor, a pocket of infection in the brain (abscess), or major bleeding inside the brain. Your doctor will check your nervous system, spinal cord and brain before doing a lumbar puncture. In some cases, a computed tomography (CT) scan or magnetic resonance imaging (MRI) scan may be done before the lumbar puncture to know that it is safe to do the puncture.
After the procedure
Call your doctor immediately if you have:
- Chills or a fever.
- A stiff neck. This may be a sign of a developing infection.
- Any drainage or bleeding from the puncture site.
- A severe headache.
- Any numbness or loss of strength below the puncture site