During a lumbar puncture (also known as a spinal tap), a small amount of cerebrospinal fluid (CSF) is extracted from the spinal (vertebral) canal using a special needle. This fluid surrounds the brain and the spinal cord, acting as a shock absorber. After being extracted, the cerebrospinal fluid is analyzed in a laboratory, which helps detect diseases of the brain and spinal cord.
The cerebrospinal fluid (CSF) is a clear fluid that protects your brain and spinal cord from trauma. The fluid also helps your central nervous system work properly by removing waste products from the brain. It is constantly produced and reabsorbed in the brain. Cerebrospinal fluid is made up of cells, water, sugars, proteins, and other substances that are essential for the balance of the nervous system.
- A spinal tap may help in diagnosing infections of the brain (meningoencephalitis), demyelinating diseases, subarachnoid bleeding, demyelinating diseases such as multiple sclerosis, headaches of unknown cause, and autoimmune diseases of the brain.
- A spinal tap is used to measure the amount of pressure in the CSF.
- Cerebrospinal fluid is collected to check for infections, inflammation, or other diseases.
- A spinal tap may be used to inject specific medication directly into the spinal cord and central nervous system. These medications include spinal anesthesia medicines before any surgery, antibiotics, contrast dye for x-ray studies such as myelography, and chemotherapeutic agents used to treat cancer.
Before the procedure:
- Before the procedure, the treating doctor does a thorough physical examination, acknowledges your medical history, and conducts blood tests to check for bleeding or clotting disorders.
- The doctor may also recommend a CT scan or MRI scan to rule out any abnormal swelling in and around the brain.
- The patient going for the procedure is asked to maintain a normal eating schedule and is advised to talk clearly about any allergies due to latex or medications.
- The patient should also ask the doctor for specific guidelines about discontinuing alcohol use and the use of aspirin and blood-thinning drugs before the procedure.
- Since it is advised not to drive immediately after the procedure, the patient must also ensure proper transportation arrangements.
During the procedure:
- You may be given a sedative to make you drowsy and relaxed. A doctor and at least one assistant will be in the room.
- You will lie on your side with your knees drawn to your chest so that your spine is curved(fetal position), and in some cases, you may sit on the table and lean forward onto some pillows instead.
- After cleaning your back with a cooling antiseptic, the doctor will numb the area of your lower back where the needle will be inserted. This may cause some brief stinging sensation.
- Then a hollow needle is inserted between the third and fourth lumbar vertebrae into your spinal canal. The needle doesn't touch the nerves of your spinal cord.
- Your doctor will collect between 5 to 20 ml of cerebrospinal fluid in 2 to 4 tubes.
- You will probably feel pressure when the needle is inserted, and some people feel a sharp stinging sensation when the needle goes through the protective dural layer that surrounds the spinal cord.
- Although you may feel some discomfort, it is important that you lie still. Let your doctor know if you are feeling pain.
- In order to measure the cerebrospinal fluid pressure, you will be asked to straighten your legs to decrease abdominal pressure and increase cerebrospinal fluid pressure. The needle is attached to a meter, and the pressure in your spinal canal is measured.
- In cases of hydrocephalus, a catheter may be inserted to continuously remove CSF and relieve pressure on the brain.
After the procedure:
- You will be asked to lie down flat on your back for up to 30 minutes, and the doctor will monitor you for a headache, dizziness or other side effects.
- When you get home, you should rest by lying down for a certain period of time as directed by your doctor.
- If you get a headache, lying down flat and drinking plenty of fluids may help to relieve it. Often the headache is more painful when you stand, but it gets better over time.
- You may also need to take an over-the-counter pain reliever. But do not take aspirin. Caffeine drinks may help to relieve headaches after a spinal tap. These include soda, coffee, or tea.
- A headache may also occur along with an upset stomach (nausea), vomiting, or dizziness.
- You can remove your bandage immediately the day after your spinal tap.
- Your doctor will inform you when your test results are available and undergo further investigations and treatment based on the report.
A lumbar puncture can help your doctor to diagnose accurately or rule out certain medical conditions, including some life-threatening conditions. Some infections, such as bacterial meningitis, can be fatal if not treated quickly. The quicker they make a diagnosis, the sooner you can choose treatment.
As with any other procedure, a lumbar puncture may also have risks and complications. Serious complications in carefully planned lumbar puncture procedure are very rare.
- A small amount of cerebrospinal fluid leak can occur from the site of needle insertion. This can cause headaches after the procedure. If the CSF leak continues, your headache can be severe.
- You may be at risk of infection because the needle breaks the surface of the skin, allowing bacteria to enter the body.
- You might have lower back pain after the local anesthetic has worn off. This usually lasts for a couple of days after the test.
- Short-term numbness of the legs may be present.
- There is a risk of bleeding in the spinal canal.
Other risks may exist depending on your specific medical condition. So before the procedure, make sure to discuss any concerns you have with your doctor.
Care at Medicover
At Medicover Hospitals, we have the most experienced team of neurologists providing exceptional neurological procedures such as lumbar puncture to our patients. Our neurologists at Medicover use an interdisciplinary approach to diagnose and treat conditions with utmost precision. We provide a wide variety of diagnostic and treatment procedures using the most advanced technologies and world-class equipment, bringing out the best possible outcomes.