What is a Lumbar Puncture and What Will I Experience?

What is a lumbar puncture?
A lumbar puncture is a test that is used to extract cerebrospinal fluid (CSF) from the spinal canal and measure the pressure of the CSF. A lumbar puncture may be ordered as a diagnostic tool to evaluate a patient for certain conditions of the brain or spine, like meningitis, Multiple Sclerosis, Guillain-Barré syndrome, or hydrocephalus.

During the lumbar puncture, a needle is inserted into the spinal canal, usually between the lumbar vertebrae L3/L4 or between L4/L5 (meaning the between the third and fourth or between the fourth and fifth vertebrae of the lumbar region, or lowest region, of the spine). Through this needle, the CSF is collected, and an instrument known as a manometer is used to test the pressure of the CSF.

What will I experience during a lumbar puncture?
The lumbar puncture is performed either in a physician’s office or in the hospital. It is performed by a physician or by another properly trained medical professional.

The procedure for performing a lumbar puncture is fairly standardized. As a patient undergoing the test, you will be almost certainly be asked to lie down on a bed or examination table, turned on your side, and draw your knees up to your chest, in the fetal position. Occasionally, a lumbar puncture can be performed with the patient sitting up, bent over forward. Your back will then be sterilized with aseptic solution.

Then, a small needle containing a local anesthetic, such as Lidocaine, will be inserted into the spine where the lumbar puncture will be performed. Once the pathway is numbed, the spinal needle is inserted into the spinal canal and the lumbar puncture is performed. The procedure takes approximately 20-30 minutes.

After the lumbar puncture is performed, you will need to lie flat on your back for at least 60 minutes. You should not be alone during this time, and will most likely be kept in the office or clinic for that period of time to make sure there are no immediate complications or reactions to the lumbar puncture.