(Cerebrospinal Fluid Analysis; Cerebrospinal Fluid Tap; Spinal Tap)
A lumbar puncture is a test of the fluid around your spine and brain. This fluid is called cerebrospinal fluid (CSF). It provides protection and nutrition to the brain and nerve cells. CSF also helps to remove waste products from the brain.
|Lumbar Puncture Method
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Reasons for Procedure
The test is done to look for abnormalities in the spinal fluid. It may be done to help diagnose conditions such as:
- Brain infection, or infection of the layers around the brain
Multiple sclerosis (MS)
- Any disorder affecting the nervous system
- Certain types of cancer
- Bleeding in the brain or spinal cord
- Excess CSF in the brain
The procedure may also be done to:
- Administer dye for imaging studies
- Drain CSF to lower pressure within the brain
Give medication directly to the spine such as
Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:
- Bleeding, which can compress the nerve roots or spinal cord
- Pain or abnormal burning, pricking, or tingling sensations in legs
- Allergic reaction to anesthetic
What to Expect
Prior to Procedure
or an MRI scan
of the head may be ordered
before the procedure. These scans make detailed pictures of your brain.
Just before the procedure, your doctor will clean the site where the needle will be inserted.
Local anesthesia will be used most often. It numbs just a small area. The medication is injected with a needle.
Description of Procedure
You will lie on your side with your knees drawn up in front. Some punctures may be done while you sit on the edge of the bed. A needle will be inserted into the spinal canal through the lower back. A sample of CSF will be taken through the needle.
During the procedure, the pressure of the CSF may be noted. If you have discomfort, the needle may need to be repositioned. It may take several minutes to collect the fluid needed. The needle will be removed. A dressing will be placed over the puncture.
Immediately After Procedure
You will lie down for 10-15 minutes. In most cases, you will be able to go home after the procedure. If you have a severe headache or need immediate treatment, you may need to stay longer.
How Long Will It Take?
About 30-45 minutes from setup to completion
Will It Hurt?
Discomfort is minimal to moderate. The anesthetic will sting when first injected.
When you return home after the procedure, do the following to help ensure a smooth recovery:
- Drink extra fluids for the next 24 hours
- Rest and remain quiet for at least 24 hours
Be sure to follow your doctor's
Call Your Doctor
After arriving home, contact your doctor if any of the following occurs:
- Severe headache or headache lasting for more than 24 hours
- Nausea or vomiting
- Signs of infection, including fever and chills
- Redness, swelling, increasing pain, bleeding, or discharge from the lumbar puncture site
- Numbness, tingling, or pain in your lower back or legs
- Weakness in your lower legs or difficulty walking
- Problems with urination or defecation
- A stiff neck
- Pain that you cannot control with the medications you've been given
If you think you have an emergency, call for medical help right away.
Family Doctor—American Academy of Family Physicians
National Institute of Neurological Disorders and Stroke
About Kids Health—The Hospital For Sick Children
Lumbar puncture (LP). EBSCO DynaMed Plus website. Available at
http://www.dynamed.com/topics/dmp~AN~T168500/Lumbar-puncture-LP. Updated October 13, 2015. Accessed October 10, 2016.
Torpy J, Lynm C, et al.
Lumbar puncture. JAMA. 2006;296(16):2050.
Lumbar puncture test.
The University of Iowa website. Available at:
http://www.uihealthcare.org/2column.aspx?id=236317. Accessed February 13, 2014.
- Reviewer: EBSCO Medical Review Board
Rimas Lukas, MD
- Review Date:
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