Lumbar puncture is the medical procedure in which a needle is inserted into the spinal cord to collect a sample of the cerebrospinal fluid.
The cerebrospinal fluid is the fluid that surrounds the spinal cord and brain.
Lumbar puncture is also called spinal tap and is done to diagnose diseases of the central nervous system including the brain and spine.
The diseases that can be diagnosed includes dementia, meningitis, inflammation of the brain tissue or spinal cord, autoimmune conditions, and many more.
Lumbar puncture can also be used to administer medications directly into the spinal canal. For example, chemotherapy drugs.
Benefits of lumbar puncture
Lumbar puncture can help your doctor accurately diagnose some life-threatening medical conditions.
The faster they diagnose and treat these conditions, the better because some conditions such as bacterial meningitis, can be fatal if not treated quickly.
Risks
A lumbar puncture is generally considered safe, but it is not without some risks.
About 10% of people who get a lumbar puncture develop a headache afterward which might come on within a few hours or a few days.
Other possible risks include bleeding close to the puncture site and discomfort or pain in your lower back.
Pain and numbness that shoots down your legs may also be experienced.
In rare cases, people experience brain herniation, which is the movement of brain tissue from its normal position in their skull.
Preparation for a lumbar puncture.
You should inform your doctor about all the medications you’re taking before a lumbar puncture to know which to stop taking.
For example, they might suggest that you stop using blood thinners like aspirin or warfarin.
Your doctor may also ask you to do a CT or MRI scan before your lumbar puncture so they can check for signs of swelling around your brain or any other problems.
Lumbar puncture procedure: What to expect.
A needle and syringe are used to conduct a lumbar puncture.
Your doctor will collect a sample of your spinal fluid in a tube attached to the syringe. Then send it to a laboratory for testing.
The procedure usually takes about 15 to 30 minutes and is not usually painful.
Your doctor will likely position you on your side or leaned over.
Then they’ll clean your back with an antiseptic solution to reduce your risk of infection.
After that, they’ll inject a hollow needle into your subarachnoid space to collect a sample of your cerebrospinal fluid. At this point, you might feel some pressure. You may feel some pressure at this point.
Your doctor will then remove the needle, then clean and bandage the punctured site.
You’ll be monitored for headache, dizziness, or other effects for a short period after the procedure.
Results
The CSF sample will be sent to a lab for testing.
The professionals in the lab will evaluate its appearance for cloudiness, and check for the presence of protein and glucose.
It may take hours or days to analyze the sample.
When the result is out, your doctor will advise you in follow-up steps to take.
