Lumbar puncture (spinal tap)

A lumbar puncture, also known as a spinal tap, is a test used to diagnose certain health conditions. During the procedure, a needle is inserted between the bones in the spine, called vertebrae, into the space that surrounds the spinal cord. This space holds cerebrospinal fluid, which is made up of cells, proteins, sugars, water, and other substances needed to keep your nervous system balanced and healthy. Removing a small sample of this fluid can help diagnose a variety of disorders.

Doctors called neurologists perform spinal tap procedures. Neurologists at Penn Medicine are among the leading neurology providers in the southeastern Pennsylvania and South Jersey region who are experts in performing lumbar puncture procedures and follow-up care. 

Spinal taps are commonly performed to diagnose medical conditions affecting the central nervous system. Your Penn Medicine provider may recommend a lumbar puncture if you have symptoms of the following conditions:  

• Bleeding in your brain, called intracranial hemorrhage 
• Brain infection, called meningitis 
• Dementia 
• Immune disorders, such as Guillain-Barre syndrome 
• Inflammation of brain tissue, called encephalitis 
• Inflammation of the spinal cord, called myelitis 
• Leukemia or other cancers 
• Multiple sclerosis 
• Swelling in the liver and brain, called Reye syndrome 

Additionally, a lumbar puncture can be used to measure cerebrospinal fluid pressure and administer medications directly into the spinal fluid. 

Before your lumbar puncture procedure, your doctor will explain how the procedure is done and give you time to ask questions. Your care team will review your medications with you, discuss your health history, and let you know how to prepare for surgery. 

On the day of the procedure, you can expect the following:  

• A spinal tap is performed under sterile conditions in a hospital or health center facility. 
• Your provider needs to access your spine. Some patients lay on their side with their knees pulled toward their chest. Others sit in a chair with their arms and head resting on a table. These positions help to widen the space between your vertebrae. It’s important to stay as still as possible during the procedure. 
• You’ll have anesthesia so you’re pain-free, but you’ll be awake during the lumbar puncture procedure. Your care team will monitor you the entire time to ensure your safety. 
• After your back is washed with antiseptic soap, your provider will insert a thin, hollow needle between two vertebrae into the space between your spinal cord and the membrane that covers your spinal cord. An X-ray called a fluoroscopy may be used to help guide the needle into place. 
• When the needle is in place, your provider measures your spinal fluid pressure and pulls a sample of cerebrospinal fluid into the needle. The needle is in your back for only a few minutes. 
• The whole procedure takes less than 30 minutes. 
• Once complete, your care team will put a bandage over the spinal tap procedure site. Most patients are released to go home after a short observation period. 

The cerebrospinal fluid sample will be sent to a laboratory for analysis. An experienced Penn Medicine lab technician will examine the fluid and perform tests that will help find a diagnosis for your symptoms. 

Recovery from a spinal tap procedure can take a few days. Your Penn Medicine care team will provide recovery instructions, including: 

• Lay on your back or side for several hours 
• Drink plenty of fluids 
• Rest as much as possible 
• Avoid strenuous activities 
• Don’t drive or operate heavy machinery for at least 24 hours 

Note that some people develop a spinal headache after a lumbar puncture. The headache may occur within hours or days of the procedure. The headache typically goes away on its own within a couple of days. Your care team may recommend over-the-counter pain medicine to help with the headache, as well as drinking water and caffeinated beverages. 

Your doctor will discuss the results of the spinal tap test with you and may recommend further evaluation or treatment based on the findings. At Penn Medicine, our mission is to find the right treatment to relieve your symptoms. We’re dedicated to guiding you through every phase of your medical journey to make sure you get the highest care and support every step of the way.