Lumbar Puncture

Lumbar punctures (LPs) are performed by one of our neurologists at Danbury Hospital’s Ambulatory Unit, so that the spinal fluid may quickly be transported to the hospital laboratory.


The LP procedure consists of the removal of cerebrospinal fluid from the lumbar (lower back) region.  This fluid supplies the nutrients to the brain and spinal cord.  The neurologist will first numb the lower back region with a local anesthetic and then place a needle through the skin to the sac containing the spinal fluid.  A small amount fluid is removed, which your body will replace in about an hour.  You may feel a burning sensation while the local anesthetic is given and pressure while the spinal needle is in place.  Overall, the LP tends to be much less uncomfortable than most people expect.

The entire LP procedure takes approximately 15 to 30 minutes.  However, you should allow for at least 1 to 2 hours to give yourself sufficient time to register at the hospital and for you to be placed in a room.  After you are registered, a neurologist on hospital duty will be paged to the Ambulatory Unit for the procedure.  Although we schedule LPs ahead of time, please be patient if the doctor is delayed with a hospital emergency.


The most common complication from an LP is a headache, called a “post-LP headache.” This is very distinctive, in that it occurs only when you sit or stand.  The headache is relieved by lying flat and occurs approximately 20% of the time after an LP.  Some suggest that lying flat for 4 to 5 hours after the LP reduces the chance of a headache.  Drinking caffeinated beverages has also been suggested as a preventive measure.  You do not need to remain in the hospital for 4 hours, but can lie flat after being driven home.

If you develop a post-LP headache, the first measure is to remain in bed and drink plenty of fluids.  You can take over-the-counter analgesics such as Tylenol.

If these measures are not helping, please call our office for further pain medication.  If this medication does not help, there is a simple procedure done by an anesthesiologist that relieves the headache. This procedure is called a “blood patch” and consists of placing a small sample of your own blood into the area around the sac containing the spinal fluid, forming a “plug” or “patch.”

If you have any further questions, please do not hesitate to ask the neurologist at the time of the LP procedure.