What is a Lumbar Puncture (LP)?

An LP (Lumbar Puncture; AKA Spinal Tap) is a procedure in which a needle is placed between two vertebrae of the lumbar (lower back) area of the spine to extract cerebrospinal fluid (CSF). CSF is a clear liquid that surrounds the brain and spinal cord and is usually extracted for diagnostic purposes, for example, diagnosing Multiple Sclerosis (MS) by looking for myelin proteins in the CSF. MS attacks the myelin around nerves which causes pieces of myelin to break away into the cerebrospinal fluid around the brain and spinal cord.

CSF is vital to literally support the brain. The CSF that your brain floats in effectively reduces the brain’s weight by 97%, which keeps the brain from crushing under its own weight!

The Procedure
The procedure is pretty simple and though many people may say it is painful I would say it where-is-csfdepends on your doctor just like your experience having an IV placed can be vastly different from nurse to nurse. My first neurologist really sucked at it and hit a nerve sending a mild sensation of electrical shocks throughout my body. My current neurologist is so good at it I don’t feel a single thing after the local anesthetics, just a minor pinch and pressure! So don’t let all the hype on the internet scare you.

So how does it work? First, they will have you get into a medical gown so they have access to your back. Next, they will either have you lie arched on your side (basically the fetal position) or arched over a table sitting up. They will feel around your spine for “the right spot”, shoot you up with some local anesthetics (usually 3 shots) and then insert the LP needle between two vertebra in your back which allows your CSF to leak out into a vial. One Band-Aid later and you’re all done!

I have read some articles online that claim that everything I am about to tell you is a myth but those claims are a total load of crap! So, with that being said, the split second they pull that needle out you should lie down (After they place the bandage on of course). My doctor usually has me lie down in the office for about an hour before letting me leave because if you sit up you will most likely get a horrible headache.

Why? Well, let’s think about it; your CSF surrounds your brain and the normal amount of fluid maintains a certain pressure in your head. After you take some of this fluid out that pressure now drops because there is less CSF pushing against your brain and skull just like removing some of the air in a car tire will lower the pressure.  By lying down the CSF that is left in your spinal cord and skull will evenly spread out and help keep the remaining pressure around your brain but if you sit up all the CSF rushes down (thanks to gravity) towards the your spinal cord further reducing the pressure that is and should be supporting your brain. Hopefully I am not painting a picture of there being no CSF around your brain if you are to sit up, they take a very small amount out.

CSF is primarily produced in a structure called the choroid plexus in the lateral, third and fourth ventricles in the brain.

With that in mind, it is recommended that you lie flat on your back for at least 24 hours after the procedure and drink as much fluid as possible! In adults, there is usually about 150ml of CSF floating around and that is replaced every 8 hours or so and drinking fluids helps replace what was taken out. You can pretty much drink anything and beverages with caffeine are said to help prevent a headache. I usually stick to water, coffee and juice but mostly water. I have been told I can even have a few beers if I want but something tells me alcohol would not help you avoid a headache so personally, I would not recommend that… Also, they say that for every drink you have with caffeine in it, you should drink an equal amount of liquid without caffeine which is something I have always tried to do.

What is a Blood Patch?
If you do get a headache, in addition to drinking fluids and lying down, regular over the counter (OTC) pain relievers like Ibuprofen or Tylenol may help as well. I have read that around 15% to 50% of patients experience this headache after an LP because the hole that was made in the spinal cord from the needle has trouble closing and your CSF continues to slowly leak. If your headache doesn’t go away in 24 hours or so you might want to contact your physician who may have you come back in to give you what is called a “blood patch”. All this is (basically) is an injection of your own blood into your spinal cord so that it will clot and help plug the hole where your CSF is leaking. I have never had this done but after my first LP? I was just about ready to ask for one because I think my headache lasted about a week or so! It was miserable! But I was skeptical of letting that doctor stick another needle into my back so I just waited it out.

So Just Remember…
Lie down, rent a movie, relax and drink plenty of fluids! After my last LP, I drank about 5 water bottles, a cup of coffee and a lemonade. I lied down for about 24 hours and took it easy the next day not doing anything strenuous that might raise my blood pressure like heavy lifting. I had NO HEADACHE and by the day after I was back on track with my life like nothing had happened!


6 thoughts on “What is a Lumbar Puncture (LP)?

  • September 27, 2014 at 11:05 pm

    uuh, I had an LP last friday, it was horrible.. i didn't really feel anything other than the first sensation, but i felt the needle going inside and all because i didn't get any shots of anesthetics even if i asked the doctor several times -_- … he told me to lay down for 15mnts or so and i did but afterward when i got out, i had pain in the same place where the injection took place, it was like i couldn't hold my body anymore, i had to sit or lay to not feel that.. but the real problem came sunday morning when i had those Horrible headaches followed by nausia if i stood orr sat down for a long time … anyway, nom it's been a week from the injection and 6 days since the headaches started, but thank god it's decreasing day by day, today i was even able to go out and spend a long time out hanging around without the headaches untill i was coming back..
    P.S. i had the LP to be sure that i do have MS , there is a chance of 1% of having another neuro disease … still waiting for the results..
    Have a good day, Matt, and thanks for everything!

    • September 28, 2014 at 1:57 pm

      ok hold on, hold on, no anesthetics? I didn't think they were allowed to do that! Also, if your headache lasts THAT long, you should have gone back for a blood patch, that would level the fluids in your spine/head back up. Hope you have been drinking lots of fluids!

  • May 14, 2015 at 6:44 pm

    I sympathize with you. I had to have LP's every other month for 2.5 years to make sure my cancer wasn't spreading. It was the most uncomfortable experience. I remember the headaches after and they were very painful. I am wondering if the migraines I get now have anything to do with having LP's for that long period of time (It's been 20 years)?

  • October 21, 2016 at 9:14 pm

    I didn’t have anesthetics either. I also had a killer headache because I didn’t follow directions. I wonder why, if the injection is (of course) on the skin side of your back, they don’t tell you to lay on your stomach as long as possible? The blood patch is essentially a scab over the injection site. That was what it took to keep my eyes from popping out of my skull.

    • October 22, 2016 at 7:48 pm

      yeah, even some doctors think it’s not true which I don’t get. Every LP I have had where I did not lie flat afterwards I had a headache but once I was told to not sit up? No issues. Doesn’t matter where the injection was, the amount of pressure in your head is different; the spinal fluid in your back flows into your brain, it’s all one area (that the fluid is in)


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