A Lumbar Puncture (Spinal Tap) is a procedure to remove a small amount of cerebrospinal fluid (CSF) from the lower spine. CSF is the fluid that surrounds the brain and spinal cord, and it contains proteins, cells, and other biological substances that are extremely important and useful for ALS research. During the procedure, a needle is inserted between two lower backbones and into the spinal canal that contains CSF.
Step 1: You will sit or lie down in a position that widens the space between the bones of your lower spine.
Step 2: The skin of your lower back will be cleansed to reduce the risk of infection. Then a small needle will be used to inject a local anesthetic (like Lidocaine) to numb the area. You will experience a mild pinching or burning sensation.
Step 3: After the area is numbed, a thin needle will be carefully inserted into your spinal canal. If CSF cannot be drawn the first time, the needle may be readjusted.
Step 4: Drops of CSF are collected into tubes. This takes about 5-10 mins.
Step 6: The needle will be removed, pressure will be applied to make sure any bleeding stops, your back will be cleansed again, and a bandage will be placed over the LP site.
Usually 20-30 mins with an additional rest period after the LP. Both pre-LP and post-LP care can differ based on site, but LPs tend to add about 90 mins to a visit.
It can differ based on site, but the LP is generally performed by the site investigator, a neurologist, or a radiologist. Regardless of title, the person performing the LP will always be a highly trained healthcare professional.
Usually, a LP is not painful. The injection of numbing medication can cause a “pinching” sensation and may sting briefly. Additionally, you may feel pressure when the spinal needle is inserted. If the needle touches one of your nerve endings floating at the base of your spine, you may feel brief discomfort or a “zap” sensation down your leg. Although this sensation may be alarming, this brief nerve contact is not dangerous, since the lower back region is below the spinal cord, has no critical nerves, and is bathed in protective CSF. There is no risk of paralysis.
Since nerve cells in the brain and spinal cord are constantly “bathing” in CSF, it contains the most relevant and informative biological materials for ALS research, including cells and proteins. When studied, these cells and proteins can provide vital information on motor neuron biology and function. In fact, CSF is so valuable to neurological research that some neurologists call it “liquid gold”. Just one donation of this “liquid gold” can support dozens of experiments that can advance our understanding of the disease and aid in the development of useful drugs and treatments.
Fortunately, there are few risks. Post-LP headaches are the most common risk. ALL ALS minimizes this risk by using a special needle that has been shown to lower the rate of post-LP headaches. With the use of the special needle, less than 5% of people who do the procedure develop a post-LP headache.
REMINDER: If you choose to have LPs, you can always change your mind and stop at any time and for any reason. Stopping will not affect your participation in ALL ALS.
The ALL ALS Consortium and all related studies are funded by the National Institutes of Health (NIH), Grant # 1OT2NS136938 and 1OT2NS136939.