A selective nerve root block is a procedure where an anesthetic and steroid are injected at the location where the nerve root exits the spinal column. This injection is beneficial in reducing inflammation at this site which will relieve pressure on the nerve being affected. Not only can it be used therapeutically, but it can also be used as a diagnostic tool as well. Doctors can use the anesthetic part of the injectate to “numb” up the nerve and conclude whether the pain is relieved during the life of the anesthetic. This will determine if the specific nerve is irritated. Disc herniation is one of the most common conditions that signal this procedure may be beneficial.
Similar to a lumbar transforaminal epidural steroid injection, the patient is positioned lying on their stomach and fluoroscopy is used to guide the procedure. A needle is inserted into the area and the anesthetic and steroid medication are injected after confirmation of correct placement using contrast dye. The injection aims to provide relief the day of the injection for a few hours while the anesthetic is active and also after the steroid takes effect, usually within 3-10 days. The goal is that the relief lasts several weeks to months, but repeating the injection may be an option if the relief duration is not desirable.
This injection requires blood thinning medications to be stopped with the prescribing doctor’s permission prior to the procedure. A driver is required to attend the appointment with the patient.
The side effects are similar to that of all procedures and include: bleeding, infection, and nerve damage. The chance of this happening is very rare as the doctor uses both a c-arm fluoroscope machine to guide him and contrast dye to ensure he is in the correct location. Potential side effects to the steroid medication include high blood sugar, facial flushing, and difficulty falling asleep. This only lasts about a day.
Reduce procedural discomfort by applying ice for 15-20 minutes every 2-3 hours to reduce injection site swelling and irritation. NSAIDs and/or Tylenol are also recommended.