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What is a Selective Nerve Root Block (SNRB)?

One of the causes of pain that passes into the extremities is irritation of one or more nerve roots. The purpose of a Selective Nerve Root Block (SNRB) is to specifically block one or more spinal nerves to decrease pain. This is done by injecting an anesthetic and anti-inflammatory steroids into the space around the nerve for the nerve block.

A Selective Nerve Root Block is similar to an epidural steroid injection, but is more specific. This will help determine which particular nerve is related to your symptoms.


What Are The Purposes for a Selective Nerve Root Block

A Selective Nerve Root Block (SNRB) ia a diagnostic procedure that is used to evaluate patients with:

  • radicular pain
  • stenosis
  • conditions that may result in nerve root compression
selective nerve root block


Once you have decided to have the injection, the following events take place:

  • Do not eat or drink anything after midnight before your nerve block injection.
  • You can take your regular heart and blood pressure medications on the morning of the nerve block injection with a sip of water. Diabetes medications should not be taken.
  • Discontinue taking anti-inflammatories three days before the nerve block injection.
  • Discontinue taking aspirin products seven days before the nerve block injection.
  • If on blood thinners, call the physician who prescribed the medication to get approval to stop taking them before the injection.
  • You will lie on a table in a procedure room.
  • The skin in the area where the injection will be made will be cleaned.
  • The skin is numbed with lidocaine.
  • Using fluoroscopy (live X-ray) for guidance, the physician directs a needle toward the area of the nerve root to be evaluated.
  • The anesthetic and steroid solution is injected.
  • The injection procedure will take about 30 minutes.
  • You will be in a recovery room for about 30 minutes.
  • It is important that you have someone to drive you home.
  • It is common to experience an increase in pain once the numbing medicine wears off.
  • The steroid does not become effective for 24 hours.
  • Activity should be restricted for the first 4-5 days after the injection.
  • You will need to make an appointment with your doctor to discuss your level of pain relief after the nerve block injection.