Selective nerve root block – SNRB
A selective nerve root block is performed under fluoroscopic guidance by placing the needle adjacent to the nerve as it exits through the foramen (opening) between two vertebrae. This technique is used for diagnostic purposes when evaluating exactly which vertebral level the pain is coming from, and may eventually help determine how many levels could require surgical decompression.However, a selective nerve root block is also used for therapeutic treatment since the local anesthetic and steroid decrease the inflammation of the nerve. Because the selective nerve root block uses lower doses of steroid than the epidural steroid injection, subsequent blocks can be performed for ongoing treatment with less concern of steroid toxicity. Placement of the needle in the nerve sheath is identified under fluoroscopic guidance by injecting a small amount of dye in the sheath.