A diagnostic selective nerve root injection or “block” is a diagnostic test done to find out if a specific nerve is the source of pain. X-ray dye is injected to be sure the needle is positioned correctly for the area to be tested. Local anesthetic medication is injected into the fatty cushion layer that surrounds the spinal nerves to temporarily “block” or interrupt the nerve signals to see if this relieves pain. The local anesthetic may provide immediate, but brief relief. After the procedure, the provider will interview and evaluate the patient to see if there is pain relief. The nerve block is only a test and any pain relief is temporary. Once the local anesthetic wears off it is expected that pain will return to its usual level. Nerve blocks are helpful diagnostic tools to assist in planning care options.
