Cervical selective nerve root block, or SNRB, is an injection used to identify the source of nerve pain in the neck and sometimes to also provide longer-term pain relief.

Nerve pain in the neck that radiates down into the shoulders, arms, and hands can develop when a cervical nerve root is compressed or inflamed due to a degenerated or herniated disc, spinal stenosis, or other degenerative spinal changes.

As the procedure begins, the patient lies face-down and may receive a sedative.

The doctor injects a local anesthetic into the skin over the area that is suspected of being the source of nerve pain.

Under X-ray guidance, the doctor injects a contrast dye to aid in correct placement of the needle at or near the suspected compressed or irritated nerves.

Once the needle is safely positioned, there is a second injection into the nerve root where it exits the foramen, a side opening where two vertebrae meet.

This injection contains lidocaine, a type of anesthetic, and may include a steroid, such as cortisone.

If the patient's nerve pain disappears when the anesthetic is injected, then the correct nerve root has been identified.

The steroid injection often works for a longer period of time than the anesthetic, helping to reduce inflammation and promote healing of irritated nerve roots.

The injection site is bandaged. Patients can usually leave the hospital the same day.