A selective nerve root block (SNRB) procedure involves the injection of a local anesthetic — sometimes combined with an anti-inflammatory (steroid) medication — into a spinal nerve root at the point where it branches away from the spinal cord. In the spine, there are many passageways (foramina) through which nerve roots exit the spinal column. If a foramen is obstructed by a bulging disc, bone spur or misaligned vertebra, the nerve root within the foramen can become pinched, which may cause it to send out pain signals that travel along the nerve’s pathway.

What can a selective nerve block do?

Sometimes, an irritated nerve root cannot be identified through a physical exam and imaging studies alone. In this situation, a physician may order a selective nerve root block for diagnostic purposes. With the highly precise insertion of a small needle into a foramen that is believed to be blocked, a physician can deliver numbing medication directly to a specific nerve root. If immediate pain relief occurs, the physician can isolate the irritated nerve and confirm the diagnosis.

In addition to diagnostic testing, SNRB injections can be used for therapeutic purposes as well. That’s because the long-acting steroid medication administered with this injection can effectively reduce painful inflammation. Specifically, as a treatment, a selective nerve block may be used to address pain caused by:

• Cervical and lumbar radiculopathy
• Bulging and herniated discs
• Spinal stenosis
• Spinal osteoarthritis
• Failed back surgery syndrome
• Other spinal conditions

How long will the effects last?

The symptom relief achieved with a selective nerve root block injection can last anywhere from several days to several months. If necessary, the procedure can be repeated, although most physicians recommend having no more than three injections administered during a one-year period.

If you are living with chronic neck or back pain, speak with your physician about the possibility of using selective nerve root block injections to diagnose or treat your symptoms.