Nerve roots exit your spinal cord and form nerves that travel into your arms or legs. These nerves allow you to move your arms, chest wall, and legs. These nerve roots may become inflamed and painful due to irritation, for example, from a damaged disc or a bony spur.

A selective nerve root block provides important information to your physician and is not a primary treatment. It serves to prove which nerve is causing your pain by placing temporary numbing medicine over the nerve root of concern. If your main pain improves after the injection then that nerve is most likely causing your pain. If your pain remains unchanged, that nerve probably is not the cause of pain.

By confirming or denying your exact source of pain, it provides information allowing for proper treatment, which may include additional nerve blocks and/or surgery at a specific level. Selective nerve root blocks are similar to epidurals, but instead of putting medication in to cover all of the nerve roots, selective blocks are done so as to cover just one or two nerve roots.

The membrane that covers the spinal cord and nerve roots in your spine is called the dura membrane. The space surrounding the dura is the epidural space. Nerves travel through the epidural space before they form the nerves that travel down your arms, along your ribs and into your legs. These nerve roots may become inflamed, for example, due to irritation from a damaged disc or contact with the bony structure of the spine. A selective epidural injection places anti-inflammatory medicine over the nerve root and into the epidural space to decrease inflammation of the nerve roots therefore reducing your pain. The epidural injection may assist the injury to heal by reducing inflammation. It may provide permanent relief or provide a period of pain relief for several months while the injury/cause of your pain is healing.

The selective nerve root block (SNRB) is a procedure that anesthetizes an individual nerve root, either within the neck (‘cervical’), or in the back (‘thoracic’ or ‘lumbar’), thought to be responsible for the patient’s pain. The nerve root sheath is injected and anesthetized with the intent of relieving this pain. This procedure is sometimes referred to as a ‘Foraminal Block.’ The SNRB procedure delivers a low volume of concentrated medication directly into the affected nerve root sleeve.

Back Pain is often multifactorial and difficult to diagnose because the symptoms overlap considerably with those of other degenerative disorders of the spine. The SNRB is useful in both the diagnosis and the treatment of back pain; therefore, it is both a diagnostic as well as a therapeutic procedure.

In other words, if we inject a medication within the suspected nerve root sleeve and the pain improves, we are fairly confident that this nerve root is responsible for the pain; conversely, if we inject a medication and the pain is no better, this implies that this nerve root is likely not responsible for the pain.