A selective nerve root block is a procedure where a small amount of corticosteroid medication and a local anesthetic agent is injected around a very specific nerve root or spinal nerve that exits out of the spinal cord. The areas of the back where this procedure can be performed include the neck (cervical), mid-back (thoracic), and lower back (lumbar) regions.

An epidural steroid injection is a similar type of treatment for pain caused by conditions such as spinal stenosis and spinal disc herniation.

The similarities between a selective nerve root block and an epidural steroid injection are as follows:

• Both involve the use of steroid medications and numbing agents.
• Similar injecting devices are used to administer the mentioned medication.
• An imaging technique called fluoroscopy is used to help guide the specialist performing the procedure to reach the correct area of pathology that needs to be treated.

Differences between these two procedures include:

• A selective nerve block can be performed as either a diagnostic or therapeutic procedure whereas an epidural steroid injection is a strictly therapeutic intervention.
• A selective nerve block targets a specific nerve that needs to be managed by injecting the medication around this structure whereas an epidural injection is injected into the epidural space of the spinal cord to offer symptomatic relief to a larger area of pathology.
• The selective block is done to manage a specific area of pathology and an epidural steroid injection is performed to manage a broader area where multiple pathologies along the spine may be present.

Efficacy of selective nerve root block

In a recent study, researchers looked at the selective nerve root block success in patients who had this procedure performed to reduce nerve-related (radicular) pain caused by intervertebral disc prolapse affecting a particular lumbar nerve root.¹

40 patients with varying degrees of disc prolapse were used in this study and the results were as follows:

• Those patients who initially complained of mild pain due to their disc prolapse reported 4.3 months of pain relief after the procedure.
• Patients with moderate pain reported 2.5 months of pain relief after the nerve root block.
• Those who complained of severe pain before the procedure only experienced pain relief straight after the procedure which came back. There was no intermediate or long-term relief in these patients.
• Of all the participants, 20% reported pain relief for up to six months after the injection.

The conclusion that was made here is that selective nerve root blocks offer short-term relief of pain caused by conditions such as spinal disc herniation. Mild and moderate pathologies seem to respond well to this treatment, whereas more severe spinal cord conditions affecting the nerves and causing problematic symptoms do better with surgical interventions.

Safety

Selective nerve root blocks are safe procedures with minimal side effects caused and even fewer complications. It is a safer procedure than an epidural steroid injection for the fact that the latter has to be performed by injecting through the epidural sac which can lead to complications that wouldn’t occur with a selective nerve root block.

All content has been reviewed and approved by orthopedic specialist Dr. Zvezdomir “Zed” Zamfirov. Dr. Zed’s practice — All Star Pain Management and Regenerative Medicine — proudly serves the Annapolis, Greater Baltimore and Washington D.C. areas. For more, contact Dr. Zed or call 443-808-1808.

Reference

1. Arun-Kumar K, Jayaprasad S, Senthil K, Lohith H, Jayaprakash K. The Outcomes of Selective Nerve Root Block for Disc Induced Lumbar Radiculopathy. Malaysian Orthopaedic Journal. 2015;9(3):17-22. doi:10.5704/MOJ.1511.002.