What is a Selective Nerve Root Block (SNRB)?

From the Guidelines

Selective Nerve Root Blocks (SNRBs) are a valuable diagnostic and therapeutic tool for managing nerve pain, particularly for conditions like radiculopathy, herniated discs, or spinal stenosis, as they can help identify the specific nerve root causing symptoms and reduce inflammation around the nerve 1.

Key Points to Consider

• SNRBs involve injecting a local anesthetic and steroid medication around a specific spinal nerve root to reduce inflammation and pain.
• The procedure is typically performed under fluoroscopic (X-ray) guidance to ensure accurate needle placement.
• Common medications used include lidocaine or bupivacaine for immediate pain relief, combined with corticosteroids like methylprednisolone or triamcinolone for longer-term anti-inflammatory effects.
• Patients may experience immediate relief from the anesthetic, while the steroid's effects develop over several days.
• SNRBs are particularly useful when conservative treatments have failed, and the diagnostic value comes from identifying the specific nerve root causing symptoms.

Potential Benefits and Risks

• Benefits: SNRBs can provide significant pain relief, improve mobility, and reduce the need for oral pain medications.
• Risks: Side effects are generally minimal but may include temporary numbness, weakness, or soreness at the injection site.
• Most patients can resume normal activities the day after the procedure, though strenuous activity should be avoided for 1-2 days.

Clinical Guidelines and Recommendations

• According to the American College of Physicians and the American Pain Society, SNRBs can be a useful diagnostic and therapeutic tool for managing nerve pain, particularly for conditions like radiculopathy, herniated discs, or spinal stenosis 1.
• The guidelines recommend considering SNRBs when conservative treatments have failed and the patient's symptoms are consistent with nerve root compression or inflammation.

From the Research

Overview of SNRB

• SNRB (Selective Nerve Root Block) is a procedure used for both diagnostic and therapeutic purposes, particularly in treating lumbar radiculopathy and avoiding surgery 2.
• It can be applied in multiple sites, including cervical and lumbar regions.

Efficacy of SNRB

• Studies have shown that SNRB can provide immediate and long-term relief of symptoms in patients with lumbar radiculopathy 2, 3.
• A significant proportion of patients (up to 54%) can avoid surgery after undergoing SNRB 2.
• The procedure has been found to be effective in reducing pain and improving functional outcomes in patients with lumbar radiculopathy 4, 5.

Comparison of Therapeutic Agents

• Research has compared the effects of corticosteroids and hyaluronic acid-carboxymethylcellulose (HA-CMC) solution in SNRB for lumbar radiculopathy 5.
• The study found no significant difference in pain improvement and functional outcomes between the two groups, suggesting HA-CMC as a potential alternative to corticosteroids.

Long-Term Follow-Up

• A minimum five-year follow-up study found that patients who avoided surgery after SNRB had significant decreases in neurological symptoms and back pain compared to baseline values 6.
• The majority of patients who avoided operative treatment for at least one year after receiving SNRB continued to avoid surgery for a minimum of five years.