Transforaminal Epidural Steroid Injection vs. Selective Lumbar Nerve Root Block

                                    A straightforward Guide for Patients

 

Both Transforaminal Epidural Steroid Injections (TFESI) and Selective Lumbar Nerve Root Blocks (SLNRB) are minimally invasive procedures performed to treat or evaluate low back and leg pain caused by nerve irritation. They are performed in a sterile procedure suite using X-ray guidance (fluoroscopy) and have similar preparation and post-procedure instructions.

 

While the precautions, positioning, and technique are largely the same, the purpose and effect of the injection differ:

 

Feature	Transforaminal Epidural Steroid Injection (TFESI)	Selective Lumbar Nerve Root Block (SLNRB)
Purpose	Therapeutic: reduces inflammation and provides pain relief from irritated spinal nerves.	Diagnostic: helps identify the exact nerve or spinal level causing pain. Relief is temporary but confirms the source of pathology.
Medication	Steroid (cortisone or corticosteroid) + local anesthetic	Usually only local anesthetic; steroid may be added in some cases depending on provider plan
Expected Effect	Pain relief can last weeks to months depending on response.	Pain relief is usually temporary (hours to a day) and primarily used to pinpoint the affected nerve.
When Used	Chronic radicular pain, sciatica, nerve inflammation, or as a therapeutic step in treatment.	When the source of nerve pain is unclear or needs confirmation before further intervention.
Procedure Steps	Patient lies face down or side; local anesthesia applied; needle placed near the affected nerve; medication injected; monitored briefly, then discharged.	Identical procedural steps to TFESI. The difference is that the injection contains a local anesthetic for diagnostic purposes.

 

 

Preparation & Aftercare

Both procedures follow the same precautions and instructions:

• Pre-procedure:
  • No solid foods for 8 hours if sedation is planned
  • Clear liquids are allowed up to 2 hours before
  • Avoid gum, candy, mints, or throat lozenges 2 hours before
  • The care team will review medications and instruct which to take

 

• Post-procedure:
  • Resume normal activities as tolerated; mild soreness is common
  • Do not soak in a bathtub or lake for 24 hours; showers are allowed
  • Pain relief may take 7–10 days (if a steroid is used in TFESI)
  • The care team will call the following day to check symptoms and recovery

 

• Sedation precautions: Do not drive or operate heavy machinery for 24 hours

 

Potential Risks

Risks are generally similar for both procedures, though SNRB is slightly lower risk because steroids are not always used:

• Pain at the injection site
• Infection (rare)
• Dural puncture (may cause headache)
• Temporary increase in pain or nerve irritation
• Bleeding, especially in patients on blood thinners
• Rare nerve or spinal cord injury
• Allergic reaction to medications

Always inform your provider if you are taking blood-thinning medications (e.g., Plavix, Aspirin, Xarelto, Warfarin, Heparin, Lovenox, Brilinta).

 

Summary

• TFESI = therapeutic; intended for lasting pain relief
• SLNRB = diagnostic; intended to confirm which nerve is the source of pain

Both procedures are performed in a safe, minimally invasive, outpatient setting with the same preparation, monitoring, and aftercare. The main difference is why the injection is given and the type of medication used.