An Overview
Epidural steroid injections (ESIs) are among the most effective non-surgical treatments for chronic spinal pain. For decades, they’ve been used to treat conditions like sciatica, herniated discs, and spinal stenosis—especially when pain radiates from the neck or lower back into the arms or legs. These injections not only reduce inflammation but can also prevent the progression of certain pain conditions.
In this article, we’ll explore the history of epidural blocks, how they work, who benefits most, and what risks and benefits patients should understand before pursuing this treatment.
A Brief History of Epidural Injections
Epidural anesthesia dates back over a century, but the use of corticosteroids in the epidural space began in the 1950s as physicians sought ways to treat radicular pain non-surgically. Over the years, the technique evolved with improved imaging guidance and safety protocols, making it a mainstay of interventional pain management.
Today, epidural injections are one of the most commonly performed procedures in pain clinics and are backed by decades of clinical use and research.
How Epidural Steroid Injections Work
The epidural space surrounds the spinal cord and nerve roots. Inflammation or compression of these nerves—often from disc herniation or spinal arthritis—can cause severe, radiating pain. By delivering a corticosteroid and a local anesthetic directly into this space, the injection reduces inflammation and helps calm irritated nerves.
In many cases, patients experience significant relief within a few days. The steroid works to reduce the underlying inflammation, while the anesthetic provides temporary numbing of the affected nerve roots.
Common Conditions Treated with Epidural Injections
Epidural steroid injections are used for a range of spinal pain syndromes, including:
- Lumbar and cervical radiculopathy (sciatica, pinched nerves)
- Spinal stenosis
- Herniated or bulging discs
- Degenerative disc disease
- Post-laminectomy syndrome (also called failed back surgery syndrome)
- Thoracic radicular pain in select cases
In some pain practices, epidural injections may also be used as part of a multimodal approach for complex regional pain syndrome (CRPS).
Are Epidural Steroid Injections Disease-Modifying?
While epidural injections don’t reverse structural spine changes, they can interrupt the cycle of inflammation and nerve sensitization. In certain patients—especially those with acute radicular pain—this can prevent progression to chronic pain.
Some studies suggest early epidural intervention may reduce the need for surgical discectomy in patients with confirmed nerve root compression. In this way, the injections may have a disease-modifying effect by halting the development of chronic neuropathic pain.
Who Should Perform Epidural Injections?
These injections must be performed by properly trained physicians using image guidance (typically fluoroscopy or CT). Qualified specialists include:
- Pain medicine physicians (usually anesthesiology or PM&R trained)
- Interventional radiologists
- Neurologists with procedural training
Proper patient selection, sterile technique, and precise targeting are critical to both effectiveness and safety.
Ideal Candidates for Epidural Blocks
Epidural steroid injections are best suited for patients who:
- Have pain that radiates into the limbs (radiculopathy)
- Show imaging findings that correlate with symptoms (e.g., disc herniation)
- Have not responded to physical therapy or medications
- Are not ready for surgery or have contraindications to it
- Need rapid pain relief to participate in rehab
They are particularly useful in the subacute phase (6–12 weeks), where inflammation is still a significant driver of symptoms.
Benefits of Epidural Injections
Epidural injections are low-risk, outpatient procedures that offer:
- Relief from nerve-related pain
- Improved ability to participate in physical therapy
- Reduced use of systemic medications, especially opioids
- Delay or avoidance of surgery
- Minimal recovery time
In many patients, a single injection provides relief for weeks or even months. Some may benefit from a short series of two to three injections over a few months.
Risks and Side Effects
Though generally safe, epidural injections are not without risk. Potential complications include:
- Dural puncture and headache
- Bleeding (especially in patients on anticoagulants)
- Infection (e.g., epidural abscess, meningitis)
- Transient numbness or weakness
- Steroid-related side effects (elevated blood sugar, flushing, insomnia)
These risks are minimized when injections are performed with imaging by experienced clinicians.
In 2014, the FDA issued a safety notice regarding serious neurologic events with unmonitored spinal injections. This underscores the importance of using image guidance and appropriate patient selection.
The Role of Nerve Ablation as an Adjunct
For patients whose pain is not primarily caused by nerve root inflammation but rather from facet joint arthritis, radiofrequency ablation (RFA) may be a better option. This procedure targets the medial branch nerves that transmit facet joint pain, using thermal energy to block pain signals.
Often, a diagnostic nerve block is used to determine whether a patient is likely to benefit from RFA. In patients with both radicular and facet pain, epidural injections and ablation may be used together as part of a customized plan.
Use in the Elderly and Non-Surgical Candidates
Epidural injections are particularly valuable in older adults or patients who cannot undergo surgery due to:
- Frailty
- Cardiopulmonary conditions
- Bleeding risk
- Poor bone health (e.g., osteoporosis)
For these individuals, ESIs provide a safer, conservative alternative to surgery and a pathway back to function with less reliance on systemic pain medications.
Final Thoughts
Epidural steroid injections remain a vital option in managing chronic spine-related pain. When used judiciously, they offer effective, targeted relief with a favorable safety profile. They can be especially beneficial in delaying surgery, enabling physical therapy, and reducing the burden of chronic pain in both younger and older patients.
If you or your patients suffer from persistent nerve-related back or neck pain, consultation with a board-certified pain specialist may be the next best step.
References
- Cohen SP et al. Epidural steroids: a comprehensive, evidence-based review. Reg Anesth Pain Med. 2013;38(3):175-200.
- Manchikanti L et al. Comprehensive evidence-based guidelines for interventional techniques in chronic spinal pain. Pain Physician. 2013;16(2 Suppl):S49-283.
- FDA. Epidural corticosteroid injection: Drug Safety Communication. 2014.
- Dreyfuss P et al. Radiofrequency neurotomy for lumbar facet pain. Spine. 2000;25(10):1270–1277.
