Epidural steroid injections (ESIs) are a commonly used, minimally invasive treatment for pain caused by inflammation of spinal nerves. They are most often employed to manage neck, back, and radiating arm or leg pain associated with conditions such as herniated discs, spinal stenosis, and degenerative disc disease. By delivering anti-inflammatory medication and numbing medication directly into the epidural space around the spinal cord and nerve roots, ESIs aim to reduce pain, improve function, and facilitate rehabilitation.
Anatomy & Rationale
The epidural space lies between the outer covering of the spinal cord (the dura mater) and the surrounding bones and ligaments of the spine. Spinal nerve roots travel through this space before exiting the spine to supply the arms or legs. When these nerves become irritated or compressed, inflammation develops, leading to pain, numbness, tingling, or weakness. Epidural steroid injections are designed to reduce this inflammation at its source rather than treating symptoms indirectly with oral medications.
Indications & Uses
Epidural steroid injections (ESI) are most commonly used for radicular pain—pain that radiates along a nerve path, such as sciatica in the leg or cervical radiculopathy in the arm. Conditions frequently treated include disc herniation, spinal stenosis, spondylosis, and post-surgical inflammation. ESIs may also be used diagnostically to help identify the specific source of nerve-related pain.
If you have this type of pain, imaging studies will be ordered and a history and physical will be performed. All this will help target the best areas to treat with the ESI.
Types of Epidural Injections
There are three primary approaches to epidural steroid injections, selected based on anatomy and the location of symptoms:
- Interlaminar injections, which deliver medication into the midline epidural space
- Transforaminal injections, which target medication near a specific nerve root
- Caudal injections, administered through the lower end of the spine
In my clinic I tend to focus on the transforaminal method. I broke my back many years ago after a parachute malfunction while in the Army, and I have received many of these ESI. I found by receiving them that the transforaminal approach is the least painful to receive.
Each approach has distinct advantages and is chosen to maximize accuracy and effectiveness.
Procedure & Recovery
Epidural steroid injections are typically performed on an outpatient basis using fluoroscopy (real-time X-ray guidance) to ensure precise needle placement. A combination of corticosteroid medication and local anesthetic is injected. The procedure usually takes less than 15 minutes, followed by a brief observation period.
Pain relief may occur within days, though some patients experience temporary soreness or a short-term increase in pain. The duration of relief varies, ranging from weeks to several months. ESIs are often used as part of a broader treatment plan that includes physical therapy and activity modification.
We inject 2 medications. The first is a long acting numbing medicine that allows the nerve to ‘reset’ by depolarizing it for 2-8 hours. Nerves that fire a lot (like a nerve where there is a lot of pain) can develop a memory and fire even when not needed. The anesthetic hopefully helps to reverse and reset that tendency. The second medicine is a powerful steroid that reduces inflammation. It takes about 1-3 weeks to really knock out the inflammation, so we wait about 3 weeks to really assess how you are doing.
Benefits
The primary benefit of epidural steroid injections is targeted pain relief without surgery and without flooding your body with a medication that goes through the entire system. By reducing inflammation, ESIs can improve mobility, decrease reliance on oral pain medications, and allow patients to participate more effectively in rehabilitation. In some cases, injections can delay or eliminate the need for surgical intervention.
Risks & Limitations
While generally safe, epidural steroid injections carry potential risks. These include infection, bleeding, nerve injury, headache from dural puncture, allergic reaction, and temporary side effects from steroids such as flushing or elevated blood sugar. Serious complications are rare when injections are performed with proper technique and imaging guidance. Importantly, ESIs do not correct structural problems in the spine; their effects may be temporary, and repeat injections may be necessary.
Conclusion
Epidural steroid injections are a valuable tool in the management of spine-related nerve pain. By delivering anti-inflammatory medication directly to irritated nerve roots, they can provide meaningful symptom relief and support recovery with minimal invasiveness. When used appropriately and as part of a comprehensive treatment strategy, epidural steroid injections play an important role in modern pain management.