The Basics of Epidural Steroid Injections in Nashville TN

An epidural steroid injection (ESI) is a common procedure used to treat inflammation associated with neck, back, or leg pain. Pain occurs when spinal nerves become inflamed from narrowing of the passages where the nerves travel, or when the nerves are compressed due to spinal stenosis and arthritis, or a herniated disc.

Why get an epidural steroid injection?

Narrowing of the spinal passages is cause by disc herniations, joint cysts, bone spurs, thickening of spinal ligaments, or misalignment of the vertebrae. The epidural space is a fat-filled space that surrounds the spinal sac, which cushions the spinal cord and nerves.

Corticosteroids injected into the epidural space produce a potent anti-inflammatory action to decrease pain and improve function. Steroids cannot cure the underlying condition, but they do break the cycle of inflammation, decreasing pain and allowing the body to tolerate the problem.

What can I expect before the ESI?

Before the ESI, the doctor will order certain imaging tests to diagnose your condition and determine what treatment option is best for you. For the ESI, you will report to the medical center, and a nurse will go over the risks, side effects, and complications. You will also sign a consent form. The nurse will place an IV catheter in your arm and give you a sedative if necessary.

How is the epidural steroid injection done?

There are three common methods for ESI: the interlaminar, caudal, and transforaminal approaches. All of these approaches involve positioning a small needle into position under x-ray guidance (fluoroscopy). Before ESI, a contrast dye is used to confirm that the medication will reach the desired area. The pain management doctor often adds a local anesthetic to the steroid to provide additional pain relief.

How are the approaches to ESI different?

With the interlaminar ESI, a needle is positioned through the skin and soft tissues of the back to reach the posterior portion of the epidural space. This allows the steroid to be delivered to a wider area, spreading to both sides of the spinal canal.

The caudal approach involves the needle being positioned just above the tailbone (coccyx), at the sacral hiatus. The transforaminal ESI is called a nerve block, and it involves positioning the needle near the nerve as it leaves the spinal cord. This method assures that the steroid only enters one region or side, and it is more specific for single nerve coverage.

What can I expect after the ESI?

With all ESI approaches, the corticosteroid starts to work within 3 days, but will not reach maximum effectiveness for one week. After the procedure, you may experience a warmth of the face and chest (steroid flush), which can persist for a few days. ESIs are done on an outpatient basis, so you will return home. However, you should take it easy for the remainder of the day, and be sure you bring someone with you to drive you home.

What are the side effects and risks associated with the ESI?

All medications have risks and side effects, but this does not mean that you will experience any or all of them. The side effects to corticosteroids include water retention, weight gain, trouble sleeping, and anxiety. The risks of the ESI include infection, bleeding, nerve damage, blood vessel injury, allergic reaction to medications, and post-dural headache.

What is the success rate for the epidural steroid injection?

Numerous clinical research studies have shown the ESI to be effective, reporting success rates of 80-90%. This safe, effective procedure can be repeated as necessary to maintain benefits. The best control of pain is achieved when ESI is combined with medications and physical therapy.


Kim D & Brown J (2011). Efficacy and safety of lumbar epidural dexamethasone versus methylprednisolone in the treatment of lumbar radiculopathy: a comparison of soluble versus particulate steroids. Clin J Pain, 27(6):518-22

McLain, RF, Kapural L, & Mekhail NA (2005). Epidural steroid therapy for back and leg pain: mechanism of action and efficacy. Spine Journal, 5:191-201.

North American Spine Society (2007). Diagnosis and treatment of degenerative lumbar spinal stenosis: Evidence-based clinical guidelines for multidisciplinary spine care. Retrieved from: