Epidural steroid injections (ESIs) are a common treatment option for many forms of low back pain and leg pain. They have been used for low back problems since 1952 and are still an integral part of the non-surgical management of sciatica and low back pain. The goal of the injection is pain relief; at times the injection alone is sufficient to provide relief, but commonly an epidural steroid injection is used in combination with a comprehensive rehabilitation program to provide additional benefit.

Most practitioners will agree that, while the effects of the injection tend to be temporary - providing relief from pain for a few months up to one year - an epidural can be very beneficial for a patient during an acute episode of back and/or leg pain. Importantly, an injection can provide sufficient pain relief to allow a patient to progress with a rehabilitative stretching and exercise program. It also allows the patient to improve his/her activity level and quality of life.

Overview

Epidural injection is the administration of medication into the epidural space. It is used to treat swelling, back pain, and inflammation associated with neurological conditions that affect nerve roots, such as a herniated disk and radiculopathy. It is the most effective in acute back pain or exacerbations where the pain has only been there for a few months. In chronic back pain, it tends to produce pain relief for a few months to one year.

Anatomy

The brain is covered by three membranes (dura, arachnoid, and pia), called the meninges that extend through the base of the skull and surround the entire spinal cord. The spinal cord travels down the entire length of the spinal column through the spinal canal. The epidural space is located between the dura and the interior surface of the spinal canal and contains veins, arteries, and fat. Epidural injection is the injection of medication into the epidural space.

Procedure

Epidural injection is usually given in an outpatient setting. Most injections are performed by anesthesiologist pain doctors, who has received the most training in this procedure. A mild sedative and a local anesthetic may be given prior to the procedure to relax the patient and numb the injection site. A local anesthetic such as bupivacaine  and a corticosteroid such as triamcinolone, are injected directly into the epidural space. (The injection is commonly called a cortisone shot.)

Effectiveness

Some patients notice improvement within hours of the injection; others improve over a number of days.  In some cases, two or three injections are given over weeks.