An Epidural Steroid Injection (ESI) is commonly used in the management of symptoms of nerve root irritation caused by disorders of the spine. These symptoms can include pain which can “shoot” down the extremities, numbness, tingling, burning or weakness. Disorders of the spine which can cause nerve root irritation include herniated disks, trauma, arthritis, and spinal stenosis. If other treatment modalities such as bed rest, drug therapy and physical therapy have not met the patient’s needs, an Epidural Steroid Injection may be considered. It should not be considered as an alternative to surgery in cases where surgery is clearly indicated.

How do epidural steroid injections work ?

Steroids are believed to provide pain relief by an anti-inflammatory effect. Steroid medication can be deposited directly to the site of the nerve root irritation by injection into the spinal epidural space. This space surrounds the nerve roots as they exit the spine, and provides an ideal location for the anti-inflammatory effect of steroids.

The patient is brought into the procedure room where an intravenous is started and blood pressure and EKG are monitored. Often sedation is provided to make the experience for the patient as confortable as possible. For added precision the procedure is often done using X-ray control (C-arm fluoroscopy). There are three general approaches:

• Standard dorsal approach - The injection is given in the middle of the back between the spinous processes as close as possible to the level of involvement

• Caudal notch approach - The needle is placed at the bottom of the spine using an exixting opening (notch.)

• Transforaminal approach - The most precise delivery method to deliver the steroids exactly near the involved nerve root .

Patients are placed in prone position on the procedure table with a cushion underneath their belly. A cool antiseptic solution is applied to the area, followed by the placement of sterile drapes. The site of the injection is numbed with a local anesthetic. A special epidural needle is then inserted between the vertebrae in a very careful and gradual manner. Proper needle position is then confirmed by injection a small amount of water soluble contrast material (EpiduroGram). Once the epidural space is identified, a cocktail of Cortisone (Depomedrol)), preservative-free Lidocaine and preservative Normal Saline is given. The needle is withdrawn, and the patient is monitored for the next few minutes. The patient is then transferred to the ambulatory unit and discharged when ready.

How many injections will be needed ?

Depending on the patient’s response, a series of three injections are planned over several weeks. If no, or little, improvement is obtained from the first injection, repeat injections can be scheduled as these can improve results.

What is the likelihood that patients will benefit from epidural steroid injections ?

Success rates from epidural steroid injections vary greatly among patients. Some trials report success rates ranging from 25-89%. Obviously, there is a great deal of variability among patients and spinal disorders. Best results are obtained in more acute cases but even patients with long-standing symptoms have received benefit from epidural steroid injections. Each patient must be evaluated on an individual basis. An initial, short-lasting beneficial response can be expected from the injection of a local anesthetic. The steroid response “kicks-in” after several days, but lasts much longer.

The beneficial effect of a series of three consecutive injections may last as little as a few weeks, to many months. In many non-surgical cases a permanent degree of pain alleviation can be achieved with improvement in functional state.