Overview
Epidural steroid injection (ESI) is a nonsurgical treatment that can help relieve pain in the neck, arm, low back, and leg pain (sciatica) caused by irritation of the spinal nerves. ESIs are performed to relieve pain caused by spinal stenosis, spondylolysis, or disc herniation. The epidural injection delivers a long-lasting steroid and an anesthetic agent to the irritated and inflamed spinal nerve. Medicines are delivered to the nerve through the epidural space, that is, the area between the protective covering of the spinal cord and vertebrae. The effects of ESI are usually temporary and vary. Pain relief may last for 1 week or up to 1 year. The goal is to reduce pain so that patients may resume their normal activities and, in some cases, continue a physical therapy program.
What is epidural steroid injection (ESI)?
This injection includes both a long-lasting steroid cortisone called a corticosteroid (e.g., triamcinolone, betamethasone) and an anesthetic (e.g., lidocaine, bupivacaine). The drugs are delivered into the epidural space of the spine, which is area between the protective covering (dura) of the spinal cord and vertebrae (Fig. 1) (see Anatomy of the Spine). ESIs can relieve symptoms caused by inflammation and pressure on the spinal nerves. Corticosteroids can reduce inflammation and can be effective when delivered directly into the site of the painful part of the neck or back.
Who is a candidate for ESI?
Patients with pain in the neck, arm, low back, or leg pain (sciatica) may benefit from ESI. Specifically those with the following conditions:
- Spinal stenosis: a narrowing of the spinal canal and nerve root canal causing back and leg pain, especially when walking.
- Spondylolysis: a weakness or fracture between the upper and lower facets of a vertebra. If the vertebra slips forward, called spondylolisthesis, it can compress the nerve roots causing pain.
- Herniated disc: occurs when the gel-like center of an intervertebral disc pushes out from the center, similar to the filling being squeezed out of a jelly doughnut. Pain results when the disc material touches a nearby nerve.
ESI has proven helpful for some patients in the treatment of the above painful inflammatory conditions. ESI can also help to determine whether surgery might be beneficial for pain associated with a herniated disc. When symptoms interfere with rehabilitative exercises, epidurals can ease the pain enough so that patients can continue their rehabilitation.
ESI should NOT be performed on people who have an infection, pregnant women, or those with bleeding problems. It may slightly elevate the blood sugar levels in patients with diabetes, typically for less than 24 hours.
Who performs ESI's?
The types of physicians who administer these injections include physiatrists (PM&R), anesthesiologists, radiologists, neurologists, and surgeons.
What happens before treatment?
A few days before the ESI treatment, the doctor who will perform the injection reviews your medical history, conducts a physical exam, and reviews previous imaging studies to help plan the best approach for the injections. Be prepared to ask any questions you may have at this appointment.
If you are taking aspirin or blood thinning medication, you may need to stop taking it several days before the ESI. Discuss any medications with your doctors, including the one who prescribed them and the doctor who will perform the injection.
Make arrangements to have someone drive you to and from your ESI appointment.
What happens during treatment?
The goal is to inject the medication as close to the pain site as possible using either a translaminar or transforaminal injection. The right type of injection one for you depends on your condition and which procedure will likely produce the best results and the least discomfort or side effects. Studies have shown that use of fluoroscopy (X-ray) to guide the needle into the epidural space is more effective than when the ESI is performed without fluoroscopy. The entire procedure usually takes less than 15 minutes.
Step 1: Prepare the patient
The injection is usually performed in an outpatient Special Procedures suite that has access to fluoroscopy. Patients can remain awake for the entire process. Sedatives can be given to help lessen anxiety. Lying face down on the table, the patient receives a local anesthetic, which will numb the skin before the injection is given. Blood pressure, heart rate, and breathing are monitored during the procedure.
Step 2: Insert the needle
With the aid of X-ray fluoroscopy, the doctor directs a needle through the skin into the epidural space. Fluoroscopy allows the doctor to see where the needle is positioned, thus ensuring that the steroid medication is delivered as close to the inflamed nerve root as possible. Some discomfort occurs but patients typically feel more pressure than pain because of small nerve supply in this area of the back.
The two types of ESIs are described.
- Translaminar injection. The needle is placed between the lamina of two vertebrae directly from the back. This method accesses the large epidural space overlying the spinal cord. Medication is delivered to the nerve roots on both the right and left sides of the inflamed area at the same time (Fig 2).
- Transforaminal injection. The needle is placed to the side of the vertebra in the neural foramen, just above the opening for the nerve root and outside the epidural space. Use of a contrast dye helps to show the nerve root on the fluoroscope. This method treats one side at a time. It is preferred for patients who undergone a previous spine surgery because it avoids any residual scars, bone grafts, metal rods, and screws (Fig. 3).
Step 3: Inject the medication
When the needle is in place, the local anesthetic and steroid medication are delivered to the epidural space. The needle is then removed.
What happens after treatment?
Most patients can walk around immediately after the procedure. After being monitored for a short time, you can usually leave the office or suite. However, take it easy for 24 to 36 hours after the injection to allow the anti-inflammatory benefits to take effect. Most patients can resume normal activities and/or participate in their physical therapy program within a few days after the ESI.
Localized soreness is usually relieved within 24 hours by using ice, reducing strenous activities, and taking a mild analgesic. Patients are advised to reduce work schedule and activities for 48 hours following the procedure to help healing.
The doctor's office will call you 4 to 5 days after the procedure to ask about your symptoms. For patients whose pain is greatly improved, further procedures or surgery may not be unnecessary. For patients whose pain is not relieved, the next steps in their care are discussed with their physicians.
What are the results?
About 50% of patients experience pain relief. If you don't notice any such benefit, additional injections likely won't help either. If you experience some pain relief, one to two more injections can be performed, usually in 2-week intervals. The benefits of ESI tend to be temporary. Some patients experience pain relief for as little as 1 week and others for up to 1 year. Most importantly, patients may experience enough relief to get moving again, resume normal activities, and/or continuing a physical therapy program.
What are the risks?
With few risks, ESI is considered an appropriate nonsurgical treatment for some patients. The potential risks are associated with inserting the needle too far and include spinal headache from a dural puncture, bleeding, infection, nerve damage, and arachnoiditis. Corticosteroid side effects may cause weight gain, water retention, and elevated blood sugar levels in diabetics. Any transient numbness and mild motor block usually resolve within 8 hours in the affected extremity (similar to the facial numbness experienced after dental work). Patients who are being treated for chronic conditions (e.g., heart disease, poorly controlled diabetes, rheumatoid arthritis, or those who cannot temporarily discontinue anti-clotting medication) should consult their physician for a risk assessment.
Sources & links
If you have more questions, please contact the Mayfield Spine Institute at 800-325-7787 or 513-221-1100. Additional information is available on the web.
Links
Spine-health.com
Redding Anesthesia Associates Medical Group
Sources
- Weinstein SM, Herring SA: NASS. Lumbar epidural steroid injections. Spine J 3(3 Suppl):37S-44S, 2003.
- Lutz GE, VAd VB, Wisneski RJ: Fluoroscopic transforaminal lumbar epidural steroids: an outcome study. Arch Phys Med Rehabil 79:1362-1366, 1998.
Glossary
anesthetic: an agent that causes loss of sensation with or without the loss of consciousness.
arachnoiditis: inflammation of the arachnoid membrane that covers the spinal cord.
chronic: a condition of slow progression that continues over a long period of time, opposite of acute.
corticosteroid: a hormone produced by the adrenal gland or synthetically. Regulates salt and water balance and has an anti-inflammatory effect.
epidural space: The area between the membrane surrounding the spinal cord and the vertebral wall that is filled with fat and small blood vessels.
fluoroscopy: an imaging device that uses x-ray or other radiation to view structures in the body in real time, or "live." Also called a C-arm.
sciatica: pain that courses along the sciatic nerve in the buttocks and down the legs. Usually caused by compression of the 5th lumbar spinal nerve.
translaminar: through the lamina.
updated: 8.2004
reviewed by: Lester Duplechan, MD and Bobbie Ryan, RN |
