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What are Epidural Steroid Injections?Stephen Endres, MD, DABPM What are epidural steroids?Epidural steroids are solutions of local anesthetic and steroid (cortisone) that are injected into the space outside the sac that holds the spinal fluid, spinal cord and nerves. This space runs from the tail bone to the back of the head. Therefore these injections can be done anywhere along the spine. These injections are done with the guidance of fluoroscopy (live action x-ray). What do epidural steroids do?Epidural steroids have two purposes. First, epidural steroids decrease the pain and tingling caused by inflammation of nerves irritated by a bulging/herniated disc or degenerative spine disease. With reduction of pain, physical therapy is facilitated, less pain medicine is needed and patients return to normal function (back to work) faster. Also, more aggressive intervention such as surgery can be avoided. Secondly, epidural steroid injections can provide diagnostic information. If a patient gets better, even for a short period of time from the injection, this usually means the area where the local anesthetic and the steroid were placed is the pain generator. Knowing what is generating the pain makes it easier for physical therapists, chiropractors and surgeons to formulate treatment plans for the patient. Who is a candidate for epidural steroids?Patients who have unrelenting back and leg pain or neck and arm pain that has not responded to at least 4 to 6 weeks of anti-inflammatories, physical therapy and/or chiropractic care are good candidates for epidural steroids. Many insurance companies mandate that patients have at least 4 to 6 weeks of conservative care before they will approve payment for an epidural steroid injection. Do I need to have an MRI first?It is not absolutely necessary to have an MRI before an epidural steroid injection. However MRIs are very helpful in determining where the injection should be placed. Many insurance companies mandate that patients have an MRI or CT scan prior to epidural steroid injections. Do the injections hurt? The injection phase of the procedure can be uncomfortable. Very small gauge needles are used to minimize the pain. The average injection time is less than 30 seconds for most procedures. What are the risks of the procedure?The risks of the procedure are small. They include: infection around nerves (less than 0.5%), bleeding or bruising around the nerves causing nerve damage (less than 0.5%), puncturing the sac that holds the spinal fluid resulting in a headache (less than 2%), and adverse or allergic reactions to the medicines used (less than 1 %). What are the side effects of the steroids used?After the injection some of the steroid does get absorbed into the blood stream. Once in the blood stream steroids can have side effects. These include irritability, trouble sleeping, mood swings, depression, elevated blood sugars (in diabetics), high blood pressure and upset stomach. The patient’s ability to make his or her own steroids may be suppressed. The steroids may limit the patient’s ability to mount an immune response to an infection. This is why we have patients wait up to 10 days after they get their flu shot before having an injection. This is also why we avoid injecting patients with steroids 4 weeks before or after elective surgery. Osteoporosis can be made worse with too much steroid. The side effects can be more severe as more steroids accumulate in the body. How many epidural steroid injections can I have?The side effects of the steroids limit how many injections a patient can have over time. Because the side effects of the steroids are dose dependent, we try to schedule the injections at least 4 to 6 weeks apart. This allows the patient to receive adequate physical therapy or chiropractic care between injections. Forty percent of the time patients are so much better after the first injection, another injection is not done. If the patient is not better after two injections, and has failed physical therapy, we usually refer the patient to a surgeon. Most insurance companies will only pay for 1 to 3 injections a year. Medicare has adopted this standard of care with a recent change in their policy. Medicare allows two epidurals for a specific pain problem separated by 4 to 6 weeks with documentation of physical therapy and anti-inflammatory use during that time.
Dr. Stephen Endres–Pain Clinic of Northwestern Wisconsin |
