Epidural Steroid Injections (ESI)
For over 50 years epidural steroid injections (ESI) have been used to treat pain originating in the spine (“spine pain”), neck pain extending into the shoulders or arms, or low back pain with associated hip, thigh, or leg pain. Today, ESIs have become an important part of non-surgical management of spine pain. An ESI can help relieve spine pain, often allowing you to progress with a rehabilitation program and to resume some normal activities. ESIs work by delivering steroids directly to inflamed, pain generating spine areas, decreasing the inflammation (irritation and swelling) that may be causing the pain.
What is an ESI?
An ESI is an injection that delivers steroids and/or anesthetic medicines directly into the epidural space, which is inside the spine, but just outside the dural sac that contains the spinal cord and nerves. The epidural space contains nerves, but not the spinal cord. There are substances in this space that cause nerve inflammation, leading to pain. Steroids reduce this inflammation. ESI works because it delivers medication directly to the inflamed area.
When is an ESI typically recommended?
In general, ESIs are used to help provide pain relief. Several common conditions can cause severe acute or chronic spine pain:
- Disc herniation
- Degenerative disc disease
- Spinal stenosis
For these and other conditions that can cause pain, an ESI is an effective non-surgical treatment option.
How is an ESI procedure done?
An ESI usually takes 15-30 minutes. You will lie flat on your stomach on an X-ray table. Using fluoroscopy (live X-ray), the physician guides a needle through your skin toward the epidural space, confirms its location by injection of X-ray dye, and then injects the steroid. Afterwards, you will be monitored for 15-20 minutes and then allowed to go home. Sedation is available if you are anxious or uncomfortable, but you must have someone else drive you home. You should rest the remainder of the day after the injection. You can resume activities the next day, but you must still obey any restrictions that your spine doctors have given.
What are the benefits?
The main benefit of the ESI series is a reduction in pain. ESIs relieve pain for 50-75% of patients. For maximum benefit, ESIs are usually given in a series of three injections, each separated by two or three weeks. You can make your next appointment before going home. If you do not get pain relief from the first injection, further injections may still help. Also, other types of injections, such as nerve root or facet blocks, may be tried depending on your pain and the way your spine looks on MRIs, CTs or X-rays.
What are the potential risks and side effects?
As with all invasive medical procedures, there are risks associated with ESIs. However, they are very uncommon:
- Infection - Minor infections occur in one to two percent of patients
- Bleeding - Bleeding is rare
- Nerve Damage - While extremely rare, nerve damage can occur directly from the needle, or from infection or bleeding
- Dural puncture - Occurs one-half of one percent of patients - It may cause a spinal headache that usually improves within a few days
- Paralysis - Not a risk
Temporary leg weakness, involving one or both sides, may result from the effects of an anesthetic medication if administered for low back ESIs. The risk is greater if a dural puncture occurs, or if you have had prior surgery. If you have had prior surgery, you may also notice delayed lower extremity numbness or weakness.
There are very rare side effects from the steroid medication:
- A temporary decrease in resistance to fight infection
- High blood sugar, particularly if you have diabetes
- Stomach ulcers
- Severe arthritis of the hips
- Increased blood pressure
- Transient flushing
- Increased appetite
ESIs should not be performed if you have an infection or a bleeding problem, or are pregnant (since X-rays are used). Occasionally, an MRI scan may be needed prior to the ESI to rule out certain conditions. Injections may be done, but with extreme caution, for patients with allergies to the injected solution, serious medical problems (such as congestive heart failure or uncontrolled diabetes) and those who are taking aspirin or other blood thinning drugs such as Ticlid or Plavix.
How frequently can epidural steroid injections be performed?
There is no research that gives a definite answer to this question. It is reasonable to perform up to three injections per series, with series separated by at least three months. A series of three injections is not always necessary. If one or two injections lessen your spine pain, some physicians may prefer to save the third injection for any recurrence of spine pain. Most physicians believe that a series of three injections provides the best chance for lasting relief.
- Notify the radiologist and nurse if you are allergic to X-ray dye or steroids
- Clear liquid diet starting four hours before procedure
- You must not drive after the procedure because of the effects of sedation - Please arrange for a ride home
- Please bring your spine MRI and CT scans with you if you have them