General Information

Epidural Steroid Injections (ESIs) are a common method of treating inflammation associated with low back related leg pain, or neck related arm pain. In both of these conditions, the spinal nerves become inflamed due to narrowing of the passages where the nerves travel as they pass down or out of the spine.

This is a glossary of spine anatomy terms:

Vertebrae: Your spine is made of ring-shaped bones called vertebrae.

Spinal column: The “rings” at the center of each vertebrae line up to form a column in your neck through the lower back (the spinal column).

Spinal cord: The spinal cord extends from the base of the brain and ends at the upper lumbar spine, continuing further down as a large bundle of nerves through the lower the spinal column.

Dura mater: A membrane called the dura mater covers and protects the spinal cord.

Epidural space: There is a small space surrounding the dura mater called the epidural space.

Nerve roots: Branches of nerves from the spinal column (nerve roots) pass through the spinal canal and extend into the neck, arms, back and legs. If something is irritating the nerve roots (such as an abnormality in one of the vertebrae or discs), pain can be felt in the neck/back and all along the nerve.

Why Get an Epidural Steroid Injection?
Generally, patients come in about one half hour prior to the procedure. The procedure itself will take 15-20 minutes but the whole process of completing paperwork, changing clothes, performing the procedure, and recovery time will be about 1- 1 ½ hours. Patients usually can eat a light meal 4 hours prior to the procedure, and they can resume their normal eating habits after the procedure. Patients should bring their MRIs or CT scans of their spines, in case they need to be reviewed or referenced for the procedure. Patients should bring a driver with them since they may have numbness/tingling or weakness in their arms or legs from the anesthetic used in the procedure and for emotional support regarding the procedure itself. Patients should plan on returning home with their driver after the procedure and not perform any activities that are too strenuous. Patients can resume their regular activities, including work the day after the procedure. Patients can resume their usual medications at home, including anticoagulation after the injection. Physical therapy can be resumed about a week after the injection.

How Are Epidural Steroid Injections Performed?
What Happens After the Injection?
What Are The Types of Epidural Steroid Injection Approaches?
The steroid will usually begin working within 1-3 days, but in some cases it can take up to a week or two to feel the benefits. Although uncommon, some patients will experience an increase in their usual pain for several days following the procedure. The steroids are generally very well tolerated, however, some patients may experience side effects, including a ‘steroid flare or flush’ (flushing of the face and chest that can last several days and can be accompanied by a feeling of warmth or even a low grade increase in temperature), anxiety, trouble sleeping, changes in menstrual cycle, or temporary water retention. These side effects are usually mild and will often resolve within a few days. If you are diabetic, have an allergy to contrast dyes, or have other serious medical conditions, you should discuss these with your doctor prior to the injection.

Epidural steroid injections have been performed for many decades, and are generally considered as a very safe and effective treatment for back and leg pain or neck and arm pain. Serious complications are rare, but could include allergic reaction, bleeding, infection, nerve damage, or paralysis. When performed by an experienced physician using fluoroscopic guidance, the risk of experiencing a serious complication is minimized. Overall, ESIs are usually very well tolerated and most patients do well.

Although not everyone obtains pain relief with ESIs, often the injections can provide you with improvement in pain and function that last several months or longer (6-12 weeks). If you get significant benefit, the injections can be safely repeated periodically to maintain the improvements. Patients who do get better may not get complete relief of their pain. A realistic goal is to achieve a major reduction in the level of pain.
Injections are also commonly coupled with other treatments (medications, physical therapy, etc) in an attempt to either maximize the benefit or prolong the effects.

Narrowing of the spinal passages can occur from a variety of causes, including disc herniations, bone spurs, thickening of the ligaments in the spine, joint cysts, or even abnormal alignment of the vertebrae (‘slipped vertebrae’, also known as spondylolisthesis). The epidural space is a fat filled ‘sleeve’ that surrounds the spinal sac and provides cushioning for the nerves and spinal cord. Steroids (‘cortisone’) placed into the epidural space have a very potent anti-inflammatory action that can decrease pain and allow patients to improve function. Although steroids do not change the underlying condition, they can break the cycle of pain and inflammation and allow the body to compensate for the condition. In this way, the injections can provide benefits that outlast the effects of the steroid itself. An epidural steroid injection may be an effective non-surgical treatment option.

ESIs can also help determine the cause of symptoms and aid in diagnosis of certain spine conditions. By placing the medicine in a precise area and monitoring the patient’s response, valuable information is gained about what nerves may or may not be involved in causing the symptoms and how to target appropriate treatment.

What Are The Risks?
Spine injections should only be done by doctors with special training. Before the ESI procedure, the doctor will get detailed pictures of the spine using MRI or CT scan, which will help determine the best approach. Typically, the patient lies face down on a table. Numbing medicine is injected into the skin. Contrast dye is injected into the area so that the structures will be visible on X-ray. Using X-ray guidance, the doctor then guides the needles to the proper location and then places the steroid medication into the precise area believed to be causing the problem. Several different steroid preparations may be used, with or without local anesthetic, to increase the volume and ensure the spread of medication to all areas causing pain. The procedure takes about 15-20 minutes. The patient is then observed for 20-30 minutes before going home. The arms or legs can be weak for a brief time after the procedure because of the numbing medicine, so patients are asked not to drive themselves home and to take care when moving about for the rest of the day. Patients may have slight discomfort for a few days after the procedure, before they begin to feel the benefits of pain relief.

There are a few contraindications to performing lumbosacral epidural steroid injections, including bleeding disorder, anticoagulation, and allergy to medications. Other contraindications include pregnancy and the inability to be positioned horizontally or to “lie prone”. Diabetes and congestive heart failure require caution by the doctor performing the procedure. The current use of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) is not an absolute contraindication, but some physicians opt to have their patients stop using these medications up to 7 days before the planned injection in order to reverse the antiplatelet effect, depending on the physician’s preference. Patients using anticoagulation or “blood thinners” for a cardiovascular disorder or stroke risk must stop these medications 2-7 days prior to the injection depending on specific anticoagulation medication they are taking. Having an ESI while actively taking an anticoagulation medication leads to risk of hematoma, which leads to risk of nerve injury and possible paralysis.

Although all precautions are taken and incidence is low, infections may be introduced by any needle stick. More common temporary side effects include bleeding, headaches, and flushing. Patients with diabetes may have a temporary increase in their blood sugar. This should be discussed with your physician prior to the procedure. Patients may also experience a temporary numbness and tingling from the anesthetics used.

If you are a potential candidate for an epidural steroid injection, it is important to note that the risks of an injection are usually outweighed by the pain relief and positive outcome of the procedure.

It is important to talk with your doctor about your personal medical history even though complications are uncommon and usually temporary, and serious complications are rare.

There are three common methods for delivering steroid into the epidural space: the interlaminar, caudal, and transforaminal approaches. All three approaches entail placing a thin needle into position using fluoroscopic (x-ray) guidance. Prior to the injection of steroid, contrast dye is used to confirm that the medication is traveling into the desired area. Often, local anesthetic is added along with the steroid to provide temporary pain relief.

An interlaminar ESI, often referred to simply as an ‘epidural injection’, involves placing the needle into the back of the epidural space and delivering the steroid over a wider area. Similarly, the caudal approach uses the sacral hiatus (a small boney opening just above the tailbone) to allow for needle placement into the very bottom of the epidural space. With both approaches, the steroid will often spread over several spinal segments and cover both sides of the spinal canal. With a transforaminal ESI, often referred to as a ‘nerve block’, the needle is placed alongside the nerve as it exits the spine and medication is placed into the ‘nerve sleeve’. The medication then travels up the sleeve and into the epidural space from the side. This allows for a more concentrated delivery of steroid into one affected area (usually one segment and one side). Transforaminal ESIs can also be modified slightly to allow for more specific coverage of a single nerve and can provide diagnostic benefit, in addition to improved pain and function.

All three procedures are performed on an outpatient basis, and you can usually return to your pre-injection level of activities the following day. Some patients request mild sedation for the procedure, but many patients undergo the injection using only local anesthetic at the skin.

Common Misconceptions about ESI
Is any preparation required prior to the procedure? Can I eat before and after my procedure?
Frequency of the procedure.
Many people think that ESI must be done three times in order to work, or that three times is the maximum number of treatments that can be given. Both are incorrect. Some patients get relief after one or two treatments, others need more. Your doctor can give you more information on how many treatments you may need.

An epidural – like in childbirth?
No. An epidural steroid injection is not the same thing as epidural anesthesia used in labor and delivery, or for certain surgeries.

Number of “sticks.”
People who may have had epidural anesthesia – for childbirth or for a surgical procedure – may be concerned about the discomfort associated with multiple needle sticks to the back. Unlike epidural anesthesia, ESI is done under X-ray guidance. This means the doctor can see exactly where to place the injection, eliminating the need for multiple sticks. Headaches, and other complications sometimes seen with epidural anesthesia, are rare following ESI using X-ray guidance.