Overview

An epidural steroid injection (ESI) is a minimally invasive procedure that can help relieve neck, arm, back, and leg pain caused by inflamed spinal nerves. ESI may be performed to relieve pain caused by spinal stenosis, spondylolysis, or disc herniation. Medicines are delivered to the spinal nerve through the epidural space, the area between the protective covering of the spinal nerves and bony vertebrae. Pain relief may last for several days or even years. The goal is to reduce pain so that you may resume normal activities and a physical therapy program.

Epidural injections can help control back pain and inflammation, which is especially helpful for people suffering from a bulging disc in the neck or back. When combined with oral medications and physical therapy, the injections can provide enough relief from bulging disc symptoms for the patient to resume normal daily activities in a relatively short amount of time.

If you are suffering from the chronic pain of a bulging disc, you are probably actively searching for a treatment that will take away the pain and help you avoid spine surgery, if at all possible. You should consult your doctor about starting a regimen of epidural injections to help reduce your pain, so you can get back to the active lifestyle you enjoy.

Epidural steroid injections deliver medication directly (or very near) the source of pain generation. In contrast, oral steroids and painkillers have a dispersed, less-focused impact and may have unacceptable side effects. Additionally, since the vast majority of pain stems from chemical inflammation, an epidural steroid injection can help control local inflammation while also “flushing out” inflammatory proteins and chemicals from the local area that may contribute to and exacerbate pain.

What Is An Epidural Steroid Injection (ESI)?

A steroid injection includes both a corticosteroid (e.g., triamcinolone, methyl-prednisolone, dexamethasone) and an anesthetic numbing agent (e.g., lidocaine or bupivacaine). The drugs are delivered into the epidural space of the spine, which is the area between the protective covering (dura) of the spinal cord and nerves and the bony vertebrae.

An epidural steroid injection delivers steroids directly into the epidural space in the spine. Sometimes additional fluid (local anesthetic and/or a normal saline solution) is used to help ‘flush out’ inflammatory mediators from around the area that may be a source of pain.

The epidural space encircles the dural sac and is filled with fat and small blood vessels. The dural sac surrounds the spinal cord, nerve roots, and cerebrospinal fluid (the fluid that the nerve roots are bathed in).

Typically, a solution containing cortisone (steroid) with local anesthetic (lidocaine or bupivacaine), and/or saline is used.

• A steroid, or cortisone, is usually injected as an anti-inflammatory agent. Inflammation is a common component of many low back conditions and reducing inflammation helps reduce pain. Triamcinolone acetonide, Dexamethasone, and Methylprednisolone acetate are commonly used steroids.
• Lidocaine (also referred to as Xylocaine) is a fast-acting local anesthetic used for temporary pain relief. Bupivacaine, a longer lasting medication, may also be used. Although primarily used for pain relief, these local anesthetics also act as ‘flushing’ agents to dilute the chemical or immunologic agents that promote inflammation.
• Saline is used to dilute the local anesthetic or as a ‘flushing’ agent to dilute the chemical or immunologic agents that promote inflammation.

Epidural injections are often used to treat radicular pain, also called sciatica, which is pain that radiates fromthe site of a pinched nerve in the low back to the area of the body aligned with that nerve, such as the back of the leg or into the foot. Inflammatory chemicals (e.g. substance P, PLA2, arachidonic acid, TNF-α, IL-1, and prostaglandin E2) and immunologic mediators can generate pain and are associated with common back problems such as lumbar disc herniation or facet joint arthritis. These conditions, as well as many others, provoke inflammation that in turn can cause significant nerve root irritation and swelling.

Steroids inhibit the inflammatory response caused by chemical and mechanical sources of pain. Steroids also work by reducing the activity of the immune system to react to inflammation associated with nerve or tissue damage. A typical immune response is the body generating white blood cells and chemicals to protect it against infection and foreign substances such as bacteria and viruses. Inhibiting the immune response with an epidural steroid injection can reduce the pain associated with inflammation.

Who Is A Candidate?

Patients with pain in the neck, arm, low back, or leg (sciatica) may benefit from ESI. Specifically, those with the following conditions:

• Spinal Stenosis: A narrowing of the spinal canal and nerve root canal can cause 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 (spondylolisthesis), it can compress the nerve roots causing pain.
• Herniated Disc: The gel-like material within the disc can bulge or rupture through a weak area in the surrounding wall (annulus). Irritation, pain, and swelling occur when this material squeezes out and comes in contact with a spinal nerve.
• Degenerative Disc: A breakdown or aging of the intervertebral disc causing collapse of the disc space, tears in the annulus, and growth of bone spurs.
• Sciatica: Pain that courses along the sciatic nerve in the buttocks and down the legs. It is usually caused by compression of the 5th lumbar or 1st sacral spinal nerve.
• Cysts: In the facet joint or the nerve root and can expand to squeeze spine structures.

Who Should Avoid Epidural Steroid Injections

ESI has proven helpful for some patients in the treatment of the above painful inflammatory conditions. ESI can also help 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 physical therapy. ESI should NOT be performed on people who have an infection or have bleeding problems (patient taking blood thinners (Coumadin, etc), or patients with a bleeding problem (hemophilia, etc)). The injection may slightly elevate the blood sugar levels in patients with diabetes. It may also temporarily elevate blood pressure and eye pressure for patients with glaucoma. You should discuss this with your physician. If you think you may be pregnant or are trying to get pregnant, please tell the doctor. Fluoroscopy x- rays used during the procedure may be harmful to the baby. Epidural steroid injections should also not be performed on patients whose pain could be related to a spinal tumor. If suspected, an MRI scan should be done prior to the injection to rule out a tumor. Injections may be done, but with caution, for patients with other potentially problematic conditions such as:

Allergies to the injected solution

Uncontrolled medical problems such as renal disease, congestive heart failure and diabetes because they may be complicated by the fluid retention that a small percentage of patients experience for a few days after the injections.

Use of high dose aspirin or other anti-platelet drugs (e.g. Ticlid, Plavix), all of which can cause bleeding from the procedure. These medications should be stopped prior to having an injection.

What Happens Before Treatment?

The doctor who will perform the procedure reviews your medical history and previous imaging studies to plan the best approach for the injections. Be prepared to ask any questions at this appointment. Patients who take take blood thinning medication (Coumadin, Heparin, Plavix, Ticlid, Fragmin, Orgaran, Lovenox, Innohep, high-dose aspirin) may need to stop taking it several days before the ESI. Discuss any medications with your doctors, including the one who prescribed the medication and the doctor who will perform the injection. The procedure is usually performed in an outpatient special procedure suite that has access to fluoroscopy. Make arrangements to have someone drive you to and from the office or outpatient center the day of the injection.

What Happens During Treatment?

The epidural steroid injection procedure takes place in a surgery center, hospital, or a physician’s clinic. Many types of physicians can be qualified to perform an epidural steroid injection, including an anesthesiologist, radiologist, neurologist, physiatrist, and surgeon. At the time of the procedure, you will be asked to sign consent forms, list medications you are presently taking, and if you have any allergies to medication. The procedure may last 15-45 minutes, followed by a recovery period. The goal is to inject the medication as close to the pain site as possible, using either transforaminal or interlaminar injection. The right type of injection depends on your condition and which procedure will likely produce the best results and the least discomfort or side effects.
Step 1: Prepare the Patient
The patient lies face down on an x-ray table. Local anesthetic is used to numb the treatment area. The patient experiences minimal discomfort throughout the procedure. The patient remains awake and aware during the procedure to provide feedback to the physician. A low dose sedative, such as Valium or Versed, is usually the only medication given for this procedure.
Step 2: Insert the Needle
With the aid of a fluoroscope (a special X-ray), the doctor directs a hollow needle through the skin and between the bony vertebrae into the epidural space. Fluoroscopy allows the doctor to watch the needle in real-time on the fluoroscope monitor, 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. There are two ways to deliver epidural steroid injections: transforaminal or interlaminar. The best method depends on the location and source of pain.

Transforaminal ESI (from the side). 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 confirm where the medication will flow when injected. This method treats one side at a time. It is preferred for patients who have undergone a previous spine surgery because it avoids any residual scars, bone grafts, metal rods, and screws.

Interlaminar ESI (from the back). The needle is placed between the lamina of two vertebrae directly from the middle of the back. Also called interlaminar, 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.

Step 3: Inject the Medication

Once the needle is in the proper position, contrast is injected to confirm the needle location. The epidural steroid solution is then injected. Although the steroid solution is injected slowly, most patients sense some pressure due to the amount of the solution used (which in lumber injections can range from 3mL to 10mL, depending on the approach and steroid used). The pressure of the injection is not generally painful. Following the injection, the patient is monitored for 15 to 20 minutes before being discharged home. Sedation is available for patient anxiety and comfort. However, sedatives are rarely necessary, as the epidural steroid injection procedure is usually not uncomfortable. If a sedative is used, some patient precautions should be taken, including not eating or drinking for several hours prior to the procedure and having a guardian available for discharge. A patient should contact his or her doctor for specific instructions. Tenderness at the needle insertion site can occur for a few hours after the procedure and can be treated by applying an ice pack for 10 to 15 minutes once or twice an hour. In addition, patients are usually asked to rest for the remainder of the day on which they have the epidural steroid injection. Normal activities (those that were done the week prior to the epidural injection) may typically be resumed the following day. A temporary increase in the pain can occur for several days after the injection due to the pressure of the fluid injected or due to local chemical irritation. Most patients can walk around immediately after the procedure. After being monitored for a short time, you usually can leave the office or suite. Someone must drive you home. Typically patients resume full activity the next day. Soreness around the injection site may be relieved by using ice and taking a mild analgesic (Tylenol). Patients should schedule a follow-up appointment with the referring or treating physician after the procedure to document the efficacy and address any concerns the patient may have for future treatments and expectations.

ESI Pain Relief Success Rate

Patients will find that the benefits of an epidural steroid injection include a reduction in pain, primarily in leg pain (also called sciatica or radicular pain). Patients seem to have a better response when the epidural steroid injections are coupled with an organized therapeutic exercise program.

Epidural Steroid Injection Success Rates

While the effects of an epidural steroid injection tend to be temporary (lasting from a week to up to a year) an epidural steroid injection can deliver substantial benefits for many patients experiencing low back pain.

When proper placement is made using fluoroscopic guidance and radiographic confirmation through the use of contrast, > 50% of patients receive some pain relief as a result of lumbar epidural steroid injections.

Pain relief is more often felt for primary radicular (leg) pain and, less prominently, low back pain.

The pain relief and control brought on by injections can improve a patient’s mental health and quality of life, minimize the need for painkiller use, and potentially delay or avoid surgery.

Success rates can vary depending on the condition that patient has and the degree of radicular leg pain that accompanies it:

Recent research reports that lumbar epidural steroid injections are successful in patients with persistent sciatica from lumbar disc herniation, with more than 80% of the injected group with disc herniation experiencing relief (in contrast to 48% of the group that received a saline placebo injection).

Similarly, in a study focused on a group of patients with lumbar spinal stenosis and related sciatica symptoms, 75% of patients receiving injections had more than 50% of pain reduction one year following the injections. The majority also increased their walking duration and tolerance for standing.

The minimally invasive approach to this surgery offers our patients a safer and effective alternative to traditional open back surgery and our patients have reported a patient satisfaction score of 96.

ESI: Risks And Side Effects

With few risks, ESI is considered an appropriate nonsurgical treatment for some patients. The potential risks associated with inserting the needle include spinal headache from a dural puncture, bleeding, infection, allergic reaction, and nerve damage / paralysis (rare). Corticosteroid side effects may cause weight gain, water retention, flushing (hot flashes), mood swings or insomnia, and elevated blood sugar levels in people with diabetes. Any numbness or mild muscle weakness usually resolves within 8 hours in the affected arm or leg (similar to the facial numbness experienced after dental work). Patients who are being treated for chronic conditions (e.g., heart disease, diabetes, rheumatoid arthritis) or those who cannot temporarily discontinue anti-clotting medications should consult their personal physician for a risk assessment.

Potential Risks Of Epidural Steroid Injections

As with all invasive medical procedures, there are potential risks associated with lumbar epidural steroid injections. In addition to temporary numbness of the bowels and bladder, the most common potential risks and complications include:

Infection. Severe infections are rare, occurring in 0.1% to 0.01% of injections. such as Osteomyelitis, a Spinal Infection.

Dural puncture (“wet tap”). A dural puncture occurs in 0.5% of injections. It may cause a post-dural puncture headache (also called a spinal headache) that usually improves within a few days. Although infrequent, a blood patch may be necessary to alleviate the headache. A blood patch is a simple, quick procedure that involves obtaining a small amount of blood from a patient from an arm vein and immediately injecting it into the epidural space to allow it to clot around the spinal sac and stop the leak.

Bleeding. Bleeding is a rare complication and is more common for patients with underlying bleeding disorders.

Nerve damage. While extremely rare, nerve damage can occur from direct trauma from the needle, or from infection or bleeding.