Lumbar Epidural Steroid Injections
Epidural injections for pain relief emerged in 1901. The first epidural injection performed used cocaine to relieve pain that was suspected to emerge from the lumbar nerve roots. Between the 1920s and 1940s, epidural injections contained mostly saline and a local anesthetic agent. The use of corticosteroids in epidural steroid injections began in 1952. The corticosteroid used during this procedure is a synthetic, man-made drug whose function is similar to that of cortisol.
Currently, epidural steroid injections are widely used both in diagnosing and treating neuropathic pain. Lumbar epidural steroid injections, in particular, are performed in the lumbar region of the lower back in order to treat pain that occurs within the lower back and legs. More specifically, corticosteroids are injected into the epidural space surrounding the spinal nerves of the lumbar region. This medication functions to reduce pain and inflammation within the area. The procedure itself is minimally invasive and does not require surgery.
The short-term efficacy of lumbar epidural steroid injections has been well documented. Moreover, this procedure has been accepted as an effective treatment option for both radicular and back pain by the United States Department of Health and Human Services and the North American Spine Society. The long-term effectiveness of this procedure is not as clear, however, and more studies are warranted.
The lumbar epidural steroid injection provides some benefits over steroids that are administered orally or other orally dispensed analgesics, such as non-steroidal anti-inflammatory drugs (NSAIDs), as the medication is delivered directly to the affected area. Additionally, successfully completed lumbar epidural steroid injections may also reduce concomitant symptoms of numbness or tingling sensations.
Though quite rare, there is some risk for potential complications associated with the lumbar epidural steroid injection procedure. As with other epidural injections, there is a risk for minor bleeding at the site of the injection, infection, spinal headache, and temporary leg weakness.
In addition, there is a specific risk for additional complications with regard to the lumbar procedure. The more commonly occurring of these include:
Backache or a postural puncture headache (occurs in between 0.5 and 1% of patients receiving lumbar injections)
Dizziness, neurocardiogenic syncope, nausea, or even vomiting
Bleeding at the trajectory of the injection
Injury to the nerve root
During the lumbar epidural steroid injection procedure, the patient is placed in the prone position on the X-ray table (i.e., lying face down flat on the table). Some physicians or pain specialists will have the patient place a small pillow under their stomach, which places a slight curve in the lower back. The surface of the skin in the area of the injection is thoroughly cleansed and sterilized. For most procedures, only a topical local anesthetic is required; however, a small portion of patients may feel too uncomfortable and request that they be sedated for the procedure.
The physician will begin by inserting a fluoroscope device into the back, which transmits a video image of the internal structures on to a computer screen. This device is then used as a guide for the physician to ensure proper placement of the injection needle into the affected area. Contrast dye can also be injected in order to confirm placement, as well as to assess the degree of medication distribution.
When the physician has assured correct placement of the injection needle, the steroid solution is injected. In some instances, the patient will report sensations of pressure that are not painful, owing to the build-up of fluid. Once the procedure has been completed, the patient is held for observation for approximately 15 to 20 minutes and is then discharged home.
In terms of needle placement, there are three different methods for performing a lumbar epidural steroid injection, which include:
Interlaminar: Needle is placed between the lamina and vertebrae of the middle back and the corticosteroid solution is delivered on either side of the spine
Transforaminal: Needle is placed into the neural foramen on the side of the vertebrae and the corticosteroid solution is delivered only to one side of the spine
Caudal: Needle is placed in the area of the large sacral canal at the tailbone
The lumbar epidural steroid injection can be effective in managing many forms of acute and chronic pain that occur within the lower back or limbs. In particular, this procedure is most effective in conditions that arise as the result of damage or irritation and inflammation of the nerves within the lumbar region.
Some common pain conditions that are treated using lumbar epidural steroid injections include:
Synovial cysts: This condition occurs as the result of cysts that form within the facet joint or in the area of the nerve root. These cysts may cause compression of the structures of the spine, which can lead to nerve pain.
Lumbar radiculopathy: This is a specific type of pain that emerges as the result of compression or inflammation of the spinal nerves. This pain is unique in that it radiates from the lower back region, down through the back of the leg, into the calf or foot.
Degenerative disc disease: This condition occurs when nerve bundles of the spine are impinged as the result of an irritated or damaged and inflamed intervertebral disc. This compression of the nerve tissue causes it to become irritated and transmit exaggerated signals of pain back to the spinal cord and brain.
Herniated disc: Similar to intervertebral disc degeneration, herniated discs occur when the intervertebral disc bulges or even ruptures and thereby places compression on the nearby spinal nerves, causing them to send exaggerated signals of pain to the spinal cord and brain.
Spinal stenosis: This condition occurs as the result of a narrowing of the spinal canal, which places pressure on the nerves inside the passageway.
Spondylosis: This condition occurs as the result of a defect in the link between the vertebrae that make up the spinal column. Over time, this defect can lead to degeneration of the structures that make up the spine and even stress fractures.
Epidural steroid injections have been used to effectively treat neuropathic pain since 1952. Lumbar epidural injections, in particular, can provide patients suffering from chronic or acute lower back and leg pain with some relief from their symptoms. The procedure is minimally invasive and does not require surgery. Previous studies have supported the short-term effectiveness of these injections; however, more work is necessary to examine the long-term benefits of the procedure.