What are Epidural Steroid Injections?
Epidural Steroid Injections Performed by Las Vegas, Summerlin, and Henderson Nevada’s Top Pain Doctors
The first epidural injection was performed in 1885 by a neurologist named James Leonard Corning. Though this seminal procedure utilized the anesthetic agent cocaine, it was not until 1901 when the injection was performed with the primary goal of providing relief from pain. During this time, two separate physicians described utilizing solutions of cocaine that they injected into the sacral hiatus. The patients of these physicians were reported to be experiencing a form of radicular pain associated with a condition known as intractable sciatica. Interestingly, by 1930 caudal injections had received strong support for their use in providing pain relief. For the most part, these injections consisted of solutions of saline and local anesthetics. It wasn’t until 1953 when the use of corticosteroids in these injections began.
Watch an Epidural Steroid Injection – Performed Live!
Epidural steroid injections are now regarded as one of the most common procedures utilized today for the treatment of chronic and debilitating pain. In particular, epidural steroid injections have received large support for the successful treatment of radicular pain (i.e., pain that radiates from the spinal cord to the limbs).
A number of prevalence studies have estimated that up to 90% of individuals will, at some point throughout their lifetime, experience with pain that interferes with activities of daily functioning. In fact, according to the Center for Disease Control (CDC), chronic pain, particularly back pain, has been linked with significant individual disability that is likely to have detrimental impacts on the individual’s functioning both at home and at work. Thus, chronic pain is associated with deleterious economic impacts as well. Indeed, some estimates have suggested that back pain alone is associated with over $100 billion in costs per year and is considered to be the leading contributor to missed work, as well as the most common cause of employment-related disability. Chronic pain conditions are also to blame for decreased productivity at work and increases in health care utilization. It is for these reasons that physicians and researchers have been dedicated to finding effective treatments to provide relief to patients suffering from a pain condition. In fact, over the course of the last ten years there has been a significant increase in randomized controlled trials that seek to identify effective pain management treatments.
By far one of the most widely utilized treatments is the epidural steroid injection. This interventional treatment technique is a minimally invasive procedure used to treat patients with back and neck pain. In fact, the United States Department of Health and Human Services and the North American Spine Society endorsed epidural steroid injections as a critical tool in improving the quality of life in patients who suffer from cervical, lumbar, and radicular pain, and assisting them in returning to their normal levels of activity. In terms of pain conditions, back pain has received extensive attention within the literature, and many of the currently available interventions for managing back pain have undergone rigorous investigation before ultimately receiving empirical support.
Given the diversity in the underlying causes of pain, it is best to discuss your condition with your physician so as to determine the best available pain management treatment plan. Most patients treated with epidural steroid injections are expected to feel an immediate reduction or elimination of their pain following the treatment. According to a study examining the use of multiple injections, there is support for the benefit of administering multiple injections over the course of the year to patients whose pain initially only moderately responded to the steroid injection. Side effects of steroids include weight gain, mood swings, arthritis, and gastric ulcers.
Anatomy of the Spine
Vertebrae: The vertebral column is the structure that is primarily referred to when talking about the spine or the backbone. The vertebral column can be found in the dorsal region of the torso. In humans, there are 24 individual vertebrae and nine fused vertebrae that make up the vertebral column. These vertebrae are made of boney tissue, containing the centrum, and a number of arches protruding from the centrum.
Spinal column: The spinal column can be divided up into several different regions. Starting at the bottom, the sacral curve is made up of four coccygeal vertebrae that form the tailbone and the sacrum. Above the sacral curve is the lumbar curve that is made up of the next five vertebrae that form the lower back, or the lumbar region. Then it is the thoracic curve that contains 12 individual vertebrae and forms the middle to upper back region. Finally, at the top is the cervical curve that creates the neck region.
Spinal cord: The spinal cord can be found within the spinal column. It is a long bundle of nerves that transfers information to and from the brain. The spinal cord begins in the top of the spinal column, at the occipital bone, and runs down through the space between the first and second lumbar. Its primary functions are to transfer motor information, control motor movements, conduit sensory information, and control some reflexes. The spinal cord is a crucial part of the human anatomy; therefore, it is well protected by both the spinal column as well as various layers of tissue known as the spinal meninges.
Dura mater: Both the brain and the spinal cord are protected by thick membranes known as meninges. These membranes are the pia mater, the arachnoid mater, and the dura mater. The name dura mater translated from Latin means “tough mother.” This is an apt name for this membrane, as its primary responsibility is to protect the brain and spinal cord from possible injury. The dura mater is tough and relatively inflexible, and also acts to contain cerebrospinal fluid.
Epidural space: The epidural space is found in the outermost part of the spinal canal. It falls just outside of the dura mater and contains lymphatics, spinal nerve roots, fatty tissue, and a number of blood vessels. It runs from where the spinal column meets the bottom of the skull all the way down to the tip of the sacrum.
Nerve roots: The place where the nerve initially leaves the central nervous system can also be referred to as the nerve root. There are two primary types of nerve roots: the cranial nerve root and the spinal nerve root. Nerve roots can be the primary sources of pain should they become irritated or damaged. Damage to nerve roots can also result in paresis (i.e., muscle weakness or partial loss of movement) or paralysis (i.e., complete loss of muscle movement).
How is an Epidural Steroid Injection Performed?
Within the spinal canal, the spinal cord is surrounded by the cerebrospinal fluid, which acts as protective padding for the nerve bundle of the spinal cord. The spinal cord and the cerebrospinal fluid are held in place within the spinal canal by a durable membrane, known as the meninges. The epidural steroid injection is given within the epidural space. The epidural space is the area just outside of the durable membrane protecting the spinal cord. The spinal cord is encased within the spinal column, which is made up of individual vertebra. The vertebral column can be divided up into several different regions. Treatment can be tailored individually depending on where the patient reports experiencing the pain.
Prior to the procedure, the patient’s skin is cleaned and prepped for the injection. If IV sedation is used, vital signs (blood pressure, heart rate, and breathing) will be monitored throughout the procedure. During the procedure the patient is asked to lie on their stomach, with their back toward the physician. Only topical anaesthetic is used on the surface of the skin prior to the injection. Using a fluoroscopic device, or an x-ray, as a guide for proper placement into the epidural space, the physician inserts the needle into the vertebrae. Contrast dye is used to test for proper placement of the needle prior to injecting the steroids, as well as appropriate distribution of the solution within the area of interest. Once proper placement has been assured, the physician administers the steroids. Moreover, steroids are administered only in the areas with the most inflammation. This reduces the amount of exposure the patient has to the steroids. The full procedure for an epidural steroid injection takes approximately fifteen minutes.
There are three types of epidural steroid injections available:
- Interlaminar: This is the most common approach and involves placement of the needle between the lamina of the two vertebrae in the middle of the back. The steroid medication along with the anesthetic is delivered to the nerves on both the right and left sides of the spine. The majority of studies examining the effectiveness of epidural steroid injections delivered at the interlaminar site have been conducted on patients with radicular pain that results from a herniated disc. Other studies examining the effectiveness of interlaminar injections have included patients with pain associated with spinal stenosis, axial back pain that does not result from a herniated disc, and failed back surgery. The advantage of this technique is that it is more targeted than the caudal injection. Thus, the pain relieving medication has a higher likelihood of reaching the adjacent spinal levels, which provides the benefit of treating bilateral pain. Less medication is also needed for interlaminar injections than a caudal site injection. However, there is an increased risk of dural puncture with the interlaminar site injection.
Must Watch Video – Transforaminal Steroid Injections
- Transforaminal: During this type of injection, the needle is placed to the side of the vertebra in the neural foramen above the opening of the nerve root in the epidural space, similar to the interlaminar approach. This method treats one side at a time, and is frequently used in patients with a history of back surgery since it avoids any bone grafts, surgical pins, or rods that may be present. Given that this particular type of injection requires that the needle be placed within the empty space on either side of the spinal column, the procedure requires the use of a fluoroscope. The fluoroscope is used to provide guidance to the physician on where to place the needle. Similar to the interlaminar approach, this injection site is more targeted. Conversely, there is less risk of dural puncture with the transforaminal injection than with the interlaminar approach. Previous studies have suggested that the transforaminal injection has better efficacy for treating spinal pain related to neuropathy when compared to both the caudal and the interlaminar injection procedures.
- Caudal: During this injection, the needle is inserted in the sacral canal area near the tailbone. Because of the size of the sacral canal, this approach allows large amounts of steroid medication to be delivered into the epidural space. In fact, the sacral hiatus is the most direct route into the epidural space. There are some benefits particularly associated with the caudal injection. One primary advantage includes a reduction in risk of dural puncture with this procedure, which is due to the distance from the thecal sac. Thus, this procedure is recommended for patients who are at risk for dural puncture, as well as neurological complications. Meta-analyses have provided some support for the pain relieving benefits of this injection. In fact, studies have shown that caudal injections can provide both short-term and long-term benefits for managing back pain and leg pain that results from a herniated disc. While there is less evidence, epidural steroid injections at the caudal site have also been shown to be beneficial for treating discogenic pain, and pain that is associated with spinal surgery and spinal stenosis. The down side, however, is that caudal epidural steroid injections provide less targeted pain relief than the transforaminal or interlaminar approaches.
Strong evidence supporting favorable outcomes on pain relief exists concerning all three methods of epidural steroid injections. In fact, many patients notice pain relief shortly after the injection. In some patients, the pain relief is short-term, and in others, it could last for several years. The precise reason as to why a patient may experience long-term pain relief over another patient whose pain returns after a brief period of being pain-free is unknown. In some cases, a series of one to two additional injections may be needed to achieve full effect. The interval between injections is at least two weeks and will be scheduled after your pain specialist assesses your situation. To date there are no known studies examining the ideal number of epidural steroid injections for relieving chronic pain. In fact, there is some controversy within the literature. More specifically, some studies report that there is no added benefit to receiving multiple injections. These studies conclude that the number of repeated injections necessary should be tailored to each individual case, particularly in cases where the patient initially experienced a positive response to the injection.
If you are experiencing problematic symptoms of pain, it is recommended that you discuss your worries and concerns with a physician. Your physician will be able to answer your questions about chronic pain and the treatment options available. In addition, your physician will likely provide you with a lot of information and educational resources about your condition. If your pain is not severe and is not causing you any significant impairment, it is likely that your physician will encourage you to make a gradual return to the typical levels of activity maintained prior to the onset of pain. Previous work in the field of back and neck pain has suggested that up to 90% of all patients will see significant improvements in their symptoms of pain by engaging in conservative treatments, such as physical therapy. However, if your pain is chronic in nature and has not responded to typical interventions, your physician may recommend epidural steroid injections.
Benefits of Epidural Steroid Injections
For many medical procedures the efficacy of the treatment is based on a number of factors. This is also true for epidural steroid injections. Factors such as the physician’s expertise and training, duration of the symptoms, or the underlying cause of symptoms can all impact the effectiveness of the procedure and the patient’s prognosis in terms of their pain condition. In general, studies have indicated that patients who report the highest response rate to the epidural injection are patients who have been experiencing symptoms for less than three months.
The goal of epidural steroid injections is pain relief. The primary benefit of this intervention is that it is quick and relatively painless. The procedure can even be performed on an outpatient basis, making epidural steroid injections the ideal alternative to surgery for the relief of many different pain conditions, including acute and chronic conditions. Further, in addition to providing patients with relief from the distressing symptoms of pain, treatment interventions are focused on reducing the level of impairment pain has on the patient’s life, as well as any accompanying disability. For instance, for patients who have had to take a leave of absence from their job owing to their pain, it is likely that a goal of treatment will be to have the patient return to work. Reaching the status of disability can be an exacerbating factor, by acting like a feedback loop. If an individual, debilitated by severe and chronic pain, does not make efforts to maintain some mobility they are risk for maintaining their own symptoms of pain.
Risks and Side Effects of Epidural Steroid Injections
Epidural steroid injections are regarded as generally safe procedures that can be conducted in an outpatient setting and have the benefit of providing patients with almost immediate relief from chronic and debilitating pain. However, as with all medical procedures, epidural spinal injections come with some risk of complication.
More specifically, in relatively few cases, these injections have been shown to cause:
- A period of several days where the patient experiences a flushing of the face and chest that is accompanied by the feeling of warmth and overall rise in temperature. This is known as the steroid flush.
- Difficulty falling asleep, staying asleep, or complaints of restless or unsatisfying sleep
- Mood swings
- Elevated blood sugar
- Water retention
- A period of several days where the patient experiences a temporary increase in pain
- Hot flashes
In some cases, numbness in the affected leg or arm may occur, but usually disappears within eight hours. Serious side effects resulting from epidural steroid injections are generally rare. These can include serious allergic reaction, bleeding, nerve damage, infection, and paralysis. Epidural steroid injections have been implicated in the onset of meningitis in a very small number of cases.
There are some individuals who are at increased risk for complications from epidural steroid injections and it is recommended that these individuals attempt alternative interventions for managing their symptoms of pain. Individuals who are at serious risk for complications resulting from the procedure and who should avoid epidural steroid injections are those who have uncontrolled blood pressure or diabetes, take blood-thinners or have a bleeding disorder, have unstable angina or congestive heart failure, have a known allergy to steroids, or who have an active infection.
Long-term effects of steroid injections, however, are not as clear. Some patients have experienced long-term benefits from the injection, while others have not. Given that these injections are safe, patients who did not enjoy long-term relief from their pain are able to receive multiple treatments over the course of a year for managing their pain.
Mechanisms of Action
There is some controversy about the mechanisms behind the analgesic benefits of epidural steroid injections. In fact, some researchers have argued that the corticosteroids are not the primary source of pain relief. Notwithstanding, the corticosteroids used in these injections are thought to provide pain relief owing to their inhibitory action on the enzymes involved in inflammation. Thus, corticosteroids block the chemicals that lead to inflammation, which is believed to be the primary source of pain in many conditions. Further, steroids have other properties beyond their anti-inflammatory characteristics that also likely play a role in their effectiveness against nerve pain. For example, steroids stabilize nerve membranes and inhibit the conductance of ions, both of which are also viable explanations for the relief of pain symptoms.
In terms of the non-steroidal mechanisms of action, it may be that the injection itself increases the blood flow to several nerve roots. This increase in blood flow is thought to slow down or suppress the transmission of pain information. Further, the solutions administered during this procedure can have cleansing effects on the injured neurons. In other words, the solutions can clear out any chemicals associated with the inflammation, thereby causing the reverse effect.
Factors Related to Poor Outcome
There are a number of factors related to poor outcome in patients who are treated with epidural steroid injections. These factors act to reduce the effectiveness of the injection, as well as increase the risk for a reoccurrence of pain. Specifically, these factors include smoking, low education, poor job satisfaction, co-existing pain complaints, somatization, poor coping skills, catastrophization, high baseline pain scores and disability, previous treatment failures, opioid use, fear avoidance behavior, secondary gain, previous spine surgery, high pain sensitivity, constant pain not increased by activity, negative or pessimistic beliefs, anxiety disorder, depression, and older age.
Conditions Related to Epidural Steroid Injections
There are a number of conditions that are expected to benefit from epidural steroid injections. Your physician must ensure an accurate identification of any existing underlying conditions prior to making any treatment recommendations. The assessment of pain will likely include a brief yet detailed history, gathered by your physician. The goal of this is to ensure an accurate diagnosis of the source of the pain that may determine in which specific location the injection needs to be administered. In many cases, the precise cause is not identified. In these instances, the physician will ensure that certain diagnoses are ruled out. Specifically, in terms of low back pain, the physician will be sure to rule out any specific spinal pathology and nerve root pain. Your physician will also generally assess for your degree of risk for persistent difficulties. These factors, also known as “yellow flags” will provide the physician with the information necessary to determine the most appropriate treatment and follow-up plan.
Almost everyone experiences some sort of back pain at some time during their lives. Back and neck pain can arise from a number of sources, based on the anatomy of the neck. Many cases of back and neck pain originate because of a degenerative process or pathology. Damage to muscles, joints, or ligaments that comprise the spinal region can also be the main source of both acute and chronic pain. Despite this, there are a number of cases of back and neck pain where physicians are unable to locate the precise source of the pain.
In general, back and neck pain is characterized by sensations of pain and discomfort that arise in the back and may radiate out toward the limbs. The specific symptoms or sensations of pain are widely varied. Some patients will experience the pain as a highly specific sharp stab, while others will describe the pain as more generalized and widespread. Further, the symptoms of back and neck pain are expected to fluctuate over time. For instance, often dependent on environmental circumstances, a patient may fluctuate in and out of recurring symptoms and exacerbations of pain.
While the specific symptom clusters generally depend on the underlying cause, some common complaints include:
- Muscle spasms
- Radiating pain
- Tingling, numbness, or weakness
- Sensitivity to touch or pressure
Patients with chronic pain conditions that do not respond to traditional pain relieving techniques may be excellent candidates for epidural steroid injections. Further, patients who suffer from the following list of conditions are potential candidates for epidural steroid injections:
- Herniated disc: A condition characterized by damaged intervertebral discs, causing them to bulge or break. This is more common in aging individuals and is a frequent cause of low back pain.
- Osteoarthritis: A chronic condition associated with cartilage damage. This damage can be the result of wear and tear across a number of years or as the result of a specific injury. If the cartilage sustains enough damage, there is a high risk of bone rubbing directly onto bone.
- Spondylolisthesis: Spondylolysis refers to the degenerative process of the spine. It is a condition occurring when the vertebrae becomes dislocated and “slip” over another. It is often referred to under nonspecific low back pain, because a large portion of patients with this anatomical deformity do not present with any related symptoms, including pain. During spondylolysis, the nerves around the weakened and slipped vertebra can become compressed. Prevalence rates of this condition within the general population are around 5%.
- Whiplash: A common cause of neck pain, whiplash is caused by sudden back-and-forth jolting movements in the neck, usually experienced in motor vehicle accidents, or rollercoaster rides. While not fatal, whiplash can result in chronic pain. This is due to damage caused to the muscles, main ligaments and cervical vertebrae as a result of the unnatural whipping forward and subsequent jerking backward of the head.
- Spinal stenosis: A condition characterized by a restriction of the spinal canal that is caused by a narrowing of the spinal column. People with spinal stenosis often experience pain while walking.
- Fractured vertebrae: Damaged vertebrae typically caused by extreme force.
- Spinal deformities: These are genetically linked problems that relate to the curvature of the spine (e.g., scoliosis or kyphosis), and generally involve the entire spine. These difficulties are relatively uncommon. Recent prevalence rates are not available; however, early estimates suggest that spinal deformities occur in about 0.8% to 1.9% of the general population.
- Compression fractures: There is a higher prevalence of this among post-menopausal women with osteoporosis and in those who have had long-term corticosteroid use. One study examining 7,000 women over the age of 65 found that 5% had sustained a compression fracture of a vertebra over the course of a four-year period. Previous evidence suggests that approximately 4% of adults seen in primary care settings can attribute their symptoms of back pain to a compression fracture.
- Infections within the spine: In some instances, cases of back pain can be attributable to a disease that has infected the spine. Spinal infection should always be considered in cases of back pain in conjunction with high fever or if the patient has recently undergone surgery, has a compromised immune system, or is a regular drug user.
- Degenerative disc disease: Degenerative disc disease is a condition related to the changes that occur within the intervertebral discs as people age. This aging of the intervertebral disc can cause tears that are believed to be the source of the pain associated with degenerative disc disease. The pain associated with this particular disease can occur throughout the spine; however, in some instances, the pain was reported to be localized to the affected intervertebral disc.
- Lumbar radiculopathy: Lumbar radiculopathy, also known as sciatica, occurs when a herniated disc (typically between the 5th lumbar (L5) and the 1st sacral spinal nerve (S1)) pushes against a nerve. This pain travels down the leg.
- Cervical radiculopathy: Cervical radioculopathy occurs when a disc in the neck is pushing against a nerve, which causes pain to travel down the arms.
- Failed back surgery: Some patients suffer from low back pain as the result of back surgery. These cases are recognized as failed back surgery because the goal of the original surgery was to provide the patient with relief from pain. In these cases, pain in the lower back is caused by scar tissue that develops around the spinal nerves of the epidural space following surgery.
Epidural steroid injections can provide therapeutic benefits in all of the above inflammatory conditions. The American Society of Interventional Pain Physicians has published an analysis of current evidence that supports this view. The researchers in this review stated that there is powerful evidence that epidural steroid injections are effective in the management of both lumbar and cervical pain. Along with their known therapeutic advantages, epidural steroid injections are also valued for their diagnostic capability. The pain relief gained from epidural injections helps confirm the source of the pain in the epidural space where the injection takes place.
Current research indicates that a successful epidural injection can prevent premature or unwarranted surgeries. During a prospective, multicenter study, known as the Spine Patient Outcomes Research Trial (SPORT), patients with herniated discs who had previous epidural steroid injections were compared to patients with herniated discs who did not receive the procedure. The results showed that 56% of the patients who had epidural steroid injections opted to not get surgical decompression compared to just 19% in the patients who did not receive any epidural steroid injections.
Chronic pain is a serious public health concern. It has been suggested that up to 90% of the population will experience a pain condition at some point in their lifetime that interferes with their daily functioning. In fact, some estimates have suggested that back pain alone is associated with annual costs exceeding $100 billion, including medical expenses and loss of productivity. There are a number of treatments available to provide patients with relief from chronic pain. In particular, epidural steroid injections have been the most widely used interventional treatment for the relief of pain originating from the nerves in the spine.
Epidural steroid injections are a safe procedure intended to be a viable non-surgical option to help relieve pain. The injections are relatively quick and painless, and can be done on an outpatient basis. Indeed, a large number of patients have reported that they benefited from a reduction in their pain almost immediately following the treatment. Moreover, patients are able to return to their daily activities without significant recovery time. The procedure has been well documented as effective in the treatment of both cervical and lumbar pain conditions. Epidural steroid injections have also received support for the treatment of radicular pain, which affects the nerves that extend out from the spinal canal causing the pain to feel as though it is radiating out to the patient’s arm or leg. Steroid injections are believed to be effective due to their anti-inflammatory qualities but the literature is still unclear. Other mechanisms for the pain relieving benefits associated with this procedure have been implicated and include increased blood flow to the nerve roots and the cleansing of inflammatory cytokines by the saline solution. Side affects of steroids include weight gain, mood swings, arthritis, and gastric ulcers.
Given the diversity in the underlying causes of pain, it is best to discuss your condition with your physician so as to determine the best available pain management treatment plan. It is generally recommended that patients attempt more conservative methods of pain relief before they are good candidates for the interventional methods, such as steroid injections. If you have a chronic pain condition that has not responded to more traditional methods of pain relief, you may be an appropriate candidate for epidural steroid injections. Most patients treated with epidural steroid injections are expected to feel an immediate reduction or elimination of their pain following the treatment, despite not receiving relief from other methods. Some patients do not experience complete relief from pain following just one injection. In these instances, it is not uncommon for the physician to recommend multiple injections. According to a study examining the use of multiple injections, there is some support for the benefit of administering multiple injections over the course of one year to patients whose pain initially only moderately responses to the steroid injection.
- Bicket MC, Gupta A, Brown CH, Cohen SP. Epidural injections for spinal pain: A systematic review and meta-analysis evaluating the “control” injections in randomized controlled trials. Anesthesiology. 2013;119(4):907-31.
- Boswell M, Hansen H, Trescot A, Hirsch J. Epidural Steroids in the management of chronic spinal pain. Pain Physician. 2003;6:319–334.
- Boswell MV, Trescot AM, Datta S, et al. Interventional techniques: evidence-based practice guidelines in the management of chronic spinal pain. American Society of Interventional Pain Physicians. Pain Physician. 2007;10(1):7-111.
- Cohen SP, Bicket MC, Jamison D, Wilkinson I, Rathmell JP. Epidural Steroids: A comprehensive, evidence-based review. Reg Anesth Pain Med. 2013;38:175-200.
- Colimon F, Villalobos F. Epidural steroid injections: Evidence and technical aspects. Techniques in Regional Anesthesia and Pain Management. 2010;14:113-119.
- Collighan N, Gupta S. Epidural steroids. Brit J Anaesth. 2010;10(1):1-5.
- Fish D, Kobayashi H, Chang T, Pham Q. MRI prediction of therapeutic response to epidural steroid injection in patients with cervical radiculopathy. Am J Phys Med Rehabil. 2009;3:239–246.
- Ghai B, Vadajae KS, Wig J, Dhillon MS. Lateral parasagittal verses midline interlaminar lumbar epidural steroid injection for management of low back pain with lumbosacral radicular pain: A double-blind randomized study. Anesth Analg 2013;117(1):219-227.
- Huston CW. Cervical epidural steroid injections in the management of cervical radiculitis: Interlaminar versus transforaminal. A review. Curr Rev Musculoskelet Med. 2009;2(1):30-42.
- Kwon JW, Lee JW, Kim SH, Choi JY, Yeom JS, Kim HJ, Kwack KS, Moon SG, Jun WS, Kang HS. Cervical interlaminar epidural steroid injection for neck pain and cervical radiculopathy: effect and prognostic factors. Skeletal Radiol. 2007;36(5):431-6.
- Livingston, E, Lynn C. Steroid injections to treat pain. JAMA. 2012;308(19):2047.
- Manchikanti L, Buenaventura R, Manhcikanti K, et al. Effectiveness of therapeutic lumbar transforaminal epidural steroid injections in managing lumbar spinal pain. Pain Physician. 2012;15:E199–E245.
- Pasqualucci A, Varrassi G, Braschi A, et al. Epidural local anesthetic plus corticosteroid for the treatment of cervical brachial radicular pain: Single injection versus continuous Infusion. Clin J Pain. 2007;23(7):551-7.