Epidural Injections are a common treatment option for many forms of neck and back pain and arm or leg pain. They have been used for spinal problems for decades and are still an integral part of the non-surgical management of radiculopathy and neck and back pain. The main goal of the injection is pain relief. At times the injection alone is sufficient to provide relief, but commonly an epidural steroid injection is used in combination with a comprehensive rehabilitation program to provide additional benefit.
An epidural can be very beneficial for a patient during an acute episode of back/neck and arm/ leg pain. Importantly, an injection can provide sufficient pain relief to allow a patient to progress with a rehabilitative stretching, strengthening and conditioning program.
Epidural injections are done under direct visualization using x-ray guidance, also known as fluoroscopy. This enables the doctor to deliver medication directly to the source of pain generation. In contrast, oral steroids and painkillers have a dispersed, less-focused impact and may have significant 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.
Treatment of Radicular (Arm or Leg) Pain with Epidural Steroid Injections
Cervical and lumbar radicular pain, often associated with numbness and tingling, and occasionally weakness, into the upper or lower extremities is most often caused by disc herniations or degenerative changes (ligament thickening, bulging discs, and bone spurs) causing spinal stenosis and nerve impingement. Early treatment often includes anti-inflammatory and other pain medications, postural and exercise education and, occasionally, epidural steroid injections.
Clinical research has shown that lumbar epidural steroid injections can, in many cases, provide significant long-term relief of pain due to nerve root irritation[1, 2], and reduce the chances of needing surgery for lumbar disc herniation with radiculopathy[3, 4]. Other studies have shown pain relief on the order of weeks or months. This is often enough time to allow patients to progress through a rehabilitation program and improve their level of function (and ability to work).
Epidural injections are often performed after a trial of conservative medication management, physical therapy, and activity modification. If needed, ESIs can help patients progress with their pain management and rehabilitation programs. If pain is severe and disabling, there are neurological signs or symptoms, or if someone is not able to fully participate or progress with their conservative treatment program, then resorting to epidural steroid injections much earlier than six weeks is reasonable and often very helpful.
If the first epidural steroid injection provides some duration of pain relief or improved strength and function, then a second injection may be considered. If there is a partial but significant response to the first injection, then it is reasonable to try a second injection in the hopes of eliminating the remaining pain. Also, if there is a very substantial response that lasts several days, weeks or months, and the pain then begins to return, then another injection would be reasonable at that time. The decision to proceed forward with a second or third injection is made in consultation with the spine care provider. It is usual to wait two weeks or more between epidural injections.
If disc herniation or spinal stenosis related arm or leg pain (radicular pain) does not respond to these conservative treatment efforts and corticosteroid injections, then surgical intervention is a reasonable option. The timing of obtaining surgical consultation depends upon the clinical situation, with this occurring much earlier in those cases with severe pain or progressive neurological deficits.
Epidural steroid injections (ESI) have been used since the 1950s for treatment of back pain [5, 6]. Since that time, ESI have changed from blind techniques performed in the office to targeted injections, performed under fluoroscopic guidance. More recent studies have suggested that targeting steroid medication to specific sites of pathology may lead to better outcomes. Ackerman treated patients with L5/S1 disc herniations with either an interlaminar, caudal, or transforaminal approach and found the transforaminal approach superior in providing pain relief . Rosenburg evaluated whether spinal stenosis, post-surgical pain, or disc pathology would respond to a TF injection, and it was found that patients with disc pathology experienced the greatest response. Data has supported the presence and significance of various inflammatory chemicals that are found at the site of disc injury [8-10]. Periradicular installation of glucocorticoids may decrease pain by many mechanisms, including: the decrease of prostaglandin and leukotriene synthesis and PMN migration, modulation of peripheral nociceptor neurons, through a direct membrane stabilization mechanism as well as the modulation of spinal cord dorsal horn cells, and may have a slight anesthetic effect . These may provide a direct means for pain relief. This, potentially sustained, pain relief may in turn allow a return to a normal functional level.
The treatment of lumbar radicular pain frequently entails a combination of medications, therapies, and injections to manage pain and return patients to their daily living and work activities. Physical therapy can play a role in non-operative care of radicular pain to help restore appropriate movement and function. Saal evaluated patients with herniated discs with radicular pain and found that 90% had good to excellent results with aggressive therapy . Not only can specific therapy help reduce pain, but it can also decrease the amount of time away from work. Physical therapy plays an important role in treating patients with radiculopathies and is occasionally prescribed to alleviate associated back and leg pain .