Diagnostic and Therapeutic Selective (Transforaminal) Epidural Spinal Injection

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What is the epidural space and why is a selective epidural helpful?
The covering over the nerves in the spine is called the dura. The sleeve-like space surrounding the dura is called the epidural space. Nerves travel through the epidural space and out of the spine through small nerve €œpassageways before traveling into your arms, chest or legs. Inflammation of these nerves from a damaged disc or from contact with a bone spur, may cause pain in your arms, chest or legs.

A selective epidural injection places anti-inflammatory medicine (cortisone) over the spinal nerve in the epidural space to reduce inflammation, and hopefully reduce your pain. By stopping or limiting nerve inflammation, the epidural injection may promote healing€.

Although not always helpful, epidural injections reduce pain and improve function in most people within 3-7 days. They may provide permanent relief or provide a period of pain relief that will allow other treatments like physical therapy to be more effective.

A selective epidural injection also provides diagnostic information. If the nerve injected becomes numb after the procedure, and that nerve is the reason for your pain, you will feel immediately better. This helps to prove that the nerve we injected is the source of your pain. This helps in guiding future treatment options including any future surgical interventions.

Number of Injections
Your doctor may order up to three epidural injections spaced approximately 2-4 weeks apart. Performing a repeat injection depends on your response to the prior injection. If you obtain excellent relief from an epidural, you do not need to have it repeated. If you have partial sustained benefit (>35% relief) the epidural can be repeated for possible additive benefit. If an epidural injection provides minimal benefit (<35 % relief), the physician may choose another injection be performed with a change in technique and/or cortisone used.

What will happen to me during the procedure?
First, an IV is started so that you may receive medicine for relaxation if you so desire. Next, while lying on a x-ray table your skin will be cleansed with an antiseptic. The physician will numb a small area of skin where the epidural needle will be inserted. Next, the physician will use x-ray guidance to direct a small needle next to the spinal nerve as it leaves the spine. He will then inject contrast dye to confirm that the medicine spreads to the affected nerve(s) and into the epidural space where the inflammation resides. After this, the physician will inject a combination of numbing medicine (anesthetic) and time released anti-inflammatory (cortisone).

What should I do and expect after the procedure?
You may have some partial numbness in your arm, chest or leg from the anesthetic after the injection. This may last several hours but you will be able to function safely as long as you take precautions. You may or may not obtain improvement in the first few hours after the injection, depending upon if the nerve that was injected was your main pain source.

  • Report your remaining pain (if any) and  record the relief you experience over the next week in a €œpain diary (provided by your physician). 
  • Take your regular medicines after the procedure, but try to limit your pain medicines the first 4-6 hours after the procedure so that the diagnostic information obtained from the procedure is accurate.
  • You may notice an increase in your pain lasting for several days. This occurs after the numbing medicine wears off but before the cortisone has a chance to work. Ice will typically be more helpful than heat during this time.
  • You may begin to notice an improvement in your pain 1-5 days after the injection. Improvements will generally occur within 10 days after the injection.

On the day of the injection, you should not drive and should avoid any strenuous activities. On the day after the procedure, you may return to your regular activities. When your pain has improved, start your regular exercise/activities in moderation. Even if you are significantly improved, gradually increase your activities over 1-2 weeks to avoid recurrence or your pain.

*SpineUniverse Editorial Comment: Dr. Dreyfuss has provided excellent information for patients who undergo this procedure. Instructions and information provided by your physician may vary.

Updated on: 07/30/14
Gerard Malanga, MD
Epidural Injections can be a very helpful adjunct in rehabilitation of patient's the spine pain that radiates into an arm or leg or in the thoracic spine around the chest or trunk. They work by placing cortisone (a potent anti-inflammatory medication) close to an inflamed nerve. This allows the patient to be fully able to regain full motion and increase the muscular support of the spine critical in the recovery and prevention of future episodes. They are generally not indicated in spine pain that does NOT radiate from an irritated spinal nerve. Most patients actually respond to just 1-2 injections; therefore, they should not be routinely performed in a "series of three". In my experience, 60 % of patients require only one injection and only 10-20 % will require 3 injections. Certainly, if there is little or no pain relief after trying 2 injections, it is unlikely that the third injection will be of benefit. In addition, most patients can be treated with a local anesthetic without the need for sedation which requires an IV and a longer recovery immediately after the procedure.
Leonardo Kapural, MD, PhD
Epidural glucocorticoid injections are commonly given to relieve pain and improve mobility without surgery, buying time for healing to occur or as an attempt to avoid surgery after other conservative approaches failed. Those injections have a good theoretical rationale, but they do not help every patient. Who then should receive an epidural glucocorticoid injection and how many? For leg pain greater than the back pain, guidelines from a respected source (Abram S. Anesthesiology 91:1937-1942, 1999) suggest that patients who had full pain relief from the first epidural injection should not receive another one but to be re-evaluated in 4 weeks and followed thereafter. Those patients who still have some residual pain after the first injection should receive a second and third injection and patients who did not get any benefit from the first injection should not receive another one. Patient selection is very important in deciding on the type of injections patients should receive. Transforaminal injections (different approach to the epidural space) may produce longer pain relief and may also predict whether a patient might benefit from surgery or not (for details, see review McLain et al, Spine Journal 2005). For patients with the diagnosis of lumbar canal stenosis, improvement after such injections may be longer lasting than it was initially thought (Kapural et al., 2005).
Todd Albert, MD
The difference between a selective nerve block and an epidural steroid injection is the specificity. A selective nerve block can be used if a specific nerve is suspected as the primary cause of the pain. We prefer this type of injection because of its enhanced diagnostic/therapeutic qualities and the fact that the needle is not placed directly into the canal housing the spinal cord.
Steven Richeimer, MD
Epidural injections can be done at any level of the spine: cervical (neck), thoracic (mid-back), lumbar (low back), and sacral (tailbone area). The thoracic epidural may be a valuable tool in the treatment of mid-back and chest wall pains. These problems might be caused by disc problems, arthritis of the spine, or even shingles.