Jose G. Veliz, M.D. M.S.A.
Medical Director
Palomar Pain Management Center
Pomerado Pain Management Center

Posted March 2, 2009 11:20 AM

Radicular pain from lumbar spine, thoracic spine and cervical spine disorders can be treated through non-surgical means using various methods.  One of these methods is through the use of epidural steroid injections (ESIs).  Sharp radiating pain which shoots from the low back into the lower limb(s) in a radicular pattern is defined as radicular pain.  Sharp shooting pain from the neck into the upper limb(s) and sharp shooting pains from the thoracic spine into the flank or chest etcetera, in a radicular distribution, are also defined as radicular pain. 

Radicular distribution is defined as specific areas of the body supplied by specific nerves.  Inflammation and/or a lesion in the nerve root results in radicular pain.  When a lesion is present in a nerve root or when inflammation is present in a nerve root, the following can occur: 

• Weakness of the muscle groups which are supplied by the involved nerve root. 
• Decreased reflexes.
• Radicular pain.
• Hypesthesia (Decreased sensitivity to touch)

ESIs can be both diagnostic and therapeutic.  Prolonged pain relief increases the likelihood that inflammation in or near the epidural space was the source of the pain.  By decreasing inflammation, ESIs are therapeutic due to the fact that chronic inflammation can lead to swelling, degeneration, and scarring of nerve roots and tissues. 

ESIs are most effective if they are combined with other treatment modalities such as physical therapy, improved posture, weight loss, manual therapy, chiropractic therapy, short term bed rest, and/or low dose medications.  Resolving personal problems (financial, marital and work related) and treating psychological problems are also effective in managing radicular pain. 

The major cause of radicular pain emanating from the cervical spine, thoracic spine and lumbar spine is inflammation of the nerve root in the epidural space.  Causes include the following:

• Leakage of inflammatory chemicals from the disc.
• Nerve root blood supply being compressed.
• Dorsal root ganglia irritation. The dorsal root ganglion contains cell bodies of nerves that relay painful sensations to the spinal cord and brain.

Steroids decrease inflammation in the epidural space and/or nerve root by the following mechanisms:

• Inflammatory chemicals are inhibited.
• Transmission of pain signals from pain nerve fibers is inhibited.
• Blood vessel leakage is decreased. 

Lumbar ESIs can be used to treat lumbar radicular pain in the following conditions:

• Spinal stenosis
• Lumbosacral disc herniation
• Facet or nerve root cyst.
• Fracture of the lumbar spine

The following conditions can be treated with thoracic ESIs:

• Post herpetic neuralgia
• Thoracic disc herniation
• Thoracic scoliosis
• Thoracic compression fracture

The following conditions can be treated with cervical ESIs:

• Post herpetic neuralgia
• Cervical disc herniation
• Post surgical cervical pain
• Cervical strains

ESIs should not be performed if you have the following conditions:

• Allergic reactions to anesthetic, corticosteroid or contrast.
• History of bleeding disorder or are currently on blood thinners.
• Infection.
• Spinal cord compression

In pregnant women, ESIs should not be performed with fluoroscopy (x-ray guidance).  Blood glucose levels should be normal in diabetic patients due to the fact that ESI steroids may temporarily increase blood glucose levels.  Diabetic patients receiving ESIs should not stop their diabetic medications and should continue adhere to a strict diabetic diet.  Due to the fact that fluid retention may occur with steroids, patients with congestive heart failure should be carefully monitored. 

Studies have shown that ESIs performed without fluoroscopy (x-ray guidance) result in incorrect placement of the medication in 30% of cases. 

Benefits of ESIs include the following:

• Decreased radicular pain.
• Decreased low back pain.
• Reduction of pain medication use.
• Allowing participation in physical therapy by decreasing pain
• Allowing participation in activities of daily living
• Improved sleep patterns   

The longer the period in which symptoms have occurred, the less effective are ESIs.  ESIs are also less effective in the following situations:

• Previous back surgery.
• Greater than 60 years of age.
• Work related injuries.
• Positive smoking.
• Work requiring heavy lifting.

ESIs can be performed using three approaches:

• Interlaminar
• Transforaminal
• Caudal

Radiographic contrast is used in ESIs in order to improve accuracy, safety and results.  One of the complications of ESIs is injection of the corticosteroid into a blood vessel.  The use of radiographic contrast along with live x-ray, can identify needle placement in a blood vessel before the corticosteroid is injected into it. 

Risks of ESIs include the following:

• Infection.
• Bleeding.
• Nerve root injury
• Spinal headache
• Spinal cord injury. 

Correct technique, clinical experience, and proper equipment result in a complication rate which is minimal when ESIs are performed. 

The medical literature is currently not clear as to the exact number of ESIs which should be administered to treat radicular pain.  In general, each injection should be performed at least two weeks apart and, if there is no benefit after the second injection, a third one should not be performed.  A history and physical examination should be performed prior to each ESI in order to assess the patient’s current status. 

Cervical and thoracic epidural steroid injections can be performed using interlaminar and transforaminal approaches.  Transforaminal, interlaminar and caudal approaches can be used in lumbar epidural injections.

The interlaminar approach is performed at the midline or just lateral to the midline.  The transforaminal approach is performed through the placement of the needle into the neural foramen which is the exit hole for the nerve root.  Caudal epidural injections are performed by placing a needle into the epidural space at the sacral canal (just above the tailbone). 

Medications used in ESIs include:

• Steroid preparation.
• Anesthetic
• Contrast agent.

As previously discussed, the corticosteroid preparation decreases inflammation.  The anesthetic is used to numb “the skin” and underlying tissue in order to allow the procedure to be performed in a comfortable manner.  Some physicians also insert a low dose anesthetic into the epidural space along with the corticosteroid preparation and contrast agent.  This can provide quick and short term relief for a few hours.  In general, the corticosteroid preparation results in decreased pain in one to seven days.  As discussed earlier, the contrast agent is used in order to assist in identifying the epidural space, and to identify misplacement of the needle into a blood vessel. 

ESIs, in combination with other treatment modalities, can decrease radicular pain, improve functionality, and enhance quality of life. 

References:

http://emedicine.medscape.com/article325733-print

Buenaventra RM, Datta S, Abdi S, et al.  Systematic Review of Therapeutic Lumbar Transforaminal Epidural Steroid Injections.  Pain Physician.  Jan-Feb 2009; 12 (1): 233-51.