Cervical radicular pain is a common cause of disability and pain in the upper extremity and neck with an annual incidence of 83.2/100,000 (1). The initial treatment is conservative and includes relative rest, use of anti-inflammatory and analgesic medication, as well as physical therapy and home exercise. For patients who have persistent and significant symptoms, interventional pain management and surgical management are considered. Cervical epidural injections are the mainstay of the interventional, non-surgical modalities. They can be considered to provide short and long-term relief when disc herniation, foraminal stenosis or central canal stenosis pathology is identified.
Cervical epidural injections can be performed by two different approaches, transforaminal and interlaminar. Transforaminal epidural injections allow delivery of medication to the ventral epidural space, while the interlaminar approach reaches the ventral epidural space in only 28% of injections (2-4). The results of cervical epidural injections remain controversial and their efficacy in decreasing the need for surgery in patients who would otherwise be operative candidates has not been thoroughly investigated. Studies have been limited by small sample sizes, lack of control groups, and lack of randomization. Kolstad et al reported that 23% (5/21) of patients waiting for cervical disc surgery cancelled surgery when assessed at four months after having a series of two cervical epidural injections (6). Lin et al reported that 63% (44/70) of patients who were deemed to be surgical candidates were able to avoid surgery with an average of 13-month follow up (7). Lee et al reported that over 80% of 98 patients evaluated with cervical radiculopathy were able to avoid surgery with a 2-year follow-up (8). Anderberg et al reported that there was no short-term difference in symptoms of cervical radiculopathy between patients who received transforaminal injections of steroid with local anesthetic versus saline with local anesthetic. However, this study did not evaluate whether the injections were successful in the patients avoiding surgery (11).
In terms of lumbar transforaminal epidural injections, Riew et al demonstrated that steroid injections obviated the need for surgery in patients with lumbar radiculopathy. Moreover, Reiw et al showed that steroid combined with local anesthetic was more effective than local anesthetic alone in a prospective, randomized, controlled, double-blinded study (9). Riew et al later studied the efficacy of cervical transforaminal epidural injections in the same fashion, but the findings were not statistically significant (p\<0.35) and not published (10).
We are not aware of any published prospective, randomized, controlled, double-blinded studies demonstrating the efficacy of cervical transforaminal epidural steroid injections. However, the North American Spine Society (NASS) Review and Recommendation Statement states that based on the literature and expert opinion, a minimum of one or two cervical epidural steroid injections would be very appropriate in the treatment of a specific episode of cervical radicular pain. This literature also suggests that a maximum of four injections can be used within six months, assuming there was a positive response and improvement seen with the previous injections.
