Epidural steroid injections are well accepted as a treatment for radicular back pain in appropriate candidates. While overall incidence of systemic side effects has not been well established, at least five biochemically proven cases of iatrogenic Cushing's Syndrome have been reported as complications of epidural steroid treatment. We present an additional case of iatrogenic Cushing's Syndrome and adrenal suppression in a middle-aged woman who received three epidural steroid injections over a four-month period. We review this case in the context of previous cases and discuss diagnostic and management issues. 1. Introduction Epidural injections of corticosteroids are an accepted and widely used treatment for radicular low back pain. Nearly 50 million in Medicare dollars went to this treatment in 1999 [1], and from 1994 to 2001, there was a 271% increase in Medicare funded lumbar epidural steroid injections [2]. A typical epidural steroid is triamcinolone in 40？mg or 80？mg doses. Some expert recommendations promote giving up to 3 injections within a year with a minimum of 30 days between injections. Further or more frequent injections are not recommended due to concerns about hypothalamic-pituitary-adrenal suppression [3]. Other practice guidelines provide no recommendations on maximum injection number or dosing interval [4]. The American Society of Interventional Pain Physicians-Interventional Pain Management comments in their 2009 guidelines that there is no “basis for reported assumptions and limitations” on epidural steroid injection doses or frequency and furthermore, that “administration must be based solely on patients’ response, safety profile of the drug, experience of the patient, and pharmacologic and chemical properties such as duration of action and suppression of adrenals [5].” However, they go on to recommend epidural steroid injections be given no more frequently than every 1-2 weeks during the diagnostic phase and thereafter no more frequently than every 2 months. 2. Case The patient is a 53-year-old Caucasian woman of Northern European ancestry referred to Endocrinology by a specialty Pain Clinic for concerns of possible hypercortisolism. She had been seen by the pain specialist for chronic radicular back pain and was given 3 doses of fluoroscopically guided epidural triamcinolone 80？mg via the caudal approach over the course of 4 months. Four weeks elapsed between her first and second doses, 10 weeks between her second and third, her last dose having been given 7 weeks prior to our initial evaluation. She noticed bloating and a buffalo
References
[1]
C. Armon, C. E. Argoff, J. Samuels, and M.-M. Backonja, “Assessment: use of epidural steroid injections to treat radicular lumbosacral pain: report of the therapeutics and technology assessment subcommittee of the American Academy of Neurology,” Neurology, vol. 68, no. 10, pp. 723–729, 2007.
[2]
J. Friedly, L. Chan, and R. Deyo, “Increases in lumbosacral injections in the medicare population: 1994 to 2001,” Spine, vol. 32, no. 16, pp. 1754–1760, 2007.
[3]
K. Levin, P. S. Hsu, and C. Armon, Lumbosacral Radiculopathy: prognosis and Treatment, UpToDate, 2009.
[4]
American Society of Anesthesiologists Task Force on Chronic Pain Management; American Society of Regional Anesthesia and Pain Medicine, “Practice guidelines for chronic pain management: an updated report by the American Society of Anesthesiologists Task Force on Chronic Pain Management and the American Society of Regional Anesthesia and Pain Medicine,” Anesthesiology, vol. 112, no. 4, pp. 810–833, 2010.
[5]
L. Manchikanti, M. V. Boswell, V. Singh et al., “Comprehensive evidence-based guidelines for interventional techniques in the management of chronic spinal pain,” Pain Physician, vol. 12, no. 4, pp. 699–802, 2009.
[6]
S. Jacobs, P. T. Pullan, J. M. Potter, and G. M. Shenfield, “Adrenal suppression following extradural steroids,” Anaesthesia, vol. 38, no. 10, pp. 953–956, 1983.
[7]
J. L. Stambough, R. E. Booth Jr., and R. H. Rothman, “Transient hypercorticism after epidural steroid injection: a case report,” Journal of Bone and Joint Surgery. American, vol. 66, no. 7, pp. 1115–1116, 1984.
[8]
M. H. Horani and A. B. Silverberg, “Secondary Cushing's syndrome after a single epidural injection of a corticosteroid,” Endocrine Practice, vol. 11, no. 6, pp. 408–410, 2005.
[9]
S. M. Tuel, J. M. Meythaler, and L. L. Cross, “Cushing's syndrome from epidural methylprednisolone,” Pain, vol. 40, no. 1, pp. 81–84, 1990.
[10]
M. C. Lansang, T. Farmer, and L. Kennedy, “Diagnosing the unrecognized systemic absorption of intra-articular and epidural steroid injections,” Endocrine Practice, vol. 15, no. 3, pp. 225–228, 2009.
[11]
S. Boonen, G. Van Distel, R. Westhovens, and J. Dequeker, “Steroid myopathy induced by epidural triamcinolone injection,” British Journal of Rheumatology, vol. 34, no. 4, pp. 385–386, 1995.
[12]
C. L. Knight and J. C. Burnell, “Systemic side-effects of extradural steroids,” Anaesthesia, vol. 35, no. 6, pp. 593–594, 1980.
[13]
R. Chou, S. J. Atlas, S. P. Stanos, and R. W. Rosenquist, “Nonsurgical interventional therapies for low back pain: a review of the evidence for an American pain society clinical practice guideline,” Spine, vol. 34, no. 10, pp. 1078–1093, 2009.
[14]
J. M. B. Burn and L. Langdon, “Duration of action of epidural methyl prednisolone. A study in patients with the lumbosciatic syndrome,” American Journal of Physical Medicine, vol. 53, no. 1, pp. 29–34, 1974.
[15]
J. Kay, J. W. Findling, and H. Raff, “Epidural triamcinolone suppresses the pituitary-adrenal axis in human subjects,” Anesthesia and Analgesia, vol. 79, no. 3, pp. 501–505, 1994.
