Are Epidural Steroid Injections Effective for Spinal Stenosis?
by Mark Moran
Epidural injections of glucocorticoids plus lidocaine offered minimal or no short-term benefit for spinal stenosis compared with epidural injections of lidocaine alone, according to a report in the July 3 New England Journal of Medicine (NEJM).
This finding is the result of the first major randomized controlled trial testing the benefit of an intervention — epidural steroid injections (ESI) — that has been widely adopted for spinal stenosis despite minimal or no evidence for its effectiveness and a greater risk of adverse events. The effectiveness of lidocaine alone was a somewhat surprising outcome from the study, researchers said.
“Going into the study the team thought there was not sufficient or robust evidence that glucocorticoid injections provided a benefit, and we believed there was enough uncertainty to justify a randomized controlled trial,” said the study co-author Jeffrey Jarvik, MD, a professor of radiology, neurological surgery, and health services, and director of the Comparative Effectiveness, Cost and Outcomes Research Center at the University of Washington.
“We were surprised at how well the lidocaine-only group did,” Dr. Jarvik said. “We should emphasize that both groups improved over time, but the steroid group did not improve substantially more than the lidocaine group while also having more adverse events.”
The multisite trial — led by Janna L. Friedly, MD, and Dr. Jarvik — randomly assigned 400 patients, who had lumbar central spinal stenosis and moderate-to-severe leg pain and disability, to receive epidural injections of glucocorticoids plus lidocaine, or lidocaine alone. The patients received one or two injections before the primary outcome evaluation performed six weeks after randomization and the first injection. The primary outcomes were the score on the Roland Morris Disability Questionnaire (RMDQ) — in which scores range from 0 to 24, with higher scores indicating greater physical disability — and the intensity of leg pain on a rating scale from 0 to 10, with 0 indicating no pain and 10 indicating “pain as bad as you can imagine.”
The glucocorticoid injectable solution consisted of 1-3 ml of 0.25 percent to 1 percent lidocaine followed by 1-3 ml of triamcinolone (60 to 120 mg), betamethasone (6-12 mg), dexamethasone (8-10 mg), or methylprednisolone (60-120 mg).
At six weeks, there were no significant between-group differences in the RMDQ score or the intensity of leg pain. A secondary subgroup analysis with stratification according to type of injection — interlaminar or transforaminal — likewise showed no significant differences at six weeks.
Patients in the steroid group did slightly better at three weeks, but the benefit over lidocaine-only did not persist to six weeks. Interestingly, the glucocorticoid-lidocaine group had more improvement with respect to symptoms of depression on the Patient Health Questionnaire Depression Scale. On the Swiss Spinal Stenosis Questionnaire, 67 percent of patients who received glucocorticoids plus lidocaine reported being very or somewhat satisfied with their treatment, as compared with 54 percent of those who received lidocaine alone.
Dr. Jarvik noted that at both three and six weeks, a significantly higher proportion of patients in the glucocorticoid-lidocaine group than in the lidocaine-alone group had morning serum cortisol levels of less than 3 μg per deciliter or less than 10 μg per deciliter.
At the same time, 21.5 percent in the glucocorticoid-lidocaine group and 15.5 percent in the lidocaine-alone group. There were more adverse events on average per person in the glucocorticoid-lidocaine group than in the lidocaine-alone group.
For the full discussion on epidural steroid injections in spinal stenosis patients, see the August 21 issue of Neurology Today. Browse our archives on steroidal injections for spinal stenosis here: http://bit.ly/NT-spine.