Epidural steroid injections may have shown modest short-term benefits but limited long-term efficacy for treating cervical and lumbar radiculopathies and spinal stenosis, according to a new systematic review from the American Academy of Neurology Guidelines Subcommittee.
In the comprehensive review, published in Neurology, investigators analyzed 90 randomized controlled trials published between January 2005 and January 2021, providing key efficacy data for both cervical and lumbar applications.
For radiculopathies, the evidence showed epidural steroid injections (ESIs) "probably reduce short-term pain (success rate difference [SRD] = –24.0%, 95% confidence interval [CI] = −34.9 to −12.6, number needed to treat [NNT] = 4) and disability (SRD = −16.0%, 95% CI = −26.6 to −5, NNT = 6)," the study authors reported. However, long-term pain reduction evidence was insufficient.
In lumbar spinal stenosis, ESIs demonstrated possible short-term disability reduction (SRD = −26.2%, 95% CI = −52.4 to 3.6, NNT = 4) but "probably do not provide short-term pain reduction," according to the review. Long-term pain control evidence was also insufficient.
"The review affirms limited efficacy of ESIs in reducing pain and disability in cervical and lumbar radiculopathies and possibly in lumbar spinal stenosis, largely in the short term," the study authors underscored.
Safety analysis revealed complication rates ranging from 2.4% to 16.8%. Most adverse effects were minor, including injection site pain and numbness. For cervical interlaminar ESIs, reported serious complications included nerve root injury, pneumocephalus, epidural hematoma, subdural hematoma, Cushing syndrome, hypotension, respiratory insufficiency, transient blindness, epidural abscess, paralysis, cord injury, and death. Additional complications reported with transforaminal cervical and lumbar ESIs include transient global amnesia, vertebral artery injury, paralysis, cord infarction, cerebellar infarction, and death.
The investigators noted significant methodology challenges, stating: "[T]he heterogeneity of outcome measures reported preclude presenting integrated data regarding effect size." They recommended future trials use minimal meaningful clinical difference as the measure of efficacy and specifically suggested paraspinal muscle injection of saline (0.5 to 1.0 mL) as an inactive placebo.
For cervical spinal stenosis, the review found insufficient evidence to determine ESI effectiveness, highlighting a critical knowledge gap.
Cost-effectiveness remains unclear because of limited data. One Dutch study of acute lumbar radiculopathy (duration = 2–4 weeks) cited in the study demonstrated potential cost benefits through improved productivity, with an incremental cost-effectiveness ratio of −$990; however, this was not statistically significant.
"The small effect size and the modest clinical efficacy for short-term benefit need to be considered when using ESIs for lumbosacral radiculopathy," the study authors emphasized, noting factors like patient demographics, health conditions, and pathophysiology should influence treatment decisions.
This American Academy of Neurology systematic review updates their 2007 assessment, providing more detailed analysis through meta-analyses and success rate difference calculations while reaching similar conclusions about limited efficacy.
Full disclosures can be found in the guidelines.
