Role of paraspinal mapping before transforaminal epidural injections for lumbar radiculopathy

The role of psychosocial factors in mediating the treatment response of epidural steroid injections for low back pain with or without lumbosacral radiculopathy: A scoping review

Epidural steroid injections (ESIs) are often used to treat low back pain (LBP) due to lumbosacral radiculopathy as well as LBP without a clear component of radiculopathy, in some cases. While it is increasingly recognized that psychosocial factors are associated with pain outcomes, few studies have assessed the contribution of these factors to common pain interventions like ESIs. This study aimed to summarize the scope and nature of how psychosocial factors are accounted for in research on ESIs for the treatment of LBP with or without lumbosacral radiculopathy and to identify gaps and recommendations for future research. A scoping review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis-Scoping Review Extension framework was conducted. Publications dated before September 2023 were searched in PubMed, CINAHL, Scopus, PsycINFO, and Google Scholar. Of the 544 records identified through database searching, a total of 51 studies cumulatively totaling 10,447 participants were included. Sample sizes ranged from 12 to 5,104 participants. Of the 51 included studies, only 10 (20%) analyzed and reported the relationship between at least one psychosocial variable and post-injection pain at any follow-up timepoint. The other 41 (80%) included no analyses examining ESI response as a function of psychosocial variables. Based on the studies that included analysis by psychosocial variables, poor psychosocial functioning appears to be associated with inferior treatments outcomes following ESI for back pain with or without lumbosacral radiculopathy. Relative to the vast body of literature on ESIs for LBP and lumbosacral radiculopathy, minimal attention has been directed to the influence of psychosocial factors on ESI treatment outcomes. Future research evaluating predictors of the effect of ESI on pain relief should include development of more comprehensive models containing modifiable psychosocial variables as predictors of ESI response.

Anatomical validation of needle placement for cervical paraspinal mapping of the multifidus

INTRODUCTION/AIMS

The paraspinal muscles are an important component of electrodiagnostic testing for radiculopathy. In the cervical region, a protocol for cervical paraspinal mapping assumes accurate placement of the electromyography (EMG) needle into the cervical multifidus. However, there is scant information regarding the accuracy of needle placement in that muscle. This study examines the accuracy of this protocol in sampling the intended multifidus muscle of cadavers.

METHODS

An experienced electromyographer directed needles to multifidus at C5, C7, and T2 spinous processes of 19 embalmed cadavers, and injected color dyes. Separately another examiner dissected the cadavers, noting whether the dye was in the correct location and whether its trajectory approached any "danger zones" of nerve, artery, or joint.

RESULTS

The dye was in the multifidus muscle 100% of the time and hit the intended bony target in 79%, 73%, and 79% of C5, C7, and T2 insertions. No insertion was found in a danger zone.

DISCUSSION

The results indicate modest accuracy for EMG needle placement as proposed in the clinical protocol. Clinical utility of this method requires more work including the establishment of norms, sensitivities, specificities, and clinical impact.

Electromyography and Therapeutic Response to Lumbosacral Epidural Steroid Injections: A Systematic Review

The association between electromyography (EMG)-confirmed lumbosacral (LS) radiculopathy and pain outcomes following epidural steroid injection (ESI) has not been systematically summarized. The primary objective of this systematic review was to summarize the effects of EMG-confirmed LS radiculopathy on pain intensity following ESI. A secondary objective was to summarize the effects of EMG-confirmed LS radiculopathy on physical functioning following ESI. An a priori protocol was registered and a database search conducted by a reference librarian from January 2000 through December 2020. The search was date-limited to ensure the results of the systematic review represented contemporary clinical practice. Study-inclusion criteria included randomized trials, prospective and retrospective studies, cross-sectional studies, case series, and case reports, age ≥18 years, and use of EMG as a prognostic tool prior to an ESI. Two independent reviewers screened all titles, abstracts, and full texts. Data were extracted using a templated electronic database. The risk of bias was assessed using the Risk of Bias in Nonrandomized Studies of Interventions tool and certainty in evidence assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach. Due to clinical heterogeneity in study characteristics, a meta-analysis was not performed. A total of 454 studies were screened, and eight nonrandomized studies met the inclusion criteria. Five studies had a moderate risk of bias, two serious risks, and one a critical risk. The key findings included four of eight nonrandomized studies reporting a significant association between EMG-confirmed radiculopathy and ESI response and four of eight nonrandomized studies reporting no significant association. Important sources of bias limited interpretation of individual study findings, and multiple sources of clinical heterogeneity limited between-study comparisons. The findings of this systematic review demonstrate that associations existed between EMG-confirmed LS radiculopathy and pain outcomes after ESI in some, but not all studies. These results should be carefully interpreted with full understanding of the risk of bias and very low certainty in evidence that characterize the nonrandomized studies comprising this systematic review.