Are electrodiagnostic study findings related to a patient's response to epidural steroid injection?

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.

Role of paraspinal mapping before transforaminal epidural injections for lumbar radiculopathy

Objectives

This study aims to investigate whether electromyography (EMG) including paraspinal mapping (PM) and specific clinical findings before the injection have a predictive role on the results in patients undergoing unilateral transforaminal epidural steroid injection (TFESI).

Patients and methods

In this prospective study, a total of 46 patients (19 males, 17 females; mean age: 44.0±10.8 years; range, 23 to 60 years) with unilateral L5 root compression confirmed by physical examination, EMG and lumbar MRI between March 2013 and January 2014 were included. The patients underwent L5 TFESI. After the injection, they were examined at 1 h, three weeks, and three months.

Results

The clinical findings and presence of acute involvement on EMG were not predictive for TFESI results; however, the patients with lower scores for the L5 segment in PM benefited more from the injection, compared to patients with higher scores for the L5 segment in PM.

Conclusion

In patients with very clearly defined L5 radiculopathy, PM EMG can give us an idea about the effectiveness of L5 TFESI.

Factors Predicting Favorable Short-Term Response to Transforaminal Epidural Steroid Injections for Lumbosacral Radiculopathy

Background and Objectives: The purpose of this retrospective study was to identify predictors of short-term outcomes associated with a lumbosacral transforaminal epidural steroid injection (TFESI). Materials and Methods: The medical records of 218 patients, who were diagnosed with lumbosacral radiculopathy and treated with a TFESI, were reviewed in this retrospective study. A mixture of corticosteroid, lidocaine, and hyaluronidase was injected during TFESI. Patients with >50% pain relief on the numerical rating scale compared with the initial visit constituted the good responder group. Demographic, clinical, MRI, and electrodiagnostic data were collected to assess the predictive factors for short-term outcomes of the TFESI. Results: A multivariate logistic regression analysis demonstrated that a shorter duration of symptoms and a positive sharp wave (PSW)/fibrillation (Fib) observed in electrodiagnostic study (EDx) increased the odds of significant improvement 2–4 weeks after the TFESI. Conclusions: Shorter duration of symptoms and PSW/Fib on EDx were predictors of favorable short-term response to TFESI.

The Value of Electrodiagnostic Studies in Predicting Treatment Outcomes for Patients with Spine Pathologies

The utility of electrodiagnostic testing for spine pathologies varies based on the underlying suspected pathology. This article reviews the data on electrodiagnostic testing for common spine pathologies, with a specific focus on the prognostic data with regard to treatment outcomes. This information is placed into context of diagnostic confidence, which is derived from the combination of disease prevalence and the sensitivity and specificity of a test.

Electromyographic Findings After Epidural Steroid Injections in Patients with Radicular Low Back Pain: A Prospective Open-Label Study

Epidural steroid injections (ESIs) are commonly used in the management of chronic lower back and leg pain. The aim of this study was to investigate the short- and long-term electromyographic and clinical outcome of patients with chronic radicular pain after ESIs. This prospective, open-label study, included patients with chronic radicular pain due to disc herniation or spinal stenosis, who underwent interlaminar, fluoroscopy-guided ESIs. Patients were assessed before ESIs, as well as after 6 and 12 months, clinically (VAS 0-10, BPI, DN4, Rolland Morris, DASS, STAI) and electromyographically for the improvement of spontaneous activity (SA) and of motor unit recruitment/interference pattern (IP/MUR). A total of 39 patients were studied, 20 (51.3%) who had a significant improvement in VAS, RM, DN4 and BPI were revealed, mainly during the first 6 months (P < 0.05). Statistically significant improvement was revealed in MUR/SA for almost all nerve roots studied. Patients with disc herniation showed a greater improvement in mean difference of MUR/SA (P < 0.05) (with a prognostic value of radicular LBP versus spinal stenosis in short- [VAS P = 0.042] and long-term improvement of pain [VAS P = 0.009]. The independent variables “MUR” and “SA” had a significant prognostic value for improvement of pain (VAS: R² = 0.287, P = 0.032 and VAS: R² = 0.277, P = 0.036 respectively). Electromyographic and clinical findings indicated a benefit from epidural steroid injections. Patients with disc herniation exhibited a better outcome, especially during the first 6 months post-treatment.

Three week results of transforaminal epidural steroid injection in patients with chronic unilateral low back related leg pain: The relation to MRI findings and clinical features

BACKGROUND

Transforaminal epidural steroid injection (TESI) is a frequently used intervention for lumbar radicular pain.

OBJECTIVE

To evaluate the value of MRI findings, neurologic assessment and the Slump test (neurodynamic test) as predictors of treatment response to TESI.

METHOD

One hundred subjects (mean age 58 [SD13], 54% females) were included in this trial. The sample was stratified by location of disc herniaton, grade of nerve root compression, clinically assessed neurologic deficit and positive Slump test.Treatment response was primarily evaluated by Visual Analogue Scale for leg pain after three weeks. Predictive value for each stratum was analyzed using logistic regression after the sample was dichotomized into definite treatment response (≥ 50% reduction of pain) and negative response (≤ 0% reduction) to TESI (the 1-49% reduction group was excluded).

RESULTS

The overall definite treatment response rate was 27%. The Slump test was the only predictor of the response to TESI (p= 0.031). The definite treatment response rates for subjects with positive and negative Slump test were 33% and 15%, respectively.

CONCLUSION

In patients with chronic low back related leg pain, MRI findings and neurologic assessment results failed to predict treatment response, whereas a positive Slump test predicted the best 3-week response to TESI.

Role of electrodiagnosis in patients being considered for epidural steroid injections

Electrodiagnostic (EDX) evaluation, and, more specifically, electromyography (EMG), has a well-established role in the diagnostic confirmation of cervical and lumbar radiculopathy. The role of EMG in prognostication, however, is less established and remains a topic of debate. The purpose of this article is to evaluate the diagnostic and prognosticating role of EMG in cervical and lumbar radiculopathies, and to assess the utility of EMG in predicting outcomes after epidural steroid injections (ESI). A review of the existing literature strongly supports a prognosticating role for EDX in predicting outcomes after lumbar ESI in lumbosacral radiculopathies (LSR). Although limited research regarding outcome prediction after cervical ESI in cervical radiculopathies has been performed, no study has specifically evaluated the utility of EMG in predicting outcomes for cervical ESI, and this topic requires further investigation. An EDX evaluation can provide clinicians with accurate and reliable diagnostic information (level I or level II evidence) in the evaluation of patients with lumbosacral radiculopathies, and can provide more valid prognostic information (level I evidence) regarding potential benefits of lumbar ESI. An EDX evaluation, therefore, can enhance a clinician's ability to advise patients on the most appropriate and efficacious evaluation and management plan for the treatment of painful radiculopathies.