Efficacy of intramuscular glucocorticoid injection in patients with lumbar radicular pain

Objective: To evaluate the effects of intramuscular betamethasone injection on pain, disability, quality of life and secondarily on electroneuromyography (ENMG) findings in patients with lumbar radicular pain. Materials and Methods: A total of 98 patients with radicular low back pain were evaluated between July 2022 and June 2023. Sixty patients who met the inclusion criteria were randomized into two groups. In addition to the standard treatment, Glucocorticoid group (GC) received intramuscular injection of betamethasone and Placebo group (PB) received isotonic 0.9% sodium chloride. Visual analog scale (VAS), Oswestry disability index (ODI), Nottingham health profile (NHP) and ENMG were performed. Patients were evaluated before treatment and after first week, first month and third month of treatment. Results: Statistically significant improvements were seen in all clinical parameters in GC group. At the end of 3rd month, statistically significant improvements were observed in VAS and NHP-Pain subscale scores in both groups (p<0.001). The change of these values over time was statistically significant in favor of GC group (p=0,015 and p=0,044, respectively). Statistically significant improvements were observed in ODI, NHP-Energy and Physical Mobility subscales and NHP-Total scores in both groups over time (p<0.05). However, no statistically significant difference was found between the groups in terms of the change of these values over time. In the NHP-Emotional Reaction, Sleep and Social Isolation subscales, statistically significant improvements were observed in the GC group (p<0.05), while the change in the PB group was not significant. The fibrillation potentials initially observed on ENMG disappeared in both groups, however no significant difference was found between the groups. Conclusion: Intramuscular single dose glucocorticoid administration in the treatment of lumbar radicular pain provided improvements on pain, disability and quality of life. Especially the effects on pain scores were superior to placebo. No superiority over placebo on ENMG findings has been demonstrated and further studies are needed in this regard. Keywords: electroneuromyography, glucocorticoid, intramuscular injection, low back pain, lumbar radicular pain