Transforaminal Epidural Steroid Injection in Lumbar Disc Prolapse: Impact on Pain Intensity and Cognitive Function in Relation to MicroRNA-155 Serum Level.

Background: Lumbar disc prolapse is a common cause of disabling low back pain. The prevalence of disc prolapses or herniation in the general population increases with age. Objective: This work aimed to evaluate the impact of transforaminal epidural steroid injection (TFESI) in lumbar disc prolapse on pain intensity, cognitive function, and miR-155 serum level. Methods: The present case-control study was conducted on 44 patients with symptomatic lumbar disc prolapse (L4-L5) and another 44 age- and sex-matched controls. Assessment of the pain intensity and functional disability was done before and 1 month after TFESI using the numeric rating scale (NRS), Oswestry disability index (ODI), and functional rating index (FRI). Cognitive assessment was done before and 1 month after TFESI. Estimation of miR-155 serum level was done for the included patients (before and 1 month after TFESI) and controls. Results: There was a statistically significant improvement in pain scales and cognitive test scores 1 month following TFESI (p value ≤ 0.05 in all comparisons). There was also a statistically significant reduction in miRNA-155 serum level in the included patients one month following TFESI (p value < 0.001). The median values for the change in NRS were 2 (1-4.75), in ODI were 18 (7-33), in FRI were 23.5 (12-31), in PALT were 1 (0-1.5), in COWAT were 2 (0.25-5), in PASAT were 3 (1.25-4), and in miRNA-155 were 0.555 (0.16-0.738). There were statistically significant correlations between miRNA-155 serum levels in the included patients and the scores of all the pain and disability scales (NRS, ODI, and FRI) and the scores of all the cognitive tests before TFESI (p value ≤ 0.05 in all correlations). Conclusion: This study highlights the epigenetic mechanisms of TFESI in lumbar disc prolapse, causing significant downregulation of miRNA-155, reduced pain intensity, and improved cognitive function. Trial Registration: ClinicalTrials.gov identifier: NCT05626283.