The Role of Temporal Changes in Pain Response After Transforaminal Epidural Steroid Injection on Treatment Success

Transforaminal epidural steroid injection (TFESI) is widely utilized in patients with lumbar disc herniation-related radiculopathy who do not respond adequately to conservative treatment and are not immediate candidates for surgery. While previous studies have demonstrated the overall effectiveness of TFESI, there is limited evidence regarding the temporal characteristics of pain relief following the procedure and how these patterns influence long-term outcomes. In routine clinical practice, patients may exhibit heterogeneous pain trajectories after TFESI, including early responders, delayed responders, transient responders, or those with minimal or no response. Identifying early pain response patterns that predict treatment success may help clinicians optimize patient counseling, follow-up strategies, and decisions regarding repeat interventions. In this prospective observational cohort study, adult patients undergoing fluoroscopy-guided TFESI as part of routine clinical care will be followed longitudinally. Pain intensity will be assessed using the Numeric Rating Scale (NRS) before the procedure; at 1 hour post-procedure; every 72 hours during the first 21 days; and at 1, 3, and 6 months. Demographic data, clinical characteristics, and radiological findings from lumbar magnetic resonance imaging will be recorded. The primary objective is to determine whether early temporal changes in pain intensity following TFESI are associated with treatment success at 3 months. Secondary objectives include evaluating treatment success at 6 months and identifying early pain response thresholds that predict favorable outcomes.