The Influence of Pain Sensitivity on the Treatment Outcome of Transforaminal Epidural Steroid Injection in Patients with Lumbar Spinal Stenosis

The aim of this study was to investigate the effect of individual pain sensitivity on the results of transforaminal epidural steroid injection (TFESI) for the patients with lumbar spinal stenosis (LSS). Seventy-seven patients with LSS were included in this study. Prospectively planned evaluations were performed twice consecutively before and 2 months after TFESI. These included a detailed medical history, a physical examination, and completion of a series of questionnaires, including pain sensitivity questionnaire (PSQ), Oswestry disability index (ODI), and visual analog scale (VAS) for back and leg pain. The correlations were analyzed among variables between total PSQ/PSQ-moderate/PSQ-minor and pain and disability level measured by VAS for back/leg pain and ODI both before and 2 months after TFESI. Two months after TFESI, there were significant decreases in VAS for back/leg pain and ODI compared with those before injection. Before injection, VAS for back pain and leg pain was highly associated with the PSQ scores including total PSQ and PSQ subscores after adjustment for age, BMI, and grade of canal stenosis. However, any subscores of PSQ and total PSQ scores were not correlated with either VAS for back pain/leg pain or ODI 2 months after TFESI with adjustment made to age, BMI, gender, and grade of canal stenosis. This study highlights that individual pain sensitivity does not influence the outcomes of TFESI treatment in patients with LSS, even though pain sensitivity has a significant negative correlation with symptom severity of LSS.