Predictive value of immediate pain relief after lumbar transforaminal epidural injection with local anesthetics and steroids for single level radiculopathy.

Abstract

To assess the predictive value of immediate pain-relief after CT-guided transforaminal epidural steroid injection (TFESI) including local anesthetics for longer-term pain relief and patients' global impression of change (PGIC) after 4 weeks. One hundred ninety-three patients (age 55.4 ± 14.9) with single-level discogenic lumbar radiculopathy and subsequent TFESI were included. Pain scores were recorded before (NRS₀), 15 min (NRS_15min), and 4 weeks (NRS_4w) after treatment using a numerical-rating-scale (NRS; 0, no pain; 10, intolerable pain). Additionally, the PGIC was assessed after 4 weeks. Two fellowship-trained musculoskeletal radiologists evaluated nerve compression of the injected level and contrast dispersion. Spearman's rank and point-biserial correlation were applied to assess associations between outcome variables and demographics/imaging findings. A p-value < 0.05 was considered to be statistically significant. There was a significant positive correlation between immediate pain-relief and longer-term pain-reduction (r = 0.24, p = 0.001) with an odds ratio of 2.0 (CI: 1.1-3.6). A good short-term response (NRS_15min ≥ 50% reduction) was associated with a persistent longer-term good response (NRS_4w ≥ 50% reduction) in 59.7% (CI: 50.9-68.0%) of patients. There was no association between short-term pain-relief and PGIC after 4 weeks (p = 0.18). Extent and location of nerve compression and contrast dispersion during TFESI did not correlate with longer-term pain-relief (all p ≥ 0.07). Our results indicate a significant positive correlation between immediate post-procedural and longer-term pain relief after TFESI in patients with lumbar radiculopathy; however, no effect of short-term pain relief is seen on PGIC after 4 weeks. Patients with good longer-term outcome (≥ 50% pain reduction) are twice as likely to have already shown good immediate pain reduction after TFESI.