Pain Reduction and Patient-Reported Mobility Satisfaction Following Ultrasound-Guided Stellate Ganglion Block in Complex Regional Pain Syndrome Type I: A Retrospective Longitudinal Cohort Study

Abstract

Background: Complex regional pain syndrome (CRPS) is a chronic, severely disabling disorder characterized by sensory, motor, and autonomic dysfunction that is disproportionate to the initial injury. Although stellate ganglion block (SGB) is widely used, evidence regarding the concordance between pain reduction and patient-reported functional restoration across different disease durations remains inconsistent. Objectives: To evaluate pain reduction using the visual analog scale (VAS) and patient-reported satisfaction with upper limb mobility following ultrasound-guided SGB in CRPS Type I, and to explore the correlation between the injury-to-SGB interval and analgesic response. Methods: This retrospective, uncontrolled cohort study evaluated 46 consecutive patients diagnosed with CRPS Type I who underwent an ultrasound-guided SGB at Imam Khomeini Hospital between 2023 and 2025. The study was reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Pain severity was assessed using the VAS before the procedure and at 1 week and 1 month after the procedure. Secondary outcomes included patient-reported satisfaction with improvements in upper limb range of motion. Results: Among 46 patients (mean age, 60.9 ± 11.8 years; 65.2% female), pain intensity decreased significantly over time after ultrasound-guided SGB. Mean VAS scores decreased from 9.04 ± 1.01 at baseline to 4.80 ± 2.14 at 1 week (mean difference, -4.24; 95% confidence interval [CI], -4.84 to -3.64; P < 0.001) and to 2.20 ± 1.15 at 1 month (mean difference from baseline, -6.84; 95% CI, -7.28 to -6.40; P < 0.001). At 1 month, 71.7% of patients reported improved mobility (partial, 56.5%, n = 26; complete, 15.2%, n = 7), whereas 26.1% (n = 12) reported minimal improvement and 2.2% (n = 1) reported no improvement. No significant correlation was observed between the injury-to-SGB interval and the magnitude of pain reduction at 1 week (ρ = -0.162, P = 0.282) or at 1 month (ρ = -0.218, P = 0.145). Transient hoarseness (13.0%) and dysphagia (8.7%) resolved spontaneously, and no major complications occurred. Conclusions: In patients with CRPS Type I, ultrasound-guided SGB was associated with significant pain reduction and favorable mobility satisfaction, with no observed association between the injury-to-SGB interval and analgesic response. Given the uncontrolled retrospective design, these findings reflect postprocedural improvements rather than definitive causal efficacy.