To compare the treatment effects of a high-dose and low-dose oral steroid regimen based on changes in the radioisotope uptake ratio (RUR) observed from three-phase bone scintigraphy (TPBS) in patients with complex regional pain syndrome type I (CRPS I), we retrospectively analyzed data of 34 patients with CRPS I from traumatic brain injury and stroke. Depending on the dose of steroid administered, patients were divided into high-dose (n = 14) and low-dose steroid groups (n = 20). We compared the severity scores, Kozin's classification scores, and RUR observed from TPBS between the two groups. There were significant changes in the severity scores and Kozin's classification between the baseline and 2 weeks from baseline (p < 0.05), however, there were no significant differences in terms of changes in the scores, classification, or the RUR observed from TPBS at 2 weeks from baseline (p > 0.05). There were no treatment-emergent adverse events (TEAEs) such as blood pressure elevation, impaired glycemic control, or gastrointestinal disturbances. Our results indicate that the efficacy profile of a low-dose oral steroid regimen is comparable to that of a high-dose regimen in alleviating symptoms in CRPS I patients. However, additional prospective, large-scale, multi-center studies are warranted to confirm our results.
Keywords: complex regional pain syndromes; high dose; low dose; radionuclide imaging; steroids.