Pamidronate Effect Compared with a Steroid on Complex Regional Pain Syndrome Type I: Pilot Randomised Trial

Objectives: This study aims to compare the effectiveness of a bisphosphonate (pamidronate) and a steroid (prednisolone) in complex regional pain syndrome (CRPS) type I during four weeks of follow-up in hemiplegic stroke patients.

Methods: Twenty-one hemiplegic stroke patients with CRPS type I were enrolled in the study. Patients were randomly assigned to receive either intravenous pamidronate (n = 11; total cumulative dose of 180 mg) or oral prednisolone (n = 10). Subjective pain and hand oedema (circumference of the middle finger, CMF, and the wrist, CW) were measured at baseline and at one, two and four weeks after the end of treatment.

Results: Both groups showed significant improvement in subjective pain VAS scores at 1-week follow-up and this effect was maintained until 4-week follow-up. Time-by-group interactions were not significant at 4-week follow-up. The reduction of the CMF observed at 1-week follow-up in both groups was maintained until 4-week follow-up in the steroid group, but until 2-week follow-up in the pamidronate group. A significant change in CW was observed at 4-week follow-up in the pamidronate group. There were no significant adverse effects in either treatment group during the follow-up period.

Conclusions: Intravenous pamidronate therapy was safe, well tolerated and appeared as effective as a steroid for pain control for post-stroke CRPS. However, this result should be interpreted with caution, since it included a relatively small number of patients. Further larger controlled studies followed over a longer period are needed to validate these findings and to determine clinical treatment standards.