Acute effects of contrast bath on sympathetic skin response in patients with poststroke complex regional pain syndrome

Abstract

Purpose Complex regional pain syndrome (CRPS) is one of the common complications in stroke patients. Sympathetic dysfunction is usually considered underlying pathology. The evidence for contrast bath (CB) used in the treatment of CRPS is limited. The aim of the study is to investigate the possible effects of CB on the sympathetic activity in poststroke CRPS. Materials and methods Stroke patients with CRPS (CRPS group) and without CRPS (control group) were included in the study. Age, gender, duration of stroke, aetiology, plegic side, dominant hand, spasticity level, Brunnstrom stages, and comorbidities were recorded. CB was performed for one session to the plegic side of the CRPS and control groups. Sympathetic skin responses (SSR) was recorded from the plegic and healthy hands of participants at pre-CB and post-CB. Results Each group consisted of 20 participants. No significant difference was detected in stroke duration, aetiology, and Brunnstrom stages between groups. Elbow spasticity level was significantly higher in CRPS group (p = .034). SSR amplitudes of plegic hands were significantly decreased after CB in CRPS and control groups (p = .0002, p = .013 respectively). Also, CB reduced the SSR amplitude of healty side in CRPS group (p = .003). There was no statistically significant change in SSR latency or percentage changes of SSR amplitude and latency after CB in both groups. Conclusion CB leads to a significant reduction in sympathetic activity of plegic side of stroke patients. Also, CB to the plegic side has an inhibitory effect on sympathetic activity of healty side in poststroke CRPS. ClinicalTrials.gov ID: NCT04198532