Abstract
OBJECTIVE: The objective of this study was to examine the effectiveness of a novel nonpharmacological intervention - breathing-controlled electrical stimulation (BreEStim) - for neuropathic pain management in spinal cord injury (SCI) patients. SUBJECTS AND METHODS: There were two experiments: 1) to compare the effectiveness between BreEStim and conventional electrical stimulation (EStim) in Experiment (Exp) 1 and 2) to examine the dose-response effect of BreEStim in Exp 2. In Exp 1, 13 SCI subjects (6 males and 7 females, history of SCI: 58.2 months, from 7 to 150 months, impairments ranging from C4 AIS B to L1 AIS B) received both BreEStim and EStim in a randomized order with at least 3 days apart. A total of 120 electrical stimuli to the median nerve transcutaneously were triggered by voluntary inhalation during BreEStim or were randomly delivered during EStim. In Exp 2, a subset of 7 subjects received BreEStim120 and 240 stimuli randomly on two different days with 7 days apart (BreEStim120 vs BreEStim240). The primary outcome variable was the visual analog scale (VAS) score. RESULTS: In Exp 1, both BreEStim and EStim showed significant analgesic effects. Reduction in VAS score was significantly greater after BreEStim (2.6±0.3) than after EStim (0.8±0.3) (P<0.001). The duration of analgesic effect was significantly longer after BreEStim (14.2±6 hours) than after EStim (1.9±1 hours) (P=0.04). In Exp 2, BreEStim120 and BreEStim240 had similar degree and duration of analgesic effects. CONCLUSION: The findings from this preliminary study suggest that BreEStim is an effective alternative nonpharmacological treatment for chronic neuropathic pain in patients suffering from SCI.