Pain modulation effect of breathing-controlled electrical stimulation (BreEStim) is not likely to be mediated by deep and fast voluntary breathing

Abstract

Voluntary breathing-controlled electrical stimulation (BreEStim), a novel non-invasive and non-pharmacological treatment protocol for neuropathic pain management, was reported to selectively reduce the affective component of pain possibly by increasing pain threshold. The underlying mechanisms involved in the analgesic effect of BreEStim were considered to result from combination of multiple internal pain coping mechanisms triggered during BreEStim. Findings from our recent studies have excluded possible roles of acupuncture and aversiveness and habituation of painful electrical stimulation in mediating the analgesia effect of BreEStim. To further investigate the possible role of voluntary breathing during BreEStim, the effectiveness of fast and deep voluntary breathing-only and BreEStim on experimentally induced pain was compared in healthy human subjects. Results showed no change in electrical pain threshold after Breathing-only, but a significant increase in electrical pain threshold after BreEStim. There was no statistically significant change in other thresholds after Breathing-only and BreEStim. The findings suggest that the analgesic effect of BreEStim is not likely attributed to fast and deep voluntary breathing. Possible mechanisms are discussed.

A novel nonpharmacological intervention – breathing-controlled electrical stimulation for neuropathic pain management after spinal cord injury – a preliminary study

“…Overall, BreEStim had greater and longer analgesic effect than EStim in SCI with chronic neuropathic pain. This observation was consistent with previous findings of better analgesic effects of BreEStim on experimentally induced pain in healthy subjects 17–19. We noticed that there was a significant difference in preintervention baseline pain levels.…”

“…We further systematically compared the analgesic effects between BreEStim and conventional EStim to a peripheral nerve, or voluntary breathing only on experimentally induced pain in healthy subjects. We observed that BreEStim resulted in a general desensitization effect (measured by elevated electrical pain thresholds in both treated and nontreated hands), while there was no such effect, or even a general sensitization effect after EStim or voluntary breathing only 17–19. The findings support preliminary clinical observations15,16 that BreEStim-induced analgesia is likely related to modification of the affective component, ie, central effect.…”

“…Furthermore, there was no dose–response effect between BreEStim120 and BreEStim240. This is the first study suggesting that BreEStim-induced analgesia observed in healthy subjects17–19 could be translated and applied to SCI patients. As mentioned earlier, pharmacological treatment is often inadequate and has considerable side effects.…”

“…These settings and protocols were similar to our recent series of BreEStim experiments 17–19. Technical details of BreEStim are available online in a methodology video article: http://www.jove.com/video/50077/ 15…”

“…Specifically, the analgesic effects of BreEStim and EStim for neuropathic pain were compared. Given the analgesic effect of BreEStim was observed in healthy subjects,17–19 it was hypothesized that BreEStim is able to produce greater analgesic effects than EStim in SCI subjects. We then explored the possible dose–response effect of BreEStim in a subset of SCI subjects.…”