Comparison of post-treatment effects of conventional and acupuncture-like transcutaneous electrical nerve stimulation (TENS): A randomised placebo-controlled study using cold-induced pain and healthy human participants.

TENS can be administered in conventional (high frequency, low intensity) or acupuncture-like (AL-TENS: low frequency, high intensity) formats. It is claimed that AL-TENS produces stronger and longer-lasting hypoalgesia than conventional TENS, although evidence is lacking. This randomised controlled parallel group study compared the effects of 30 minutes of AL-TENS, conventional TENS, and placebo (no current) TENS, on cold-pressor pain threshold (CPT), in 43 healthy participants. Results showed a greater increase in mean log(e) cold-pressor pain threshold relative to baseline for both AL-TENS and conventional TENS vs. placebo TENS, and for AL-TENS vs. placebo 5 and 15 minutes after TENS was switched off. There were no statistically significant differences between conventional TENS vs. placebo or between AL-TENS vs. conventional TENS at 5 or 15 minutes after TENS was switched off. In conclusion, AL-TENS but not conventional TENS prolonged post-stimulation hypoalgesia compared to placebo TENS. However, no differences between AL-TENS and conventional TENS were detected in head-to-head comparisons.

PMID: 22007892