Effect of unmodulated 5-KHz alternating currents versus Transcutaneous Electrical Nerve Stimulation on mechanical and thermal pain, tactile threshold, and peripheral nerve conduction: a double-blind, placebo-controlled, crossover trial

Publication date: Available online 23 December 2016
Source:Archives of Physical Medicine and Rehabilitation
Author(s): Juan Avendaño-Coy, Julio Gómez-Soriano, Carlos Goicoechea-García, Julian Angel Basco-López, Julian Taylor
ObjectiveTo investigate the effect of unmodulated 5-KHz alternating current on mechanical pain threshold (MPT), heat pain threshold (HPT), tactile threshold (TT), and peripheral nerve conduction (PNC) compared to TENS and sham stimulationSettingNational referral centerDesignRandomised double-blind placebo controlled crossover trial.ParticipantsThirty-eight healthy volunteers. No dropouts or adverse events were reported.InterventionTENS, unmodulated 5-KHz currents, and sham stimulation were applied on the radial nerve for 20 minutes with a 24-hour washout period between them and concealed intervention allocation.Main outcome measuresFour measures pre-, during and 2 post-interventions. Algometry was used to assess MPT, a Peltier thermode for HPT using the method of limits, Von Frey filaments for TT, and radial nerve compound action potential (CAP).ResultsNo differences were observed on MPT, HPT, and PNC when 5-KHz and TENS were compared. However, TT increased 56.2 mN (95% CI 28.8-83.6) in TENS group compared to 5-KHz group during intervention. Compared to sham stimulation during intervention, MPT increased 4.7N (95% CI 0.3-9.2) using 5-KHz and 10.4N (95% CI 3.517.3) with TENS. TT increased 17.2 mN (95% CI 4.7-29.7) with 5-KHz and 73.4 mN (95% CI 47.5-99.2) with TENS. However, HPT increased 1.0 ºC (95% CI 0.2-2.0) only with TENS. For the PNC, no differences were found among the three groups.ConclusionUnmodulated 5-KHz current produced an increase in somatosensory thresholds that was greater than placebo but not when compared TENS; however, participants perceived 5-KHz currents more comfortable and showed more habituation to them.



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