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

• Published in: Archives of Physical Medicine and Rehabilitation Vol. 98; no. 5; pp. 888 - 895
• Main Authors: Avendaño-Coy, Juan, Gómez-Soriano, Julio, Goicoechea-García, Carlos, Basco-López, Julian Angel, Taylor, Julian
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2017; Elsevier BV
• Subjects: Adolescent; Adult; Cross-Over Studies; Double-Blind Method; Electric stimulation; Female; Hot Temperature; Hot Temperature - adverse effects; Humans; Male; Neural Conduction; Neural Conduction - physiology; Pain; Pain - classification; Pain - rehabilitation; Pain Threshold; Pain Threshold - physiology; Peripheral Nerves; Peripheral Nerves - physiology; Physical Medicine and Rehabilitation; Rehabilitation; Transcutaneous Electric Nerve Stimulation; Transcutaneous Electric Nerve Stimulation - methods; Young Adult; MPT; TT; TENS; CAP; PNC; CI; Pain threshold; Rehabilitation; Electric stimulation; HPT; Neural conduction; Transcutaneous electric nerve stimulation; compound action potential; transcutaneous electrical nerve stimulation; peripheral nerve conduction; heat pain threshold; confidence interval; mechanical pain threshold; tactile threshold
• ISSN: 0003-9993; 1532-821X; 1532-821X
• DOI: 10.1016/j.apmr.2016.11.020

To 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 with transcutaneous electrical nerve stimulation (TENS) and sham stimulation. National referral center. Randomized, double-blind, placebo-controlled crossover trial. Healthy volunteers (N=38). No dropouts or adverse events were reported. TENS, 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. Four measures were taken: before, during, and 2 after the 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. No differences were observed on MPT, HPT, and PNC when 5-kHz current and TENS were compared. However, TT increased 56.2mN (95% confidence interval [CI], 28.8–83.6) in the TENS group compared with the 5-kHz current group during intervention. Compared with sham stimulation during intervention, MPT increased 4.7N (95% CI, 0.3–9.2) using 5-kHz current and 10.4N (95% CI, 3.5–17.3) with TENS. TT increased 17.2mN (95% CI, 4.7–29.7) with 5-kHz current and 73.4mN (95% CI, 47.5–99.2) with TENS. However, HPT increased 1.0°C (95% CI, 0.2–2.0) only with TENS. For the PNC, no differences were found among the 3 groups. Unmodulated 5-kHz current produced an increase in somatosensory thresholds that was greater than placebo but not when compared with TENS; however, participants perceived 5-kHz currents to be more comfortable and showed more habituation to them.