Selective effect of kilohertz high-frequency alternating current (KHFAC) stimulation on nociception: a crossover double-blind randomized sham-controlled trial

This study aimed to investigate the effects of transcutaneous kilohertz high-frequency alternating current (KHFAC) stimulation at frequencies of 30, 40, and 50kHz compared to sham stimulation on experimental pain and sensory and motor outcomes.

A randomized, double-blind, sham-controlled crossover study involving 34 healthy participants was conducted. Four interventions (30, 40, 50kHz and sham) were administered, and stimulation was applied for 20 minutes on the median nerve of the non-dominant hand. Primary outcomes included heat pain threshold (HPT), pressure pain threshold (PPT), and adverse effects. Secondary outcomes comprised static two-point discrimination sensitivity, isometric pinch strength, and median sensory nerve action potentials (SNAPs).

Active KHFAC stimulation, particularly at 40kHz, effectively increased both the PPT and HPT without affecting the tactile threshold or motor function, inducing mild skin-related adverse effects. These findings have potential implications for people with pain-related pathologies.