The effects of a single-session cathodal transcranial pulsed current stimulation on corticospinal excitability: A randomized sham-controlled double-blinded study.

Abstract

Transcranial pulsed current stimulation (tPCS) of the human motor cortex has received much attention in recent years. Although the effect of anodal tPCS with different frequencies has been investigated, the effect of cathodal tPCS (c-tPCS) has not been explored yet. Therefore, the aim of the present study was to investigate the effect of c-tPCS at 4 and 75Hz frequencies on corticospinal excitability (CSE) and motor performance. In a randomized sham-controlled crossover design, fifteen healthy participants attended three experimental sessions and received either c-tPCS at 75Hz, 4Hz or sham with 1.5mA for 15min. Transcranial magnetic stimulation and grooved pegboard test were performed before, immediately after and 30min after the completion of stimulation at rest. The findings indicate that c-tPCS at both 4 and 75Hz significantly increased CSE compared to sham. Both c-tPCS at 75 and 4Hz showed a significant increase in intracortical facilitation compared to sham, whereas the effect on short-interval intracortical inhibition was not significant. The c-tPCS at 4Hz but not 75Hz induced modulation of intracortical facilitation correlated with the CSE. Motor performance did not show any significant changes. These results suggest that, compared with sham stimulation, c-tPCS at both 4 and 75Hz induces an increase in CSE.