Aim: To evaluate the effect of peripheral electrical stimulation (PES), with directed or diverted attention, on excitability of the sensorimotor cortices and sensory threshold in healthy adults.

Study design: Within participant repeated measures design. Motor evoked potentials (MEP), somatosensory evoked potentials (SSEP) and sensory threshold were measured before and after 30 minutes of PES. Three different stimulation paradigms were applied in a random order, at least 48 hours apart.

Participants: Twelve healthy participants (seven women, five men, mean age = 40 ± 12 years).

Interventions: Three different stimulation conditions were tested using low frequency, wide pulse width, below motor threshold stimulation.

1. Thirty minutes of PES with directed attention
2. Thirty minutes of PES with diverted attention
3. Thirty minutes of sham PES

Main measures: Corticomotor excitability using single pulse transcranial magnetic stimulation (TMS), excitability of the primary somatosensory cortex using median nerve SSEPs, and sensory thresholds using Semmes-Weinstein monofilaments.

Results: There were no significant changes in motor evoked potentials, somatosensory evoked potentials and sensory threshold following PES with directed or diverted attention.

Conclusion: In healthy adults, 30 minutes of PES with directed or diverted attention did not result in an increase in corticomotor excitability, excitability of the primary somatosensory cortex or a decrease in sensory threshold. PES parameters such as duration, frequency, pulse width and intensity and / or the combination of these parameters are likely to have contributed to the findings of the current study. Further research is required to determine optimal PES parameters before it can be implemented clinically.