125. Transcutaneous spinal DC Stimulation (tsDCS) elicits prolonged functional changes in the human brain

Whether tsDCS can modulate human brain functions is unclear. Our aim was to assess the effects induced by dorsal tsDCS on EEG and visual evoked potentials (VEPs) in healthy humans. We evaluated in ten healthy subjects the EEG power spectrum (C3–C4–P3–P4–O1–O2) and visual evoked potentials before (baseline) and at different intervals (0 min = T1, 30 min = T2) after anodal tsDCS over the thoracic spinal cord (T10–T12, 2.5 mA, 20  min). VEPs were elicited by reversal (1,9 Hz) of a horizontal square grating (two contrasts:K20–K100%). As control experiment EEG and VEPs were also tested before and after tsDCS over the right posterior chest wall 15 cm aside from the spine (chest DCS). Anodal tsDCS failed to influence the EEG power spectrum over the visual cortex, but it increased the alpha power over the motor (C3–C4, p  = 0.0048) and somatosensory (P3–P4, p  = 0.0129) cortices at T2. Anodal tsDCS dampened the VEP P1 amplitude ( p  = 0,0061) and increased the VEP N1 latency ( p  = 0,041). Chest DCS left all variables unchanged ( p  > 0.05). Anodal tsDCS induces prolonged changes in VEPs and in EEG in sensorimotor areas. tsDCS might influence spontaneous and evoked brain activity through its effect on ascending spinal pathways.