Discussion
The present study found an effect of anodal low-thoracic tsDCS on PREP using CE, but it was not an inhibitory effect as excepted. While the N1P1-amplitude of PREP decreased under all other measuring conditions, it remained unchanged after low-thoracic anodal tsDCS when stimulating the lower limb. This missing decrease may be interpreted as a kind of suspended habituation effect or a sensitization, respectively. Since it has already been described that anodal tsDCS induces a local modulation of synaptic efficacy at the spinal cord level, the fact that there was an effect on PREP with CE but not on SEP would indicate that PREP is a nociceptive stimulus that is transmitted via the spinothalamic tract.