Transcutaneous Electrical Stimulation Influences The Time-Frequency Map Of Cortical Activity - A Pilot Study

Phantom limb pain (PLP) is pain felt in the missing limb in amputees. Somatosensory input delivered as high-frequency surface electrical stimulation may provoke a significant temporary decrease in PLP. Also, transcutaneous electrical nerve stimulation (TENS) is a somatosensory input that may activate descending inhibitory systems and thereby relieve pain. Our aim was to investigate changes in cortical activity following long-time sensory TENS. Time-frequency features were extracted from EEG signals of Cz and C4 channels (contralateral to the stimulation site) with or without TENS (2 subjects). We found that the TENS caused inhibition of the spectral activity of the somatosensory cortex following TENS, whereas no change was found when no stimulation was applied.