文摘
The effect of transcutaneous electrical nerve stimulation (TENS) on the central nervous system amplification process was investigated, in particular in the medial lemniscal pathway. Short latency somatosensory evoked potentials (SSEPs) were recorded in 10 healthy normal volunteers. Amplitude changes for each of the SSEP components (the N9 brachial plexus potential, P14 potential that originates from the cervicomedullary junction, spinal N13/P13 generated by the cervical dorsal horn, and cortical N20/P25 potentials) were studied at stimulus strengths from the threshold (40 % maximum stimulus) to three times the threshold (maximum). Results suggest that sensory amplification begins at the P14 generator source near the cuneate nucleus. There were no statistically significant difference in sensory amplification between P14 and cortical N20/P25, indicative that the cuneate nucleus is the main site of the central amplifying process.