Influence of Transcutaneous Electrical Nerve Stimulation on Cutaneous Silent Period

ABSTRACT

OBJECTIVE: To investigate the influence of high frequency transcutaneous electrical nerve stimulation (TENS) on cutaneous silent period. METHOD: Cutaenous silent period was recorded before and after high frequency TENS application in sixteen healthy adults (11 males, 5 females). Onset latency, duration, and minimum stimulation intensity to evoke cutaneous silent period were compared. In 7 male subjects, temporal changes of cutaneous silent period were observed after TENS application. RESULTS: Minimum stimulation intensity to evoke cutaneous silent period was significantly increased after high frequency TENS application (p<0.05) and yet, onset latency and duration showed no significant change. The increase in minimum stimulation intensity to evoke cutaneous silent period was maintained for 30 minutes after TENS and returned to the baseline level thereafter. CONCLUSIONS: These results suggest that high frequency TENS increase the depolarization threshold of A-delta fiber and this peripheral effect may be one of the pain control mechanisms of TENS.