Short-term high-frequency transcutaneous electrical nerve stimulation decreases human motor cortex excitability.
Several previous studies have shown that periods of changed sensory input can have after effects on the excitability of the corticospinal system. Here we test whether the parameters of peripheral stimulation conventionally used to treat pain with transcutaneous electrical nerve stimulation (TENS: 90 Hz) also have modulatory effects on the motor system. We measured the amplitude of motor evoked potentials (MEPs) elicited by the focal transcranial magnetic stimulation in the right abductor pollicis brevis and first dorsal interosseous muscles before and after 30 min TENS over the right thenar eminence. In addition, we evaluated tactile and 2-point discrimination thresholds at the same site. TENS transiently reduced MEPs and increased sensory thresholds. This suggests that short-term TENS might have an inhibitory effect on both the sensory and motor systems.
Mima
Tatsuya
T
Human Brain Research Center, Kyoto University Graduate School of Medicine, Human and Brain Research Center, Kyoto 606-8507, Japan. mima@kuhp.kyoto-u.ac.jp
Oga
Tatsuhide
T
Rothwell
John
J
Satow
Takeshi
T
Yamamoto
Jun-ichi
J
Toma
Keiichiro
K
Fukuyama
Hidenao
H
Shibasaki
Hiroshi
H
Nagamine
Takashi
T
D000328:Adult; D000344:Afferent Pathways / Q000502:physiology*; D019054:Evoked Potentials, Motor / Q000502:physiology*; D006801:Humans; D008280:Magnetics; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D010525:Peripheral Nerves / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012684:Sensory Thresholds / Q000502:physiology; D013997:Time Factors; D014110:Touch / Q000502:physiology; D004561:Transcutaneous Electric Nerve Stimulation / Q000379:methods*