title: Different effects of transcutaneous electric nerve stimulation and electroacupuncture at ST36-ST37 on the cerebral cortex.
abstract: BACKGROUND
  The effects of transcutaneous electric nerve stimulation (TENS) and electroacupuncture (EA) on the cerebral cortex are largely unclear. The purpose of the present study was to investigate the effect of TENS and EA on the cerebral cortex by examining their effect on the median nerve-somatosensory evoked potentials (MN-SEPs).
  
  
  METHODS
  Twenty volunteers were studied. The cortical and cervical spinal potentials were recorded by median nerve stimulation at the left wrist. Sham TENS, 2 Hz TENS and 2 Hz EA were applied to both ST36 and ST37. MN-SEPs were recorded during sham TENS, 2 Hz TENS and 2 Hz EA, with at least 1 week interval for each subject. One-way analysis of variance was used to determine the differences in latency and amplitude of the MN-SEPs observed in the stimulation and post-stimulation periods compared with baseline. Scheffe's post hoc correction was employed to identify pairwise differences.
  
  
  RESULTS
  No differences in mean latency were found between the stimulation procedures during the stimulation and post-stimulation periods. 2 Hz EA but not sham TENS or 2 Hz TENS caused higher mean amplitudes in N20 and N30 during the stimulation and post-stimulation periods.
  
  
  CONCLUSIONS
  EA, but not TENS, induces changes in certain components of the signal.
authors.affiliation: Graduate Institute of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan Department of Traditional Chinese Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Yu-Tien
authors.initials: YT
authors.lastname: Kang
authors.affiliation: Department of Neurology, Taichung Hospital, Ministry of Health and Welfare, Taichung, Taiwan.
authors.forename: Yi-Sheng
authors.initials: YS
authors.lastname: Liao
authors.affiliation: Graduate Institute of Integrated Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan Department of Chinese Medicine, China Medical University Hospital, Taichung, Taiwan Research Center for Chinese Medicine and Acupuncture, China Medical University, Taichung, Taiwan.
authors.forename: Ching-Liang
authors.identifier: http://orcid.org/0000-0002-8187-4716
authors.initials: CL
authors.lastname: Hsieh
mesh_terms: D015669:Acupuncture Points; D000328:Adult; D000704:Analysis of Variance; D002540:Cerebral Cortex / Q000502:physiology*; D015671:Electroacupuncture; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000502:physiology; D004561:Transcutaneous Electric Nerve Stimulation; D055815:Young Adult
keywords: CLINICAL PHYSIOLOGY