title: Cortical activation change induced by neuromuscular electrical stimulation during hand movements: a functional NIRS study.
abstract: OBJECTIVE
  Neuromuscular electrical stimulation (NMES) has been used in the field of rehabilitation for a long time. Previous studies on NMES have focused on the peripheral effect, in contrast, relatively little is known about the effect on the cerebral cortex. In the current study, we attempted to investigate the change of cortical activation pattern induced by NMES during execution of hand movements in normal subjects, using functional near infrared spectroscopy (fNIRS).
  
  
  METHODS
  Twelve healthy normal subjects were randomly assigned to the NMES group (six subjects) and the sham group (six subjects). We measured oxy-hemoglobin (HbO) in six regions of interest (ROI) during pre-NMES and post-NMES motor phase; the left dorsolateral and ventrolateral prefrontal cortex, premotor cortex, primary sensory-motor cortex (SM1), hand somatotopic area of SM1, and posterior parietal cortex. Between the pre-NMES and the post-NMES motor phases, real or sham NMES was applied on finger and wrist extensors of all subjects during a period of 5 minutes.
  
  
  RESULTS
  In all groups, during the pre-NMES motor phase, the HbO value in the hand somatotopic area of the left SM1 was higher than those of other ROIs. In the NMES group, during the post-NMES motor phase, HbO value variation in the hand somatotopic area of the left SM1 showed a significant decrease, compared with that of sham group (p < 0.05). However, in the sham group, similar aspect of results in HbO values of all ROIs was observed between pre-NMES and post-NMES motor phases (p > 0.05).
  
  
  CONCLUSIONS
  Results of this study showed that NMES induced a decrease of cortical activation during execution of hand movements. This finding appears to indicate that application of NMES can increase the efficiency of the cerebral cortex during execution of motor tasks.
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Jang
authors.forename: Woo Hyuk
authors.initials: WH
authors.lastname: Jang
authors.forename: Pyung Hun
authors.initials: PH
authors.lastname: Chang
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Jin
authors.forename: Young Gi
authors.initials: YG
authors.lastname: Kim
authors.affiliation: Department of Physical Therapy, College of Health Sciences, Dankook University, 119, Dandae-ro, Dongnam-gu, Cheonan-si, Chungnam 330-714, Republic of Korea. eangbul@hanmail.net.
authors.forename: Sang Seok
authors.initials: SS
authors.lastname: Yeo
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared