title: Using electrodiagnostic machine to study movement rhythm variation.
abstract: BACKGROUND
  Hand movement constitutes the most common daily activities in our life. Hand dexterity is often impaired in patients with neurological disease. We developed an adjunct method, based upon the electrodiagnostic software, for study of motor control and hand dexterity.
  
  
  METHODS
  Thirty-two normal subjects, 2 stroke patients and 2 Parkinson patients were included in the study. All of them were right-handed, and were asked to pace rhythmic finger tapping at a comfortable rate without cue or any external stimuli. A trigger kit was designed to transform the finger tapping. After using the triggering mode and adjusting the sweep speed, 2 tapping signals were simultaneously displayed on the screen. The first signal was the triggering potential, and the variation in timing of the second signal represented the variation in timing of the inter-response interval. Twenty sweeps were recorded, superimposed and measured on the screen. Movement rhythm variation (MRV) was defined as b/a x 100 (b = [maximal interval of finger tapping - minimal interval of finger tapping]; a = [maximal interval of finger tapping + minimal interval of finger tapping]/2). Each subject started with right hand and then left hand.
  
  
  RESULTS
  MRV measurement showed excellent intrarater (r = 0.97) and interrater (r = 0.97) reliability. In normal right-handed subjects, the MRV was better in right hand than in left hand (right 16.5 +/- 4.1% and left 21.0 +/- 7.6%; p < 0.05). The MRV improved in stroke patients along with the recovery and improved in Parkinson patients after levodopa treatment.
  
  
  CONCLUSIONS
  MRV was a good method to provide quantitative data for assessment of hand dexterity. Our study also showed the potential role of MRV in motor control study.
authors.affiliation: Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Chuen-Der
authors.initials: CD
authors.lastname: Kao
authors.forename: Jen-Tse
authors.initials: JT
authors.lastname: Chen
authors.forename: Yi-Chung
authors.initials: YC
authors.lastname: Lee
authors.forename: Din-E
authors.initials: DE
authors.lastname: Shan
authors.forename: Yung-Yang
authors.initials: YY
authors.lastname: Lin
authors.forename: Robert
authors.initials: R
authors.lastname: Chen
authors.forename: Petrina S T
authors.initials: PS
authors.lastname: Chung
authors.forename: Zin-An
authors.initials: ZA
authors.lastname: Wu
authors.forename: Kwong-Kum
authors.initials: KK
authors.lastname: Liao
mesh_terms: D000328:Adult; D000368:Aged; D004568:Electrodiagnosis / Q000295:instrumentation*; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D010300:Parkinson Disease / Q000503:physiopathology; D020521:Stroke / Q000503:physiopathology