Using electrodiagnostic machine to study movement rhythm variation.
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.
Kao
Chuen-Der
CD
Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
Chen
Jen-Tse
JT
Lee
Yi-Chung
YC
Shan
Din-E
DE
Lin
Yung-Yang
YY
Chen
Robert
R
Chung
Petrina S T
PS
Wu
Zin-An
ZA
Liao
Kwong-Kum
KK
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