Assessment of motor neuron excitability in parkinsonian rigidity by the F wave.
F-wave responses from abductor pollicis brevis muscle occurred more frequently, with a larger amplitude and longer duration in rigid parkinsonian patients than in age-matched normal controls. F-wave potentiation during voluntary contraction was impaired in parkinsonian patients. These findings suggest that spinal motor neuron excitability is enhanced in rigidity. F-wave amplitude was significantly correlated to the clinical evaluation of motor disability, so that the F wave may be regarded as a useful approach to quantitative evaluation of rigidity.
D000368:Aged; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D009127:Muscle Rigidity / Q000473:pathology / Q000503:physiopathology*; D010300:Parkinson Disease / Q000473:pathology / Q000503:physiopathology*; D011930:Reaction Time