Independence of soleus H-reflex tests in control and spastic subjects shown by principal components analysis

R. B. Willemse, J. H. Koelman, L. J. Bour, B. W. Ongerboer de Visser

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Different soleus H-reflex tests are used in the study of neurophysiological mechanisms of motor control. We studied the interdependence pattern of a number of soleus H-reflex tests, i.e., vibratory inhibition, the ratio of the reflex response to direct muscle potential (H/M ratio) and the homonymous recovery curve with a principal components analysis in 48 healthy controls and 38 patients with signs of the upper motoneuron syndrome. In controls, the analysis showed 3 independent principal components (PCs). Vibratory inhibition and H/M ratio loaded on separate components. Late facilitation and late inhibition variables of the recovery curve loaded on the third component due to the positive correlation (P < 0.001) between these variables. In spastic patients the analysis identified 4 independent PCs corresponding with vibratory inhibition, H/M ratio, late facilitation and late inhibition variables, respectively. The findings suggest that the mutual independence of the different soleus H-reflex tests in patients with the upper motoneuron syndrome has retained the control situation to a large extent
Original languageEnglish
Pages (from-to)440-443
Number of pages4
JournalElectroencephalography and Clinical Neurophysiology
Issue number6
Publication statusPublished - Dec 1994


  • Adolescent
  • Adult
  • Aged
  • Electromyography
  • H-Reflex/physiology
  • Humans
  • Middle Aged
  • Motor Neuron Disease/physiopathology
  • Multivariate Analysis
  • Muscle Spasticity/physiopathology
  • Muscle, Skeletal/physiopathology
  • Recruitment, Neurophysiological/physiology

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