Soleus H-reflex tests in spasticity and dystonia: A computerized analysis

L.J. Bour*, B.W. Ongerboer de Visser, J.H.T.M. Koelman, G.J. van Bruggen, J.D. Speelman

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

29 Citations (Scopus)
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In 54 healthy individuals, and in 25 spastic and 7 dystonic subjects, soleus H-reflex vibratory inhibition, H M ratio, and homonymous recovery curves obtained at two stimulus intensity levels were investigated in the same subject. In spasticity, the most prominent changes consist of a diminution of the vibratory inhibition at stimulus intensities lower than needed for a maximum H-reflex and an increase in the H M ratio. These results suggest that presynaptic inhibition is reduced mainly at low-intensity levels and that excitability of motoneurons is increased. Recovery curves in spasticity do not show such significant changes as found for the recruitment curves. In dystonia, prominent changes occur in the late facilitatory phase of the recovery curve obtained at 0.5 Hmax stimulus intensity, suggesting increased interneuronal activity. Vibratory suppression may be diminished, but H M ratio is unaltered. A multivariate analysis was used to identify variables that discriminated between control, spastic, and dystonic subjects. The analysis yielded two canonical variables that are a linear combination of four H-reflex variables that contribute significantly to the group classification. Based on these two canonical variables, each group can be properly differentiated quantitatively.

Original languageEnglish
Pages (from-to)9-19
Number of pages11
JournalJournal of electromyography and kinesiology
Issue number1
Publication statusPublished - 1991
Externally publishedYes


  • Dystonia
  • Recovery
  • Recruitment
  • Soleus H-reflex
  • Spasticity


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