H-reflex modulation during gait in multiple sclerosis patients with spasticity
Authors:
- 1 April 1995
- journal article
- Published by Hindawi Limited in Acta Neurologica Scandinavica
- Vol. 91 (4) , 239-246
Abstract
The aim of the present study was to quantitate the Hoffmann (H-) reflex modulation in the soleus muscle of spastic multiple sclerosis patients during walking at different stimulus strengths, and to quantitate the influence of the excitation level of the soleus muscle on the H-reflex. The H-reflex modulation was quantified by the minimum H-reflex in the swing phase and the modulation index introduced by Yang et al. (1). Stimulus strengths were matched between subjects, and only stimuli intensities, which reflect modulation in the H-reflex with true neurophysiological origin, were used. Based on this approach, we found that the reflex modulation is impaired in moderate spastic patients at both a strong and a weak afferent input to the motoneuron pool in consistency with studies on severe spastic patients. This study concludes that the H-reflex modulation in the spastic patients is only related to the excitation level of the muscles, whereas both the excitation level and other factors than the excitation level are known to influence the H-reflex modulation in healthy subjects.Keywords
This publication has 14 references indexed in Scilit:
- Simulations of the alpha motoneuron pool electromyogram reflex at different preactivation levels in manBiological Cybernetics, 1994
- Contribution of peripheral afferents to the activation of the soleus muscle during walking in humansExperimental Brain Research, 1991
- H-Reflex Modulation During Walking in Spastic Paretic SubjectsCanadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques, 1991
- Mechanical and electromyographic responses to stretch of the human ankle extensorsJournal of Neurophysiology, 1991
- Sensitivity of monosynaptic test reflexes to facilitation and inhibition as a function of the test reflex size: a study in man and the catExperimental Brain Research, 1990
- Difference in the amplitude of the human soleus H reflex during walking and running.The Journal of Physiology, 1987
- A method for simulating the reflex output of a motoneuron poolJournal of Neuroscience Methods, 1987
- Amplitude modulation of the soleus H-reflex in the human during walking and standingThe Journal of Neuroscience, 1986
- Tension development and muscle activation in the leg during gait in spastic hemiparesis: independence of muscle hypertonia and exaggerated stretch reflexes.Journal of Neurology, Neurosurgery & Psychiatry, 1984
- Interactions between voluntary and postural mechanisms of thehuman motor system.Journal of Neurophysiology, 1970