title: Effects of afferent stimulation rate on inhibitory spinal pathways in hemiplegic spastic patients.
abstract: OBJECTIVE
  It has recently been demonstrated in the cat and in healthy subjects that the effects of repetitive afferent fibre stimulation depends on the target spinal neurones. The purpose of this series of experiments was therefore to determine whether central nervous system lesions modify the behaviour of the inhibitory spinal pathways in response to repetitive activation of afferent fibres.
  
  
  METHODS
  The H-reflex technique was used to study the effect of increasing the conditioning stimulus rate from 0.16 to 1 Hz on disynaptic inhibition and on presynaptic Ia inhibition on the affected side of 36 hemiplegic patients.
  
  
  RESULTS
  The major finding was that, similar to results previously obtained in healthy subjects, increasing the conditioning stimulus rate in hemiplegic patients leads to an increase in the synaptic efficiency of inhibitory spinal circuits. Furthermore, a significant correlation was found between the severity of flexor carpi radialis muscle spasticity and the amount of disynaptic inhibition.
  
  
  CONCLUSIONS
  The reinforcement of inhibitory spinal networks induced by repetitive stimulation of afferent fibres is preserved in spastic patients, whereas the mechanisms underlying this phenomena might be altered.
  
  
  CONCLUSIONS
  The results of these experiments open up a number of possibilities for novel spasticity therapies based on non-invasive techniques.
authors.affiliation: UPMC Univ Paris 06 Er 6 Physiologie et Physiopathologie de la Motricité chez l'Homme, Médecine Physique et Réadaptation, Hôpital Pitié Salpêtrière, 75013 Paris, France.
authors.forename: N
authors.initials: N
authors.lastname: Roche
authors.forename: V
authors.initials: V
authors.lastname: Achache
authors.forename: A
authors.initials: A
authors.lastname: Lackmy
authors.forename: P
authors.initials: P
authors.lastname: Pradat-Diehl
authors.forename: J C
authors.initials: JC
authors.lastname: Lamy
authors.forename: R
authors.initials: R
authors.lastname: Katz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004525:Efferent Pathways / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D006429:Hemiplegia / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation; D009433:Neural Inhibition / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology*; D012720:Severity of Illness Index; D013116:Spinal Cord / Q000503:physiopathology*; D013569:Synapses / Q000502:physiology; D013997:Time Factors