title: Soleus H-reflex tests and clinical signs of the upper motor neuron syndrome.
abstract: Soleus H-reflex tests are used for elucidating pathophysiological mechanisms in motor control. The cumulative vibratory inhibition of the soleus H-reflex, the ratio of the reflex to direct muscle potential (H to M ratio) and the recovery curve of the soleus H-reflex were studied in 38 patients with varying signs of the upper motor neuron syndrome for a possible relation with clinical features. The results were compared with those obtained from a group of healthy volunteers. The magnitude of vibratory inhibition decreased with increase of hypertonia. The H to M ratio increased as the activity of the tendon reflex was enhanced and correlated to a lesser degree with muscle tone. Both the H to M ratio and late facilitation of the soleus H-reflex recovery curve were elevated in clonus. The findings suggest that alterations in the results of soleus H-reflex tests relate to specific clinical features of the upper motor neuron syndrome. Possible pathophysiological implications are discussed.
authors.affiliation: Department of Clinical Neurophysiology, Medical Centre, AZ-Amsterdam, The Netherlands.
authors.forename: J H
authors.initials: JH
authors.lastname: Koelman
authors.forename: L J
authors.initials: LJ
authors.lastname: Bour
authors.forename: A A
authors.initials: AA
authors.lastname: Hilgevoord
authors.forename: G J
authors.initials: GJ
authors.lastname: van Bruggen
authors.forename: B W
authors.initials: BW
authors.lastname: Ongerboer de Visser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000503:physiopathology*; D009132:Muscles / Q000503:physiopathology; D011999:Recruitment, Neurophysiological / Q000502:physiology; D014732:Vibration