Hemiplegic spasticity: neurophysiologic studies.
The excitability of segmental reflex pathways in normal subjects and in patients with hemiplegia has been examined by conditioning the monosynaptic H reflex with a 200 msec burst of vibration applied to the tendo Achilles. In 6 normal subjects, the burst of vibration produced a short-latency facilitation of soleus motoneurons (attributed to monosynaptic excitation) which was followed by a longer-latency inhibition. A similar response was observed in 8 patients with hemiplegia, but the late inhibition was significantly less. The loss of an inhibitory mechanism may contribute to the exaggerated reflexes observed in patients with hemiplegia.
D000328:Adult; D006181:H-Reflex; D006429:Hemiplegia / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D009128:Muscle Spasticity / Q000503:physiopathology*; D009420:Nervous System / Q000503:physiopathology; D009433:Neural Inhibition; D012021:Reflex, Abnormal / Q000503:physiopathology*; D012023:Reflex, Monosynaptic; D014732:Vibration