Objective: To get more insight in the pathophysiological basis of periodic lim b movement disorder (PLMD) with or without restless legs syndrome (RLS), we inve stigated whether these patients have spontaneous changes ...Objective: To get more insight in the pathophysiological basis of periodic lim b movement disorder (PLMD) with or without restless legs syndrome (RLS), we inve stigated whether these patients have spontaneous changes in H-reflexes or show altered reflex patterns after (external) inhibition or excitation of the relevan t spinal segment. Methods: The ratio of the peak-to-peak values of the maximal soleus H-reflex and the maximal direct muscle potential (H/M ratio), H-reflex recruitment curves, vibratory inhibition and recovery curves of the soleus H-r eflexin double stimulus experiments were measured in 9 PLMD patients and 11 cont rols. Results: In comparison to controls the vibratory inhibition, predominantly reflecting pre-synaptic inhibitory action, was depressed in PLMD patients. The soleus H-reflex recovery curves showed increased late facilitation and depress ed late inhibition, both reflecting diminished inhibition due to post-synaptic central activity. Conclusions: Our data indicate diminished inhibition at spinal level in PLMD patients. This is probably due to altered function of the descend ing spinal tracts, peripheral influence or changes at the inter-neural circuitr y at spinal level itself, or combinations of these 3 possibil ities. Significance: The results of this study give further insight in the pat hophysiology of PLMD and RLS by stressing the importance of diminished central i nhibition.展开更多
文摘Objective: To get more insight in the pathophysiological basis of periodic lim b movement disorder (PLMD) with or without restless legs syndrome (RLS), we inve stigated whether these patients have spontaneous changes in H-reflexes or show altered reflex patterns after (external) inhibition or excitation of the relevan t spinal segment. Methods: The ratio of the peak-to-peak values of the maximal soleus H-reflex and the maximal direct muscle potential (H/M ratio), H-reflex recruitment curves, vibratory inhibition and recovery curves of the soleus H-r eflexin double stimulus experiments were measured in 9 PLMD patients and 11 cont rols. Results: In comparison to controls the vibratory inhibition, predominantly reflecting pre-synaptic inhibitory action, was depressed in PLMD patients. The soleus H-reflex recovery curves showed increased late facilitation and depress ed late inhibition, both reflecting diminished inhibition due to post-synaptic central activity. Conclusions: Our data indicate diminished inhibition at spinal level in PLMD patients. This is probably due to altered function of the descend ing spinal tracts, peripheral influence or changes at the inter-neural circuitr y at spinal level itself, or combinations of these 3 possibil ities. Significance: The results of this study give further insight in the pat hophysiology of PLMD and RLS by stressing the importance of diminished central i nhibition.
