Soleus H-reflex inhibition during gait initiation in Parkinson's disease

✍ Scribed by Koichi Hiraoka; Yoshimi Matsuo; Kazuo Abe

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 88 KB
• Volume: 20
• Category: Article
• ISSN: 0885-3185
• DOI: 10.1002/mds.20448

✦ Synopsis

Abstract

The soleus H‐reflex excitability during gait initiation was investigated in Parkinson's disease. Eleven patients participated in this study. Patients stepped forward as soon as the start signal flashed. Soleus H‐reflex was evoked from the trailing leg 100, 300, or 600 msec after the start signal. The electromyographic activity in the soleus muscle immediately before evoking the H‐reflex and the ankle joint motion were recorded. The soleus H‐reflex was inhibited 300 msec after the start signal. The amount of the soleus H‐reflex inhibition was inversely correlated with the Hoehn and Yahr stage; Items 14, 29, and 31 of the Unified Parkinson's Disease Rating Scale; and the delay of the onset of the ankle dorsiflexion from the start signal. In contrast, the amount of electromyographic activity immediately before evoking the H‐reflex was not significantly correlated with those measures but was significantly correlated with Item 22 of the Unified Parkinson's Disease Rating Scale. Those findings indicate that the amount of soleus H‐reflex inhibition during gait initiation depends on the severity of the disease. Abnormality of descending command may be related to the severity‐dependent H‐reflex inhibition. © 2005 Movement Disorder Society