Subclinical abnormal EMG activation of the gastrocnemii during gait analysis in restless legs syndrome: A preliminary report in 13 patients

Objective: The purpose of this study was to detect the eventual presence of a minor voluntary motor involvement in restless legs syndrome (RLS), not detectable clinically, which might be observed by means of a sophisticated instrumental analysis of movement, such as gait analysis. Subjects and methods: Gait analysis was performed and surface EMG activity was recorded in 13 RLS patients and 8 normal controls from 8 muscles: tibialis anterior, gastrocnemius lateralis, gastrocnemius medialis, and soleus in both legs. Results: Ten out of the 13 RLS patients and none of the normal control group showed a mild abnormality of the EMG activation of the gastrocnemius muscles during gait which, however, had no detectable effects on its kinematics. Conclusions: These preliminary results might be interpreted as the effect of an impaired supraspinal dopaminergic control with possible action on spinal structures involved in the control of gait. If confirmed in future studies, this mild EMG abnormality might constitute an additional supportive feature for the diagnosis of RLS in difficult cases.