Combined movement of multi-joint muscles activates a smaller area compared to the sum of areas activated by respective single-joint muscles after restoration of paresis

Abstract

Awake surgery provides accurate localization of brain function based on rapid reversible neurological changes during surgical manipulation. In this study, hand clenching rapidly deteriorated due to surgical manipulation during awake surgery and instantly recovered not by hand clenching alone but by combined movement of hand clenching and elbow flexion. Postoperative fMRI (functional MRI) showed a smaller area activated by combined movement of hand clenching and elbow flexion than the sum of areas activated by hand clenching alone and elbow flexion alone. Conversely, the activated area by combined movement of hand clenching and elbow flexion was almost the same as the sum of areas by hand clenching alone and elbow flexion alone in fMRI of normal volunteers. These findings indicate reorganization of the motor area by combined movement including the motor function of previous transient weakness, and might suggest the effectiveness of combined movement to improve motor paresis in rehabilitation.

Keywords:

• Awake surgery
• Brain tumor
• Combined movement
• fMRI
• Reorganization

We wish to thank H. Shinoura for assistance with manuscript preparation.