The activation of the cortical hand area by toe tapping in two bilateral upper-extremities amputees with extraordinary foot movement skill

Yu, Xiaojing; Zhang, Shizheng; Liu, Hai; Chen, Yizhang

doi:10.1016/j.mri.2005.10.024

« Previous Next »Magnetic Resonance Imaging
Volume 24, Issue 1 , Pages 45-50, January 2006

The activation of the cortical hand area by toe tapping in two bilateral upper-extremities amputees with extraordinary foot movement skill

Xiaojing Yu
- Department of Radiology, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou City 310016, Zhejiang Province, China
- Department of Radiology, Wujing Hospital, Hangzhou City 310053, Zhejiang Province, China
- Corresponding author. Department of Radiology, Sir Run Run Shaw Hospital, Hangzhou City 310016, Zhejiang Province, China. Tel.: +86 13516800020; fax: +86 571 86032876.
Shizheng Zhang
- Department of Radiology, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou City 310016, Zhejiang Province, China
Hai Liu
- Department of Radiology, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou City 310016, Zhejiang Province, China
Yizhang Chen
- Department of Neurobiology, Medical College of Zhejiang University, Hangzhou City 310006, Zhejiang Province, China

Received 2 August 2005; accepted 8 October 2005. published online 19 December 2005.

Abstract

Functional reorganization of the human brain after an arm amputation has been documented in several investigations, but as far as we know, there has been no report on amputees with skilled foot movement ability. To further assess the power of functional reorganization of the brain after an amputation, we investigated two bilateral upper-extremities amputees who were professional sculptors and painters with their feet. Performance tests showed that they possessed high foot movement ability. Functional MRI data indicated that toe tapping of the amputees not only activated the classical foot primary motor cortex, but also activated the hand area. In the T1-weighted MRI, the central sulci of both amputees kept their characteristic shape. Our study suggests that there is a remarkable power of neural plasticity in the motor cortex, and the maturation of the cortex develops in response to daily practice. The possible mechanisms of the reorganization are tentatively discussed.

Keywords: Cortical plasticity, Foot movement, Amputee, Functional magnetic resonance imaging (fMRI)