TMS mapping and fMRI were used to investigate changes in the motor cortex representation of the hand in a patient with complete loss of right hand function following traumatic avulsion of the cervical roots C7 and C8. Both TMS and fMRI demonstrated an expansion of the motor representation of the forearm into the hand area contralateral to the injured side. fMRI of the hand area, however, revealed that this area could still be activated when the patient was instructed to imagine finger tapping with his plegic hand. These results indicate that the plegic hand is still represented in the motor cortex, despite the fact that the same cortical area is also now active during movements involving forearm muscles.
1Departments of Neurology, Aachen Technical University, Pauwelsstr. 30, D-52057 Aachen, Germany
2Departments of Neuroradiology, Aachen Technical University, Pauwelsstr. 30, D-52057 Aachen, Germany
3Human Cortical Physiology Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
4Corresponding Author: Rudolf Töpper
Acknowledgements: This study was supported by the Interdisziplinäres Zentrum Prävention und Kompensation von Störungen des ZNS and the START program of the Medical Faculty of the RWTH Aachen. B.B. received a grant (Bo 1576/1–1) from the Deutsche Forschungsgemeinschaft. The authors are grateful to Dr Stuart Fellows for his comments on the manuscript.
Received 20 August 1999 accepted 2 November 1999