Original Research ARTICLE
Peripheral nervous system reconstruction reroutes cortical motor output - brain reorganization uncovered by effective connectivity
- 1Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Austria
- 2High Field MR Centre, University Clinic for Radiology and Nuclear Medicine, Medical University of Vienna, Austria
- 3TU-BioMed Association for Biomedical Engineering, Technische Universität Wien, Austria
- 4Institute of Psychology, University of Graz, Austria
- 5AUVA Research Centre, Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Austria
Cortical reorganization in response to peripheral nervous system damage is only poorly understood. In patients with complete brachial plexus avulsion and subsequent reconnection of the end of the musculocutaneous nerve to the side of a phrenic nerve, reorganization leads to a doubled arm representation in the primary motor cortex. Despite homuncular organization being one of the most fundamental principles of the human brain, movements of the affected arm now activate 2 loci: the completely denervated arm representation and the diaphragm representation. Here we investigate the details behind this peripherally triggered reorganization, which happens in healthy brains. fMRI effective connectivity changes within the motor network were compared between a group of patients and age matched healthy controls at 7 Tesla (6 patients and 12 healthy controls). Results show the establishment of a driving input of the denervated arm area to the diaphragm area which is now responsible for arm movements. The findings extend current knowledge about neuroplasticity in primary motor cortex: a denervated motor area may drive an auxilliary area to reroute its motor output.
Keywords: Dynamic causal modelling (DCM), functional magnetic resonance imaging (fMRI), Phrenic Nerve, Brachial plexus avulsion, peripheral nerve reconstruction
Received: 24 Aug 2018;
Accepted: 05 Dec 2018.
Edited by:Peter Sörös, University of Oldenburg, Germany
Reviewed by:Mo Chen, University of Minnesota Twin Cities, United States
Lotta Fornander, Region Ostergotland, Sweden
Copyright: © 2018 Amini, Fischmeister, Matt, Schmidhammer, Rattay and Beisteiner. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Roland Beisteiner, Medical University of Vienna, Study Group Clinical fMRI, Department of Neurology, Vienna, Austria, email@example.com