1. Spinal Cord Injury Center, Balgrist University Hospital, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
2. Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
3. Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom.
4. Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.