1. Department of Molecular Neuroscience and Reta Lila Weston Institute, University College London Institute of Neurology, London, London, United Kingdom
2. Department of Neurology, Faculty of Medicine University of Thessaly, Larissa, Greece
3. Taub Institute, Sergievsky Center, Department of Neurology, Columbia University, New York, New York, USA
4. Department of Neurology, Medical School of National and Kapodistrian University of Athens, Athens, Greece
5. Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, United Kingdom
6. Unit of Functional Neurosurgery, Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, University College London, London, United Kingdom