1. Sobell Department of Motor Neuroscience and Movement Disorders; University College London (UCL) Institute of Neurology; London United Kingdom
2. Dipartimento di Scienze Neurologiche e del Movimento; Università di Verona; Verona Italy
3. Department of Molecular Neuroscience; UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery; London United Kingdom
4. University Medical Center Hamburg-Eppendorf (UKE); Neurology Hamburg Germany
5. Second Department of Neurology; Kapodistrian University of Athens; Greece
6. Neurology Clinic; Philipps University; Marburg Germany
7. The Lysholm Department of Neuroradiology; National Hospital for Neurology and Neurosurgery; London United Kingdom