1. Sobell Department of Motor Neuroscience and Movements Disorders, Institute of Neurology, University of London, London, United Kingdom
2. Department of Neurology and Clinical Neurophysiology, Academic Hospital Bogenhausen of the Technical University of Munich, Munich, Germany
3. Department of Psychiatry and Behavioural Sciences, University College and the National Hospital for Neurology and Neurosurgery, London, United Kingdom
4. Department of Neuropsychiatry, The National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom