The late Charles David Marsden was Professor of Neurology at the Institute of Neurology/Neurosurgery at Queen Square and a leading figure in the study of Movement Disorders. Among his many significant scientific contributions were the pioneering of evoked responses, and transcranial electrical and magnetic stimulation as methods of demonstrating conduction in neuronal pathways, and establishing the existence and importance of long latency reflexes in maintaining posture. Together with Professor Stanley Fahn, of the Neurological Institute in New York, he founded the Movement Disorder Society and its scientific journal Movement Disorders. He died in 1998. Ivan Donaldson is on the Board of Directors of the New Zealand Brain Research Institute, Christchurch New Zealand, and was for many years affiliated with the Institute of Neurology and Neurosurgery at Queen Square. He was Associate Professor at the Christchurch School of Medicine and Consultant Neurologist at Christchurch Hospital. Kailash Bhatia is a Professor of Clinical Neurology in the Sobell Department of Movement Neuroscience at the Institute of Neurology and an Honorary Consultant Neurologist at the National Hospital for Neurology. His main research interest is in movement disorders, specifically the merging of clinical, electrophysiological and imaging methods to provide insights into the pathophysiology of conditions like dystonia and Parkinson's disease. Susanne A Schneider worked for three years in the field of movement disorders at the National Hospital for Neurology and Neurosurgery, Queen Square, London. In her PhD thesis she studied the clinical and electrophysiological aspects of genetic movement disorders, leading to more than thirty publications. She is currently working at the Interdisciplinary Center of Genetic Movement Disorders and the Department of Clinical and Molecular Neurogenetics at the Department of Neurology, University of Lübeck, Germany.