1. National Parkinson Foundation International Centre of Excellence, Department of Neurology, King's College Hospital and King's College, Denmark Hill, London, UK
2. Department of Neurology, Technical University Dresden, Dresden, Germany
3. National Parkinson Foundation International Centre of Excellence, Department of Neurology, King's College Hospital, Denmark Hill, London, UK
4. Department of Neurosurgery, King's College Hospital, Denmark Hill, London, UK