1. National Hospital for Neurology and Neurosurgery, London, United Kingdom
2. UCL Queen Square Institute of Neurology, London, United Kingdom
3. Royal National Ear Nose and Throat & Eastman Dental Hospital, London, United Kingdom
4. University of Leicester, Leicester, United Kingdom
5. National Hospital for Neurology and Neurosurgery, Royal National Ear Nose and Throat & Eastman Dental Hospital, and UCL Institute of Neurology, London, United Kingdom