1. Headache Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
2. NIHR-Wellcome Trust King’s Clinical Research Facility, SLaM Maudsley Biomedical Research Centre, King’s College Hospital, London, UK
3. Department of Neurology, Hospital Nuestra Señora Del Rosario, Madrid, Spain
4. Department of Neurology, Bangalore Medical College and Research Institute, Bangalore, India
5. Department of Neurology, Auckland City Hospital, Auckland, New Zealand