1. Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology and Neuroscience King's College London London UK
2. Department of Neurology Bangalore Medical College and Research Institute Bangalore India
3. NIHR‐Wellcome Trust King's Clinical Research Facility King's College Hospital London UK
4. Department of Neurology Taipei Municipal Wanfang Hospital Taipei Taiwan
5. Department of Neurology, School of Medicine, College of Medicine Taipei Medical University Taipei Taiwan
6. Department of Neurology Ghent University Hospital Ghent Belgium
7. Division of Neurology, Department of Medicine National University Hospital, National University Health System Singapore Singapore
8. Yong Loo Lin School of Medicine National University of Singapore Singapore Singapore
9. Department of Neurology University of California Los Angeles California USA