1. Department of Neuromedicine and Movement Science, NTNU Norwegian University of Science and Technology, Trondheim, Norway
2. NorHEAD, Norwegian Headache Research Centre, Norway
3. Department of Psychology, NTNU Norwegian University of Science and Technology, Trondheim, Norway
4. National Advisory Unit on Headaches, Department of Neurology and Clinical Neurophysiology, St. Olavs Hospital, Trondheim, Norway
5. Department of Physical Medicine and Rehabilitation, St. Olavs Hospital, Trondheim, Norway
6. UCL Queen Square Institute of Neurology, London, United Kingdom