Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway.
NorHEAD, Norwegian Headache Research Centre, Oslo, Norway.
Department of Neurology, NeuroClinic, Norway, Lillestrøm, Norway.
Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy University of Gothenburg, Gothenburg, Sweden.