1. Department of Neuromedicine and Movement Science, NTNU Norwegian University of Science and Technology, Trondheim, Norway
2. Norwegian Advisory Unit on Headache, Department of Neurology and Clinical Neurophysiology, St Olavs University Hospital, Trondheim, Norway
3. Department of Neurosurgery, St Olavs University Hospital, Trondheim, Norway
4. Department of Neurology and Clinical Neurophysiology, St Olavs University Hospital, Trondheim, Norway