1. O. Sjaastad and H. Hovdahl, Department of Neurology, Regionsykehuset, Trondheim University Hospital, Trondheim, Norway; C. Saunte, Department of Otorhinolaryngology, Regionsykehuset, Trondheim University Hospital, Trondheim, Norway; H. Breivik, Department of Anaesthesiology, Regionsykehuset, Trondheim University Hospital, Trondheim, Norway; E. Grønbâk, Department of Surgery, Whittaker (S.A.) Ltd., Tabuk, Saudi Arabia