1. Head and Neck Research Group, Research Centre, Akershus University Hospital
2. Department of Neurology, Akershus University Hospital
3. Faculty Division Akershus University Hospital, University of Oslo, Nordbyhagen
4. Faculty Division Ullcvaal University Hospital, University of Oslo
5. Helse Ost Health Services Research Centre, Akershus University Hospital, L⊘enskog
6. Department of Neurology, Ullevaal University Hospital, Oslo, Norway