1. Department of Physical Medicine and Rehabilitation Stavanger University Hospital Stavanger Norway
2. Centre for Movement Disorders, Stavanger University Hospital Stavanger Norway
3. Department of Mathematics and Physics University of Stavanger Stavanger Norway
4. Department of Neurology Stavanger University Hospital Stavanger Norway
5. Department of Clinical Medicine University of Bergen Bergen Norway
6. Department of Neurology Haukeland University Hospital Bergen Norway
7. Department of Chemistry, Bioscience and Environmental Engineering University of Stavanger Stavanger Norway