1. University of Groningen, University Medical Center Groningen, Department of Neurology; Groningen The Netherlands
2. Haga Ziekenhuis (Haga Hospital), Department of Neurology; The Hague The Netherlands
3. European Medical School Oldenburg-Groningen; Carl von Ossietzky Universität Oldenburg; Oldenburg Germany
4. University of Groningen, University Medical Centre Groningen, Department of Genetics; Groningen The Netherlands