1 Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Center of Expertise for Parkinson's and Movement Disorders, Nijmegen, Netherlands.
2 Radboud University Medical Center, Research Institute for Medical Innovation, Department of Neurology, Center of Expertise for Parkinson's and Movement Disorders, Nijmegen, Netherlands.
3 Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Center of Expertise for Parkinson's and Movement Disorders, Nijmegen, Netherlands bas.bloem@radboudumc.nl.