1. Department of Neurology; University Medical Center Groningen, University of Groningen; The Netherlands
2. Department of General Practice; University Medical Center Groningen, University of Groningen; The Netherlands
3. MRC Centre for Neuropsychiatric Genetics and Genomics; Institute of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University; United Kingdom
4. Department of Neurology; Academic Medical Center, University of Amsterdam; Amsterdam The Netherlands
5. Department of Neurology; Haga Teaching Hospital; The Hague The Netherlands
6. Department of Pediatrics; Beatrix Children's Hospital; University Medical Center Groningen, University of Groningen; Groningen The Netherlands