1. University of Groningen, University Medical Center Groningen, Department of Neurology; Groningen The Netherlands
2. University of Groningen, University Medical Center Groningen, Department of Clinical Neurophysiology; Groningen The Netherlands
3. Department of Endocrinology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
4. Department of Medicine Surgery and Neurosciences; University of Siena, Eye tracking and Visual Application Lab (EVA Lab)-Neurology and Neurometabolic Unit; Siena Italy
5. Department of Neuroscience, Department of Ophthalmology; The Johns Hopkins University, The Johns Hopkins Hospital, Department of Neurology, Department of Otolaryngology-Head and Neck Surgery; Baltimore Maryland USA
6. University of Groningen, Division of Metabolic Diseases, University Medical Center Groningen; Groningen The Netherlands
7. University of Groningen, Department of Genetics, University Medical Center Groningen; Groningen The Netherlands