1. Institute of Medical Statistics, Informatics and Epidemiology; University of Cologne; Germany
2. Department of Neurology; University Hospital Cologne; Germany
3. Department of Pediatric Neurology; Cook Children's Medical Center; Fort Worth; Texas; United States of America
4. Complex Motor Disorders Service, Pediatric Neuroscience; Guy's & St Thomas' Hospitals Foundation Trust & King's College Hospital Foundation Trust, King's Health Partners; London; United Kingdom
5. Department of Pediatric Neurology; University Hospital; Cologne; Germany