Department of Pediatric Neurology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität, Humboldt-Universität, Berlin Institute of Health, Berlin, Germany; Center for Chronically Sick Children, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität, Humboldt-Universität, Berlin Institute of Health, Berlin, Germany; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität, Humboldt-Universität, Berlin Institute of Health, Berlin, Germany. Electronic address: ellen.knierim@charite.de.