1. Department of Clinical Neurophysiology Turku University Hospital and University of Turku Turku Finland
2. Department of Pediatrics and Adolescent Medicine Turku University Hospital and University of Turku Turku Finland
3. Department of Paediatric Neurology Tampere University Hospital Tampere Finland
4. Department of Otorhinolaryngology Turku University Hospital and University of Turku Turku Finland
5. Department of Biostatistics Faculty of Medicine University of Turku Turku Finland