[1] Uppsala Univ, Dept Womens & Childrens Hlth, Uppsala, Sweden
[2] Univ Oulu, Oulu Univ Hosp, PEDEGO Res Unit, Dept Pediat & Adolescence, Oulu, Finland
[3] Univ Oulu, Oulu Univ Hosp, Med Res Ctr, Oulu, Finland
[4] Univ Helsinki, Helsinki Univ Hosp, Childrens Hosp, Dept Child Neurol, Helsinki, Finland
[5] Univ Helsinki, Helsinki Univ Hosp, Dept Pediat & Adolescence, Helsinki, Finland
[6] Oulu Univ Hosp, Dept Neurol, Oulu, Finland
[7] Turku Univ, Turku Univ Hosp, Dept Pediat & Adolescent Med, Turku, Finland
[8] Univ Eastern Finland, Kuopio Univ Hosp, Pediat Res Unit, Kuopio, Finland