[1] Natl Ctr Epilepsy, Sandvika, Norway
[2] Akershus Univ Hosp, Helse Ost Hlth Serv Res Ctr, Oslo, Norway
[3] Akershus Univ Hosp, Dept Neurol, Oslo, Norway
[4] Ullevaal Univ Hosp, Dept Pediat, Div Woman & Child, Oslo, Norway
[5] Univ Oslo, Dept Neurol, N-0316 Oslo, Norway