[1] Turku Univ, Cent Hosp, Dept Clin Neurophysiol, FIN-20521 Turku, Finland
[2] Univ Virginia, Sch Med, Dept Neurol, Charlottesville, VA 22908 USA
[3] Vaasa Cent Hosp, Dept Neurol, Vaasa, Finland
[4] Univ Siena, Inst Neurol Sci, I-53100 Siena, Italy
[5] Univ Bologna, Inst Clin Neurol, Bologna, Italy
[6] Univ Toronto, Toronto, ON, Canada
[7] Hosp Sick Children, Dept Genet, Toronto, ON M5G 1X8, Canada
[8] Hosp Sick Children, Dept Pediat, Div Neurol, Toronto, ON M5G 1X8, Canada
[9] Turku Univ, Cent Hosp, Dept Radiol, Turku, Finland
[10] Univ Turku, Cent Hosp, Dept Pathol, FIN-20520 Turku, Finland