[1] Univ Milan, Dept Clin Sci L Sacco, I-20157 Milan, Italy
[2] Kuopio Univ Hosp, Dept Clin Neurophysiol, Kuopio, Finland
[3] Kuopio Univ Hosp, Dept Neurol, Kuopio, Finland
[4] Kuopio Univ Hosp, Dept Clin Radiol, Kuopio, Finland
[5] Univ Eastern Finland, Dept Neurol, Kuopio, Finland
[6] Univ Eastern Finland, Dept Appl Phys, Kuopio, Finland
[7] Univ Eastern Finland, Dept Clin Neurophysiol, Kuopio, Finland
[8] Univ Liege, Cyclotron Res Ctr, Coma Sci Grp, Liege, Belgium