[1] Hop Roger Salengro, CHRU, Gamma Knife Ctr, Dept Neurosurg, Lille, France
[2] Univ Toulouse 3, Fac Med, F-31062 Toulouse, France
[3] Neurosci Res Ctr, Ist Galeazzi, Dept Neurosurg, Milan, Italy
[4] Karolinska Inst, Dept Clin Neurosci, SE-17177 Stockholm, Sweden