[1] Univ Barcelona, Hosp Clin, Neurol Serv, Barcelona, Spain
[2] Univ Barcelona, Hosp Clin, Inst Invest Biomed August Pi Sunyer, IDIBAPS, Barcelona, Spain
[3] Univ Barcelona, Bank Teixits Neurol, Serv Cientif Tenics, Barcelona, Spain
[4] Mem Sloan Kettering Canc Ctr, Dept Neurol, New York, NY 10021 USA