[1] Pontificiae Univ Catolica Rio Grande do Sul, Inst Cerebro, Porto Alegre, RS, Brazil
[2] Pontificiae Univ Catolica Rio Grande do Sul, Hosp Sao Lucas, Porto Alegre, RS, Brazil
[3] Pontificiae Univ Catolica Rio Grande do Sul, Fac Med, Dept Neurol, Porto Alegre, RS, Brazil
[4] Pontificiae Univ Catolica Rio Grande do Sul, Porto Alegre, RS, Brazil
[5] Hosp Clin Porto Alegre, Dept Oncol, Porto Alegre, RS, Brazil
[6] Pontificiae Univ Catolica Rio Grande do Sul, Hosp Sao Lucas, Inst Cerebro, BR-90160090 Porto Alegre, RS, Brazil