1 Discipline of Neurosurgery, Santa Casa de São Paulo Medical School, Cesário Mota Júnior Street, 122, Vila Buarque, 01221-020 São Paulo, SP Brazil.
2 Discipline of Neurosurgery, Santa Casa de São Paulo Medical School, Cesário Mota Júnior Street, 122, Vila Buarque, 01221-020 São Paulo, SP Brazil ; Arnaldo Vieira de Carvalho Cancer Institute, São Paulo, Brazil.