1 Department of Neurosurgery, Atenas Medical School, Passos, MG, Brazil.
2 Department of Neurosurgery, State University of Ponta Grossa, PR, Brazil; Post Graduation Program, State University of Ponta Grossa, PR, Brazil.
3 Department of Neurosurgery, Atenas Medical School, Passos, MG, Brazil; Division of Neurosurgery, School of Medicine-University of São Paulo (FMUSP), Hospital das Clínicas / FMUSP, São Paulo, SP, Brazil.
4 Post Graduation Program, State University of Ponta Grossa, PR, Brazil.
5 Department of Neurosurgery, State University of Ponta Grossa, PR, Brazil.