1 Department of Neurosurgery, State University of Ponta Grossa, Brazil.
2 Department of Neurosurgery, University of Sao Paulo, Brazil; Department of Neurosurgery, Atenas Medical School, Passos-MG, Brazil. Electronic address: nicollasrabelo@hotmail.com.
3 Department of Neurosurgery, Atenas Medical School, Passos-MG, Brazil.
4 Department of Neurosurgery, University of Sao Paulo, Brazil.