1. Neurosurgery Department, School of Medicine, Universidade Federal do Vale do São Francisco, Petrolina PE, Brazil
2. Neurosurgery Department, Federal University of Pernambuco, Recife, PE, Brazil
3. Neurosurgery Department, University of Pernambuco, Recife, PE, Brazil
4. Neurosurgery Department, Federal University of Pernambuco, Recife, Brazil
5. Neurosurgery Department, Hospital Beneficiência Portuguesa, São Paulo, SP, Brazil
6. Neurosurgery Department, Hospital da Restauração, Recife, PE, Brazil