1. Department of Neurosurgery, Instituto de Neurologia de Goiania, Goiânia, GO, Brazil
2. Faculty of Medicine, Universidade Federal de Goiás, Goiânia, GO, Brazil
3. Department of Neurosurgery, Hospital Geral de Goiânia, Goiânia, GO, Brazil
4. Department of Surgery, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil