1. Department of Neurosurgery, The Center for Advanced Neurology and Neurosurgery (CEANNE Brazil), Brazil
2. Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
3. Neurosurgery Service, Hospital Padilla, Tucumán, Argentina
4. Department of Neurosurgery. Hospital da Força Aérea do Galeão, Rio de Janeiro, RJ, Brazil
5. Neurosurgery Service, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina
6. Department of Neurosurgery, Universidade de São Paulo, São Paulo, SP, Brazil
7. Department of Neurosurgery, Centro Universitário Atenas, Paracatu, MG, Brazil