1. Departament of Neurosurgery, Getúlio Vargas University Hospital - Federal University of Amazonas, Manaus, AM, Brazil,
2. Department of Neurosurgery, Hospital Maradei - Clínica dos Acidentados, Belém, PA, Brazil,
3. Department of Neurosurgery, Hospital Regional do Baixo Amazonas, Santarém, PA, Brazil,
4. Department of Neurosurgery, University of São Paulo, São Paulo, SP, Brazil.