1. Department of Cerebrovascular and Skull Base Surgery, Institute of Neurosurgery Asenjo, Providencia, Santiago, Chile
2. Department of Neurological Sciences, University of Chile, Santiago, Chile
3. Department of Neurosurgery, Clínica Las Condes, Santiago, Chile
4. Department of Neurosurgery, San Pablo Hospital, Coquimbo, Chile,
5. Department of Neurosurgery, Hospital das Clinicas da Faculdade de Medicina, University of Sao Paulo, Brazil.
6. Department of Neurosurgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA,
7. Department of Neurosurgery, San Borja Arriarán Hospital, Santiago, Chile
8. Department of Neurosurgery, Virgen de la Salud Hospital, Toledo, Madrid, Spain,
9. Department of Neurosurgery, Herminda Martin Hospital, Chillán, Chile
10. Department of Neurology and Neurosurgery, Jose Joaquín Aguirre Clinical Hospital, Santiago, Chile
11. Department of Neurosurgery, Sanatorio Allende, Córdoba, Argentina,