1. Universidad Autonoma de Centroamerica (UACA), School of Medicine, San José, Costa Rica;
2. Department of Neurosurgery, Fundación Clínica Valle del Lili, Cali, Colombia;
3. Neurosurgery Section, Universidad del Valle, Cali, Colombia;
4. Department of Neurosurgery, Loscobos Medical Center, Bogotá, Colombia;
5. Department of Neurosurgery, Universidad del Bosque, Bogotá, Colombia; and
6. Department of Neurosurgery, Brain and Spine Associates, Monroe, Louisiana