1. Department of Neurosurgery, Neurosurgery Teaching Hospital, Baghdad, Iraq
2. Department of Neurosurgery, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
3. Department of Neurosurgery, College of Medicine, Baghdad University, Baghdad, Iraq
4. Department of Neurosurgery, Universidad de Cartagena, Cartagena de Indias, Colombia