1. Department of Neurosurgery, Neurosurgery Teaching Hospital, Baghdad, Iraq
2. Department of Neurosurgery, University of Al-Nahrain, Baghdad, Iraq
3. Department of Neurosurgery, College of Medicine, University of Baghdad, Baghdad, Iraq
4. Department of Neurosurgery, College of Medicine, University of Al-Iraqia, Baghdad, Iraq,
5. Department of Neurosurgery, Azerbaijan Medical University, Baku, Azerbaijan
6. Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio, United States.