1. Faculty of Medicine and Health Sciences, Department of Anesthesia and Resuscitation Technology, An-Najah National University, Nablus, Palestine
2. Pain Clinic, Hospital Virgen de las Nieves, Granada, Faculty of Medicine, Granada Instituto de Investigacion Biosanitaria IBS, Granada, Spain
3. Department of Neurosurgery, Hospital Virgen de las Nieves, Granada, Spain