1. Neurosurgery Unit, Department of Head and Neck Surgery ARNAS Garibaldi Catania Italy
2. Experimental Biomedicine and Clinical Neurosciences, School of Medicine, Postgraduate Residency Program in Neurological Surgery, Neurosurgical Clinic Azienda Ospedaliera Universitaria Policlinico (AOUP) “Paolo Giaccone” Palermo Italy
3. Neurosurgery Clinic Birgunj Nepal
4. Department of Neurosurgery Cannizzaro Hospital, Trauma and Gamma Knife Center Catania Italy