1. Department of Neurosurgeon - Pain Therapy, San Giovanni-Addolorata Hospital, Roma, Lazio, Italy
2. Department of Neurosurgery, San Giovanni-Addolorata Hospital, Roma, Lazio, Italy
3. Department of Neurosurgery, Virgen de la Arrixaca University Hospital, El Palmar, Murcia, Spain
4. Unit of Interventional and Surgical Pain Management, Guglielmo da Saliceto Hospital, Piacenza, Emilia-Romagna, Italy