1. Pain Relief and Palliative Care Unit, La Maddalena Cancer Center, Palermo, Italy, Palliative Medicine, Department of Anesthesia, and Intensive Care, University of Palermo, Palermo, Italy,
2. Pain Relief and Palliative Care Unit, La Maddalena Cancer Center, Palermo, Italy
3. Department of Clinical Neuroscience, University of Palermo, Palermo, Italy