1. Division of Neurology, Garibaldi Hospital, Catania, Italy
2. Otalaryngology Department, University of Padua, Padua, Italy
3. Neuromuscular Diseases Unit, National Neurological Institute “Carlo Besta,“ Milan, Italy
4. Division of Endocrinology, Department of Internal and Specialistic Medicine, University of Catania, Garibaldi Hospital, Catania, Italy