1. University of Athens Medical School, Department of Neurology, 1 Neurological Clinic, Eginition Hospital, Athens, Greece
2. University of Athens Medical School, Sleep Study Unit, Eginition Hospital, Athens, Greece
3. Critical Care and Pulmonary Services, Center of Sleep Disorders, Evangelismos Hospital, Athens, Greece
4. Department of Neurosciences, University of Pisa, Pisa, Italy
5. University of Athens Medical School, Department of Neurology, 2 Neurological Clinic, ATTIKON University General Hospital, Haidari, Athens, Greece