1. Sleep Research Centre; Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy
2. Sleep Medicine Unit, Neurocenter of Southern Switzerland, Ospedale Civico, Lugano, Switzerland
3. Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
4. Department of Somnology, Tokyo Medical University, Tokyo, Japan
5. Division of Sleep Medicine, Kansai Electric Power Medical Research Institute, Osaka, Japan
6. Multiple Sclerosis Center, Neurocenter of Southern Switzerland, Ospedale Civico, Lugano, Switzerland
7. Neuropsychology and Behavioural Neurology Research Unit, Neurocenter of Southern Switzerland, Ospedale Civico, Lugano, Switzerland