1 Sleep Medicine Centre, Neurophysiopathology Unit, Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy. Electronic address: dott.claudioliguori@yahoo.it.
2 Sleep Medicine Centre, Neurophysiopathology Unit, Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy.
3 Sleep Medicine Centre, Neurophysiopathology Unit, Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy; Fondazione Santa Lucia IRCCS, Rome, Italy.
4 Department of Orthopedics and Traumatology, University of Rome "Tor Vergata", Rome, Italy.