1. University of Illinois and Carle Clinic Association, Urbana, Illinois
2. Department of Neurology, Johns Hopkins University, Baltimore, Maryland
3. Seton Hall University School of Graduate Medical Education and New Jersey Neuroscience Institute at JFK Medical Center, Edison, New Jersey
4. Worldwide Epidemiology, GlaxoSmithKline R&D, Harlow, United Kingdom
5. Premark Services, Crawley Down, United Kingdom
6. Sleep Disorders Center, Università Vita-Salute and IRCCS H San Raffaele, Milan, Italy