 The SSQ is a daily sleep diary where subjects record their sleep activities and report the quality of their sleep over the past 24 hours on an 11 point numeric rating scale ranging from 0 very poor to 10 excellent. The RLS-NDI measures the impacts of RLS on next day functioning. The impacts include activities of daily living i.e., work, household chores, cognitive functioning i.e., concentration, forgetfulness, mental tiredness, alertness, emotional functioning i.e., irritability, depressed mood, physical functioning i.e., physical tiredness, active leisure activities, energy, daytime sleepiness, and social functioning i.e., relationships, social activitiessituations. The final measure consists of 14 items assessed today and rated on a numeric rating scale. Subjects will be instructed to complete the daily diary and the RLS-NDI over the 7 days preceding Visit 4 PSG 2 visit and Visit 7 PSG 4 visit. 