Background - Restless leg syndrome (RLS), a condition affecting millions of Americans, is characterized by uncomfortable sensory symptoms relived by voluntary or involuntary movements. Objectives -To test our hypothesis that sensorimotor gating is deficient in RLS. Methods - In a controlled proof-of-principle clinical study, sensorimotor gating will be assessed through the use of validated electrophysiological tests of prepulse inhibition, in 17 adult patients with RLS and 17 matched healthy controls. Risks and benefits -Risks involved in this study are minimal, and deemed reasonable in relation to potential benefits. This investigation will lead to a better understanding of the pathophysiology of RLS.
* INCLUSION CRITERIA: Subjects who meet all of the following inclusion criteria at screening will be eligible to participate in the study: 1. Male or female subjects aged 18 to 80. 2. For patients only, diagnosed with primary RLS based on the presence of a characteristic clinical history and the IRLSSG diagnostic criteria. 3. Normal physical and neurological examination. 4. Subject is willing to adhere to protocol requirements as evidenced by written, informed consent. 5. No clinically significant abnormalities on clinical chemistry or hematology examination at the pre-study medical evaluation. 6. Negative pre-study urine drug screen. EXCLUSION CRITERIA: Subjects meeting any of the following exclusion criteria will not be enrolled or will be immediately excluded from the study, as appropriate: 1. History of any medical condition that can reasonably be expected to compromise scientific integrity of the study; 2. Patient unwilling or unable to stop their usual mediations for RLS; 3. Subjects unable or unwilling to discontinue a prohibited concomitant medication 4. Subjects unwilling to sign an informed consent or to comply with protocol requirements. 5. Subjects with clinical and/or biological evidence of secondary RLS (e.g. renal failure (end-stage renal disease), iron deficient, anaemia or pregnancy at baseline).