 The objective of this study is to evaluate the effects of stimulation of dopaminergic D2, D3 receptors on spinal cord excitability and on the severity of symptoms in patients with mild to moderately advanced restless legs syndrome. In a controlled proof-of-principle clinical study, the acute efficacy of ropinirole will be assessed through the use of validated electrophysiological tests and severity scales. Safety will be monitored by means of frequent clinical evaluations and laboratory tests. 