Effect of Ropinirole on Spinal Cord Reflexes and Restless Legs Syndrome

This study will examine the effects of the drug Ropinirole on spinal cord reflexes and on symptoms of restless legs syndrome (RLS). Patients with RLS have uncomfortable sensations in the legs, usually in the evening or early part of the night. Most patients also have periodic involuntary leg movements. The condition tends to worsen over time, resulting in severe discomfort and sleep disturbances. Ropinirole affects chemical messengers thought to be involved in spinal cord function and in modulating RLS symptoms. Healthy normal volunteers and patients with RLS between 18 and 80 years of age may be eligible for this study. Patients must have mild to moderate RLS and periodic limb movements. All candidates will be screened with a medical history, physical and neurological evaluations, electromyogram (see below), polysomnogram (see below), electrocardiogram (ECG), and blood and urine tests. They may also have magnetic resonance imaging (MRI) or computerized tomography (CT) scans and a chest x-ray. Participants must stop taking all medications prohibited by the study for at least 1 week before the study starts and throughout its duration. The study will last approximately 2 to 3 weeks for healthy volunteers and 7 to 8 weeks for patients. Participants will undergo the following baseline evaluations: electroencephalography (EEG), a measure of brain wave activity; polysomnography (PSG), an overnight sleep study; electromyography (EMG), a measure of muscle activity; and spinal flexor reflex studies (spinal cord responses to electrical stimulation). For these studies, several electrodes are attached to the scalp or to the legs and arms using a cream that helps conduct brain signals through the cables to be recorded. The nervous system activity can be assessed at rest or after stimulation with an electric current. For EMG, a small needle is inserted into a few muscles and the subject is asked to relax or to contract the muscles. The electrical activity of the muscle cells is