Restless legs syndrome: a sensorimotor disorder of sleep/wake motor regulation.

Restless legs syndrome (RLS) remains an underappreciated sensorimotor disorder of sleep/wake regulation. It is one of the few sensorimotor disorders that is provoked by rest and that also follows a clear circadian pattern. Recent epidemiologic studies have verified that the condition is common in populations derived from the north and west of Europe, and have begun to uncover some of the genetic substrate of the disorder. New instruments have been developed to facilitate diagnosis and assessment of severity. The pathogenesis of the condition remains uncertain, but recent discoveries implicate areas of the nervous system from the spinal cord up to the basal ganglia. A current hypothesis undergoing vigorous exploration is that the condition results from a deficiency of dopaminergic function based on abnormalities of iron transport and storage. Therapeutically, studies have shown the dopamine agonists to be the most reliable treatment for severe cases, whereas other recent studies have successfully utilized a number of other medications, including levodopa, opioids, and anticonvulsants. New standards provide guidelines for management of RLS and make specific pharmacotherapeutic recommendations.