The neurobiology and treatment of restless legs syndrome.

Background: Restless legs syndrome (RLS) is a relatively common neurological disorder affecting sleep and health-related quality of life. Neuroimaging studies, autopsy investigations and experimental studies using animal models have been conducted to investigate the potential causes of RLS, resulting in the generation of multiple pathophysiological hypotheses. Methods: This paper reviews the neurobiology and pharmacotherapy of RLS, with a critical analysis of the heterogeneity and methodological limitations of the existing scientific literature. Results: Although several neurotransmitter systems dysfunction and neuroanatomical abnormalities have been implicated in RLS pathogenesis, dopamine dysfunction within basal ganglia pathways, iron deficiency and opioid system abnormalities have consistently been found to be involved. Their involvement is further strengthened by the therapeutic effectiveness of dopaminergic agents, iron supplementation and opioid medications. Discussion: Converging evidence from neuroimaging, autoptic and animal studies points towards dopamine dysregulation and iron metabolism alterations as the main contributors to RLS pathophysiology. The possible interactions between different neurotransmitter systems should guide further neuropharmacological research in order to improve therapeutic efficacy for this disabling condition.