Restless legs syndrome and periodic limb movements of sleep.

Restless legs syndrome describes a curious need to stretch and move in response to an unpleasant feeling in the legs. For most people who have this, as they are drifting off to sleep there is a twitch of the toe, foot and ankle followed by another and then another. The limb movements are strikingly periodic and are described as such by frustrated bed partners. The pathophysiology remains debated but is likely to involve dopaminergic dysfunction and ascending arousal systems. Despite a prevalence of 5-10% in the general population, the variable nature of symptoms and difficulty describing the dysaesthesia often leads to delay in treatment. This article outlines the diagnostic criteria, medication and comorbidities that modify symptoms, the impact of restless legs syndrome on health, and symptomatic management. Several licensed therapies are effective but the dopamine agonists in particular can cause challenging side effects and paradoxically worsen symptoms over time. Case histories are reviewed to guide physicians.