[Symptomatic causes of restless legs syndrome.]

Restless legs syndrome (RLS) is characterized by discomfort and paresthesias in the legs with urge to move the legs, worsening of the symptoms with the rest or inactivity, present or exacerbation in the evening or night and partial or total relief with movement. The diagnosis is primarily clinical. RLS is idiopathic, with family history in 40-60% of the cases, or symptomatic associated conditions such as iron deficiency, uremia, pregnancy, Parkinson's disease, neuropathy or myelopathy. Although the pathophysiology of RLS remains unknown, it has been implicated a central dopaminergic dysfunction. In the last years it has increased the interest and has been published several papers about RLS, that make significant contributions to the current understanding of the syndrome. The aim of this paper is to review the cur-rent advances in the field of RLS, with special emphasis on symptomatic causes of the syndrome, from both epidemiological and pathophysiological points of view.