ABSTRACT
In 1945, Dr Karl-Axel Ekbom of Sweden published a monograph on a “hitherto overlooked disease in the legs,” which he called “restless legs” (1). For many years considered a rare curiosity, restless legs syndrome (RLS) is today recognized as one of the commonest neurologic disorders with a prevalence rate of at least 1 in 25. With the introduction of polygraphic monitoring of sleep, it became evident that many patients studied in sleep laboratories jerked their legs rhythmically through parts of the night. These movements, originally called nocturnal myoclonus, are now known as periodic limb movements of sleep (PLMS). Although PLMS can occur in association with RLS, they more often occur independently. The two conditions are frequently confused, and undue significance is often ascribed to the presence of PLMS on a polysomnogram (PSG).
