Restless legs syndrome ( U S ) was first described by Ekbom in 1945 and is characterized by an uncontrollable urge to move the legs when lying in bed at night or during periods of prolonged rest.g,'" It has been associated with a variety of medical conditions ranging from iron deficiency anemia to varicose veins to chronic obstructive pulmonary disease. The relationship of RLS with polyneuropathy, however, is unclear. Although the International Classification of Sleep Disorders and others state that a diagnosis of RLS cannot be made in the setting of p~lyneuropathy,~~~~' some authors suggest that RLS can actually be caused by polyneuropathy." Indeed, Salvi et al. described a family with amyloid polyneuropathy and RLS.24 Most recently, Iannaccone et al. found electrophysiologic and pathologic evidence for a mild axonal polyneuropathy in 8 consecutive patients seen with the primary complaint of RLS. '' In this study, we prospectively evaluated patients with polyneuropathy to determine the prevalence of RLS in this population.
Methods
Over a 2-year period, all patients referred to a neuromuscular clinic for evaluation of polyneuropathy were questioned as to the presence of symptoms consistent with RLS.
The criteria for the diagnosis of RLS were based on those of the International Classification of Sleep Disorders2' and included: (1) A complaint of an un-