The term restless legs syndrome (RLS) was first introduced by Karl A Ekbom, a Swedish neurologist and surgeon, in 1945, although the earliest description of restless legs associated with sleep disabilities possibly came from Sir Thomas Willis, an English physician, in 1672.1 2 More recently, abnormal involuntary movements during sleep such as nocturnal myoclonus (subsequently termed periodic limb movements during sleep (PLMS)) have been reported to be associated with RLS.3 4