Restless legs syndrome
- The Movement Disorders Unit, Department of Neurology
- University Department of Clinical Neurosciences, King's College Hospital
- London, UK
- University Hospital of Lewisham, London, UK
- Guy's, King's, and St Thomas's Medical School, London, UK
- Department of Clinical Neurophysiology, University of Goettingen, Germany
- Dr K Ray Chaudhuri, Movement Disorders Unit, Mapother House, King's College Hospital, Denmark Hill, London SE5 9RS, UK ray.chaudhuri{at}kingshc.nhs.uk
- The Movement Disorders Unit, Department of Neurology
- University Department of Clinical Neurosciences, King's College Hospital
- London, UK
- University Hospital of Lewisham, London, UK
- Guy's, King's, and St Thomas's Medical School, London, UK
- Department of Clinical Neurophysiology, University of Goettingen, Germany
- Dr K Ray Chaudhuri, Movement Disorders Unit, Mapother House, King's College Hospital, Denmark Hill, London SE5 9RS, UK ray.chaudhuri{at}kingshc.nhs.uk
- The Movement Disorders Unit, Department of Neurology
- University Department of Clinical Neurosciences, King's College Hospital
- London, UK
- University Hospital of Lewisham, London, UK
- Guy's, King's, and St Thomas's Medical School, London, UK
- Department of Clinical Neurophysiology, University of Goettingen, Germany
- Dr K Ray Chaudhuri, Movement Disorders Unit, Mapother House, King's College Hospital, Denmark Hill, London SE5 9RS, UK ray.chaudhuri{at}kingshc.nhs.uk
- The Movement Disorders Unit, Department of Neurology
- University Department of Clinical Neurosciences, King's College Hospital
- London, UK
- University Hospital of Lewisham, London, UK
- Guy's, King's, and St Thomas's Medical School, London, UK
- Department of Clinical Neurophysiology, University of Goettingen, Germany
- Dr K Ray Chaudhuri, Movement Disorders Unit, Mapother House, King's College Hospital, Denmark Hill, London SE5 9RS, UK ray.chaudhuri{at}kingshc.nhs.uk
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
Epidemiology
Surveys in the white population suggest that adult prevalence figures of RLS may range between 5% and 15%.5-7 The prevalence seems to increase with age, although retrospective assessments indicate that onset of the syndrome may occur before the age of 20 in up to 43% of adult cases.8 9 The MEMO study, a population based survey of an elderly population, reported a higher prevalence of RLS in women, which however, did not change with age, unlike men.7 There are currently no data available on prevalence of RLS in other ethnic groups such as Asian or black populations. Periodic limb movements in sleep were first reported by Lugaresi et al, who showed polysomnographically recorded PLMS (more than five/hour) in up to 87.8% of patients with RLS.4 Prevalence estimates of PLMS are variable and range from 6% in the general population to 58% in a subpopulation of subjects over 60 years old.10 It should be emphasised that PLMS occur in various sleep disorders and other neurological diseases and may increase with age, whereas RLS remains a clinical diagnosis by definition.11
Pathophysiology and clinical associations
The underlying causes of RLS or PLMS remain unclear and as such various aetiologies including central and peripheral nervous systems, vascular, genetic, iatrogenic, and metabolic components have been proposed (table 1). The central dopaminergic system, particularly the striatonigral system, has been implicated …
