Four essential criteria

This summary is taken from:

Management of restless legs syndrome in primary care

Developed by RLS:UK

The International Restless Legs Syndrome Study Group (IRLSSG) has proposed a set of diagnostic criteria for RLS. Revised criteria for the diagnosis of RLS were formulated from a consensus conference held at the National Institutes of Health on May 1-3 2002 in Bethesda, Maryland, USA.

Diagnosis of restless legs syndrome (RLS) can be made if all of the following four criteria are met:

• A need to move the legs, usually accompanied or caused by uncomfortable, unpleasant sensations in the legs. Any kind of sensation may be a manifestation of RLS and a wide variety of descriptions have been used ranging from "painful" or "burning" to "Elvis legs". Sometimes the need to move is present without the uncomfortable sesnations and sometimes the arms or other body parts are involved in addition to the legs.
• The need to move and unpleasant sensations are exclusively present or worsen during periods of rest or inactivity such as lying or sitting.
• The need to move and unpleasant sensations are partially or totally relieved by movement such as walking or stretching at least as long as the activity continues.
• The need to move and unpleasant sensations are generally worse or exclusively occur in the evening or night.

Associated features

• Clinical course is usually progressive. Adults of all ages can be affected but the prevalence increases with ag; most commonly RLS affects middle-aged individuals
• RLS is commonly accompanied by sleep disturbances

Differential diagnosis

• Nocturnal leg cramps
• Akathisia
• Peripheral neuropathy
• Vascular disease (e.g. varicose veins or deep vein thrombisis)
• Painful legs/toes
• Intermittent claudication
• Attention-deficit hyperactivity disorder in children
• Anxiety/generalised anxiety disorder

Aetiology

• The majority of cases are primary with unknown origin
• Genetic predisposition and a chemical imbalance in the brain may play a role in some patients
• The three major reversible secondary causes of RLS - pregnancy, iron-deficiency anaemia and end-stage renal disease  - are related to depleted iron stores
• Other secondary causes include : vitamin B12/folate deficiency; peripheral neuropathy; Parkinson's disease; fibromyalgia; rheumatoid arthritis; spinocerebellar ataxia; Charcot-Marie-Tooth disease (type 2)

Investigations

• Physical examination is often normal, important examinations include: neurological - particularly of the peripheral nervous system; vascular - to exclude vascular causes
• Required bood tests include: full blood count; iron studies; serum ferritin; serum B₁₂/folate; serum glucose; urea and electrolytes; thyroid function tests
• Patients with severe RLS and insomnia may require sleep studies such as polysomnography or immobilisation tests

General principles

• Treatment needs to be initiated when a score of 15 or more is reached on the international restless leg severity scale
• The RLS 10-item questionnaire with a maximum score of 40 and scores above 15 are regarded as moderate to severe restless legs syndrome
• All current drugs licensed for treatment of RLS are for moderate to severe restless legs syndrome
• Treatment depends on the severity and frequency of symptoms
• Mild RLS may be managed with reassurance and lifestyle changes
• Severe cases may require drug therapy
• Secondary causes and exacerbating factors should be identified and corrected: iron supplementation for anaemia and other cases of deficiency; switching concomitant treatment (RLS can be worsened by anti-depressants, calcium channel blockers, anti-nausea drugs and some anti-allergy medications); limiting other triggers (e.g. avoiding a high intake of caffeine or alcohol consumed during the evening)
• Mineral supplementation (magnesium, potassium and calcium) may prove useful