[Restless legs syndrome and its clinical forms: diagnosis]

Restless legs syndrome (RLS) diagnosis is clinically ascertained on four associated essential criteria according to the recommendations of the workshop at the National Institute of Health published in 2003. Supportive clinical features can help to resolve any diagnosis uncertainty. RLS severity is assessed by a validated rating scale also useful for therapeutic decision and evaluation. Idiopathic forms (familial or sporadic) are the most frequent. Nevertheless secondary forms must be recognized, and etiology, associated pathologies and risk factors investigated. Periodic leg movements (PLM) during wakefulness and more frequently during sleep are present in almost 80 % of patients with RLS. These PLM can be recorded during a suggested immobilization test or during a polysomnography. Deleterious consequences of RLS are important: attention-deficit hyperactivity or tiredness and asthenia, cognitive deficit, psychiatric illness and detrimental impact on quality of life. This high prevalent syndrome is actually better defined but still under-diagnosed probably due to the patients' difficulties to describe their feelings. Practitioners would benefit to interview more systematically their patients complaining of poor sleep about legs discomfort and movements in the evening and at night.