Indications for performing polysomnography in the diagnosis and treatment of restless legs syndrome

Restless legs syndrome (RLS) is diagnosed clinically by evaluating the patient's complaints. Diagnostic criteria based on the clinical symptoms were defined by the International Restless Legs Syndrome Study Group. Laboratory and/or neurophysiological assessments can differentiate a primary (idiopathic) RLS from a secondary (associated with an other disease) RLS. Some differential diagnostic and therapeutic issues may, however, require polysomnographic assessment. An investigation in the sleep laboratory should be considered in the following cases: 1) in patients with "atypical" RLS symptoms to support the diagnosis, before pharmacological treatment is begun; 2) in patients on sufficient dopaminergic treatment but still suffering from sleep disturbance, in order to exclude other sleeprelated disorders; 3) in patients with mild RLS but marked daytime sleepiness as the main symptom; 4) to support the diagnosis in young patients with severe RLS before dopaminergic treatment is begun or in patients with severe RLS before the start of a treatment with opiates; 5) in patients with RLS and sleep-related respiratory disorders; 6) and finally in patients who are involved in a formal expert's opinion report. Further indications may exist in exceptional cases. A recommendation for performing polysomnography should be always made by a clinician experienced in the diagnosis and treatment of sleep disorders.