Restless Leg Syndrome and Periodic Limb Movements of Sleep.

Restless leg syndrome is one of the most common causes of severe insomnia, and is easily diagnosed by patient history alone. Formal sleep studies are rarely, if ever, indicated. The only routine laboratory study indicated is a serum ferritin level. The majority of patients with restless leg syndrome obtain substantial relief with a variety of medications. Although the majority of restless leg syndrome patients demonstrate periodic limb movements on polysomnographic study, the true clinical significance, if any, of periodic limb movements identified by polysomnographic study in the absence of restless leg syndrome symptoms remains to be determined.