Restless legs syndrome and periodic limb movements during sleep: diagnosis and treatment

Restless legs syndrome (RLS) and periodic limb movements during sleep (PLMS) have been known for over 300 years, and they may be present in as many as 25% of patients who have sleep disorders. These patients generally present with insomnia. These disorders often remain undiagnosed for an average of 16 years and patients have seen an average of 13 physicians for their symptoms. Therefore, these disorders merit the attention and interest of the practitioner, so that such patients can be evaluated and treated without delay.

The important features of these disorders are the following: (1) their recognition since 1685, (2) they may comprise up to 25% of all sleep disorders, (3) they require differentiation from many other disorders, and (4) effective treatment is available. Although it is believed that RLS and PLMS are 2 clinical manifestations of the same central nervous system dysfunction, they are generally discussed separately, as different nosological entities.

RLS and PLMS are common neurologic disorders and increase in prevalence with aging. These disorders can be disabling conditions, causing sleep disturbance at night and excessive sleepiness during the day. Polysomnography and the suggested immobilization test are used to support the clinical diagnosis of RLS and PLMS. Although levodopa alleviates symptoms, rebound and augmentation occur frequently, limiting the long-term usefulness of this agent. The direct dopamine receptor agonists such as pergolide, pramipexole, ropinirole, and cabergoline have largely replaced levodopa as the most effective treatment for RLS and PLMS.