Restless leg syndrome

Alternative names:

nocturnal myoclonus; RLS

Definition:

A sleep disorder characterized by leg discomfort during sleep, which is only relieved by frequent movements of the legs.

Causes, incidence, and risk factors:

Restless leg syndrome (RLS) occurs most often in middle-aged and older adults. It is worsened by stress. The disorder consists of sensations in the lower legs that make the person uncomfortable unless the legs are moved. The sensations usually occur shortly after going to bed but may also occur during the daytime. The abnormal sensations occasionally occur in the upper leg, the feet, or the arms in addition to the lower leg. The cause is unknown. There are often no obvious vascular or neurologic abnormalities associated with the disorder. Sometimes RLS can be associated with peripheral nerve diseases.

There is an irresistible urge to walk or move the legs to relieve the discomfort, resulting in periodic episodes of leg movements during early sleep stages. The symptoms may last for 1 hour or longer. RLS can result in a decreased quality of sleep (insomnia) with subsequent daytime sleepiness, anxiety or depression, and confusion or slowed thought processes from lack of sleep.