Restless Legs Syndrome (RLS) is a neurologic sensorimotor disorder that is characterized by an overwhelming urge to move the legs when they are at rest. The urge to move the legs is usually, but not always, accompanied by unpleasant sensations. It is less common but possible to have RLS symptoms in the arms, face, torso, and genital region. RLS symptoms occur during inactivity and they are temporarily relieved by movement or pressure. Symptoms of RLS are most severe in the evening and nighttime hours and can profoundly disrupt a patient's sleep and daily life.
RLS affects approximately 10% of adults in the U.S. Researchers believe that RLS is commonly unrecognized or misdiagnosed as insomnia or other neurological, muscular or orthopedic condition. RLS may also be confused with depression. According to the Restless Legs Syndrome Foundation, approximately 40% of people with RLS complain of symptoms that would indicate depression if assessed without knowledge or consideration of a sleep disorder.
RLS runs in families and may have a genetic component. In a recent study, the first RLS gene was discovered and was shown to account for approximately 50% of RLS cases. However, the researchers who identified the RLS gene cautioned that having it does not guarantee RLS. Rather, there are likely to be medical, environmental or other factors involved in translating RLS genetic susceptibility into RLS symptoms. Another recent RLS study also found that a genetic variant may account for about half of RLS cases and revealed an association between RLS and a gene for limb development, suggesting the possibility that RLS has components of a developmental disorder.
RLS also affects about 2% of children, according to a recent study of more than 10,000 families in the U.S. and U.K. The study also found a strong genetic component to RLS; more than 70% of children with RLS had at least one parent with the condition. There is also evidence suggesting that children with attention deficit hyperactivity disorder (ADHD) and a family history of RLS are at risk for more severe ADHD.