Individuals with restless legs syndrome (RLS) report discomfort in their legs, and less often their arms, that are associated with an irresistible urge to move or rub the affected limbs. This occurs when individuals are immobile, especially at night when they are trying to sleep. During these episodes, the person will get up to walk about to suppress the abnormal sensations. When asked to describe the nature of the discomfort, affected individuals almost always have difficulty. Most often they describe tightening, pulling, or crawling sensations. When these feelings are intense they may interfere substantially with sleep and there is consequent excessive sleepiness during the day. Patients with severe RLS note that their symptoms can make it difficult for them to remain confined to a car or airplane seat for more than a short time. Some patients experience RLS symptoms intermittently, sometimes over a series of nights, but then they may remain symptom-free for days, months, or even years.
Most people with RLS also have periodic limb movements (PLMs) during sleep. These PLMs occur in trains of five or more limb jerks with an interval of 10 to 60 seconds between jerks. Sometimes the PLMs severely disrupt sleep, but more often they do not disrupt sleep substantially, if at all.
RLS can be associated with a number of other conditions or it can occur without any underlying medical problem. There is a 50% chance in some families that children of an affected individual will develop RLS. Some women experience RLS only during pregnancy. Iron deficiency may trigger RLS; there appears to be a lack of iron in areas of the brain that exert control of movements. Iron treatment should be considered in RLS patients with serum ferritin levels below 50. Treatment with iron supplements can correct the condition in these individuals. Kidney failure and diabetes cause dysfunction of peripheral nerves and are associated with a relatively high rate of RLS and PLMs. Similarly, sciatic can predispose an individual to RLS.
RLS becomes more prevalent and more severe with aging. Both men and women are equally affected.
The diagnosis of RLS depends mostly on the individual's history. Laboratory testing can detect PLMs, but not RLS.
A variety of medications have been used successfully to treat RLS. However, none of these are consistently tolerated or helpful to all patients. Dopaminergic drugs that are FDA-approved for treating Parkinsonism can suppress RLS symptoms. A minority of patients who initially experience a successful response to this treatment note that they begin having a breakthrough of RLS symptoms earlier in the day. This is called augmentation. Narcotics and benzodiazepines can suppress RLS, but these can be sedating and addictive. More recently, certain anti-epilepsy drugs, including gabapentin, topiramate, and zonisamide, have been found to be variably effective for RLS. Of course, iron should be prescribed for patients with underlying iron deficiency.