Restless leg syndrome (RLS), also known as Ekbom’s syndrome, is a discomfort, not pain, verbalized as pins and needles, a crawling sensation, or cramping mainly in the calves but sometimes noted in the thighs or arms. Males and females are equally affected, and RLS occurs most commonly in the elderly. Iron deficiency, pregnancy, and renal failure are associated with RLS. Caffeine, stress, or fatigue may worsen the symptoms. The sensation is generally bilateral and occurs only during rest and inactivity and is quickly relieved by walking or moving the legs.
RLS can be a very disturbing condition. When a patient attempts to resume sleep, the discomfort returns, causing insomnia. Clinical examination may reveal evidence of underlying systemic disease or mild peripheral neuropathy, but is more often normal. Mild or intermittent symptoms usually require no treatment.
Researchers at the University of Montreal conducted a study on familial aggregation of restless legs syndrome. The study included 249 participants with RLS who were treated at a specialized sleep center in Montreal and were followed for 15 years. The researchers interviewed the participants with familial RLS and 479 of their family members. They found that about 90% of the families included in the study showed a vertical transmission consistent with a dominant-like inheritance pattern. It was found that the mean age at onset of the condition was 28 and the mean duration was 24 years. It was then discovered that age at onset was significantly earlier in the offspring than in the parents, although the researchers noted that could be the result of increased awareness in the family. The data collected also revealed that more women develop RLS and that women tend to have it more severe than men. The researchers were able to conclude that siblings of an affected individual had a 3.6-fold increased risk of developing the condition and offspring had a 1.8-fold increased risk.1
1 Xiong L, Montplaisir J, Desautels A, et al. Family study of restless legs syndrome in Quebec, Canada: clinical characterization of 671 familial cases. Arch Neurol. May2010;67(5):617-22.