The first multinational study to assess patients considered to have diagnostic criteria for Restless Legs Syndrome (RLS), a chronic and disruptive neurological disorder characterized by a compelling urge to move the legs, found that the condition is common, under-diagnosed, and can significantly impact sleep and daily activities.

Results of the R.E.S.T. (RLS Epidemiology, Symptoms, and Treatment) General Population Study, a population-based survey completed by telephone and face-to-face interviews, are published in the current issue of the Archives of Internal Medicine, a peer-reviewed journal of the American Medical Association. Another arm of the R.E.S.T. study, called the R.E.S.T. Primary Care Study, was published in the May 2004 issue of the journal Sleep Medicine, and included epidemiological information on RLS gathered from patients and doctors at primary care centers in the US and Europe.

After obtaining background information from 15,391 study participants, researchers collected details from the respondents that reported experiencing RLS symptoms at any time in the past year, about the frequency and nature of their RLS symptoms, the degree of associated distress, and prior physician consultation and diagnosis. The percentage of patients who reported having RLS symptoms at any frequency was 7.2 per cent. A subset of these patients (2.7 per cent of study participants overall), defined as RLS sufferers, reported having symptoms two to three times per week and symptoms that were moderately or severely distressing (n="416)." Eighty-one percent of these RLS sufferers (n="337)" reported discussing their symptoms with a primary care physician yet only 6.2 percent indicated that they were given a diagnosis of RLS.

"One of the biggest issues facing those with symptoms of Restless Legs Syndrome is obtaining appropriate diagnosis and management," said Nancy L. Earl, M.D., Group Director Clinical Neurology, GlaxoSmithKline, the company that funded the R.E.S.T. General Population Study. "Millions of people suffer from RLS yet some physicians may not connect certain physical and sensorimotor symptoms to RLS, resulting in a sizeable population that is not getting medical attention or diagnosis."

In addition to a compelling urge to move the legs, RLS is characterized by uncomfortable or some times painful sensations in the legs often described as creeping-crawling, tingling, pulling or tightening. Symptoms of RLS generally occur at rest, such as when sitting, lying or sleeping, and are temporarily relieved by movement. RLS encompasses a range of severity that includes mild, moderate and severe symptoms.

The frequency of any RLS symptoms in the total study population was approximately twice as high for women as it was for men (9 per cent vs. 5.4 per cent). Prevalence of the condition increased up to age 79 and then declined. While RLS patients are generally older, of the group defined as RLS sufferers, 36 per cent of the RLS sufferers in the R.E.S.T. General Population study were age 49 or younger.

The R.E.S.T. General Population study found that among the subset of patients defined as RLS sufferers, more than 75 per cent of these patients reported at least one sleep related symptom. Disturbance of daytime activities was reported by 55.5 per cent of RLS sufferers. Disrupted sleep, the inability to fall asleep and insufficient hours of sleep are common among RLS sufferers.

Quality of life was evaluated in this study using the Short Form - 36 Health Survey (SF36), an extensively tested and validated tool that assesses eight dimensions of health-related quality of life: physical functioning, physical limitations on normal role activities, bodily pain, general health, energy and vitality, social functioning, emotional limitations on normal role activities, and mental health.

Researchers observed that the RLS sufferers had lower quality of life scores than the general population and concluded that their quality of life appears to be comparable with that experienced by patients with other chronic medical conditions such as type 2 diabetes and clinical depression.

The study authors believe that patient complaints of sleep abnormalities as well as daytime performance-related effects including difficulty concentrating should be clues to physicians that a patient may be suffering from RLS.

Of the RLS sufferers identified in the study that did seek medical attention (81 per cent), 74.8 per cent recalled receiving a diagnosis for their symptoms, but only 6.2 per cent reported being diagnosed with RLS. Poor circulation (18.3 per cent), arthritis (14.3 per cent) and back problems (12.7 per cent) were the most common diagnoses reported.