THURSDAY, Nov. 10 (HealthDay News) -- People with early Parkinson's disease are not more likely to have restless legs syndrome, but many people with Parkinson's do report leg motor restlessness, according to the results of a new Norwegian study.

People with restless legs syndrome, or RLS, have an overwhelming urge to move their legs. This typically occurs at night during rest, and the sensation is relieved by movement. By contrast, leg motor restlessness is characterized by the urge to move the legs throughout the day, and this sensation does not improve with movement.

Both RLS and Parkinson's disease, which is a chronic and progressive movement disorder that affects nearly 1 million people in the United States, do respond to the same drugs, but that is where their connection ends. Medications that boost levels of the brain chemical dopamine treat both conditions.

To better understand the relationship between RLS and Parkinson's, Michaela Gjerstad of Stavanger University Hospital in Norway and colleagues compared leg symptoms among 200 people who were recently diagnosed with Parkinson's disease and had not started taking any medication to those of 173 people who did not have Parkinson's. Previous studies that have shown a link between the two conditions looked mainly at people with advanced Parkinson's who had been taking dopamine drugs for years.

According to the new report published online Nov. 9 ahead of print in the journal Neurology, people with early Parkinson's do have a threefold increased risk for leg motor restlessness, compared to people without this neurodegenerative disease. However, RLS was not more common among people with Parkinson's disease, the study showed.

"The study showed that people with Parkinson's disease do have some nonspecific leg symptoms even before they are started on medication," said Dr. Roy Alcalay, an assistant professor of neurology at Columbia University Medical Center in New York City, and an advisor for the Parkinson's Disease Foundation, who was not involved with the study.

"The risk of pure RLS isn't significant in people with Parkinson's disease compared to those without it," Alcalay said. "People who are diagnosed with RLS and are concerned about their risk of Parkinson's should be reassured," he added. "Most people with RLS won't convert to Parkinson's disease, but there are nonspecific leg symptoms that can come on early even before a Parkinson's disease diagnosis is made by a neurologist."

Commenting on the study, Dr. Michele Tagliati, director of the Movement Disorders Program at Cedars-Sinai Medical Center in Los Angeles, said the new findings mirror what he has observed in practice. "None of my RLS patients have developed Parkinson's disease," he said. "I would not consider RLS as a risk factor for Parkinson's. The medications are the same, but that doesn't mean that they are similar."

In a news release from the American Academy of Neurology, one of the authors of an editorial accompanying the study, Dr. John Morgan of Georgia Health Sciences University in Augusta, noted that "time will tell whether the majority of these people with leg motor restlessness will go on to develop restless legs syndrome, or whether the restlessness improves after they start taking dopamine drugs."

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