For the estimated 30 million Americans who experience nighttime restlessness due to restless legs syndrome, a recent study offers both a caution and a reassurance: While the condition may carry a small increased risk of Parkinson’s disease, the very medications used to treat it appear to offer protection.
The finding highlights the complex relationship between two conditions that both involve the brain’s dopamine system and underscores why careful diagnosis and follow-up matter for people living with chronic movement disorders.
A Surprising Protective Effect
Patients with restless legs syndrome had a significantly higher risk of Parkinson’s disease than patients without restless legs syndrome, according to the study published in JAMA Network Open.
However, patients who were treated with dopamine agonists had much lower rates of Parkinson’s disease, even lower than patients who do not have restless legs.
Dopamine agonists, which are often prescribed to treat Parkinson’s disease, include pramipexole, ropinirole, and rotigotine. They are typically available in pill and patch forms.
Researchers analyzing data from nearly 20,000 people in South Korea found that patients who were not treated with dopamine agonists had an increased risk of developing Parkinson’s disease and tended to be diagnosed with the disease sooner than controls.
Among treated patients, only 0.5 percent were diagnosed with Parkinson’s disease over a 15-year period. By contrast, 2.1 percent of untreated patients developed the disease—more than four times the rate.
The findings suggest a disease connection between restless legs syndrome and Parkinson’s disease, though researchers do not know why prescribing dopamine agonists reduced the risk of Parkinson’s disease.
Dopamine agonists act like dopamine—a neurotransmitter that controls movement—in the body. Patients with Parkinson’s disease are often deficient in dopamine, which causes them to experience tremors when moving. Dopamine agonists reduce tremors in patients with Parkinson’s disease and in patients with restless legs, reducing their urge to move their legs, though the reason why the drug works remains unclear.
Understanding Restless Legs Syndrome
Restless legs syndrome is characterized by an uncomfortable urge to move the legs—symptoms that worsen at rest and in the evening and show partial or temporary relief with movement, Dr. Luke Barr, a board-certified neurologist, director of a comprehensive stroke center in the Midwest, and chief medical officer at SensIQ, who was not involved in the study, told The Epoch Times.
The condition, which is more prevalent in women and affects up to 10 percent of the population, is typified by an uncomfortable “crawling” sensation in the legs, felt primarily at night, and accompanied by an almost irresistible urge to move.
“It is typically an inner sensory-motor phenomenon,” Barr said.
Restless legs syndrome worsens when at rest, improves with movement, and can be caused by health issues, including iron deficiency anemia, kidney disease, diabetes, and multiple sclerosis. For those most severely affected, restless legs syndrome can disrupt sleep, harm mental health, and take a toll on relationships and careers.
Magnesium oxide and vitamin B6 have been found to significantly improve sleep quality and restless legs syndrome symptoms, with magnesium showing greater effectiveness.
The Importance of Accurate Diagnosis
While the protective effect of treatment is encouraging, experts emphasize the importance of accurate diagnosis. Sleep disorders, which can occur in many Parkinson’s disease patients, also involve periodic leg movements and can sometimes be mistaken for restless legs syndrome.
Barr noted that Parkinson’s disease presents differently than restless legs syndrome, with hallmark motor signs such as slowness of movement and speed (bradykinesia), rigidity, a resting tremor that only affects one side early in the disease, and reduced arm swing or changes in gait and posture.
He added that early Parkinson’s disease often includes nonmotor warning signs—such as loss of smell, sleep disturbances, constipation, anxiety, or depression—that do not occur in classic restless legs syndrome.
A limitation of the study is that it included no information verifying whether clinicians—such as neurologists or sleep specialists—confirmed the diagnoses, raising the possibility of misdiagnosis in some cases, Dr. Mark S. Baron, a professor of neurology, wrote in an editorial accompanying the study.
The authors also could not establish a cause-and-effect relationship between the two conditions or confirm a shared brain pathway dysfunction.
What This Means for Patients
Barr noted that the study is not a cause for alarm, but it does justify a thoughtful, informed approach.
“I recommend patients and clinicians keep a low threshold for reevaluation if new symptoms appear,” he said. “Especially signs of Parkinsonism or prodromal non-motor features.”
Barr said the takeaway for clinicians is to pay close attention to the details of patients’ sleep and movement symptoms, remain alert for signs that point to another or changing diagnosis, and continue reassessing patients over time rather than assuming the condition will stay the same.
For patients, he noted, staying informed, reporting new symptoms promptly, and partnering with their clinician for periodic reassessment is a reasonable and measured response to the study findings.
