New data from the Women's Health Study are linking migraine and restless legs syndrome. The association appears to be similar for migraine with and without aura.
"It is well known that migraine carries a wide comorbidity spectrum including stroke, pain, and depression," Markus Schürks, MD, from the University Hospital of Essen in Germany, told Medscape Medical News. "Restless legs syndrome appears to be a new condition that should be added to the list of potential migraine comorbidities."
"This is important because restless legs syndrome can also be a severe and debilitating disorder that may hugely impair quality of life, but at the same time is often treatable," Dr. Schürks said. "In clinical practice it is relatively straightforward to diagnose with a few simple questions."
The results were published March 6 online in Cephalalgia.
In this new paper, the researchers looked at 31,370 female health professionals with detailed self-reported information on migraine, including aura status. About 22% of women reported migraine.
At the nine-year follow-up, investigators assessed restless legs syndrome and found women with migraine were more likely to have the movement disorder.
Table. Multivariable-Adjusted Risk for Restless Legs Syndrome
|Patients||Odds Ratio (95% Confidence Interval)|
|Migraine ||1.22 (1.13 - 1.32)|
|Migraine with aura||1.27 (1.10 - 1.48)|
|Migraine without aura||1.24 (1.09 - 1.40)|
|New migraine at follow-up||1.30 (1.10 - 1.54)|
However, the researchers found that prior migraine did not appear to be associated with restless legs syndrome.
"Our results were not totally unexpected," Dr. Schürks said. Previous reports and small clinic-based studies had shown that restless legs syndrome occurs frequently among people with migraine, he pointed out.
In both conditions, disturbance of iron and dopamine metabolism have been implicated. Brain iron deposition has been reported in patients with migraine, and increased iron accumulation is associated with repeated attacks. Iron deficiency is also thought to play a role in at least a subset of patients with restless legs.
Growing List of Comorbid Conditions
In a previous US study of 50 patients with headache, reported in 2003 by researchers led by William Young, MD, from the Jefferson Headache Center in Philadelphia, Pennsylvania, 34% met the criteria for restless legs syndrome (CNS Spectr. 2003;8:450-456).
Asked by Medscape Medical News to comment on these latest results, Dr. Young, a spokesperson for the American Academy of Neurology, said this study confirms the link and adds restless legs syndrome to the growing list of migraine comorbid conditions.
"This study puts restless legs into one category, but it's important to remember there are two types of restless legs syndrome," Dr. Young added. "There can be important differences between genetic cases and those with neuropathy."
Dr. Young adds that many studies, including this one, don't look at medications. "That is a problem," he said. "The patients in this study are also generally younger than the typical migraine patient, so that needs to be taken into account as well."
Dr. Young suggests there may be opportunities to simultaneously treat migraine and restless legs. "That would be ideal," he noted.
The Women's Health Study and this new analysis were funded by the National Heart, Lung, and Blood Institute. The Women's Health Study also received funding from the National Cancer Institute. Dr. Schürks is a new employee of Bayer HealthCare Germany Pharmaceuticals and has received funding from the Migraine Research Foundation. Dr. Young has disclosed no relevant financial relationships.
Cephalalgia. Published online March 6, 2012. Abstract
Allison Shelley • Medscape Medical News © 2012 WebMD, LLC