Restless Limbs, Migraine, and Bruxism May Form a 'Triad'

Caroline Helwick

October 18, 2013

NEW ORLEANS — There may be an association between restless limbs syndrome, migraine headaches, and bruxism, a new study suggests.

"I have accumulated a large number of patients with restless limbs syndrome (RLS) in my practice, and I designed a questionnaire for them to learn more about their condition," said lead author David J. Dickoff, MD, assistant clinical professor of neurology at Mount Sinai Hospital, New York, New York. Dr. Dickoff also has a private practice in Westchester, New York.

The results of the questionnaire confirmed these conditions often coexist, he told Medscape Medical News. "There is a strong clinical and genetic association of RLS, bruxism — grinding or clenching of the teeth — and migraine headaches," Dr. Dickoff maintained.

He presented his findings here at the American Neurological Association (ANA) 2013 Annual Meeting.

"Triad" Identified in Half of Patients

The study was based on survey results from 870 patients who met formal criteria for RLS. Patients completed a 35-question survey that asked about demographic characteristics, symptoms, associated medical conditions, family history, and response to therapy. Charts were reviewed and interviews conducted to complete and clarify the data.

Of 870 respondents with RLS, 549 also had symptoms suggestive of migraine (63%), 289 had bruxism (33%), and 240 had all 3 conditions (28%), he reported.

Headache features such as nausea, light sensitivity, and sound sensitivity, as well as migraines, present in at least 1 family member, pointed to the diagnosis of migraines in those surveyed. "Interestingly, two thirds of RLS patients are women, and two thirds of migraine sufferers are also women, and this is what we found on our survey," he added.

Of 470 who fully answered all the survey questions regarding headaches and bruxism, 364 (78%) had migraines, 281 (60%) had bruxism, and 245 (52%) had the full triad. Only 15% of patients who responded to all questions reported only RLS symptoms, Dr. Dickoff said.

"Family history data showed that 65% of patients acknowledged at least 1 first-degree relative with RLS, migraines or bruxism," he added. One quarter of these patients had family members with 2 of these conditions, and 8% had a family history of the triad.

This suggests to me, in fact, that bruxism is really 'restless jaw.' Dr. David J. Dickoff

The findings also suggest that headaches associated with bruxism, previously attributed to temporomandibular joint dysfunction, may actually be migraines and may respond to the same treatment as for RLS, he said.

In his patients with bruxism, 76% reported that treatment of RLS also ameliorated their grinding and clenching.

"We found that, in all likelihood, bruxism — which up until now has had no effective medical treatment — responds to dopamine agonists, the drugs we give for RLS. This suggests to me, in fact, that bruxism is really 'restless jaw,'" Dr. Dickoff said in an interview with Medscape Medical News.

The average age at onset of RLS in these patients was 41 years, but RLS was not diagnosed until age 53. His patients presented with many common conditions: insomnia (80%), headache (74%), pain (72%), numbness (70%), tingling (66%), and other "vague symptoms" that had been mistaken for other ailments for years, he said.

"We looked at what happened to these patients during this treatment gap, and found that during these 12 years one third of the patients had surgery designed to treat pain or other neurological symptoms, such as joint replacements, back surgery, surgery for carpal tunnel syndrome. Many had more than one operation in hopes of curing their undiagnosed pain and other neurological symptoms," he said.

"These data, if they can be supported by prospective studies, will improve the identification and diagnosis of all 3 conditions," Dr. Dickoff added.

"Doctors have to be able to see this in holistic way," he suggested. "When patients present to sleep specialists with insomnia, the physician should ask about headaches and limb symptoms. Patients presenting to headache specialists should be asked about sleep."

A More Cautious Interpretation

Beth Ann Malow, MD, professor of neurology at Vanderbilt University, Nashville, Tennessee, and director of the Vanderbilt Sleep Disorders Clinic, commented on the findings for Medscape Medical News. Her interpretation of the study findings was more cautious.

"I think the common denominator might be that RLS interrupts sleep, and a lack of sleep can provoke migraines," she suggested. As for the association with bruxism, her explanation was similar. "Arousals from sleep can lead to nonspecific tooth grinding… I just think it's possible that general sleep deprivation is the underlying basis for these findings," she said.

Dr. Dickoff and Dr. Malow have disclosed no relevant financial relationships.

American Neurological Association (ANA) 2013 Annual Meeting. Abstract #M1120. Presented October 14, 2013.


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