Migraine May Double Bell Palsy Risk

Migraine may double the risk of Bell palsy.

Migraine headaches may double the risk of Bell palsy, according to a new study.

“Migraine is a previously unidentified risk factor for Bell’s palsy,” stated the researchers led by senior author Shuu-Jiun Wang, MD, with National Yang-Ming University and Taipei Veterans General Hospital in Taipei, Taiwan. “This is a very new association between migraine and Bell’s palsy. Our study also suggests that these two conditions may share a common underlying link.”

Bell palsy, which causes 1-sided facial weakness, often is considered a benign condition that usually resolves within 2 weeks. More severe cases may require physical therapy or corticosteroids to reduce swelling and inflammation.

Frequently seen by neurologists, the disorder affects between 11 and 40 per 100,000 persons each year. Onset most frequently occurs between ages 15 and 60 years.

The exact etiology of Bell palsy remains unknown. Some research suggests the condition may be triggered by a viral infection, such as viral meningitis or a cold sore, that causes facial nerves to swell. Other studies also indicate an association between migraine and facial and limb weakness, the researchers stated.

Dr Wang and colleagues conducted a nationwide cohort study using data from the Taiwan National Health Insurance Research Database. The study included nearly 137,000 adults, 1 group with migraine and 1 without, who were monitored for an average of just more than 3 years.

During the follow-up period, 671 patients in the migraine cohort and 365 matched controls received a new diagnosis of Bell palsy. Even after accounting for other factors that could increase the risk of the condition, such as diabetes mellitus (DM), high blood pressure, and sex, the researchers found that Bell palsy was twice as likely to develop in persons with migraines than in those without migraines.

Bell palsy has been associated with ischemia in some cases, particularly among older patients who have risk factors for vascular disease, such as hypertension or DM, the researchers noted. "Migraine is associated with various vascular disorders and asymmetrical facial blood perfusion, which raises the suspicion of ischemic mononeuropathy of the facial nerve," they stated.

The study has limitations, the researchers noted. All patients with migraine in the study had active disease, and therefore the study did not include patients who may have had previous or nonactive migraine headaches.

In addition, the control group may have included patients who had migraine but did not go for treatment. As a consequence, the study may have underestimated the risk of Bell palsy among patients with migraine.

“Infection, inflammation, or heart and vascular problems could be shared causes for these diseases,” Dr Wang said. “If a common link is identified and confirmed, more research may lead to better treatments for both conditions.”

The researchers published their results in the December 17, 2014, online issue of Neurology.