Migraine is one of the most common disabling medical conditions in the US, affecting around 36 million Americans. But as if having a severe headache disorder is not enough, a new study finds that people with migraine may be at much higher risk of Bell’s palsy – a condition that causes facial paralysis.
The research team – including Dr. Shuu-Jiun Wang of the National Yang-Ming University and Taipei Veterans General Hospital in Taiwan – publish their findings in the journal Neurology.
Bell’s palsy affects around 40,000 Americans every year, with onset most common between the ages of 15 and 60 years. Symptoms of the condition include twitching and weakness in one or both sides of the face, partial or complete paralysis, drooping of the eyelid or corner of the mouth, drooling, eye or mouth dryness and taste impairment.
Patients with mild cases of Bell’s palsy may not require treatment, as symptoms often disappear by themselves within 2 weeks. More severe cases, however, may need to be treated with physical therapy or steroids to reduce swelling and inflammation.
The exact causes of Bell’s palsy are unclear, although previous research has suggested the condition may be triggered by a viral infection – such as viral meningitis or the cold sore virus – that causes facial nerves to swell.
According to Dr. Wang and colleagues, past studies have also indicated an association between migraine and facial and limb weakness. In this latest study, the team set out to see whether there is a link between migraine and Bell’s palsy.
To reach their findings, the researchers analyzed information from the Taiwan National Health Insurance Research Database.
- Bell’s palsy is named after Sir Charles Bell – a Scottish surgeon who first described the condition in the early 19th century
- Symptoms of Bell’s palsy usually develop suddenly and reach their peak within 2 days
- Both men and women are at equal risk of developing Bell’s palsy, although it is more common among people with diabetes or those who have cold or flu.
They identified two groups of 136,704 individuals aged 18 years and older; one group had neurologist-diagnosed migraine and the other group did not. Both groups were followed for an average of 3.2 years.
During the follow-up period, the team found that 671 individuals with migraine developed Bell’s palsy, compared with only 365 people who did not have migraine. Even after accounting for other risk factors for Bell’s palsy – such as diabetes, hypertension and sex – the team calculated that people with migraine were twice as likely to develop the condition than those without migraine.
The researchers explain there may be a number of underlying mechanisms that account for the association between migraine and Bell’s palsy.
They point to the theory that viral infections may be a cause of the condition and explain that recurrent migraine attacks may trigger inflammation of cranial nerves. They say this may “predispose the facial nerve to demyelination after viral infection.”
In addition, they note that Bell’s palsy has been associated with ischemia in some cases, particularly among older people with risk factors for vascular disease, such as hypertension or diabetes. “Migraine is associated with various vascular disorders and asymmetrical facial blood perfusion, which raises the suspicion of ischemic mononeuropathy of the facial nerve,” they add.
Commenting on the team’s findings, Dr. Wang says:
“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. If a common link is identified and confirmed, more research may lead to better treatments for both conditions.”
The researchers say their study is subject to some limitations. For example, they note that all patients with migraine in the study had active migraine; the study did not consider patients who may have had previous or nonactive migraine, which may have affected the results.
What is more, they point out that the control group may have consisted of patients who had migraine but did not seek out treatment for the condition, which may have led to an underestimation in the risk of Bell’s palsy among migraine patients.
Medical News Today recently reported on a study published in the journal Headache, which found that a type of meditation called mindfulness-based stress reduction may ease migraine.