BARCELONA, Spain — Migraine is widely considered a predominantly female disorder. Its frequency, duration, and severity tend to be higher in women, and women are also more likely than men to receive a migraine diagnosis. However, gender expectations, differences in the likelihood of self-reporting, and problems with how migraine is classified make it difficult to estimate its true prevalence in men and women.
Epidemiologists and migraine specialists discussed these apparent sex differences and the difficulties in obtaining accurate estimates of migraine prevalence in a debate session at the 17th European Headache Congress in Barcelona.
Different Symptoms
Headache disorders are estimated to affect 50% of the general population ; tension-type headache and migraine are the two most common. According to epidemiologic studies, migraine is more prevalent in women, with a female-to-male ratio of 3:1. There are numerous studies of why this might be, most of which focus largely on female-related factors, such as hormones and the menstrual cycle.
"Despite many years of research, there isn't one clear factor explaining this substantial difference between women and men," said Tobias Kurth of Charité – Universitätsmedizin Berlin, Germany. "So the question is: Are we missing something else?"
One factor in these perceived sex differences in migraine is that women seem to report their migraines differently from men, and they also have different symptoms. For example, women are more likely to than men to report severe pain , and their migraine attacks are more often accompanied by photophobia, phonophobia, and nausea, whereas men's migraines are more often accompanied by aura.
"By favoring female symptoms, the classification system may not be picking up male symptoms because they're not being classified in the right way," Kurth said, with one consequence being that migraine is underdiagnosed in men. "Before trying to understand the biological and behavioral reasons for these sex differences, we first need to consider these methodological challenges that we all apply knowingly or unknowingly."
Christian Lampl, professor of neurology at Konventhospital der Barmherzigen Brüder Linz, Austria, and president of the European Headache Federation, told Medscape Medical News, "I'm convinced that this 3:1 ratio which has been stated for decades is wrong, but we still don't have the data. The criteria we have [for classifying migraine] are useful for clinical trials, but they are useless for determining the male-to-female ratio.
"We need a new definition of migraine," he added. "Migraine is an episode, not an attack. Attacks have a sudden onset, and migraine onset is not sudden — it is an episode with a headache attack."
Inadequate Menopause Services
Professor Anne MacGregor of St. Bartholomew's Hospital in London, United Kingdom, specializes in migraine and women's health. She presented data showing that migraine is underdiagnosed in women; one reason being that the disorder receives inadequate attention from healthcare professionals at specialist menopause services.
Menopause is associated with an increased prevalence of migraine, but women do not discuss headache symptoms at specialist menopause services, MacGregor said.
She then described unpublished results from a survey of 117 women attending the specialist menopause service at St. Bartholomew's Hospital. Among the respondents, 34% reported experiencing episodic migraine and an additional 8% reported having chronic migraine.
"Within this population of women who were not reporting headache as a symptom [to the menopause service until asked in the survey], 42% of them were positive for a diagnosis of migraine," said MacGregor. "They were mostly relying on prescribed paracetamol and codeine, or buying it over the counter, and only 22% of them were receiving triptans.
"They are clearly being undertreated," she added. "Part of this issue is that they didn't spontaneously report headache as a menopause symptom, so they weren't consulting for headache to their primary care physicians."
Correct diagnosis by a consultant is a prerequisite for receiving appropriate migraine treatment. Yet, according to a US study published in 2012, only 45.5% of women with episodic migraine consulted a prescribing healthcare professional. Of those who consulted, 89% were diagnosed correctly, and only 68% of those received the appropriate treatment.
A larger, more recent study confirmed that there is a massive unmet need for improving care in this patient population. The Chronic Migraine Epidemiology and Outcomes (CaMEO) Study, which analyzed data from nearly 90,000 participants, showed that just 4.8% of people with chronic migraine received consultation, correct diagnosis, and treatment, with 89% of women with chronic migraine left undiagnosed.
The OVERCOME Study further revealed that although many people with migraine were repeat consulters, they were consulting their physicians for other health problems.
"This makes it very clear that people in other specialties need to be more aware about picking up and diagnosing headache," said MacGregor. "That's where the real need is in managing headache. We have the treatments, but if the patients can't access them, they're not much good to them."
Moheb Costandi is a freelance writer based in London.
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