“Historically, about half the patients who had them would kill themselves [because] the pain was so bad,” says Merle Diamond, MD, the managing director of the Diamond Headache Clinic and the director of the Diamond Inpatient Headache Unit at Saint Joseph Hospital in Chicago. “It’s a knife-searing pain. People have described it as having a hot poker through their eye or somebody stabbing them through their skull.” Although this debilitating condition has been more frequently reported among men, a new study published this month in Neurology, the journal of the American Academy of Neurology, indicates that women with the disorder may experience longer and more chronic episodes compared with men. “Cluster headache is still often misdiagnosed in women, perhaps because some aspects can be similar to migraine,” says study author Andrea C. Belin, PhD, of the Karolinska Institutet in Stockholm, Sweden. “But, according to our results, females generally may be more gravely affected by cluster headache than males. I still meet female study participants who have been told by neurologists that they can’t have cluster headache since they’re women, even though the symptoms match. We want to increase the awareness that women can have cluster headache, too.”
What’s the Difference Between Cluster Headache and Migraine?
A typical cluster headache can last anywhere from 15 minutes to three hours. Migraines are very different in that they can last 4 to 72 hours, says Nada Hindiyeh, MD, a headache specialist and co-chair of the American Headache Society’s electronic media committee. Another distinction: “Cluster attacks are strictly unilateral — they do not shift sides of the head. Migraine headaches can be unilateral but they do not have to be, and can be all over the head,” says Dr. Hindiyeh. A cluster headache may produce a drooping eyelid, a red eye, stuffy nostril, or flushing of the face or ear. More than 37 million Americans have migraine, while cluster headache affects fewer than one million Americans, according to the Human Health Project. Dr. Diamond characterizes someone with migraine as wanting to pull the covers over their head, not wanting any noise or lights, and not wanting to move around. “If you have cluster headache, on the other hand, you may be pacing around. I’ve seen people banging their heads against the wall just to kind of get themselves away from the level of pain they’re having,” she says.
Women Are Twice as Likely to Have Cluster Headache as a Chronic Issue Compared With Men
For this latest research, Dr. Belin and her colleagues analyzed data from 874 people diagnosed with cluster headache (two-thirds were male and one-third were female) who answered a detailed questionnaire about their symptoms, medications, headache triggers, and lifestyle habits. While all participants had cluster headache, the study authors found that the percent of women diagnosed with chronic cluster headache was about double — 18 percent compared with 9 percent of men. Chronic cluster headache was defined as recurring cluster headache attacks for one year or more without interruption, or with short intermissions with no symptoms that last fewer than three months. Belin and collaborators also noted that the women in the study had longer-lasting attacks compared with the men. About 8 percent of women said headache bouts lasted an average of four to seven months, compared with 5 percent of men, while 26 percent of women said bouts on average lasted less than one month, compared with 30 percent of men. Women were also more likely than men to report that their attacks occurred at various times throughout the day, 74 percent versus 63 percent. Finally, 15 percent of the female participants reported having a family member with a history of cluster headache, compared with 7 percent of the males.
Many Women With Cluster Headache May Be Misdiagnosed
The fact that the condition has been linked primarily to men may help explain misdiagnosis in women, according to Belin. That may be changing, however. In an accompanying editorial in Nuerology, investigators wrote that estimates of the male to female sex ratio for cluster headache was once thought to be 6 to 1, but has decreased over the decades to values as low as 1.3 to 1. Robert Cowan, MD, a professor in the Stanford University School of Medicine department of neurology and neurological sciences, says that the prevalence of a condition in one sex over the other should not make it more difficult to diagnose. “Whether it is 2 times or 3 times as common in one sex or the other is not really important,” says Dr. Cowan. “It is not difficult at all if you know the criteria. For example, breast cancer is about 100 times more common in women than men. But it still happens [in men]. You need to know these statistics, but what is important is that you recognize the clinical presentation.” Although the study did not explore the causes of more chronic cluster headache in women, Cowan speculated that estrogen — the sex hormone responsible for the development of the female reproductive system — could be to blame. “Cluster is viewed as a disorder originating or regulated by the hypothalamus [an area of the brain that produces hormones],” said Cowan. “The hypothalamus is rich in estrogen receptors, so that might be a clue.”
The Bottom Line on Women and Cluster Headache
In summing up their findings, the study authors stressed that doctors still misdiagnose cluster headache in women, perhaps because certain symptoms of the disease in female patients resemble those of migraine. “It is therefore of utmost importance for physicians to be aware of these sex differences when working in the clinic and meeting headache patients to be able to give the most effective treatment as fast as possible,” concluded the researchers.
