Cluster headache--sex differences

Comment: Sex-specific differences in cluster headache—

Not a males-only disorder

Tim P. Jürgens

First published February 15, 2017  American Academy of Neurology

Cluster headache (CH) has long been regarded as a males-only disorder. However, the male to female ratio (M/F) of up to 6.2:1 in patients with CH onset before 1960 has fallen to 2.1:1 for patients with onset in the 1990s—similar to that found by Lund et al.1 Lifestyle changes may have contributed to this phenomenon, or an increased awareness of the condition in women.

Lund et al. examined further sex-specific aspects of CH in a well-characterized sample. There was a diagnostic delay of up to 6.6 years in all patients, and a higher rate of misdiagnosis in women—with migraine being the most common.1 The reason for the high rate of misdiagnosis in women is uncertain. While phonophobia and photophobia were equally frequent in both sexes, the frequency of nausea and vomiting is not reported. As migraine was the most frequent misdiagnosis in women, and migraine prevalence is twice as high in women, migraine could have been suspected empirically. It is furthermore known that the above features can prolong the diagnostic delay of CH by years. This delay has declined over the last years, but is still too long.

Another intriguing finding was that chronic CH prevalence was highest among women. Previous studies support this notion: in late-onset CH, women experience chronic CH nearly as often as men.2 Sex hormones and their differential effects on pivotal structures such as the hypothalamus cannot fully explain these observations.

There is still much to learn about sex-specific aspects in CH. What we do know from studies on familial CH is that diagnosing CH is easier than diagnosing migraine3 and the patient's sex should not prevent us from doing so rapidly.