Sex Change Can Cause Headache
Wed Aug 18, 2004 04:24 PM ET
By Karla Gale
NEW YORK (Reuters Health) - New research involving male-to-female
transsexuals lends further credence to the theory that sex hormones are
involved in migraine generation, physicians report in the medical journal
Neurology.
"We know that migraine is more frequent in women than in men,"
co-investigator Dr. Tamara Pringsheim told Reuters Health, "so a lot of
research goes into what estrogen does to the brain."
A new way to examine this issue, she added, is to look at a population of
genetic males who take antiandrogens and estrogen to induce female sex
characteristics.
Pringsheim, at the University of Toronto, and Dr. Louis Gooren, at Free
University Amsterdam, distributed questionnaires regarding headache
symptoms and frequency to 50 transsexuals who had recently undergone sex
reassignment surgery, all of whom were taking hormonal therapy.
Thirteen (26 percent) fulfilled criteria for migraine or probable
migraine, similar to the number of cases of migraine in genetic females
that would be expected. In contrast, the expected number of cases of
migraine in genetic males is significantly lower.
Pringsheim and Gooren theorize that the increased prevalence of migraine
is related to the effect of hormone therapy on nitric oxide, a known
migraine trigger.
"Normally, vascular reactivity is different in men than in women because
of estrogen's effect on nitric oxide," Pringsheim explained.
"Interestingly, cardiologists who have studied vascular reactivity in
male-to-female transsexuals found something similar -- that they have
enhanced arterial activity -- so we know the hormones are doing something
to the blood vessels."
She acknowledged that other mechanisms may be at play, such as the stress
of gender reassignment or adoption of a female gender role. Follow-up
studies that include headache histories and neurological examinations to
confirm the diagnosis of migraine should shed more light on these issues.
SOURCE: Neurology, August 10, 2004.
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