Science

Menstrual cramps affect brain

The pain of menstrual cramps may change women's brains, a brain scanning study suggests.

The pain of menstrual cramps may change women's brains, a brain scanning study suggests.

Menstrual cramps, formally known as primary dysmenorrhea, are the most common gynecological disorder in women of childbearing age.

The lower abdominal pain starts when menstrual flow begins and the ongoing pain stimulus can cause changes throughout the nervous system, researchers say.

In the September issue of the journal Pain, researchers in Taiwan report abnormal changes in the structure of the brain in patients with menstrual cramps.

The changes in the brain's grey matter were present even in the absence of pain, the researchers said.

"This shows that not only sustained pain but also cyclic occurring menstrual pain can result in longer-lasting central changes," said Dr. Jen-Chuen Hsieh, a professor at the Institute of Brain Science at National Yang-Ming University in Taipei.

The functional consequences still need to be established, but the results show the adolescent brain is vulnerable to menstrual pain, Hsieh said.

The researchers used a brain scan known as optimized voxel-based morphometry to study the brain anatomy of 32 young women who said they experienced moderate to severe menstrual cramps regularly for several years, and another 32 women who did not report such pain.

Women who reported menstrual pain showed decreases in volume in regions of the brain thought to be involved in processing transmission, processing higher level sensory processing, and pain modulation and regulation of endocrine function.

"Our findings highlight that longer lasting central changes may occur not only in sustained chronic pain conditions but also in cyclic occurring pain conditions," the study's authors concluded.

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