Brain regions managing emotion and pain are wired differently in sufferers.
Premenstrual tension, also called premenstrual syndrome or PMS, is familiar to much of the world’s population and the subject of much wry commentary. Thirty to 40 percent of reproductive-age women suffer from it. Symptoms include irritability, depression, anxiety, food cravings and headaches. Recently researchers have learned that the amygdala, an important brain region for managing pain processing and the integration of memory and emotion, is influenced by the hormonal fluctuations of the menstrual cycle.
Using functional and structural magnetic resonance imaging, scientists from China’s Guangxi University of Chinese Medicine and Xidian University in Xi'an, China compared the amygdalas of 20 women who had PMS with 21 women without it. All the women were scanned within five days before menstruation onset, when PMS is usually at its worst. They found that women experiencing PMS symptoms had amygdalas that were larger and wired differently from those in women without PMS.
The strength of the relationships -- termed functional connectivity -- between the amygdala and other brain regions involved in emotional and pain processing, such as the hippocampus and orbitofrontal cortex, correlated with the severity of the women’s PMS symptoms. The study also suggests that in women with PMS, amygdala size waxes and wanes according to the menstrual cycle, a finding not seen before in amygdala imaging studies. The researchers reported their findings in the journal European Radiology last December.