Primary dysmenorrheal (PDM), also known as menstrual cramps or period pains, can cause abnormal changes in brain structure, a study published in the medical journal Pain reveals.

PDM is the most common gynecological disorder in women of childbearing age. Pain in the lower abdomen typically starts with the onset of menstrual flow - this persistent pain stimulus can cause changes throughout the nervous system, the authors explain.

Lead researchers Professor Jen-Chuen Hsieh, MD, PhD, Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan, said:

"Our results demonstrated that abnormal GM [gray matter] changes were present in PDM patients even in absence of pain. This shows that not only sustained pain but also cyclic occurring menstrual pain can result in longer-lasting central changes. Although the functional consequences remain to be established, these results indicate that the adolescent brain is vulnerable to menstrual pain. Longitudinal studies are needed to probe hormonal interaction, fast-changing adaptation (intra-menstrual cycle) and whether such changes are reversible or not."

The study consisted of 32 patients who suffer from PDM, and another 32 participants (controls) who were pain free during their periods. MRI scans of each participant were obtained when the PDM patients were not experiencing pain, and maps of gray matter (GM) were created. Both the total GM volume and the GM volume of specific brain areas were determined for both PDM patients and controls.

Significant gray matter volume changes were observed in the anatomical maps of the patients who suffered from menstrual cramps. Abnormal decreases were found in regions involved in pain transmission, higher level sensory processing, and affect regulation while increases were found in regions involved in pain modulation and in regulation of endocrine function.

Source: Medical News Today, 11 August 2010
Author: Christian Nordqvist