Endometriosis pain

New study sheds light on endometriosis pain

New science suggests that women with endometriosis often have several types of pain conditions because their abnormal growths develop a nerve supply that communicates with the brain.

Professor Karen Berkley from Florida State University is the lead researcher in a study that shows that endometrial cysts become supplied by sympathetic and sensory nerves that could contribute to both the different types of pain associated with endometriosis and the body's ability to maintain the disease. The new nerves likely sprout from those that supply the blood vessels that grow along with and nourish the cysts, Berk

Professor Berkley and her colleagues drew the conclusion after research on human tissue replicated results that she and her colleagues found last year on rats with surgically induced endometriosis.

"It's been a mystery - clinically - why there is such a co-occurrence between endometriosis and other painful conditions we wouldn't think would be related: irritable bowel syndrome, interstitial cystitis and even migraines," Berkley said. "It may happen in part because this new nerve supply comes into the central nervous system and interacts with information coming from other organs, such as the colon and bladder, that the brain may interpret as pain."

The types of nerves that develop in the cysts, the agents that activate them, the sites in the central nervous system where the nerves deliver information and how the information is modulated by oestrogen all influence how the disease will manifest itself, according to the researchers. Thus, the variability of the nerve supply of the cysts in different individuals may help explain why symptoms and severity of pain vary so greatly in women who have endometriosis.

SOURCES

Berkley KJ, Rapkin AJ, Papka RE. The pains of endometriosis. Science 2005;308:1587-1589.

Berkley KJ, Dmitrieva N, Curtis KS, Papka RE. Innervation of ectopic endometrium in a rat model of endometriosis. Proc Natl Acad Sci USA 2004;101(30):11094-8.