title: Chronic pelvic pain and endometriosis: translational evidence of the relationship and implications.
abstract: BACKGROUND
  Many clinicians and patients believe that endometriosis-associated pain is due to the lesions. Yet causality remains an enigma, because pain symptoms attributed to endometriosis occur in women without endometriosis and because pain symptoms and severity correlate poorly with lesion characteristics. Most research and reviews focus on the lesions, not the pain. This review starts with the recognition that the experience of pain is determined by the central nervous system (CNS) and focuses on the pain symptoms.
  
  
  METHODS
  Comprehensive searches of Pubmed, Medline and Embase were conducted for current basic and clinical research on chronic pelvic pain and endometriosis. The information was mutually interpreted by a basic scientist and a clinical researcher, both in the field of endometriosis. The goal was to develop new ways to conceptualize how endometriosis contributes to pain symptoms in the context of current treatments and the reproductive tract.
  
  
  RESULTS
  Endometriotic lesions can develop their own nerve supply, thereby creating a direct and two-way interaction between lesions and the CNS. This engagement provides a mechanism by which the dynamic and hormonally responsive nervous system is brought directly into play to produce a variety of individual differences in pain that can, in some women, become independent of the disease itself.
  
  
  CONCLUSIONS
  Major advances in improving understanding and alleviating pain in endometriosis will likely occur if the focus changes from lesions to pain. In turn, how endometriosis affects the CNS would be best examined in the context of mechanisms underlying other chronic pain conditions.
authors.affiliation: Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bldg. 10, CRC, RM 1-3140, 10 Center Dr. MSC 1109, Bethesda, MD 20892-1109 USA. strattop@mail.nih.gov
authors.forename: Pamela
authors.initials: P
authors.lastname: Stratton
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Berkley
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000503:physiopathology; D004715:Endometriosis / Q000150:complications* / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D004717:Endometrium / Q000294:innervation; D005260:Female; D006801:Humans; D008599:Menstruation Disturbances / Q000150:complications; D010147:Pain Measurement / Q000379:methods; D017699:Pelvic Pain / Q000188:drug therapy / Q000209:etiology* / Q000601:surgery; D011247:Pregnancy; D011248:Pregnancy Complications; D051381:Rats; D014591:Uterine Diseases / Q000150:complications