Pubmed
 2019 Mar;98(3):327-336. doi: 10.1111/aogs.13508. Epub 2018 Dec 30.

Reduced pain thresholds and signs of sensitization in women with persistent pelvic pain and suspected endometriosis.

Author information

1. Department of Obstetrics and Gynecology, Linköping University, Norrköping, Sweden.
2. Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
3. Pain and Rehabilitation Center and Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
4. Center for Sensory-Motor Interactions, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark.
5. Department of Obstetrics and Gynecology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.

Abstract

INTRODUCTION:

Endometriosis is a gynecological disorder that may cause considerable pelvic pain in women of fertile age. Determining pain mechanisms is necessary in order to optimize the treatment of the disease. The objective of the study was to evaluate pain thresholds in women with persistent pelvic pain with and without confirmed endometriosis, and healthy, unaffected controls, and analyze how pain thresholds in these cohorts related to duration of pelvic pain, quality of life, and symptoms of anxiety and depression.

MATERIAL AND METHODS:

Pain thresholds for heat, cold and pressure were assessed with quantitative sensory testing on six locations on a reference group of 55 healthy women and on 37 women with persistent pelvic pain who had been admitted for diagnostic laparoscopy on the suspicion of endometriosis. Validated instruments were applied to assess quality of life and symptoms of anxiety and depression. Data were analyzed by means of uni- and multivariate analysis of variance and Spearman's rank-order correlation.

RESULTS:

The women with persistent pelvic pain had significantly lower pain thresholds compared with the reference women. In the women with pain, no differences were observed in pain thresholds between women with (n = 13) and women without (n = 24) biopsy-proven endometriosis. The duration of pelvic pain correlated significantly positively with reduced pain thresholds, ie, the longer the duration, the more sensitization. In the persistent pelvic pain group, pain thresholds for heat correlated significantly with the Short Form Health Survey 36 dimension of bodily pain, and thresholds for cold correlated with Short Form Health Survey 36 bodily pain and with symptoms of depression.

CONCLUSIONS:

Our results showed widespread alterations in pain thresholds in women with persistent pelvic pain that are indicative of central sensitization and a time-dependent correlation. Women with pelvic pain and suspicion of endometriosis should probably be treated more thoroughly to prevent or at least minimize the concomitant development of central sensitization.

KEYWORDS:

chronic pain; endometriosis; health-related quality of life; pain thresholds; persistent pelvic pain; quantitative sensory testing; sensitization


Dr. K's Comment:

While this study improves our understanding about the nature and progression of pain, it is equally critical (or even more important) to focus on treating properly and effectively the cause of the pain in the first place. And by proper and effective, I mean complete excision of endometriosis.

The study also note widespread alterations in pain thresholds in women with persistent pelvic pain that are indicative of central sensitization and a time-dependent correlation. This basically means that the longer the endometriosis remain untreated, the longer the woman will be in pain and with time it may be more difficult to treat the pain effectively even when the disease has been treated properly and effectively by complete excision. 

Therefore, act now! If you have pelvic pain for more than 6 months, you have up to a 80-90% chance of having endo at the time of surgery and it's time to get your endometriosis treated properly.