Thursday, September 11, 2014

Nerve fibers and pain in endometriotic lesions


[Relationship between pain and nerve fibers distribution in multiple endometriosis lesions].

[Article in Chinese]

Abstract

OBJECTIVE:

To investigate the relationship between the distribution of nerve fibers in multiple endometriosis lesions and pelvic pain.

METHODS:

From Sept. 2007 to Sept. 2008, 120 endometriosis patients treated in Peking Union Hospital were enrolled in this study, which including 19 cases with stage I, 29 cases with stage II, 44 cases with stage III and 28 cases with stage IV. The pain symptom was evaluated by visual analogue scales (VAS) score and nerve fibers in multiple endometriosis lesions were detected by immunohistochemical staining.

RESULTS:

The number of nerve fibers in multiple endometriosis lesions were (29.74+/-17.33)/mm2 in uterosacral ligament, (24.53+/-13.34)/mm2 in vaginal septum, (17.09+/-10.09)/mm2 in uterus rectum crux, (6.77+/-4.21)/mm2 in peritoneal endometriosis lesions, (0.07+/-0.25)/mm2 in endometriosis ovarian cyst wall. The number of nerve fibers in uterosacral ligament was mostly correlated with the degree of pain (r=0.56). The nerve fibers of uterus rectum crux and vaginal septum were correlated with defecation pain (r=0.58 and 0.41) and dyspareunia (r=0.82 and 0.67), which were significantly higher than those in endometriosis leision in peritoneum and ovary. There was no significant different number of nerve fibers among different stage disease (P>0.05).

CONCLUSION:

There was significantly different distribution of nerve fibers in multiple endometriosis lesions, which was correlated with dysmenorrhea, anus pain, dyspareunia and chronic pelvic pain, not with clinical staging.
http://www.ncbi.nlm.nih.gov/pubmed/20646536

____________________________________________________________________________________

Endometriosis-associated nerve fibers, peritoneal fluid cytokine concentrations, and pain in endometriotic lesions from different locations.

Abstract

OBJECTIVE:

To assess the relationship between endometriotic lesions with associated nerve fibers with both pain and peritoneal fluid (PF) cytokine concentrations based on lesion location.

DESIGN:

An observational study.

SETTING:

University hospital.

PATIENT(S):

Premenopausal women undergoing laparoscopy.

INTERVENTION(S):

The pain experienced by patients was recorded before surgery and ectopic endometrial tissue excised and matching PF collected during laparoscopy. Immunohistochemistry was performed on endometriotic tissue sections to identify nerve fibers and PF cytokine concentrations determined.

MAIN OUTCOME MEASURE(S):

The pain experienced by women with endometriosis, the lesion locations, and the prevalence and proximity of nerve fibers to endometriotic lesions, as well as the PF concentrations of multiple cytokines.

RESULT(S):

Lesions from the rectovaginal septum were significantly more likely to be associated with a nerve fiber and report more menstrual pain than lesions from other regions. The PF glycodelin concentrations were also significantly higher in samples with an endometriotic-associated nerve. In peritoneal endometriotic lesions significantly more menstrual pain was reported when endometriotic lesions were associated with nerve fibers, although no difference was observed between the cytokine concentrations. Ovarian endometriotic lesions were rarely associated with nerve fibers.

CONCLUSION(S):

The presence of endometriosis-associated nerve fibers appear to be related to both the pain experienced by women with endometriosis and the concentration of PF cytokines; however, this association varies with the lesion location.

http://www.ncbi.nlm.nih.gov/pubmed/22154765

____________________________________________________________________________________

2011 Jun 30;95(8):2772-4. doi: 10.1016/j.fertnstert.2011.01.150. Epub 2011 Feb 19.

Nerve fibers and menstrual cycle in peritoneal endometriosis.

Abstract

There was no difference in the density of nerve fibers across the menstrual cycle in peritoneal endometriotic lesions. These findings may explain why patients with peritoneal endometriosis often have painful symptoms throughout the menstrual cycle.

Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
http://www.ncbi.nlm.nih.gov/pubmed/21334610

____________________________________________________________________________________

"

RESULTS:

The positive rate and density of PGP9.5-immunoreactive nerve fibers in peritoneal endometriotic leision were 62% (10/16) and (3.8+/-1.7)/mm2 in endometriosis patients with pain, which were significantly higher than 19% (3/16) and (1.7+/-0.5)/mm2 in endometriosis patients without pain (P<0.05) and 25% (5/20) and (1.3+/-0.6)/mm2 in peritoneal tissues in women without endometriosis (P<0.05). However, no differences were found between endometriosis patients without pain and women without endometriosis (P>0.05). Moreover, the density of PGP9.5-immunoreactive nerve fibers in peritoneal lesions in endometriosis patients with pain was positively correlated with the severity of pain (r=0.855, P<0.05). In addition, the density of PGP9.5-immunoreactive nerve fibers in peritoneal lesions was statistically higher in endometriosis patients with chronic pelvic pain and (or) dysmenorrhea than those in endometriosis patients with other type of pain (P<0.05), which was not associated with active lesion, site and staging (P>0.05).

CONCLUSION:

It suggested that PGP9.5-immunoreactive nerve fibers might confer the mechanism of pelvic pain with endometriosis."
http://www.ncbi.nlm.nih.gov/pubmed/20646535

___________________________________________________________________________________

"The nerve fiber density (mean +/- standard deviation/mm(2)) in peritoneal endometriotic lesions from hormone-treated women with endometriosis (10.6 +/- 2.2/mm(2)) was statistically significantly lower than in peritoneal endometriotic lesions from untreated women with endometriosis (16.3 +/-10.0/mm(2)). Nerve growth factor and nerve growth factor receptor p75 expression in peritoneal endometriotic lesions were slightly reduced in hormone-treated women with endometriosis compared with untreated women with endometriosis.
CONCLUSION(S):
Progestogens and combined oral contraceptives reduced nerve fiber density and nerve growth factor and nerve growth factor receptor p75 expression in peritoneal endometriotic lesions" http://www.ncbi.nlm.nih.gov/pubmed/18976764