Chronic pelvic pain central sensitization uncovered by Convergences pelvic pain score | Image Credit: © Chinnapong - © Chinnapong - stock.adobe.com.
The Convergences pelvic pain (PP) score can be used to determinepelvic sensitization in patients with chronic pelvic pain (CPP) according to a recent study published in the American Journal of Obstetrics & Gynecology.
- The Convergences pelvic pain (PP) score is a tool that can help identify pelvic sensitization in patients with chronic pelvic pain (CPP).
- Patients with CPP often experience complex manifestations, including pain and dysfunction in various pelvic areas, leading to diagnostic uncertainty and treatment failure.
- Central sensitization in women with CPP can be diagnosed by considering their history, pelvic organ sensitivity, and the spatial and temporal diffusion of pain.
- A recent study compared women with high sensitization (HS-CPP) and low sensitization (LS-CPP) and found that HS-CPP patients reported more painful diseases, increased duration of suffering, and reduced quality of life.
- The Convergences PP score can be a valuable tool for physicians to validate patients' symptoms related to central pain sensitization in women with CPP.
Complex manifestations are often seen in patients with CPP, including pain and dysfunction in the lower urinary tract, genital tract, lower gastrointestinal tract, and perineal muscles. Patients with CPP often face diagnostic uncertainty and treatment failure because of these manifestations.
In a central sensitization, patients would present with reduced nociceptive thresholds, a longer and more severe response to a nociceptive stimulus, and spatial extension of the painful area. The diagnosis of a central sensitization in women with CPP should account for a woman’s history, pelvic organ sensitivity, and spatial and temporal diffusion of pain.
Currently, there are no studies assessing the differences in pain thresholds between women with CPP with a high score of sensitization(HS-CPP)vs a low score of sensitization(LS-CPP). To investigate these differences, investigators conducted a prospective, single-blind, comparative study.
Participants were aged between 25 and 65 years, were experiencing over 3 months of pelvic pain, and had no injury potentially liked to the pain complaints. Exclusion criteria included major depression, initial pain estimated at 10 at of 10 on a visual analogue score (VAS), active genitourinary tract infection, and posttraumatic stress disorder.
Further exclusion criteria included pelvic or abdominal malignancy history, anal stenosis deep bladder or rectal endometriosis, advanced prolapse, refusal to undergo neurophysiological tests; pregnancy or breastfeeding; poor understanding of the local language, isolated dysmenorrhea, being deprived of liberty, and convergences PP of 5 out of 10.
Medical, surgical, gynecologic, and psychological history was obtained during the initial consultation visit. Patients rated pain severity on a 0-to-10 Numerical Rating Scale (NRS).
Premenopausal women with periods attended an assessment visit during the follicular phase, undergoing assessments of anxiety, catastrophic thinking, and quality of life. Between the 2 visits, participants were asked to maintain identical antalgic treatment. Four neurophysiological tests were completed, with a VAS score reported every 30 seconds until a score of 3 out of 10 was reached or 15 minutes passed.
Participants also received a bladder test using a method which allowed bladder sensitivity to be assessed without retrograde catheterization. Descriptions of bladder sensitivity included first sensation, first urge, and maximum tolerance.
A series of rectal isobaric distensions were measured using an electronic barostat to determine rectal sensory thresholds. Parameters recorded include rectal compliance, sensation intensity at each pressure step, and pain sensation. Participants also completed a muscular sensory test, with sensitivity measured using an algometer.
There were 53 participants included in the analysis, 35.8% of whom had endometriosis, 32.1% bladder pain syndrome, and 28.3% vestibulodynia. More painful diseases diagnosed and increased duration of suffering were reported in women with higher sensitivity scores than those with LS-CPP. Women with HS-CPP women also had a reduced quality of life score.
HS-CPP and LS-CPP participants had a similar bladder maximum capacity, volume of first sensation, and volume of first urge. However, HS-CPP participants had significantly increased pain at these thresholds.
Pain sensation at the maximum step tested in the rectal test was not reached by 16.7% of the HS-CPP population vs 44.4% of the LS-CPP population. Compared to LS-CPP women, HS-CPP women had decreased rectal compliance at 6-, 11-, 16-, and 21-mm Hg.
In all vulvar areas tested, HS-CPP women had decreased pain pressure thresholds. Pain intensity was low and did not significantly differ between groups.
These results indicatedcentral pain sensitization, lower pain thresholds, and prolonged and diffuse extension of pain can be determined using the Convergences PP score in women with CPP. Investigators concluded physicians can use the Convergences PP score to validate patients’ symptoms.
Cardaillac C, Levesque A, Riant T. Evaluation of a scoring system for the detection of central sensitization among women with chronic pelvic pain. American Journal of Obstetrics & Gynecology. 2023;229(5):530.E1-530.E17. doi:10.1016/j.ajog.2023.07.044