Novel Insights into Present and Future Pain in People with Urologic Pain Syndromes
Two recent reports have revealed important new information about pain patterns and other symptoms in people with the urologic chronic pelvic pain syndromes (UCPPS) interstitial cystitis/bladder pain syndrome (IC/BPS) and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), and the detection of future pain trends through noninvasive brain imaging. This research was conducted by investigative teams from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. The Network is using approaches that “look beyond” the bladder and prostate—the traditional focal points for study of these syndromes—to uncover meaningful information about the not-well-understood UCPPS and their relationships to other chronic pain conditions that could set the stage for future interventions.
In the first report, the research team set out to capture information about pain location, severity, and associated health and quality-of-life factors in women and men with UCPPS enrolled in the Network. To do this, 233 women with IC/BPS and 191 men with either IC/BPS or CP/CPPS were surveyed using multiple questionnaires assessing urologic, nonurologic, and psychosocial symptoms, and quality of life. For example, questionnaire items included measures or ratings of urinary frequency and urgency, pelvic pain, sleep, commonly co-occurring chronic pain conditions such as irritable bowel syndrome, and stress. They were also asked to look at a “body map”—two drawings representing the front and back of the body partitioned into 45 numbered sites, comprising eight body regions—and to check off any site in which they had experienced pain in the past week. From these data, the investigators found that, whereas a quarter of participants reported pain only in the pelvic region, 75 percent reported pain in both pelvic and nonpelvic regions. They then subdivided the latter group into two groups: “intermediate pain” for people who checked sites in one to two nonpelvic regions, and “widespread pain” for people who checked sites in three to seven nonpelvic regions. Intriguingly, there were no differences in pelvic pain severity or urinary symptoms across the three groups. In contrast, nonpelvic pain severity, prevalence of chronic overlapping pain conditions, worsening psychosocial health, and poor quality of life increased as the number of pain regions increased. Notably, more women than men experienced widespread pain, and women were more likely to report a greater burden of nonpelvic and nonurinary symptoms and conditions as their pain locations increased.
The investigators then compared just the intermediate and widespread pain groups to see if there were any significant differences among study participants with UCPPS who reported nonpelvic pain. This comparison yielded results similar to the three-group comparison for pelvic pain and urinary symptoms, nonpelvic pain, and several other health measures, but also revealed more gender-specific differences. For example, compared to individuals in their respective intermediate pain groups, men with widespread pain were more likely to have migraines and anxiety, while women were more likely to have irritable bowel syndrome and sleep disturbance. The differences found in this study among people diagnosed with UCPPS have significant implications for better understanding the cause(s) and/or development of these syndromes, for research studies on potential treatment approaches, and for clinical diagnosis and personalized care.
Numerous studies have uncovered brain changes in people with UCPPS compared to people without these syndromes, and a second Network research team investigated whether there was a brain “signature” in people with UCPPS of several years duration that could predict future changes in pain. Such knowledge could potentially identify brain factors involved in worsening or relief of pain and reveal a therapeutic target(s) for study. Using a brain imaging technique that measures the strength of functional interactions among different brain regions while at rest, researchers conducted voluntary brain scans on a subset of participants shortly after their enrollment in the Network. These scans and subsequent analyses yielded 13,530 brain connectivity measures per person. The team then compared analyses of the brain imaging data from 34 women and 18 men to their pelvic pain symptom status—categorized as “improvement” or “nonimprovement”—at 3, 6, and 12 months, to see if the brain scans could predict symptom trends. They found that their imaging analyses correctly predicted symptom trends in 73 percent of participants for the 3-month period following the scan. Further analyses revealed that the top 100 brain region connections that were more robust in “improvers” versus “nonimprovers” fell predominantly within a part of the brain associated with attention to sensory information.
Additional experiments will need to be performed in larger groups of people and under varying conditions to confirm, optimize, and extend these findings. However, this study is the first to demonstrate the feasibility of predicting pain symptom changes in women and men with UCPPS and has provided preliminary insights important to understanding the biology of pain and improving symptom management in these people.