Interstitial Cystitis - Elucidation of Psychophysiologic and Autonomic Characteristics (the ICEPAC Study): design and methods

Does maladaptive cardiovagal modulation extend to gastric modulation in women with chronic pelvic pain?

BACKGROUND

Women with chronic pelvic pain (CPP) have poor cardiovagal modulation. It is unclear whether this finding reflects a broader abnormality across many systems such as gastro-vagal modulation.

AIM

To determine if maladaptive cardiovagal activity in females with CPP is accompanied by maladaptive gastric myoelectric activity.

METHODS

A total of 36 health controls (HC) and 75 CPP underwent supine (10 min), then upright (tilted 70° head up; 30 min), and back to supine (10 min) positions. High-frequency heart rate variability (HF-HRV; 0.15-0.4 Hz) was measured as an index of cardiovagal activity. Cutaneous electrogastrography (EGG) assessed gastric myoelectric activity pre- and during-upright tilt. EGG measures from 16 HC and 31 CPP patients were available for analysis and included relative percentage of gastric activity within the normal (2-4 cpm) and tachygastria (4-10 cpm) ranges, plus ratio of normal/tachygastria.

RESULTS

HF-HRV was lower in CPP individuals at all time points (each p < .05). CPP individuals showed lesser decrease in HF-HRV from supine to upright, and poorer HF-HRV recovery from upright back to supine (F[1, 106] = 4.62, p = .034). HC showed increase in tachygastria activity (t[15] = -2.09, p = .054) while the CPP group showed no change in tachygastria activity from pre-upright to upright (t[30] = -0.62, p = .537).

CONCLUSIONS

Individuals with CPP going from supine to upright demonstrate an impairment in both tachygastria and the parallel decrement in HRV. These results support the hypothesis of a generalized blunting in the physiological modulation in CPP individuals affecting both cardiovascular and gastric systems.

Personal cell therapy for interstitial cystitis with autologous stromal vascular fraction stem cells

Background:

The objective of this study was to evaluate whether autologous stem-cell-based therapy may mitigate the symptoms of interstitial cystitis.

Methods:

Stromal vascular fraction (SVF) rich in stem cells and derived from autologous adipose tissue was deployed into 109 men and women with interstitial cystitis/painful bladder syndrome as a surgical procedure. This stem-cell-rich biologic product was injected both systemically and regionally into pelvic floor targets. Patients were queried about quality of life and symptom and bother subjective outcomes tests every 3 months for 2 years.

Results:

A total of 78 patients reported a positive response at 1 year. Symptom and bother metrics were statistically improved at 1 year. There were minimal adverse events associated with the harvesting, procurement, and clinical deployment of SVF.

Conclusion:

Interstitial cystitis is a complex clinical problem that is known for its resistance to conventional therapies. SVF as an autologous personalized regenerative strategy shows good safety and efficacy and may potentially have a role in the mitigation of interstitial cystitis.

Autonomic neurophysiologic implications of disorders comorbid with bladder pain syndrome vs myofascial pelvic pain

AIMS

The neuropathophysiology of a debilitating chronic urologic pain condition, bladder pain syndrome (BPS), remains unknown. Our recent data suggests withdrawal of cardiovagal modulation in subjects with BPS, in contrast to sympathetic nervous system dysfunction in another chronic pelvic pain syndrome, myofascial pelvic pain (MPP). We evaluated whether comorbid disorders differentially associated with BPS vs MPP shed additional light on these autonomic differences.

METHODS

We compared the presence and relative time of onset of 27 other medical conditions in women with BPS, MPP, both syndromes, and healthy subjects. Analysis included an adjustment for multiple comparisons.

RESULTS

Among 107 female subjects (BPS alone = 32; BPS with MPP = 36; MPP alone = 9; healthy controls = 30), comorbidities differentially associated with BPS included irritable bowel syndrome (IBS), dyspepsia, and chronic nausea, whereas those associated with MPP included migraine headache and dyspepsia, consistent with the distinct autonomic neurophysiologic signatures of the two disorders. PTSD (earliest), anxiety, depression, migraine headache, fibromyalgia, chronic fatigue, and IBS usually preceded BPS or MPP. PTSD and the presence of both pelvic pain disorders in the same subject correlated with significantly increased comorbid burden.

CONCLUSIONS

Our study suggests a distinct pattern of comorbid conditions in women with BPS. These findings further support our hypothesis of primary vagal defect in BPS as compared with primary sympathetic defect in MPP, suggesting a new model for chronic these pelvic pain syndromes. Chronologically, PTSD, migraine, dysmenorrhea, and IBS occurred early, supporting a role for PTSD or its trigger in the pathophysiology of chronic pelvic pain.

Development of a standardized, reproducible screening examination for assessment of pelvic floor myofascial pain

BACKGROUND

Pelvic floor myofascial pain is common, but physical examination methods to assess pelvic floor muscles are defined poorly. We hypothesized that a simple, transvaginal pelvic floor examination could be developed that would be highly reproducible among providers and would adequately screen for the presence of pelvic floor myofascial pain.

OBJECTIVE

The purpose of this study was to develop a simple, reproducible pelvic floor examination to screen for pelvic floor myofascial pain.

STUDY DESIGN

A screening examination was developed by Female Pelvic Medicine & Reconstructive Surgery subspecialists and women's health physical therapists at our institution and tested in a simulated patient. We recruited 35 new patients who underwent examinations by blinded, paired, independent examiners. Agreement was calculated with the use of percent agreement and Spearman's rank correlation coefficient.

RESULTS

The final examination protocol begins with examination of the following external sites: bilateral sacroiliac joints, medial edge of the anterior superior iliac spine, and cephalad edge of the pubic symphysis (self-reported pain: yes/no). The internal examination follows with palpation of each muscle group in the center of the muscle belly, then along the length of the muscle proceeding counter-clockwise: right obturator internus, right levator ani, left levator ani, left obturator internus (pain on a scale of 0-10). Thirty-five patients were enrolled. Correlation was high at each external (0.80-0.89) and internal point (0.63-0.87; P<.0001).

CONCLUSION

Our newly developed, standardized, reproducible examination incorporates assessment of internal and external points to screen for pelvic floor myofascial pain. The examination is straightforward and reproducible and allows for easy use in clinical practice.

Stress-induced autonomic dysregulation of mitochondrial function in the rat urothelium

AIM

Chronic stress exacerbates the symptoms of most pain disorders including interstitial cystitis/bladder pain syndrome (IC/BPS). Abnormalities in urothelial cells (UTC) occur in this debilitating bladder condition. The sequence of events that might link stress (presumably through increased sympathetic nervous system-SNS activity) to urothelial dysfunction are unknown. Since autonomic dysregulation, mitochondrial dysfunction, and oxidative stress all occur in chronic pain, we investigated whether chronic psychological stress initiated a cascade linking these three dysfunctions.

METHODS

Adult female Wistar Kyoto rats were exposed to 10 days of water avoidance stress (WAS). Bladders were then harvested for Western blot and single cell imaging in UTC cultures.

RESULTS

UTC from WAS rats exhibited depolarized mitochondria membrane potential (Ψm ∼30% more depolarized compared to control), activated AMPK and altered UT mitochondria bioenergetics. Expression of the fusion protein mitofusion-2 (MFN-2) was upregulated in the mucosa, suggesting mitochondrial structural changes consistent with altered cellular metabolism. Intracellular calcium levels were elevated in cultured WAS UTC, consistent with impaired cellular function. Stimulation of cultured UTC with alpha-adrenergic (α-AR) receptor agonists increased reactive oxidative species (ROS) production, suggesting a direct action of SNS activity on UTC. Treatment of rats with guanethidine to block SNS activity prevented most of WAS-induced changes.

CONCLUSIONS

Chronic stress results in persistent sympathetically mediated effects that alter UTC mitochondrial function. This may impact the urothelial barrier and signaling, which contributes to bladder dysfunction and pain. This is the first demonstration, to our knowledge, of a potential autonomic mechanism directly linking stress to mitochondrial dysfunction.

Comparison of Voiding Dysfunction Phenotypes in Women with Interstitial Cystitis/Bladder Pain and Myofascial Pelvic Pain: Results from the ICEPAC Trial

OBJECTIVE

To evaluate whether voiding parameters differ in patients with the common overlapping pelvic pain disorders, interstitial cystitis/bladder pain syndrome (IC/BPS), and myofascial pelvic pain (MPP).

METHODS

Uroflow and voiding diary assessed voiding phenotypes in this prospective cohort study (ICEPAC) of women comparing IC/BPS, IC/BPS +MPP, MPP, and healthy control (HC) subjects.

RESULTS

In 36 HC, 24 IC/BPS, 37 IC/BPS + MPP, and 14 MPP subjects, the voiding diary measurements indicate lower voided volumes in IC/BPS and IC/BPS + MPP groups (185 ± 24 mL, 169 ± 20 mL, respectively) compared to HC and MPP groups (294 ± 24 mL, 226 ± 36 mL, respectively; P <.05, P <.05), as well as higher 24-hour voiding frequency (11.6 ± 0.8 and 11 ± 1.2 voids/24 hours, respectively; HC 7.1 ± 0.5 voids/24 hours; P <.05, P <.05; MPP group 9 ± 1.2 voids/24 hours; P <.05, P <.05). Uroflow showed higher HC average flow rate (12.87 ± 0.92) compared to IC/BPS, IC/BPS+MPP, and MPP (8.31 ± 1.20, 8.02 ± 0.80, 8.17 ± 1.38, respectively; P <.01, P <.01, P <.05) and peak flow rate (27.0 ± 1.83) and IC/BPS, IC/BPS+MPP and MPP (16.20 ± 2.2, 17.33 ± 1.64, 17.21 ± 2.69 respectively; P <.01, P <.01, P <.05).

CONCLUSION

This quantitative evaluation of voiding diary and uroflow metrics reveals distinct voiding phenotypes, which can aid in the diagnosis of chronic pelvic pain syndromes. Patients with IC/BPS had more pain with a full bladder despite similar overall pain scores. Peak and average flow rates do not provide any differentiating power between IC/BPS and MPP patients. A longer time to peak flow may favor MPP though this finding needs confirmation.

The Pelvis and Beyond: Musculoskeletal Tender Points in Women With Chronic Pelvic Pain

OBJECTIVE

To determine the feasibility of a detailed pain sensitivity assessment using body-wide musculoskeletal tender points (TPs) in women with different types of chronic pelvic pain (CPP) and compare phenotypic differences.

MATERIALS AND METHODS

Seventy women with CPP and 35 pain-free women underwent musculoskeletal evaluation of TPs in the pelvic floor, abdomen, groin, inner thigh, and all 18 fibromyalgia TPs. Patients scored elicited pain on a numeric rating scale. TP pain scores were used for intergroup comparison and intragroup correlation.

RESULTS

Women with CPP were grouped as having either bladder pain syndrome (BPS, n=24) or myofascial pelvic pain (MPP, n=11) singularly or both concomitantly (BPS+MPP, n=35). TP pain scores for all evaluations were higher in women with CPP compared with healthy women (P<0.001). Women with BPS+MPP had elevated TP pain for each evaluation compared with women with BPS alone. Pelvic floor and fibromyalgia TP scores correlated strongly in the MPP group, moderately in the BPS+MPP group, and weakly in the BPS alone group. Although some moderate and strong correlations between different body locations were present in all 3 groups, only the BPS+MPP group showed moderate to strong correlations between all body TPs.

CONCLUSIONS

Detailed musculoskeletal evaluation of women with CPP is feasible and well tolerated. Careful phenotyping differentiated BPS, MPP, and BPS+MPP groups. Attending to the differences between these groups clinically may lead to more effective treatment strategies and improved outcomes for patients with CPP.

Sensory mapping of pelvic dermatomes in women with interstitial cystitis/bladder pain syndrome

AIM

To describe a sensory map of pelvic dermatomes in women with Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS). We hypothesized that if IC/BPS involves changes in central processing, then women with IC/BPS will exhibit sensory abnormalities in neurologic pelvic dermatomes.

METHODS

Women with IC/BPS and healthy controls underwent neurologic examination that included evaluation of sharp pain sensitivity and vibration in dermatomes T12, L1, L2, S1-5. Peripheral nervous system sensitivity to pressure, vibration, and pinprick were scored using numeric rating scales (NRS). Bilateral comparisons were made with Wilcoxon signed-rank test and comparisons between groups were made by the Mann-Whitney U-test.

RESULTS

Total of 74 women with IC/BPS and 36 healthy counterparts were included. IC/BPS and control groups had similar age (43.0 ± 14.1 and 38.6 ± 15.3 years, P = 0.14) and BMI (28.9 ± 8.0 kg/m² and 26.9 ± 8.4 kg/m² , P = 0.24), respectively. Women with IC/BPS reported hyperalgesia (elevated bilateral NRS pain intensity) in all pelvic dermatomes compared to healthy controls. S4-S5 region had the highest pain intensity in all participants. All IC/BPS participants exhibited vibration sensation hypoesthesia, at least unilaterally, in all of the pelvic dermatomes except L1 compared to healthy controls.

CONCLUSION

This detailed map of neurologic pelvic dermatomes in women with IC/BPS found hyperalgesia in all pelvic dermatomes, and some evidence of vibration sensation hypoesthesia, compared to healthy controls. These findings support the hypothesis that IC/BPS may involve changes in central signal processing biased towards nociception.

Autonomic Testing in Women with Chronic Pelvic Pain

PURPOSE

We determined whether abnormal autonomic nervous system innervation of the bladder underlies IC (interstitial cystitis)/BPS (bladder pain syndrome) differently than other chronic pelvic pain.

MATERIALS AND METHODS

In this institutional review board approved protocol 39 healthy controls and 134 subjects were enrolled, including 36 with IC/BPS, 14 with myofascial pelvic pain and 42 with IC/BPS plus myofascial pelvic pain. Three subjects were excluded from study. Autonomic nervous system evaluations included deep breathing, the Valsalva maneuver, and the tilt table and sudomotor tests. The latter evaluates autonomic neuropathy. A modified validated composite autonomic laboratory score was applied.

RESULTS

Median age in the IC/BPS group was 47.5 years (range 21 to 78), greater than in healthy controls (34 years, range 20 to 75, p = 0.006), the myofascial pelvic pain group (33 years, range 22 to 56, p = 0.004) and the IC/BPS plus myofascial pelvic pain group (38 years, range 18 to 64, p = 0.03). Body mass index did not significantly differ but the myofascial pelvic pain and IC/BPS plus myofascial pelvic pain groups had a higher body mass index than healthy controls (p = 0.05 and 0.03, respectively). Cardiovascular and adrenergic indexes did not differ. The tilt table test showed more orthostatic intolerance in all chronic pelvic pain groups. Tilt table test diagnoses (orthostatic hypotension, postural tachycardia syndrome and reflex syncope) were rare. Baseline heart rate was higher in all chronic pelvic pain groups (p = 0.004). Compared to healthy controls all myofascial pelvic pain groups showed significantly more clear-cut autonomic neuropathy, defined as a sweat score of 3 or greater (vs IC/BPS plus myofascial pelvic pain p = 0.007 and vs myofascial pelvic pain p = 0.03).

CONCLUSIONS

Some chronic pelvic pain types show autonomic neuropathy and some show vagal withdrawal. In all types orthostatic intolerance likely reflects central sensitization and perhaps catastrophizing. Some of these findings suggest novel therapeutic targets.

Novel research approaches for interstitial cystitis/bladder pain syndrome: thinking beyond the bladder

Despite years of basic and clinical research focused on interstitial cystitis/bladder pain syndrome (IC/BPS), including clinical trials of candidate therapies, there remains an insufficient understanding of underlying cause(s), important clinical features and a lack of effective treatments for this syndrome. Progress has been limited and is likely due to many factors, including a primary focus on the bladder and lower urinary tract as origin of symptoms without adequately considering the potential influence of other local (pelvic) or systemic factors. Traditionally, there has been a lack of sufficiently diverse expertise and application of novel, integrated methods to study this syndrome. However, some important insights have been gained. For example, epidemiological studies have revealed that IC/BPS is commonly associated with other chronic pain conditions, including fibromyalgia, irritable bowel syndrome and chronic fatigue syndrome. These observations suggest that IC/BPS may involve systemic pathophysiology, including alterations of the central nervous system in some patients. Furthermore, there may be multiple causes and contributing factors that manifest in the symptoms of IC/BPS leading to multiple patient sub-groups or phenotypes. Innovative research is necessary to allow for a more complete description of the relationship between this syndrome and other disorders with overlapping symptoms. This report provides examples of such innovative research studies and their findings which have the potential to provide fresh insights into IC/BPS and disorders associated with chronic pain through characterization of broad physiologic systems, as well as assessment of the contribution of the bladder and lower urinary tract. They may also serve as models for future investigation of symptom-based urologic and non-urologic disorders that may remain incompletely characterized by previous, more traditional research approaches. Furthermore, it is anticipated a more holistic understanding of chronic urologic pain and dysfunction will ensue from productive interactions between IC/BPS studies like those described here and broader cutting-edge research endeavors focused on potentially related chronic pain disorders. A more comprehensive vision for IC/BPS inquiry is anticipated to yield new insights into basic disease mechanisms and clinical characteristics that will inform future research studies that will lead to more effective therapies and improved clinical care for these patients.