Abnormal pedal thermoregulation in interstitial cystitis

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

BACKGROUND AND PURPOSE

Interstitial cystitis/bladder pain syndrome (IC/BPS) is relatively common and associated with severe pain, yet effective treatment remains elusive. Research typically emphasized the bladder's role, but given the high presence of systemic comorbidities, the authors hypothesized a pathophysiologic nervous system role. This paper reports the methodology and approach to study the nervous system in women with IC/BPS. The study compares neurologic, urologic, gynecologic, autonomic, gastrointestinal, and psychological features of women with IC/BPS, their female relatives, women with myofascial pelvic pain (MPP), and healthy controls to elucidate the role of central and peripheral processing.

METHODS AND RESULTS

In total, 228 women (76 IC/BPS, 76 MPP, 38 family members, and 38 healthy controls) will be recruited. Subjects undergo detailed screening, structured neurologic examination of limbs and pelvis, tender point examination, autonomic testing, electrogastrography, and assessment of comorbid functional dysautonomias. Interpreters are blinded to subject classification. Psychological and stress response characteristics are examined with assessments of stress, trauma history, general psychological function, and stress response quantification. As of December 2012, data collection is completed for 25 healthy controls, 33 IC/BPS ± MPP, eight MPP, and three family members. Recruitment rate is accelerating and strategies emphasize maintaining and encouraging investigator participation in study science, internet advertising, and presentations to pelvic pain support groups.

CONCLUSION

The study represents a comprehensive, interdisciplinary approach to sampling autonomic and psychophysiologic characteristics of women with IC/BPS. Despite divergent opinions on study methodologies based on specialty experiences, the study has proven feasible to date and different perspectives have proved to be one of the greatest study strengths.

COMORBIDITY OF INTERSTITIAL CYSTITIS WITH OTHER UNEXPLAINED CLINICAL CONDITIONS

PURPOSE

The aims of this review are 1) to consider the hypothesis that interstitial cystitis (IC) is not a single disease entity in all patients by reviewing the evidence for the presence of IC subtypes and for the comorbidity of various unexplained clinical conditions in some patients with IC, and 2) to describe recent results obtained in humans and in cats with severe feline IC (FIC) that suggest the presence of an underlying neuroendocrine abnormality.

MATERIALS AND METHODS

The IC literature concerning comorbidity with other disorders was reviewed and these findings were compared with those of investigators studying the comorbid disorders and comparable data on cats with FIC.

RESULTS

A significant overlap of symptoms exists among a number of unexplained clinical conditions and a common stress response pattern of increased sympathetic nervous system function in the absence of comparable activation of the hypothalamic-pituitary-adrenal axis occurs in a subset of patients with many of these conditions. A comparable pattern exists in cats with FIC, which also includes increased corticotropin releasing factor activity and decreased adrenocortical reserve.

CONCLUSIONS

Further investigation of the stress response system of patients with IC seems merited, which may provide novel approaches to therapy in some patients.

In vivo models of interstitial cystitis

PURPOSE

We systematically identified and evaluated various animal models that have been studied to help identify the underlying mechanisms of and possible treatment options for interstitial cystitis.

MATERIALS AND METHODS

Models of interstitial cystitis published between 1983 and 2001 were obtained by searching MEDLINE and other Internet databases using cystitis and model as the primary key words. Models with characteristics of interstitial cystitis similar to those defined by National Institutes of Arthritis, Diabetes, Digestive and Kidney Diseases criteria were reviewed. Some articles describing animal models with similar pathological conditions in other organs were also included to enlarge the base of potentially relevant material.

RESULTS

We identified and evaluated some 16 animal models of interstitial cystitis, which we categorized as bladder inflammation induced by intravesical administration of an irritant or immune stimulant, systemic and environmentally induced inflammation, and a naturally occurring model of interstitial cystitis that occurs in cats. Some abnormalities identified in humans and cats with interstitial cystitis can be reproduced in healthy animals using luminal, systemic or environmental stimuli. At the level of the bladder the source of stimulation cannot be discriminated. Variability in the extent of bladder distention complicated the interpretation of some studies. In addition, the noxious stimuli used can affect many epithelial surfaces as well as the urothelium, suggesting they are nonspecific responses to injury rather than specific to interstitial cystitis.

CONCLUSIONS

No model in bladder injury in healthy animals currently reproduces as many features of interstitial cystitis as the naturally occurring disease in cats. While induced models of relative injury may help to provide insight into the bladder response to injury, feline interstitial cystitis follows a similar chronic waxing and waning time course as does interstitial cystitis in humans, which may be more suitable for studying the effects of stressors on the severity of clinical signs as well as newly proposed therapies.

Increased plasma norepinephrine concentration in cats with interstitial cystitis

PURPOSE

Interstitial cystitis is a chronic urological syndrome affecting humans and domestic animals, including cats (feline interstitial cystitis). The symptoms of interstitial cystitis seem to be exacerbated by stress, suggesting involvement of the sympathetic nervous system and/or hypothalamic-pituitary-adrenal axis. Others have described sympathetic nervous system abnormalities in patients with interstitial cystitis but to our knowledge no data on plasma catecholamine concentrations or hypothalamic-pituitary-adrenal axis function in such patients have been reported. To evaluate the role of these systems in cats with feline interstitial cystitis we simultaneously measured baseline plasma concentrations of catecholamines and their metabolites to assess sympathetic activity, and the response of plasma adenocorticotropic hormone and cortisol concentrations to the infusion of corticotropin-releasing factor.

MATERIALS AND METHODS

Eight healthy cats and 8 with feline interstitial cystitis were anesthetized and a catheter was placed in the external jugular vein. Four hours after recovery samples were obtained for high performance liquid chromatography analysis of plasma norepinephrine, dihydroxyphenylglycol, epinephrine, dihydroxyphenylalanine, dopamine and dihydroxyphenylacetic acid. In 4 cats per group 1 microg. ovine corticotropin-releasing factor per kg. body weight was infused and blood samples were collected at intervals for 120 minutes for determining adenocorticotropic hormone and cortisol.

RESULTS

Significant increases in plasma norepinephrine and dihydroxyphenylglycol as well as a trend toward increased epinephrine were found, whereas no effect on dihydroxyphenylalanine, dopamine, dihydroxyphenylacetic acid, adenocorticotropic hormone or cortisol was identified in cats with feline interstitial cystitis.

CONCLUSIONS

These results support and extend previous studies identifying an increase in sympathetic activity in cats with feline interstitial cystitis.

Visceral pain in humans: lessons from animals

Acute and persistent neuropathic and inflammatory injuries of healthy animals have contributed importantly to our current understanding of nociception and pain. Studies have differentiated somatic from visceral nociceptive input, and elucidated the pathways of transduction, transmission, perception, and modulation of the input. Other animal studies have identified important genetic and environmental influences on responses to nociception. Studies of naturally occurring visceral pain syndromes in animals also have added to our understanding of comparable syndromes in humans. Because of the aversive nature of pain, use of healthy animals to study pain in the service of other animals and humans is a decision to be taken carefully, and carries with it the responsibility of treating the animals as humanely as possible.

Interstitial cystitis: update on etiologies and therapeutic options

Interstitial cystitis (IC) is a syndrome of pelvic and/or perineal pain, urinary urgency, and frequency. It is now agreed that IC is a multifactorial syndrome, not a single condition. A variety of etiologies for IC have been proposed, but none has been definitively proven. Since the etiologies for IC remain unknown, the current treatments are empiric. This article will review the major theories of etiology for IC and discuss the current treatment options with relevance to the proposed etiologies. No single treatment is effective for all IC patients. Therefore, the approach is to try different treatments, alone or in combination, until symptom relief is satisfactory. In some cases, none of the empiric IC treatments are successful. These patients require adjunctive pain management, and a small minority of IC patients resort to surgery if all other options fail.

Elevated urinary norepinephrine in interstitial cystitis

OBJECTIVES

To measure urinary catecholamines and determine the extent to which they may be elevated in urine from patients with interstitial cystitis (IC).

METHODS

Random urine samples from patients with IC (n = 111) and urine from normal volunteers (n = 92) were acidified on collection (voided and catheterized specimens) and assayed for catecholamine (norepinephrine or normetanephrine) by enzyme-linked immunosorbent assay. Creatinine levels in these urine samples were also measured.

RESULTS

Analysis of the data indicated that patients with IC had a higher urinary level of the neurotransmitter norepinephrine compared with the measured levels in the urine of normal volunteers (89.1 +/- 58.3 versus 54.9 +/- 37.1 microg/g creatinine, P <0.05). The metabolite normetanephrine was similar in the urine samples from these two groups. Urine from patients with bladder outlet obstruction (n = 11) did not have elevated amounts of urinary norepinephrine. The norepinephrine levels were not statistically different in the urine samples from patients with symptomatic and asymptomatic IC. The elevated urinary levels in patients with IC did not decrease after treatment with sodium pentosanpolysulfate (Elmiron), heparinoids, dimethyl sulfoxide, or combinations of these during 1 to 15 months of treatment.

CONCLUSIONS

Norepinephrine was found to be elevated in the urine from patients with IC compared with urine from normal controls. This would be consistent with increased sympathetic (adrenergic) activity from the bladders of patients with IC or possibly from increased adrenal activity, since stress is associated with symptom increase in some patients with IC. Norepinephrine levels did not decrease with treatment nor did they differ between symptomatic and asymptomatic patients at the time of urine collection.

Interstitial cystitis

Interstitial cystitis (IC) is a multifactorial syndrome with symptoms of pelvic or perineal pain, urinary frequency and urgency. The etiologies are unknown, but several theories have been proposed. Diagnosis is often delayed because most of the conventional evaluation is normal. Pelvic examination is normal except for bladder tenderness. Urodynamics are normal except for increased bladder sensitivity and low capacity. Urinalysis, urine culture and office cystoscopy are also normal. The diagnostic test is cystoscopy under anesthesia with bladder distension. Small submucosal hemorrhages (glomerulations) or ulcers appear after distension. Many empiric treatments have been proposed for IC. None is universally effective, and so treatments are tried sequentially until good symptom relief is achieved. Bladder distension gives excellent (but transient) relief in some patients, especially those with severe bladder inflammation (who also tend to be older). A variety of oral, intravesical and adjunctive treatments are also described.