The Overlap of Interstitial Cystitis/Painful Bladder Syndrome and Overactive Bladder

OBJECTIVE We evaluated the prevalence of positive potassium sensitivity and cystoscopy with hydrodistention findings in patients with overactive bladder. METHOD This was a prospective cohort study of 98 patients who presented with overactive bladder symptoms. The diagnosis of overactive bladder is established by the presence of irritable voiding symptoms. All patients completed a PUF questionnaire and underwent potassium sensitivity testing. Eighty patients underwent urodynamic testing, and 42 patients underwent cystoscopic hydrodistention while under general anesthesia. RESULTS The Potassium Sensitivity Test was positive in 59 (60.2%) of the 98 patients, 37 (56%) of wet overactive bladder patients, and 22 (68.8%) of dry overactive bladder patients. Their mean PUF score was 7. Thirty-three (78.5%) of the patients who underwent cystoscopic hydrodistention had glomerulations consistent with NIH criteria for interstitial cystitis, and 26 of these patients tested positive for potassium sensitivity. Fifty-one (63.8%) of the patients who underwent urodynamics tested positive for potassium sensitivity. CONCLUSION Many patients with symptoms of overactive bladder with little or no pain have cystoscopic evidence of interstitial cystitis and a positive Potassium Sensitivity Test. Therapies directed toward the uroepithelial dysfunction and neural upregulation associated with interstitial cystitis/painful bladder syndrome may be an important adjunct for patients who have failed or have had a partial response to anticholinergic therapy and behavior modification.