Urodynamic findings of the painful bladder syndrome/interstitial cystitis: a comparison with idiopathic overactive bladder.

PURPOSE In this study we identify the characteristics of the urodynamic results in patients with painful bladder syndrome/interstitial cystitis and in those with idiopathic overactive bladder. MATERIALS AND METHODS The fluoroscopic urodynamic study results were analyzed retrospectively in 40 consecutive female patients with painful bladder syndrome/interstitial cystitis and 78 female patients with idiopathic overactive bladder between October 2005 and August 2007. Before treatment a symptom assessment, questionnaires, 3-day voiding diary and laboratory tests were performed at the initial outpatient clinic visit. All patients had been diagnosed and grouped according to painful bladder syndrome/interstitial cystitis or overactive bladder based on the clinical features before cystoscopy, potassium chloride sensitivity test and urodynamic investigation. RESULTS Mean (+/-SD) age of patients with painful bladder syndrome/interstitial cystitis and overactive bladder was 57.8 (+/-12.9) and 61.9 (+/-11.9) years, respectively. Maximum flow rate and voided volume based on free uroflowmetry were significantly different between the 2 groups (p <0.05). For the static urethral pressure profile there was a significant difference between the groups in terms of maximal urethral closing pressure and maximal urethral pressure (p <0.05). For filling cystometry the volumes at each interval (first desire, normal desire, strong desire) and the volumes at maximum cystometric capacity were significantly lower (p <0.001) in patients with painful bladder syndrome/interstitial cystitis, as was bladder compliance (p = 0.025). No involuntary detrusor contraction was observed in the painful bladder syndrome/interstitial cystitis group but it was observed in 53 patients (67.9%) with overactive bladder (chi-square p <0.001). There was no significant difference in maximal detrusor pressure on voiding and fluoroscopic results between the 2 groups (p >0.05). Logistic regression analysis after adjusting for age, symptom duration, number of major comorbidities and disease groups showed that all variables in the urethral pressure profile were not significantly different between the painful bladder syndrome/interstitial cystitis and overactive bladder groups. CONCLUSIONS This study showed that the urodynamic results were significantly different between the painful bladder syndrome/interstitial cystitis and overactive bladder groups. Combined with other clinical findings urodynamic studies might provide additional information to confirm a diagnosis of painful bladder syndrome/interstitial cystitis.