Is the beneficial effect of antimuscarinics related to motor or sensory changes in the bladder?

Introduction and hypothesis The aim of the study was to assess the sensory and motor effects of antimuscarinic treatment on the bladder in women with overactive bladder, detrusor overactivity demonstrated on urodynamics and a mean bladder wall thickness (BWT) greater than 5 mm. Methods Fifty-eight women underwent treatment with antimuscarinics in 12 weeks. Before treatment and at 1, 2, 6 and 12 weeks of treatment, women completed the patient perception of bladder condition (PPBC) single-item global questionnaire, indicated the severity of their urgency on a visual analogue scale (VAS) and underwent transvaginal ultrasound to determine mean bladder wall thickness (BWT). Results PPBC and VAS scores for urgency declined throughout the treatment course whereas mean BWT declined during the first 6 weeks of treatment and then reached a plateau after falling to below 5 mm. Conclusion The mechanism of action of antimuscarinics appears to be a complex interaction of sensory and motor components.