Central nervous system findings on functional magnetic resonance imaging in patients before and after treatment with anticholinergic medication

Abstract

Purpose: Anticholinergic medications are commonly used to treat urinary urgency and frequency. Muscarinic receptors are located in areas beyond the detrusor muscle. In this study we measured changes in central nervous system activity in patients with lower urinary tract symptoms treated with tolterodine or a placebo.

Materials and methods: A total of 20 female patients with urinary frequency were randomized to 4 weeks of treatment with tolterodine or a placebo. Functional magnetic resonance imaging based on blood oxygenation level dependant imaging of the brain during bladder filling was performed before and after treatment. For each patient the bladder was filled by a urethral catheter and emptied 5 times.

Results: Multiple brain areas showed significant activation with bladder filling compared to the empty state and many areas also showed deactivation. Overall brain activation with bladder filling was decreased after treatment in both groups. After treatment 2 areas of the parietal cortex (precuneus and postcentral gyrus) showed significantly greater activity in patients treated with tolterodine vs placebo. Two areas of the cerebellum (anterior lobe and culmen) showed significantly greater activity in the placebo group, and these were also areas of significant deactivation in the tolterodine group.

Conclusions: Brain activity changes as well as the areas of activation after treatment of lower urinary tract symptoms in patients with an anticholinergic medication or placebo are different in the 2 groups. Whether this finding represents action at the central nervous system or the bladder level is not known.