Abstract     To evaluate the effect of Tolterodine on urethral and bladder afferent nerves in women with detrusor overactivity (DO) in comparison to placebo, by studying the changes in the current perception threshold (CPT).

METHODS:   Women with overactive bladder symptoms and idiopathic DO were recruited and randomized in a double-blind manner between placebo and tolterodine extended release. All women underwent CPT testing of the bladder and urethra using a Neurometer constant current stimulator. CPT values were determined at three frequencies, including 2,000 Hz (corresponding to Aβ-fibers), 250 Hz (corresponding to Aδ-fibers), and 5 Hz (corresponding to C fibers) before and 7 days on treatment. CPT values before and on treatment were compared using a Wilcoxon Signed Rank test.

RESULTS:  Twenty women (mean age 46 years) were studied. There was no statistical difference between the two groups in terms of age, ethnicity, severity of symptoms and pre-treatment CPT values. Only in the tolterodine group there was a significantly increased CPT value at 5 and 250 Hz upon both urethral and bladder stimulation after 1 week of treatment. When compared with placebo, women taking tolterodine had significantly increased Bladder CPT values at 5 Hz (P-value <0.05). The electrical stimulation with 5 Hz was described as urgency.

CONCLUSIONS: This is a randomized placebo control study evaluating the effect of antimuscarinics on sensory nerve function in women with DO. Our results support the animal studies that antimuscarinics have an effect on sensory function. Neurourol. Urodynam. © 2011 Wiley Periodicals, Inc.

Abstract

Objectives  Cerebral ischaemia is a leading cause of death and disability, including severe complications such as memory disturbance, palsy, and spasticity. Central post-stroke pain (CPSP) is a complication of cerebral ischaemia, and is characterized clinically by spontaneous pain and attacks of allodynia and dysaesthesia. However, the detailed mechanisms of CPSP are not well established. Herein, we have examined alterations of the current stimulus threshold of primary afferent neurons or the nociceptive threshold against mechanical stimuli in mice receiving left middle cerebral artery occlusion (MCAO). Methods  Alterations of current stimulus threshold and the development of mechanical allodynia in hind paws were measured after MCAO using a Neurometer and the von Frey filament test, respectively. Key findings  Development of cerebral infarction was clearly observed on day 1 and day 3 after MCAO. For the estimation of current stimulus threshold measured by the Neurometer, the sensitivity of Aδ and Aβ fibres (at 2000 and 250 Hz stimulation, respectively) was significantly increased on day 3 after MCAO, while that of C fibres (at 5 Hz stimulation) was unaltered. In addition, the paw withdrawal threshold of the left hind paw as measured by the von Frey filament test was significantly decreased on day 1 and day 3 after MCAO when compared with day 0, while that in the right hind paw was not different. Conclusions  The data suggested the development of bilateral hyperaesthesia in this model. Further, mechanical allodynia developed in the ipsilateral side to the MCAO. Potentially, myelinated A fibre-specific hypersensitization after stroke may have contributed to these symptoms.