Bladder-anal reflex

The purposes of this study were to evaluate the bladder-anal reflex (BAR) latency in asymptomatic women and determine the pathway of the reflex using selective anesthesia and neuromuscular block.

Urinary incontinence, voiding dysfunction, and pelvic organ prolapse are common problems in women. Evaluation of pelvic nerve function often augments the clinical assessment of these women. Urethral-anal and clitoral-anal reflex testing have been reported as methodologies to assess patients with neurogenic disorders. A bladder-anal reflex is also obtainable but has not been reported previously in the literature. Twenty-two subjects and two patients were recruited for evaluation of the BAR.

This study has allowed us to estimate reference ranges for BAR latency and threshold. We defined the upper limit of these reference ranges as two standard deviations above their respective means. For the BAR latency, the upper limit of the reference range is 91 msec. Any latency value above this limit should be considered abnormal. The upper limit for the BAR threshold reference range is 37.7 mA. Lower thresholds are not thought to be clinically meaningful due to the presence of several low sensory thresholds in this asymptomatic normal population.

The BAR was obtainable in asymptomatic women and compatible with known anatomy and innervation of the lower urinary tract.