Sacral reflexes and urinary incontinence in women: new concepts

The physiology of urinary continence is complex and the respective role of active and passive mechanisms is still subject to debate. Many different sacral reflexes are involved in these processes. The present literature review focuses on the neuromuscular mechanisms, which are involved in the pathophysiology of female stress urinary incontinence (SUI).

We performed a systematic review of the literature in the Medline, Pascal and Embase databases by using the following keywords: reflex, perineal, sacral, urethral pressure, urethra, pelvic floor, fatigue, continence, incontinence and muscle.

In recent years, new pathophysiological hypotheses concerning abnormal pelvic floor muscle reflex responses to stress have been discussed and included an abnormal time course of pelvic floor muscle activation during coughing. It has also been suggested that unusually rapid fatigue of the pelvic floor muscle reflex may be involved in some women.

Overall, there are arguments in favour of the involvement of neuromuscular dysfunction in the pathophysiology of female SUI - particularly dysfunctional and delayed pelvic floor muscle reflex responses during coughing. It would be useful to establish whether these neuromuscular dysfunctions may be remedied by physiotherapeutic pelvic floor muscle training.