Neurourology and pelvic floor dysfunction.

Abstract

The levator ani muscles, endopelvic fascia, and muscular structures of the sphincter and the pelvic floor musculature (PFM) comprise one system. The physiological organization of Onuf's nuclei and of levator ani motorneurons as well as the reflex control of the tonic activity, that is essential for the generation of maintained force in slow-twitch muscle fibers, is an important part of the normal function of this system. In the human the motor cortex is crucial in voluntary motor control also of PFM, but other areas in the brain are involved in activities of the PFM related to emotional behavior e.g. micturition. Coordination between the urinary bladder, the urethra and the PFM is mediated by multiple reflex pathways organized in the brain and spinal cord. Some reflexes promote urine storage, whereas others facilitate voiding. It is also possible that individual reflexes might be linked together in a serial manner to create complex feedback mechanisms. The control of striated muscle in neurological lesions of the lower urinary tract is an active area of research and is producing results that are relevant to the problems of the neurogenic and idiopathic overactive bladder, whether these are caused by central nervous system or peripheral nerve lesions.