Editorial Comment to Brain activity during bladder filling and pelvic floor muscle contractions: A study using functional magnetic resonance imaging and synchronous urodynamics

Abstract

The frontal cortex is regarded as the higher center for micturition, because lesions in the frontal cortex; for example, the prefrontal cortex, medial superior/middle frontal gyri, anterior cingulate cortex, insula and supplemental motor area, produce marked lower urinary tract dysfunction in humans. Overactive bladder (urinary urgency and frequency) as a result of detrusor overactivity is a common bladder abnormality in the aforementioned brain areas. Functional neuroimaging in normal volunteers using single-photon emission computed tomography, positron-emission tomography, functional magnetic resonance imaging, and near infrared spectroscopy has been applied to observe brain activation in response to bladder fullness and urination; and the activated areas strikingly overlap the lesions described in clinical studies. Among the brain areas, anterior cingulate cortex and insula are thought to be “primary”, and the prefrontal cortex is “secondary” (presumably modulatory) in regulating micturition. The constellation of these cortical areas seem to “switch on and off” the spino–bulbo–spinal micturition reflex involving the midbrain periaqueductal grey and the pontine micturition center.1-3 Krhut et al. studied 20 healthy female volunteers who participated in bladder push and pull, and pelvic floor contraction paradigm for urodynamics-functional magnetic resonance imaging.4 The results were in agreement with the previously reported results. In addition, that study successfully highlighted the role of the pelvic floor, though already suggested by others,5-7 that bilateral primary motor area (midline medial surface), bilateral supplementary motor area (similar) and left precentral gyrus are significantly activated by pelvic floor contraction. In order to manage patients' pelvic floor, for both diagnosis and treatment, the brain is worth looking at. None declared.