Brain Response Provoked by Different Bladder Volumes: A Near Infrared Spectroscopy Study

Aims: In order to understand frontal lobe responses in bladder sensation in healthy subjects, we examined the cortical localization of response to the different bladder volumes. Methods: Frontal blood flow was measured non-invasively in 24 resting adults using multi-channel near infrared spectroscopy(NIRS). Changes in bladder volume were induced by infusing and releasing water from the bladder. Two states of bladder sensation have been induced, "first desire to void'' and "strong desire to void. Results: NIRS analysis revealed that cerebral responses to bladder sensation were associated with increased levels of oxy-hemoglobin in the bilateral frontal cortex. The responses became stronger in the state of strong desire to void at enlarged bladder volume (P < 0.01). These results indicate that bilateral frontal areas are involved in bladder perception related to increased urine volumes in adults. Conclusions: The dynamic changes in cerebral blood oxygenation were similar to those assessed in other methodologies such as f-MRI and PET. This result suggests that NIRS study might be available for investigating the mutual relationship between bladder and brain in patients suffering from neurological problems and urinary tract symptoms. Neurourol. Urodynam. 30:529-535, 2011. (C) 2011 Wiley-Liss, Inc.