INTRODUCTION AND OBJECTIVES: Control of micturition is dependent upon an extensive brain neural network. Cortical activity related to pelvic floor muscle (PFM) contractions has been demonstrated using fMRI but is not in routine clinical care due to expense, limited access and restriction to the supine position. Functional near infra-red spectroscopy (fNIRS) which detects changes in oxyhemoglobin (O2Hb) and deoxyhemoglobin (hHb) concentrations is non invasive, maps cortical activity in real time and allows upright posture. Objective: examine patterns of frontal cortical brain O2Hb using fNIRS during PFM contraction and relaxation at capacity and related to voluntary uroflow in natural voiding posture. METHODS: N=12 studies; subjects, healthy volunteers, men (age 24-55 yrs), women (age 24-78 yrs). A protocol proving PFM control by fMRI was replicated then extended to include spontaneous voiding, uroflow and post void residual urine. fNIRS was performed using a 4x4 optode grid (Artinis Medical Systems) over the frontal cortex, at 10 Hz. At bladder capacity, following natural filling subjects imitated voiding by releasing or imitated interruption of voiding by contracting PFMs for 10 sec over 10 repetitions followed by voluntary voiding (seated or standing for males). O2Hb and hHb patterns were captured, then linked to uroflow in video format. RESULTS: In men and women PFM contraction and relaxation induced a repetitive activation pattern in the frontal cortex with increases in DO2Hb evident. There was an increase in DO2Hb detectable in the lateral prefrontal area (Brodmann’s areas) following permission to void at capacity with urge. Fig 1: demonstration of cerebral O2Hb static images from fNIRS video before permission to void (A), following permission to void (B), at Q max (C) and following voiding (D). CONCLUSIONS: A clinical protocol for fNIRS mapping to detect activation of the frontal cortical micturition region during voluntary uroflow and during PFM is presented for future clinical studies. To our knowledge, this is the first study confirming fNIRS activation patterns detected during micturition-related activity in cortical structures during natural voiding posture corresponding to those previously demonstrated in fMRI.