1661 A NEW MICTURITION CENTER IN PONS AFTER XIAO PROCEDURE FOR NEUROGENIC BLADDER IN PATIENTS WITH SPINA BIFIDA-AN FMRI STUDY

Abstract

INTRODUCTION AND OBJECTIVES: A somatic-autonomic reflex procedure (Xiao Procedure) can result in voluntary voiding control in Spina Bifida patients with neurogenic bladder (Xiao, 2005,J.Urol). To clarify the underlying mechanism, an 7 year fMRI study on brain micturition center was carried out. METHODS: Fourteen young adult patients with spina bifida and neurogenic bladder were enrolled in a fMRI study on brain micturition center pre and post-Xiao Procedure, compared with 13 healthy adult volunteers as normal control. The experiment was performed on a 3T MR scanner (Philips, Achiva) for the functional brain map and a high resolution T1-weighted scan. RESULTS: (1), The voiding activated regions for normal control group located in pons and suprapontine structures including frontal cortex, PCG, CMA, SMA, opercula, hypothalamus, thalamus, cerebellum and PAG (fig1). (2), The pre-operative group showed very few active regions associated with “voiding” in the brain frontal cortex, occipital lobe and cerebellum (fig2). (3), The post-operative group showed remarkable differences from pre-operative group in voiding activated regions. The active regions of post-operative group were similar to those in normal control in suprapontine structures CMA, SMA, opercula, hypothalamus, thalamus and cerebellum, with slight differences in occipital lobe and PCG. There were also new, strong and consistent activations in pons, but the locations were quite different from those in normal control group. (Fig. 3). (4), The most important results were discovered in pons. No activation was found in the pons in pre-operative patients even at p 0.05 uncorrected, while new, strong and consistent activations were recorded in pons in post-operative group even at p 0.00001 uncorrected. Most interestingly, the voiding activated regions in the pons of post-operation group is obviously different form those in normal control (Fig4). CONCLUSIONS: Xiao Procedure can result in brain functional reorganization for a new voiding control center mainly in Pons of Spina Bifida patients.