PD1-10 SUPRASPINAL CONTROL OF LOWER URINARY TRACT FUNCTION IN PATIENTS WITH SPINAL CORD INJURY: AN FMRI STUDY

Abstract

INTRODUCTION AND OBJECTIVES: The control of the lower urinary tract (LUT) is a complex, multilevel process involving both the peripheral and central nervous system. Most patients with spinal cord injury (SCI) suffer from neurogenic LUT dysfunction and LUT symptoms severely impair the patients’ health-related quality of life. Although there are several concepts regarding neuronal control and perception in the normal and pathological LUT condition, the exact mechanisms involved remain to be elucidated. METHODS: In this functional magnetic resonance imaging (fMRI) study, we prospectively assessed 20 patients (mean age 43 years old, range 25e75) with cervical and thoracic SCI (12 with complete and 8 with incomplete lesion) suffering from neurogenic detrusor overactivity. All subjects underwent data acquisition in a 3 Tesla scanner. The scan paradigm (SP) comprised 3 different bladder stimulations: (1) repetitive bladder filling of 100mL body warm saline starting with an empty bladder, (2) repetitive infusion and withdrawal (100mL) of body warm saline starting with a pre-filled bladder and (3) repetitive bladder filling of 100mL cold saline. Date was analysed using SPM8. Second-level random effects group analysis (at a voxel-threshold of P<0.001 using false discovery rate correction at cluster level) was performed to account for between subject variability. Only subjects with significant activity (first-level analysis, P1⁄40.05 familywise error rate) were included. RESULTS: 6 subjects had to be excluded from certain analysis due to excessive head motions, autonomic dysreflexia or urinary incontinence during data acquisition. At first-level analysis, we found significant activation in 67% (12/17), 56% (9/15) and 66% (10/15) for SP (1), (2) and (3), respectively. At second-level analysis, significant activation was found in all 3 SP. (1): right inferior frontal gyrus (BA 45), left middle frontal gyrus (BA 10/46), left superior medial frontal gyrus, dorsal posterior cingulate area (BA 31) and bilateral middle temporal gyrus (BA21); (2): anterior left insula and inferior parietal lobe; (3): right precentral gyrus (BA 6) and left superior parietal lobe (BA 7). Activations were seen in both complete and incomplete SCI patients. CONCLUSIONS: In our patients with SCI, significant brain activation similar as reported for healthy subjects, non-neurological and other neurological patients with detrusor overactivity was detected. SP (1) showed activation in more brain areas than (2) and (3). Our findings suggest that extra-spinal sensory pathways might also be involved in LUT control.