NM09 BRAINSTEM FUNCTIONAL CONNECTIVITY IS ALTERED IN WOMEN WITH MULTIPLE SCLEROSIS AND VOIDING DYSFUNCTION

Introduction: The brainstem contains structures involved in regulating the lower urinary tract (LUT) and maintaining continence, but due to its small size and noise it is unstudied. By employing 7 MRI imaging in conjunction with urodynamics (UDS), we performed blood oxygenation level dependent (BOLD) functional MRI (fMRI) on subcortical structures in women with multiple sclerosis (MS) and voiding dysfunction (VD). We identified four different regions of interest (ROIs) from the periaqueductal gray (PAG), pontine micturition center (PMC), and pontine storage center (PSC), with altered functional connectivity (FC) impacting the regulation of their lower urinary tract symptoms (LUTS).

Methods: We recruited women diagnosed with MS and VD, defined by either a post-void residual to bladder capacity ratio of ≥ 40%, a Liverpool Nomogram percentile > 10%, or dependence on self-catheterization. Before undergoing MRI scans, participants fully emptied their bladders. After acquiring anatomical images, fMRI scans were conducted while sterile saline was infused into the bladder. FC was computed using the CONN toolbox in MATLAB with contrast maps generated on BOLD signals from seed-to-voxel analysis using predetermined ROIs (p < 0.05).

Results: Nine women (mean age 53.40, 35-77) with MS and VD underwent BOLD fMRI with UDS. In comparison to ten controls, we find significant differences across all ROIs (Figure 1). Most notably we find that PAG1and PMC1have complex activation and inhibition patterns with the rest of the cortex. Both regions exert connectivity on their ipsilateral sides, with influence in the supplementary motor areas (SMA) and prefrontal cortex. Other regions studied show smaller more localized activation/deactivation patterns, which may lower the setpoint of continence.

Conclusions: These findings offer insight into the brainstem's FC in women with MS experiencing VD. These findings highlight the complex neural pathways that contribute to LUTS in MS patients, particularly in the disruption of connectivity between the PAG, PMC, and cortical areas such as the SMA and prefrontal cortex. Understanding these networks allows for more targeted therapeutic interventions.