PD15-06 ALTERED BRAINSTEM FUNCTIONAL CONNECTIVITY IN FEMALE MULTIPLE SCLEROSIS PATIENTS WITH VOIDING DYSFUNCTION

INTRODUCTION AND OBJECTIVE:
Multiple sclerosis (MS) is a demyelinating disease of the central nervous system. A common complication of MS is neurogenic lower urinary tract dysfunction (NLUTD), affecting 10% of patients at diagnosis and up to 90% over time. Key brainstem regions are known to regulate lower urinary tract function. This study examines brainstem connectivity in female MS patients voiding dysfunction (VD), comparing them to healthy volunteers.

METHODS:
We included nine female MS patients (mean age: 54.8 years) with symptomatic VD and ten healthy female volunteers (mean age: 28.9 years). Prior to scanning, all subjects had their bladders fully emptied. Most scans were conducted on a 7T MRI scanner, except for two MS patients using a 3T scanner due to safety concerns with metallic implants. Each session included anatomical imaging and functional MRI scans following warm water infusion into the bladder. Data preprocessing and analysis were done using CONN toolbox in SPM12 software (MATLAB). We conducted seed-to-voxel analysis using predefined regions of interest (ROIs) based on prior studies, with contrast maps generated using nonparametric statistics at a voxel significance threshold of p<0.05.

RESULTS:
Compared to healthy volunteers, MS patients with VD displayed distinct connectivity patterns across four ROIs (Figure 1). During full bladder state, midbrain ROIs 1 and 2 demonstrated negative connectivity with interoceptive processing regions, including insular cortex and frontal operculum. Periaqueductal gray (PAG) showed positive connectivity with the precentral and postcentral gyri and the anterior cingulate gyrus, while pontine micturition center (PMC) displayed negative connectivity with the cerebellum. During the empty bladder state, midbrain ROIs 1 and 2 showed negative connectivity with areas of default network, whereas PAG exhibited positive connectivity with the cerebellum.

CONCLUSIONS:
These initial findings offer insight into the brainstem’s functional connectivity in women with MS andVD, potentially deepening our understanding of the underlying mechanisms and enabling more precise therapeutic interventions.