Assessment of Sacral Spinal Cord Activity Using 3T fMRI During Pelvic Floor Contractions

de Rijk M1, Fernandez Chadily S1, Heesakkers J2, van Koeveringe G2, van den Hurk J3

Research Type

Pure and Applied Science / Translational

Abstract Category

Neurourology

Abstract 89
Neurobiology
Scientific Podium Short Oral Session 9
Wednesday 23rd October 2024
16:45 - 16:52
Hall N105
Anatomy Imaging Pelvic Floor
1. Division of Neuroscience, Department of Urology, Institute for Mental Health and Neuroscience, Faculty of Health, Medicine, and Life Science, Maastricht University, 2. Department of Urology, Maastricht University Medical Center+, 3. Scannexus Ultra-High Field MRI Center
Presenter
Links

Abstract

Hypothesis / aims of study
In this original study, we evaluated the feasibility of using 3 Tesla functional magnetic resonance imaging (fMRI) to measure changes in activity in the sacral spinal cord during voluntary contraction and relaxation of the pelvic floor. Voluntary control of the lower urinary tract (LUT), therefore the maintenance of continence, is highly dependent on efficient bi-directional communication between the sacral spinal cord and the brain. Measuring activity in the sacral spinal cord is largely underexplored due to the difficult accessibility using conventional fMRI data analysis techniques. However, evaluation of physiological and pathophysiological functional states in this area is important to improve our understanding of non-neurogenic LUT conditions such as dysfunctional voiding, non-obstructive retention or Fowler’s syndrome. Additionally,  neurogenic patients with conditions such as multiple sclerosis, Parkinson’s disease, or multiple systems atrophy,  which commonly present with LUT dysfunction, may present with maladaptive activity patterns in the brain or spinal cord. Gaining access to evaluate functional and structural integrity of the sacral spinal cord is essential to improve our understanding of the contribution of (mal)adaptive changes in this region associated with LUT dysfunction and will help to improve the diagnostic and therapeutic options for these patients. In the current study, we designed a protocol and data-analysis pipeline to measure changes in blood-oxygen-level-dependent (BOLD) signal in the sacral spinal cord during voluntary contraction and relaxation of the pelvic floor.
Study design, materials and methods
For this proof of concept we collected data from 1 healthy female volunteer on two separate recording days. The participant was trained by a pelvic floor physiotherapist to perform isolated contractions of the pelvic floor. MRI data were obtained using a 3T MAGNETOM Prisma Fit (Siemens) scanner and Spine Matrix Coil (Siemens). The participant was instructed to lie down on the scanner bed in supine position, with bent knees and calves supported by a foam cushion. First we obtained anatomical data of the sacral spinal cord with our main region-of-interest centered around the S1 segment of the spinal cord. Next the participant was instructed to perform repeated sustained contraction and relaxation of the pelvic floor in blocks of 8 seconds each (i.e., 8 seconds on, 8 seconds off), with 24 repetitions. Data was preprocessed (slice-scan-time and motion corrected, temporally filtered) and differences in activity between contraction and relaxation of the pelvic floor was statistically assessed.
Results
On both recording days we observed voxels that statistically change in their activity between contraction and relaxation of the pelvic floor (p ≤ 0.05). We found significant changes in activity in voxels in both the ventral horn (at the approximate location of Onuf’s nucleus), as well as the dorsal horn (figure 1).
Interpretation of results
Our results indicate that assessment of sacral spinal cord activity using 3T fMRI is feasible. We show that the ventral horn of the S1 segment changes significantly in activity between contraction and relaxation of the pelvic floor. In addition to the ventral horn, we also observe a change in activity in the dorsal horn which indicates that sensory processes also changes consistently with our task (most likely these are proprioceptive processes associated with pelvic floor contractions). This proof of concept suggests that functional neuroimaging using fMRI of the spinal cord is a tool that can be utilized to study LUT control in this region of the central nervous system.
Concluding message
In conclusion, our study successfully demonstrates the feasibility of utilizing 3T fMRI to investigate changes in sacral spinal cord activity during pelvic floor contractions and relaxations. The further refinement of this novel approach holds promise for enhancing diagnostic and therapeutic strategies for individuals with a spectrum of both neurogenic and non-neurogenic LUT conditions.
Figure 1 Figure 1
Disclosures
Funding Faculty of Health, Medicine, and Life Sciences, Maastricht University Clinical Trial No Subjects Human Ethics Committee METC Maastricht Helsinki Yes Informed Consent Yes
Citation

Continence 12S (2024) 101431
DOI: 10.1016/j.cont.2024.101431

14/11/2024 09:29:36