NCT04846387

Mapping of the Human Brainstem During Continence and Micturition: Noninvasive 7-T fMRI Study

High-resolution Mapping of the Human Brainstem During Continence and Micturition: in Vivo Noninvasive 7 Tesla fMRI Study

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 20 (actual)
• Sponsor: The Methodist Hospital Research Institute · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

The lower urinary tract (bladder, bladder neck, urethra and urethral sphincter) has two functions: Storage (Continence) and voiding (micturition). Lower urinary tract dysfunction (LUTD) includes symptoms in the storage phase (such as urinary frequency, urgency, incontinence) or micturition phase (such as voiding dysfunction, hesitancy and urinary retention), or both. Proper urinary tract function is controlled by a complex network of peripheral and central nervous system. A delicate and complex switch exists between storage of urine and elimination of urine and in humans, the control over this switch is located in brain stem. Although significant research efforts have been utilized to understand supraspinal neural control of LUTs in humans, our understanding of the brainstem in humans is very limited, mainly due to the small size of nuclei. The extensive involvement of the brainstem in LUTS control has urged us to look into a better way to investigate and identify the brainstem nuclei involved throughout the entire bladder cycle, especially in neurogenic patients. To our knowledge, there has been no published study using high-resolution MRI (7 Tesla) to study the role of brainstem specifically in LUT. Brainstem evaluation in regards to LUT function in a thorough and accurate manner using high-resolution techniques is of high priority for benign urology and National Institute of Health. The findings from this proposal will lay the foundation to study of brainstem control in the bladder cycle in neurogenic patients with high-resolution neuroimaging, and will be seminal research in the field. The investigators hypothesize that Grey matter (blood-oxygen-level-dependent BOLD) signals and functional connectivity (FC) evaluation of the brainstem regions involved in continence and micturition are superior in 7T when compared to 3T in humans allowing assessment of the variations between men and women. Brainstem Regions of Interest (ROIs) include Pontine Storage Center (PSC) ("L region of the pons) and PAG are expected to be activated during the storage (continence) phase and Pontine Micturition Center (PMC) ("M" region of the pons) are expected to be activated during the voiding (micturition) phase.

Detailed description

The current proposal will be the first 7-Tesla study evaluating brain and specifically brainstem control over LUT. The study will utilize a noninvasive functional MRI (fMRI) protocol that allows for evaluation of brainstem activity during continence and micturition in real-time, using high-resolution neuroimaging techniques (7T fMRI) in both men and women. The study will recruit 20 healthy subjects (10 male and 10 female) for participation in this study. The participants for this study will undergo a few tests including a uroflow, PVR and a protocol training session during screening at visit 1, and a fMRI at visit 2. During screening, subject will be asked to come to their appointment with a full bladder. For the uroflow, they will urinate into a special funnel connected to a measuring instrument in a private bathroom followed by measuring Post void residual volume through PVR scanner. This is to ensure that they do not have any urological issue which can disqualify them from the study. At this visit, we will also instruct them about the urine voiding-holding task, our noninvasive fMRI paradigm which will involve having the participant drink 500-750 mL of water approximately 20 minutes prior to the start of their scan, which the subjects will be performing during the fMRI portion of the study at visit 2. The subsequent Grey matter (BOLD) signals and functional connectivity (FC) analysis will allow investigators to further the current understanding of brainstem control of the LUT and bladder cycle.

Conditions

• Healthy

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Magnetic Resonance Imaging (MRI)	A T1-weighted Anatomical Image, Diffusion Weighted Image, and functional MRI (fMRI) of "empty bladder" image will be obtained. Additionally, fMRI image during "full bladder" state and voiding/holding tasks will be obtained.
DIAGNOSTIC_TEST	Post-Void Residual	The patient's post-void residual is determined using a portable ultrasound machine after emptying the bladder just prior to entering the MRI scanner and immediately after the MRI scan.
DIAGNOSTIC_TEST	Uroflowmetry	Patients will urinate into a funnel connected to an electric flow meter to record urine flow rates in mililters per second. This is used as part of the screening process.
BEHAVIORAL	Questionaire - AUA Symptom Score	Subjects will fill out questionnaire asking about urinary symptoms. The range is 0-35.

Timeline

• Start date: 2021-01-18
• Primary completion: 2023-12-31
• Completion: 2023-12-31
• First posted: 2021-04-15
• Last updated: 2025-04-10

Locations

1 site across 1 country: United States