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NCT Number: NCT04846387

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

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.

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Key information

Conditions

Healthy Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Lower Urinary Tract Symptoms Male Urogenital Diseases Pathological Conditions, Signs and Symptoms Signs and Symptoms Urinary Bladder Diseases Urinary Bladder, Overactive Urogenital Diseases Urologic Diseases Urological Manifestations

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Houston Methodist Hospital

Houston, Texas, 77030, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Healthy adult male and female volunteers ≥18 years of age with no neurological disease and genitourinary abnormalities will be screened:
  • Post-Void Residual (PVR) < 20% of their bladder capacity OR
  • Above 10 percentile of Liverpool nomogram

AND

  • AUASS score < 7 will be eligible to participate in the study.

Exclusion criteria

  • history of clinically relevant genitourinary malignancy or surgery such as:
  • anti-incontinence procedures
  • urethral strictures
  • advanced pelvic organ prolapse
  • any neurological disorders
  • history of seizures,
  • pregnancy or planning to become pregnant,
  • and contraindications to MRI will be excluded.
  • Research team members who are involved with the data collection and the data analysis for this study.

Treatment and study plan

Magnetic Resonance Imaging (MRI)

Diagnostic Test

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.

Post-Void Residual

Diagnostic Test

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.

Other names: PVR

uroflowmetry

Diagnostic Test

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.

Questionaire - AUA Symptom Score

Behavioral

Subjects will fill out questionnaire asking about urinary symptoms. The range is 0-35.

Other names: AUASS

Primary outcomes

  1. Blood Oxygen Level Dependent (BOLD) signals intensity

    Time frame: 2 years

    BOLD signal intensity in the regions of interest during empty bladder, full bladder, and micturition in healthy males and females

Secondary outcomes

  1. Blood Oxygen Level Dependent (BOLD) signals

    Time frame: 2 years

    Differences in BOLD signal intensity in brainstem ROIs during micturition between genders

  2. Uroflow measure

    Time frame: 2 years

    Maximum Qmax of urine (ml/sec): The range is between 0-40 mL/sec.

  3. Postvoid Residual

    Time frame: 2 years

    Postvoid Residual (PVR) of urine in mL: The range is between 0-900 mL.

  4. Urinary symptoms scores

    Time frame: 2 years

    Urinary symptom scores (no unit): The range is between 0-35. A higher score is associated with a worse outcome.

  5. Mean Diffusivity (MD)

    Time frame: 2 years

    MD is a scalar value that describes the degree of diffusivity. MD of white matter tracts that are implicated in brain control of bladder are of interest.

  6. Fractional Anisotropy (FA)

    Time frame: 2 years

    FA is a scalar value between zero and one that describes the degree of anisotropy of a diffusion process. A value of zero means that diffusion is isotropic (equally restricted) in all direction. No units. FA of white matter tracts that are implicated in brain control of bladder are of interest.

Sponsors and collaborators

Lead sponsor

The Methodist Hospital Research Institute

Other

Registry information

Official study title

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

Important dates

Study start
2021
Primary completion
2023
Study completion
2023
First posted
Apr 15, 2021
Registry last updated
Apr 10, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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