The Modulatory Effect of Female Sex Hormones on Spinal Neuroplasticity (TMSpine)

March 25, 2026 updated by: Yasin Dhaher, University of Texas Southwestern Medical Center

TMSpine: The Modulatory Effect of Female Sex Hormones on Spinal Neuroplasticity

The goal of this project is to test our central hypothesis that the spinal cord neuroplasticity in females will be modulated by the level of estradiol concentration. under aim 1 we will determine the influence of estradiol fluctuations on spinal circuit excitability post afferent (sensory) mediated subthreshold motor priming in young healthy females and males. We will use an established repetitive peripheral nerve electrical stimulation with a stimulation intensity below the motor threshold to prime the spinal motor circuits. under aim 2 we seek to characterize the input output property of spinal circuit excitability after descending drive (motor) mediated priming in young healthy male participants. in aim 3 we will examine the influence of estradiol fluctuations on descending drive mediated motor priming in young healthy females.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Texas
      • Dallas, Texas, United States, 75390
        • Recruiting
        • University of Texas Southwestern Medical Center
        • Contact:
          • Yu-Chen Chung, PT, Ph.D.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

(1) Healthy females (2) Healthy males (control)

Description

FEMALES

Inclusion Criteria:

  • Ages 18-39 years
  • Eumenorrheic (regular monthly cycles of 24-35 days)
  • Moderately active (less than 7 hours of vigorous physical activity per week)
  • History of pregnancy is allowed if patient is in post-lactation phase

Exclusion Criteria:

  • History of musculoskeletal or orthopedic injury of the spine, hip, knee, ankle or foot
  • History of neurological injury of the peripheral or central nervous system
  • Current smoker
  • History of disordered eating
  • History of stress fracture in the lower limb
  • History of a connective tissue disorder (Marfan's syndrome, Ehlers-Danlos disease)
  • Pacemaker, metal implants in the head and spine region
  • Pregnancy
  • On a hormonal contraceptive regimen (oral, transdermal or vaginal)
  • History of menstrual dysfunction (primary or secondary amenorrhea, oligomenorrhea, anovulatory cycles, polycystic ovarian disease)
  • Started or stopped taking oral contraceptives within the previous 6 months
  • Exercise vigorously more than 7 hours per week or currently participating in competitive level sports.

MALES

Inclusion Criteria:

  • Ages 18-39
  • Moderately active (less than 7 hours of vigorous physical activity per week)

Exclusion Criteria:

  • History of musculoskeletal or orthopedic injury of the spine, hip, knee, ankle or foot
  • History of neurological injury of the peripheral or central nervous system
  • Current smoker
  • History of disordered eating
  • History of stress fracture in the lower limb
  • History of a connective tissue disorder (Marfan's syndrome, Ehlers-Danlos disease)
  • Pacemaker, metal implants in the head and spine region

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Healthy Females
Device: Magstim Rapid2

AIM 1: Investigate the estradiol effect on spinal circuit excitability post afferent (sensory) mediated subthreshold motor priming in young healthy women and men.

AIM 2: Characterize the Input output property of spinal circuit excitability following descending drive (motor) mediate priming in young healthy participants

AIM 3: Examine the estradiol effect on spinal circuit excitability following descending drive (motor) mediated priming in young healthy females
Healthy Males (control)
Device: Magstim Rapid2

AIM 1: Investigate the estradiol effect on spinal circuit excitability post afferent (sensory) mediated subthreshold motor priming in young healthy women and men.

AIM 2: Characterize the Input output property of spinal circuit excitability following descending drive (motor) mediate priming in young healthy participants

AIM 3: Examine the estradiol effect on spinal circuit excitability following descending drive (motor) mediated priming in young healthy females

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Spinal circuit excitability
Time Frame: Baseline 1, Post-60mins after peripheral nerve stimulation
Change in Spinal circuit excitability will be assessed by measuring Hoffmann reflex/ M wave ratio of the soleus muscle. Higher scores indicate poorer outcome.
Baseline 1, Post-60mins after peripheral nerve stimulation
Change in Motor neuron excitability
Time Frame: Baseline 2, Post-60mins after priming
Changes in motor neuron excitability, as quantified by Delta-F values.
Baseline 2, Post-60mins after priming
Change in spinal reflex expression
Time Frame: Baseline 2, Post-60mins after priming
Baseline 2, Post-60mins after priming
Change in descending drive mediated motor priming
Time Frame: Baseline 2, Post-60mins after priming
Baseline 2, Post-60mins after priming

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Texas Southwestern Medical Center

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Yasin Dhaher, Ph.D., University of Texas Southwestern Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 1, 2020

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 21, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 21, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 24, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 30, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 25, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • STU-2020-0738

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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