Adults 60 to 75, any sex, with Cognitive Dysfunction. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Cortical Excitability: Resting Motor Threshold (RMT).Primary· Up to 10 minutes. This is a single day trial. Testing session will last a total of 3 hours.
Resting motor threshold (rMT) was determined using the Parameter Estimation by Sequential Testing (PEST) algorithm during a single-pulse transcranial magnetic stimulation (TMS) protocol. Surface electromyography (EMG) was used to record motor evoked potentials (MEPs) from the target muscle. rMT was defined as the minimum stimulation intensity over the motor cortex hotspot required to elicit an MEP of at least 50 μV in peak-to-peak amplitude in 50% of trials.
Stimulation intensity on the TMS device is expressed as a percentage of the maximum stimulator output (MSO), which ranges from 1-100% on
Group
Value
95% CI
Mild Cognitive Impairment
51.1
± 6.6
Healthy Controls
51.8
± 8.3
Cortical Excitability: Stimulus Response Curve. Measured With EMG, This Measures Motor Response to Various Intensities of Magnetic Pulse StimuliSecondary· Up to 30 minutes. This is a single day trial. Testing session will last a total of 3 hours.
Measured with surface EMG during single-pulse TMS paradigm. The outcome measure is derived from the varying Motor-Evoked Response potentials that are induced by variable TMS stimulation intensities. Specifically, this outcome measure is the slope of the stimulus-response curve, which is fitted to model the rise in MEP amplitude with rising TMS intensity.
Group
Value
95% CI
Mild Cognitive Impairment -- Active Muscle Condition
Cortical Excitability: Cortical Silent Period. Measured With EMG, This is a Direct Measure of Cortical Inhibition.Secondary· Up to 10 minutes. This is a single day trial. Testing session will last a total of 3 hours.
Measured with surface EMG during single-pulse TMS paradigm. Participants will be asked to voluntary contract hand muscle, at 20% of their maximum contraction force. A TMS pulse is applied while participants are applying this voluntary contraction. The cortical silent period is defined as the duration between the observed motor evoked potential and the resumption of muscle voluntary contraction.
Group
Value
95% CI
Mild Cognitive Impairment
131.30
± 10.24
Healthy Controls
151.91
± 6.73
Baseline Functional Magnetic Resonance Imaging (fMRI) to Observe Functional Activation of Brain Networks Prior to Intervention.Secondary· Up to 30 minutes. This is a single day trial. Testing session will last a total of 3 hours.
This resting state fMRI scan measured functional connectivity patterns at baseline prior to a non-invasive brain stimulation protocol targeting the primary motor cortex (M1). We measured resting-state functional connectivity between the left M1 and the left somatosensory cortex (S1). Functional connectivity was quantified using Pearson correlation coefficients between the time series of the two regions, which were then Fisher Z-transformed to normalize the distribution. The unit of measure is the Fisher Z-transformed correlation value (unitless).
Group
Value
95% CI
Mild Cognitive Impairment
0.741
± 0.314
Healthy Controls
0.534
± 0.282
Post Functional Magnetic Resonance Imaging (fMRI): Change in Functional Connectivity Following TMS.Secondary· Up to 30 minutes. This is a single day trial. Testing session will last a total of 3 hours.
This outcome measure assesses the change in resting-state functional connectivity between the left primary motor cortex (M1) and the left somatosensory cortex (S1), measured immediately after TMS was applied to the left M1. Functional connectivity was quantified using Pearson correlation coefficients between the time series of the two regions, which were then Fisher Z-transformed to normalize the distribution. The unit of measure is the Fisher Z-transformed correlation value (unitless). Positive values reflect an increase in functional connectivity from baseline, whereas negative values indica
Group
Value
95% CI
Mild Cognitive Impairment
-0.068
± 0.302
Healthy Controls
-0.060
± 0.526
Sponsor's own description
The overarching purpose of this study is to develop a technique that is capable of identifying neurophysiological biomarkers sensitive enough to detect preclinical dementia by integrating Transcranial Magnetic Stimulation (TMS) and Functional Magnetic Resonance Imaging (fMRI). More specifically, this project has two specific aims:
* 1\. To characterize cortical excitability and its relation to cognitive function using single-pulse TMS paradigm in Mild Cognitive Impairment (MCI) and healthy older adults.
* 2\. To delineate cortical plasticity and its association to cognitive function using repetitive TMS paradigm and resting-state fMRI in MCI and healthy older adults.
Techniques to artificially and precisely stimulate brain tissue are increasingly recognized as valuable tools both in clinical practice and in cognitive neuroscience studies among healthy individuals. Transcranial magnetic stimulation (TMS) is a non-invasive approach to stimulate the brain. Importantly, unlike other invasive brain stimulation techniques (e.g., surgical deep brain stimulation), no surgery, anesthesia, or sedation is involved. Instead, TMS involves placing a magnetic coil on the surface of the head. This coil then generates a magnetic field that is about the same strength as the magnetic field used by MRI machines, and when this magnetic field rapidly alternates, the neurons under the coil are excited.
Extensive guidelines have been published by experts in the field to ensure safe use, and the thousands of patients \& research participants who have received TMS in compliance with these guidelines demonstrate the safety of this practice. Depending on the method of use, TMS is very versatile -- it can be used to study research questions pertaining to the neural circuitry of the brain, it can be used as a diagnostic device, and it can be used therapeutically to treat various neurological conditions.
In this study, the investigators intend to further study the potential for diagnostic applications of TMS. More specifically, TMS and brain imaging techniques will be used in combination in order to more sensitively diagnose dementia - perhaps even before symptoms emerge. Right now, there is no reliable method for doing so and it is difficult to distinguish between the forgetfulness of healthy aging and the early signs of disease. Our approach may provide a more sensitive diagnostic tool, which is likely to improve clinical outcomes.
Publications & conference data
No peer-reviewed publications indexed yet for this trial. Completed trials usually publish results within 12-18 months.
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Sponsor: as reported to ClinicalTrials.gov by University of Arizona
Last refreshed: 11 June 2025
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03652012.