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CompletedNCT02677740Updated Nov 18, 2019Results posted

Mechanisms of Non-Invasive Neuromodulation Interventions: Influence on Human Neurochemistry and Functional Connectivity

An interventional study of Inhibitory rTMS (1 Hz) and Excitatory rTMS (5 Hz) in Non-invasive Neuromodulation in Healthy Subjects, sponsored by University of Minnesota. Completed at 1 site in United States. Open to male participants aged 21 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2019-11-18.

Sponsored by University of Minnesota · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
8
Allocation
Randomized
Ages
21 Years to 40 Years
Sex
Male
01

Study summary

The aim of this project is to increase our understanding of how two different protocols of repetitive transcranial magnetic stimulation (rTMS), inhibitory (1 Hz) and excitatory (5 Hz), applied over the primary motor cortex of the presumed dominant hemisphere, affect functional connectivity and neurochemistry in the brain.

Read the detailed description

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation method which is effective for treating both psychiatric and non-psychiatric disorders, such as posttraumatic stress disorder, obsessive compulsive disorder, pain syndromes and for improving motor function in neurodegenerative diseases or following stroke. rTMS uses series of brief pulses of magnetic field applied to the surface of the head for a period of time (e.g. 20 minutes). The effects of rTMS are transient, and critically dependent upon the location, frequency and intensity of stimulation. Several studies have provided evidence that rTMS can influence the excitability and function of neurons (neuromodulation) for up to one hour, both near to, and distant from, the site of stimulation. However it is still unclear how these transient local and distant changes in function induced by specific rTMS protocols are mediated. In this project we will combine expertise in Magnetic Resonance Imaging (MRI), Magnetic Resonance Spectroscopy (MRS) and rTMS neuromodulation to develop and test protocols for examining the changes produced by non-invasive brain stimulation on healthy subjects. rTMS will be applied outside the scanner using standard TMS coils and MRI/S at 7 Tesla will be acquired before and immediately after rTMS. Our aim is to increase the understanding of how the two different rTMS protocols, inhibitory (1 Hz) and excitatory (5 Hz), applied over the primary motor cortex of the presumed dominant hemisphere, affect functional connectivity and neurochemistry in the brain.

02

Conditions studied

  • Non-invasive Neuromodulation in Healthy Subjects

Keywords

  • MRI
  • MRS
  • rTMS
03

In context

Lead sponsor

University of Minnesota is the lead sponsor of 1,184 studies on the registry; 195 are open to participants now.

Of its 132 completed or terminated interventional studies of FDA-regulated products, 91 (69%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
21 Years to 40 Years
Sexes eligible
Male
Accepts healthy volunteers
Yes

Inclusion criteria

Those volunteers who are evaluated as normal and not met exclusion criteria will be potential candidates for this study.

Exclusion criteria

Exclusion Criteria:

The following participants will be excluded from this study, including but not limited to:

  • Females
  • Left handed males
  • Participants who never underwent MRI at 7 Tesla

Participants with:

  • any type of bio-implant activated by mechanical, electronic, or magnetic means (e.g. cochlear implants, pacemakers, neurostimulators, bio stimulators, electronic infusion pumps.)
  • any type of ferromagnetic bio-implant that could potentially be displaced or damaged, such as aneurysm clips, metallic skull plates, etc.
  • non-removable piercing or permanent eyeliner
  • retained metal in their body, either from a medical procedure or an injury

Participants who:

  • have been diagnosed by a physician as having a psychiatric disorder, substance abuse, neurological and/or cardiovascular disease
  • have cardiac or known circulatory impairment, and/or the inability to perspire (poor thermoregulatory function)
  • have hyper- or hypotension or arrhythmias
  • have known conditions which can lead to emergency medical care
  • had a head injury that caused them to lose consciousness for more than 30 minutes or have amnesia for more than 24 hours
  • had a brain tumor or stroke
  • had one or more seizures, or been given a diagnosis of epilepsy
  • have a history of sleep apnea or head trauma that may have caused Traumatic Brain Injury (TBI)
  • have a history of anxiety, syncope, panic attacks and/or claustrophobia
  • cannot adhere to the experimental protocol for any reason
  • started taking chemotherapy or immunomodulatory agents, or had any radiation treatment that could affect the brain
  • are currently on any medication
05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Outcomes assessor)
Enrollment
8 participants (actual)

Study arms

  • Experimental
    Inhibitory rTMS (1 Hz)

    Subjects are exposed to a 20-min inhibitory rTMS intervention that transiently suppresses the excitability of cortical structures beneath the site of stimulation. Subjects undergo MRI and MRS both before and right after the rTMS intervention.

    Device: Inhibitory rTMS (1 Hz)

  • Experimental
    Excitatory rTMS (5 Hz)

    Subjects are exposed to a 20-min excitatory rTMS intervention that transiently increases the net excitability of cortical structures beneath the site of stimulation. Subjects undergo MRI and MRS both before and right after the rTMS intervention.

    Device: Excitatory rTMS (5 Hz)

Interventions

  • DeviceInhibitory rTMS (1 Hz)

    Participants receive rTMS at a rate of 1 Hz, applied with a 70-mm figure-eight TMS coil connected to a stimulator, over the motor cortex hotspot contralateral to the dominant arm for 20 minutes at an intensity of 90% resting motor threshold (RMT) for a total of 600 TMS pulses. The total number of stimuli applied is well within the published safety guidelines for use of rTMS. rTMS is applied outside the scanner, whereas functional connectivity and neurochemistry are measured with MRI and MRS, respectively, at 7 Tesla. The MRI/MRS data are collected right before and immediately after the inhibitory rTMS intervention.

  • DeviceExcitatory rTMS (5 Hz)

    Participants receive rTMS at a rate of 5 Hz, applied with a 70-mm figure-eight TMS coil connected to a stimulator, over the motor cortex hotspot contralateral to the dominant arm for 20 minutes at an intensity of 90% RMT for a total of 600 TMS pulses. The total number of stimuli applied is well within the published safety guidelines for use of rTMS. rTMS is applied outside the scanner, whereas functional connectivity and neurochemistry are measured with MRI and MRS, respectively, at 7 Tesla. The MRI/MRS data are collected right before and immediately after the excitatory rTMS intervention.

06

What researchers measure

Primary outcomes

  1. Percent Change of GABA Concentration in a Voxel Encompassing the Left Motor Cortex, Measured at 30 Min After rTMS

    GABA concentration is quantified with MRS at 7 Tesla. Percent change of GABA concentration is calculated from baseline (i.e., pre-rTMS).

    Time frame: Baseline/Pre-rTMS and 30 min after rTMS

  2. Percent Change of GABA Concentration in a Voxel Encompassing the Right Motor Cortex, Measured at 60 Min After rTMS

    GABA concentration is quantified with MRS at 7 Tesla. Percent change of GABA concentration is calculated from baseline (i.e., pre-rTMS).

    Time frame: Baseline/Pre-rTMS and 60 min after rTMS

  3. Percent Change of Functional Connectivity in Left Motor Cortex, Where Functional Connectivity is Measured as a Dimensionless Fractional Amplitude of Low-frequency Fluctuations (fALFF), at 80 Min After rTMS

    Functional connectivity is measured with MRI at 7 Tesla as a dimensionless fractional amplitude of low-frequency fluctuations (fALFF). This is an index which reflects the intensity of spontaneous regional brain activity. It is calculated as the ratio of power spectra of low frequency (0.01-0.08 Hz) to that of the entire frequency range. Percent change of functional connectivity is calculated from baseline (i.e., pre-rTMS).

    Time frame: Baseline/Pre-rTMS and 80 min after rTMS

  4. Percent Change of Functional Connectivity in Right Motor Cortex, Where Functional Connectivity is Measured as a Dimensionless Fractional Amplitude of Low-frequency Fluctuations (fALFF), at 80 Min After rTMS

    Functional connectivity is measured with MRI at 7 Tesla as a dimensionless fractional amplitude of low-frequency fluctuations (fALFF). This is an index which reflects the intensity of spontaneous regional brain activity. It is calculated as the ratio of power spectra of low frequency (0.01-0.08 Hz) to that of the entire frequency range. Percent change of functional connectivity is calculated from baseline (i.e., pre-rTMS).

    Time frame: Baseline/Pre-rTMS and 80 min after rTMS

07

Results

Posted Aug 6, 2019
Limitations and caveats
The study was initially registered with a larger number of subjects (30) than what the pilot funds allowed (8) to allow more studies in the future. However, we decided to close the protocol after 8 studies reported here to avoid prolonged inactivity.

Participant flow

Participant flow — Overall Study
MilestoneInhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)
Started71
Completed71
Not completed00

Outcome measures

PrimaryPercent Change of GABA Concentration in a Voxel Encompassing the Left Motor Cortex, Measured at 30 Min After rTMS

GABA concentration is quantified with MRS at 7 Tesla. Percent change of GABA concentration is calculated from baseline (i.e., pre-rTMS).

Time frame:
Baseline/Pre-rTMS and 30 min after rTMS
Reported as:
Mean · percent change
Percent Change of GABA Concentration in a Voxel Encompassing the Left Motor Cortex, Measured at 30 Min After rTMS
percent changeInhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)
Percent Change of GABA Concentration in a Voxel Encompassing the Left Motor Cortex, Measured at 30 Min After rTMS8 ± 9-27 ± NA
PrimaryPercent Change of GABA Concentration in a Voxel Encompassing the Right Motor Cortex, Measured at 60 Min After rTMS

GABA concentration is quantified with MRS at 7 Tesla. Percent change of GABA concentration is calculated from baseline (i.e., pre-rTMS).

Time frame:
Baseline/Pre-rTMS and 60 min after rTMS
Reported as:
Mean · percent change
Percent Change of GABA Concentration in a Voxel Encompassing the Right Motor Cortex, Measured at 60 Min After rTMS
percent changeInhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)
Percent Change of GABA Concentration in a Voxel Encompassing the Right Motor Cortex, Measured at 60 Min After rTMS-6 ± 64 ± NA
PrimaryPercent Change of Functional Connectivity in Left Motor Cortex, Where Functional Connectivity is Measured as a Dimensionless Fractional Amplitude of Low-frequency Fluctuations (fALFF), at 80 Min After rTMS

Functional connectivity is measured with MRI at 7 Tesla as a dimensionless fractional amplitude of low-frequency fluctuations (fALFF). This is an index which reflects the intensity of spontaneous regional brain activity. It is calculated as the ratio of power spectra of low frequency (0.01-0.08 Hz) to that of the entire frequency range. Percent change of functional connectivity is calculated from baseline (i.e., pre-rTMS).

Time frame:
Baseline/Pre-rTMS and 80 min after rTMS
Reported as:
Mean · percent change
Percent Change of Functional Connectivity in Left Motor Cortex, Where Functional Connectivity is Measured as a Dimensionless Fractional Amplitude of Low-frequency Fluctuations (fALFF), at 80 Min After rTMS
percent changeInhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)
Percent Change of Functional Connectivity in Left Motor Cortex, Where Functional Connectivity is Measured as a Dimensionless Fractional Amplitude of Low-frequency Fluctuations (fALFF), at 80 Min After rTMS-2 ± 119 ± NA
PrimaryPercent Change of Functional Connectivity in Right Motor Cortex, Where Functional Connectivity is Measured as a Dimensionless Fractional Amplitude of Low-frequency Fluctuations (fALFF), at 80 Min After rTMS

Functional connectivity is measured with MRI at 7 Tesla as a dimensionless fractional amplitude of low-frequency fluctuations (fALFF). This is an index which reflects the intensity of spontaneous regional brain activity. It is calculated as the ratio of power spectra of low frequency (0.01-0.08 Hz) to that of the entire frequency range. Percent change of functional connectivity is calculated from baseline (i.e., pre-rTMS).

Time frame:
Baseline/Pre-rTMS and 80 min after rTMS
Reported as:
Mean · percent change
Percent Change of Functional Connectivity in Right Motor Cortex, Where Functional Connectivity is Measured as a Dimensionless Fractional Amplitude of Low-frequency Fluctuations (fALFF), at 80 Min After rTMS
percent changeInhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)
Percent Change of Functional Connectivity in Right Motor Cortex, Where Functional Connectivity is Measured as a Dimensionless Fractional Amplitude of Low-frequency Fluctuations (fALFF), at 80 Min After rTMS-1 ± 1017 ± NA

Adverse events

Collected over approximately 4 hours. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Inhibitory rTMS (1 Hz)0/7 (0%)0/7 (0%)7/7 (100%)
Excitatory rTMS (5 Hz)0/1 (0%)0/1 (0%)1/1 (100%)
Most frequent other events
Most frequent other events
EventInhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)
SleepinessGeneral disorders3/71/1
Metallic TasteGeneral disorders1/71/1
Anxiety/Worry/NervousnessPsychiatric disorders2/70/1
WarmthGeneral disorders1/70/1
HeadacheGeneral disorders1/70/1
Tooth PainGeneral disorders1/70/1
Shoulder PainGeneral disorders1/70/1

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)Inhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)Total
<=18 years000
Between 18 and 65 years718
>=65 years000
Age, Continuous
Age, Continuous(years)Inhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)Total
Mean28 ± 722 ± NA27 ± 7
Sex: Female, Male
Sex: Female, Male(Participants)Inhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)Total
Female000
Male718
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Inhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)Total
American Indian or Alaska Native000
Asian101
Native Hawaiian or Other Pacific Islander000
Black or African American000
White617
More than one race000
Unknown or Not Reported000
Region of Enrollment
Region of Enrollment(participants)Inhibitory rTMS (1 Hz)Excitatory rTMS (5 Hz)Total
United States718
08

Study locations

1 site
  • Center for Magnetic Resonance Research, Dept. of Radiology, University of Minnesota
    Minneapolis, Minnesota 55455, United States
09

References and documents

Publications

  • Emara TH, Moustafa RR, ElNahas NM, ElGanzoury AM, Abdo TA, Mohamed SA, ElEtribi MA. Repetitive transcranial magnetic stimulation at 1Hz and 5Hz produces sustained improvement in motor function and disability after ischaemic stroke. Eur J Neurol. 2010 Sep;17(9):1203-1209. doi: 10.1111/j.1468-1331.2010.03000.x. Epub 2010 Apr 8. PubMed 20402755 ↗
  • Machado S, Bittencourt J, Minc D, Portella CE, Velasques B, Cunha M, Budde H, Basile LF, Chadi G, Cagy M, Piedade R, Riberio P. Therapeutic applications of repetitive transcranial magnetic stimulation in clinical neurorehabilitation. Funct Neurol. 2008 Jul-Sep;23(3):113-22. PubMed 19152730 ↗
  • Rossi S, Hallett M, Rossini PM, Pascual-Leone A; Safety of TMS Consensus Group. Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research. Clin Neurophysiol. 2009 Dec;120(12):2008-2039. doi: 10.1016/j.clinph.2009.08.016. Epub 2009 Oct 14. PubMed 19833552 ↗
  • Bednarik P, Tkac I, Giove F, DiNuzzo M, Deelchand DK, Emir UE, Eberly LE, Mangia S. Neurochemical and BOLD responses during neuronal activation measured in the human visual cortex at 7 Tesla. J Cereb Blood Flow Metab. 2015 Mar 31;35(4):601-10. doi: 10.1038/jcbfm.2014.233. PubMed 25564236 ↗
  • Smith SM, Beckmann CF, Andersson J, Auerbach EJ, Bijsterbosch J, Douaud G, Duff E, Feinberg DA, Griffanti L, Harms MP, Kelly M, Laumann T, Miller KL, Moeller S, Petersen S, Power J, Salimi-Khorshidi G, Snyder AZ, Vu AT, Woolrich MW, Xu J, Yacoub E, Ugurbil K, Van Essen DC, Glasser MF; WU-Minn HCP Consortium. Resting-state fMRI in the Human Connectome Project. Neuroimage. 2013 Oct 15;80:144-68. doi: 10.1016/j.neuroimage.2013.05.039. Epub 2013 May 20. PubMed 23702415 ↗

Study documents

  • Protocol and statistical analysis plan · Jun 1, 2019

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Nov 18, 2019, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT02677740
Lead sponsor
University of Minnesota
Responsible party
Sponsor
First posted
Feb 9, 2016
Start date
Aug 29, 2016
Primary completion
Mar 19, 2017
Completion
Mar 19, 2017
Results posted
Aug 6, 2019
Last update
Nov 18, 2019

Study contacts

Silvia Mangia, PhD
principal investigator · Dept. of Radiology, University of Minnesota

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Nov 2019. You cannot join it, but the record below documents what was studied.

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