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Brain State-dependent Stimulation to Improve Movement

Not Applicable
Recruiting
Conditions
Healthy
Interventions
Device: TMS
Behavioral: Object directed grasping
Registration Number
NCT05103176
Lead Sponsor
University of Michigan
Brief Summary

Repetitive transcranial magnetic stimulation (rTMS) is a powerful tool to non-invasively modulate brain circuits, brain plasticity, and behavior. This proposal will test the hypothesis that controlling behavioral state during focal multi-day rTMS of a brain region involved in grasping movements will enhance the functional specificity of the neuromodulation action among distributed brain regions involved in voluntary motor control and concomitantly improve manual dexterity. Results from this study will be used to optimize rTMS therapy for individuals with neuromotor impairments by controlling behavioral state to improve the efficacy of rTMS treatment.

Healthy volunteers that qualify for this study will have motor skill assessments and basic neuromotor testing (using neurophysiology with TMS and functional Magnetic Resonance Imaging (fMRI) scans). Participants will be asked to come in for up to nine sessions that include 1 screening session, 5 consecutive daily rTMS sessions and 3 assessment sessions with resting-state and task-based fMRI, neurophysiology with TMS, and hand motor tasks over the course of 3-4 weeks.

Detailed Description

This study will examine a particular type of rTMS, known as theta burst stimulation (TBS), which has been shown to induce longer lasting effects than other forms of rTMS, making TBS an important tool for therapeutic applications. While TBS provides relatively focal stimulation, effects on the brain occur through interconnected networks in ways that are poorly understood. Moreover, stimulation is highly state-dependent, and the use of rTMS in most therapeutic settings, such as the treatment of motor impairments, leaves behavioral state uncontrolled. Augmenting rTMS therapy by inducing specific behavioral states is an attractive idea for improving therapeutic rTMS, but the relevant knowledge base is sparse. To address this critical gap, this exploratory R21 proposal will examine the effects of TBS and behavioral state on brain and motor behavior. The investigators will test the broad hypothesis that when TBS is applied during a controlled behavior state, motor function will be facilitated, compared to stimulation when behavioral state is uncontrolled. The investigators will focus on the posterior parietal cortex (PPC), and associated parietofrontal circuits, which subserve skilled grasp control, an ability known to be impaired in stroke, traumatic brain injury, and other motor disorders. The investigators will collect functional magnetic resonance imaging (fMRI), neurophysiological measures with TMS, and behavioral measures in all subjects for three different interventions.

In Aim 1, the investigators will show improvement in action performance by manipulating the behavioral state during PPC stimulation.

In Aim 2, the investigators will demonstrate modulation of neurophysiological aftereffects of PPC stimulation on motor output by manipulating behavioral state.

In Aim 3, the investigators will assess the relationship between brain connectivity, plasticity and behavior in response to the behavioral state during brain stimulation.

Impact: Results will provide insights into the effects of rTMS and behavioral state on the brain and behavior. This knowledge will lay a mechanistic foundation for future studies to show how controlling behavioral state during rTMS can improve therapeutic efficacy in neurological disorders.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
65
Inclusion Criteria
  • Women of child bearing age cannot be pregnant or trying to become pregnant
  • Ability to tolerate small, enclosed spaces without anxiety
  • Ability and willingness to give informed consent to participate
  • No history of neurological disorder
  • Right handed
  • English speaking
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Exclusion Criteria
  • Are left-handed
  • Are younger than 18 or older than 50 years old
  • Women who are pregnant, suspect they are pregnant, or are attempting to become pregnant
  • Have metal anywhere in the head, excluding the mouth
  • Have a pacemaker, deep brain stimulator, vagus nerve stimulator or any other medically implanted device
  • Have cochlear hearing implants
  • Are taking GABAergic, NDMA-receptor antagonist, or other drug known to influence neural receptors
  • Have any of the below conditions that would put participants at increased risk of having a seizure: a personal or family history of seizure/epilepsy, taking prescription drugs that lower the threshold for seizures, recent history of excessive alcohol consumption, history of alcohol addiction/dependence, recent history of recreational drug use, history of drug addiction/dependence
  • Have been diagnosed with any of the following: a stroke, brain hemorrhage, brain tumor, encephalitis, multiple sclerosis, Parkinson's disease or Alzheimer's disease, depression in the past 6 months, attention deficit disorder, schizophrenia, manic depressive (bipolar) disorder, normal pressure hydrocephalus or increased intra-cranial pressure, diabetes requiring insulin treatment, any serious heart disorder or liver disease
  • Have had a migraine in the past month
  • MRI specific exclusion criteria: Any relevant history of open-heart surgery, artificial heart valve, brain aneurysm surgery, braces or extensive dental work, cataract surgery or lens implant, or artificial limb or joint. History of foreign metallic object in the body such as bullets, BB's, pellets, shrapnel, or metalwork fragments. Claustrophobia, have uncontrollable shaking, or cannot lie still for one hour.
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Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
To PPC, with concurrent taskTMSThis arm will receive intermittent theta bust stimulation to the PPC site while subjects perform a grasp task
To PPC, without a concurrent taskTMSThis arm will receive intermittent theta bust stimulation to the PPC site without a concurrent task
To PPC, with concurrent taskObject directed graspingThis arm will receive intermittent theta bust stimulation to the PPC site while subjects perform a grasp task
To vertex, with concurrent taskObject directed graspingThis arm will receive intermittent theta bust stimulation to the vertex site (control condition) while subjects perform a grasp task
To vertex, with concurrent taskTMSThis arm will receive intermittent theta bust stimulation to the vertex site (control condition) while subjects perform a grasp task
Primary Outcome Measures
NameTimeMethod
Percentage change in amplitude of motor evoked potential (MEP) to immediate post-intervention.Baseline and immediate post-intervention (up to 60 min)

Motor cortical excitability is measured by electromyography using MEPs elicited by TMS

Change from baseline functional connectivity to PPC stimulation target within the cortical grasping network to immediate post-intervention.Baseline and immediate post-intervention (up to 60 min during fMRI)

Resting-state connectivity of low frequency BOLD fluctuations for a seed at the PPC

Percentage change in the time to complete the nine-hole peg test (9-HPT) to immediate post-interventionBaseline and immediate post-intervention (up to 30 min)

9-hole peg test is a manual dexterity measure, estimated as the time required to complete the task (seconds)

Change from baseline Blood Oxygen Level-Dependent (BOLD) activation, voxelwise in the cortical grasp network to immediate post-intervention.Baseline and immediate post-intervention (up to 60 min during fMRI)

Parietal-frontal cortical grasping network defined by BOLD change while subject performs the precision force-tracking task

Secondary Outcome Measures
NameTimeMethod
Percentage change in amplitude of motor evoked potential (MEP) to 1-week post-intervention.Baseline and 1-week post-intervention (up to 60 min)

Motor cortical excitability is measured by electromyography using MEPs elicited by TMS

Percentage change in accuracy to precision force-tracking task to immediate post-interventionBaseline and immediate post-intervention (up to 60 min during fMRI and outside scanner)

Squared distance (error) from the cursor to the target in precision force-tracking task, estimated as the root mean squared error (RMSE)

Percentage change in the mean choice reaction time to immediate post-interventionBaseline and immediate post-intervention (up to 30 min)

Mean reaction time for subjects responding in the 2-choice reaction time control task, for correct responses

Percentage change in the mean choice reaction time to 1-week post-interventionBaseline and 1-week post-intervention (up to 30 min)

Mean reaction time for subjects responding in the 2-choice reaction time control task, for correct responses

Change from baseline functional connectivity to PPC stimulation target within the cortical grasping network to 1-week post-intervention.Baseline and 1-week post-intervention (up to 60 min during fMRI)

Resting-state connectivity of low frequency BOLD fluctuations for a seed at the PPC

Percentage change in the normalized motor evoked potential (MEP) size to immediate post-intervention.Baseline and immediate post-intervention (up to 60 min)

Parietal-motor functional connectivity is measured by electromyography using MEPs elicited by dual-site TMS, while subjects perform an object-directed grasp/subjects are at rest

Percentage change in the time to complete the nine-hole peg test (9-HPT) to 1-week post-interventionBaseline and 1-week post-intervention (up to 30 min)

9-hole peg test is a manual dexterity measure, estimated as the time required to complete the task (seconds)

Change from baseline Blood Oxygen Level-Dependent (BOLD) activation, voxelwise in whole brain to immediate post-intervention.Baseline and immediate-intervention (up to 60 min during fMRI)

Parietal-frontal cortical grasping network defined by BOLD change while subject performs the precision force-tracking task

Change from baseline Blood Oxygen Level-Dependent (BOLD) activation, voxelwise in whole brain to 1-week post-intervention.Baseline and 1-week post-intervention (up to 60 min during fMRI)

Parietal-frontal cortical grasping network defined by BOLD change while subject performs the precision force-tracking task

Percentage change in accuracy to precision force-tracking task to 1-week post-interventionBaseline and 1-week post-intervention (up to 60 min during fMRI and outside scanner)

Squared distance (error) from the cursor to the target in precision force-tracking task, estimated as the root mean squared error (RMSE)

Percentage change in the normalized motor evoked potential (MEP) size to 1-week post-intervention.Baseline and 1-week post-intervention (up to 60 min)

Parietal-motor functional connectivity is measured by electromyography using MEPs elicited by dual-site TMS, while subjects perform an object-directed grasp/subjects are at rest

Change from baseline Blood Oxygen Level-Dependent (BOLD) activation, voxelwise in the cortical grasp network to 1-week post-intervention.Baseline and 1-week post-intervention (up to 60 min during fMRI)

Parietal-frontal cortical grasping network defined by BOLD change while subject performs the precision force-tracking task

Trial Locations

Locations (1)

University of Michigan

🇺🇸

Ann Arbor, Michigan, United States

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