Physiology of Interregional Connectivity in the Human Brain
Physiology of Interregional Connectivity in the Human Brain
What it found
We found no results in the registry or in papers.
What was tested
Treatment tested
- Single-pulse transcranial magnetic stimulation (spTMS)
- Paired associative stimulation (PAS)
Compared with
- Repetitive transcranial magnetic stimulation (rTMS)
What it measured
Main measures
Changes in EEG effective connectivity
Experiment A: Within-session (before versus after PAS at 1 and 60 minutes). Experiment B: Within-session (before versus after PAS at 1 and 60 minutes). Across-sessions (persistence of changes up to 1
MRI lesionsNerve conduction testsChanges in resting-state EEG coherence
Experiment A: Within-session (before versus after PAS at 1 and 60 minutes). Experiment B: Within-session (before versus after PAS at 1 and 60 minutes). Across-sessions (persistence of changes up to 1
MRI lesionsNerve conduction tests
Other measures (3)
Motor evoked potentials (MEPs)
Experiment A: Within-session (before versus after PAS at 1 and 60 minutes). Experiment B: Done only in patients where the M1 was targeted with PAS.
MRI lesionsMyelin repairNerve conduction testsMRI functional connectivity
Experiment A: Baseline. Experiment B: Baseline to 1 month after the last PAS session.
MRI lesionsNerve conduction testsMRI structural connectivity
Experiment A: Baseline. Experiment B: Baseline to 1 month after the last PAS session.
MRI lesionsNerve conduction tests
Who could take part
MS (type not specified) · 18 to 85
Show the full criteria
Inclusion criteria
Inclusion Criteria for Healthy Participants: * Age from 18 to 85 years * Right-handed * Normal hearing and (corrected) vision * Able to understand and give informed consent * English speaker Inclusion Criteria for Patients: * Age from 18 to 85 years * Stroke (ischemic subcortical, intermediate level, chronic phase 3 weeks or more from lesion) * TBI (closed-skull, intermediate level, chronic phase 3 weeks or more from lesion) * MS (white matter subcortical lesion) * Clinical and radiological evidence supporting the above diagnoses * One or more behavioral symptoms possibly linked to the white matter lesion(s) * Stable medical condition * English speaker
Exclusion criteria
Exclusion Criteria for Healthy Participants: * Cardiac pacemaker or pacemaker wires; neurostimulators; implanted pumps * Metal in the body (rods, plates, screws, shrapnel, dentures, IUD) or metallic particles in the eye * Surgical clips in the head or previous neurosurgery * Any magnetic particles in the body * Cochlear implants * Prosthetic heart valves * Epilepsy or any other type of seizure history * Any neurological diagnoses or medications influencing brain function * History of significant head trauma (i.e., extended loss of consciousness, neurological sequelae) * Known structural brain lesion * Significant other disease (heart disease, malignant tumors, mental disorders) * Significant claustrophobia; Ménière's disease * Pregnancy (ruled out by urine ß-HCG if answers to screening questions suggest that pregnancy is possible), breast feeding * Non prescribed drug use * Failure to perform the behavioral tasks or neuropsychological evaluation tests * Prisoners Exclusion Criteria for Patients: * Same as above, excluding the requirement of no structural brain lesion, and medications influencing brain function are allowed * Patients with cortical lesions or CSF-filled cysts/cavities near the TMS sites * MS patients with acute exacerbation
As registered. Criteria can change, so ask the trial team or your neurologist.
About this trial
In the sponsor's words
The purpose of this study is to understand the physiology of connectivity between cortical regions in the human brain in healthy participants and in patients with white matter lesions. Specifically, the investigators will examine the effects of paired associative stimulation (PAS) which consists in delivering brief (\< 1 ms) current pulses separated by a short millisecond-level time interval ("asynchrony") to two cortical areas. The used techniques are all non-invasive and considered safe in humans: transcranial magnetic stimulation (TMS), electroencephalography (EEG), magnetic resonance imaging (MRI), and functional MRI (fMRI). Based on prior literature in animals and human studies, it is hypothesized that PAS may increase or decrease effective connectivity between the stimulated areas depending on the asynchrony value. The main outcome measure is source-resolved EEG responses evoked by single-pulse TMS; this is a more direct measure of neuronal changes occurring at the targeted cortical area than motor evoked potentials (MEPs) or sensor-level EEG responses used in previous studies.
Papers
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History
Started
May 2017
Main results due
Nov 2020
Finished
Nov 2020