MRI Guided Closed-loop TMS-EEG

Summary

The goal of this interventional study is to develop an individualized approach using transcranial magnetic stimulation (TMS) in a high-precision manner. This approach will use TMS to modulate brain activity at multiple locations simultaneously. Functional magnetic resonance imaging (fMRI) and electroencephalograph (EEG) will record the responses and guide the stimulation. Specifically, the placement and orientation of TMS coils will be tailored to stimulate the targeted functional brain areas informed by fMRI. To maximize the interventional effect, stimulation pulses will be delivered based on EEG oscillations.

Interventions

• TMS · DEVICE

  The target locations of TMS will be cortical regions defined by either anatomical landmarks or functional regions derived from the individual's functional and structural MRI for Aim 1. TMS target locations for Aim 2 and 3 are determined by Aim 1's results. These TMS target regions will be guided by a navigation system. TMS will be parametrically varied with combinations of pulse strength and frequencies based on experimental conditions. TMS strength will be referred to the resting motor threshold (rMT), which will be determined independently for each participant. TMS pulses will be delivered at fixed time instants for Aim 2 and at time instants based on the phase of oscillatory neural activity for Aim 3.

Published eligibility criteria

Verbatim from the registry. Only the site can decide how these apply to a specific patient.

Inclusion Criteria for Healthy participants:

* Ages between 18 and 65 years;
* Healthy with no history of neurological impairment;
* Normal or correct-to-normal vision.

Inclusion Criteria for aMCI patients:

* Age 50-80 years;
* MCI clinical criteria: (a) self- or informant-reported cognitive complaint; (b) preserved independence in functional abilities; and (c) absence of dementia;
* Objective cognitive impairment supported by the following measures of general cognitive function: (a) Mini-Mental State Exam (MMSE) 24-27 (inclusive); (b) Montreal Cognitive Assessment (MoCA) 18-26 (inclusive); or (c) Clinical Dementia Rating Scale score of 0.5;
* Normal or correct-to-normal vision.

Exclusion Criteria for all participants:

* Women who are pregnant or breastfeeding;
* History of seizure (childhood febrile seizures are acceptable and these subjects may be included in the study), history of epilepsy in self or first degree relatives, stroke, brain tumor, brain surgery, head injury, known structural brain lesion;
* Have metal in the eye or skull area, brain stimulator, surgical metal, clips in the brain, cochlear implants, mental fragments in the eye, as these make TMS unsafe;
* Have non-MRI compatible metal in the body, for example metallic (forromagnetic) implants (e.g., cardiac pacemaker, aneurysm clip);
* Subjects who are uncomfortable in small closed spaces (have claustrophobia), unable to lie comfortably supine for up to 1 hour, and would feel uncomfortable in the MRI machine;
* Participation in any other study involving non-invasive brain stimulation less than two weeks ago;
* Abnormal findings on neurological examination that we will perform.

Sites (1)

• Sunnybrook Health Sciences Centre, Toronto, Ontario · Recruiting