A New Generation of Magnetoencephalographs for High Speed Functional Brain Imaging

Hospices Civils de Lyon80 enrolled

Overview

The goal is to perform a first evaluation of the capabilities of a new generation of non-invasive magnetoencephalography whole head device using optically pumped magnetometers using Helium 4 as the sensitive element (OPM He4) to record brain magnetic activities. The investigators will record 1) healthy subjects stimulated with visual, auditory, somesthesic and motor stimuli and 2) athletes who suffered a mild concussion. The main hypothesis is that the OPM magnetoencephalographs (MEG) system will be able to detect brain activity. The secondary hypothesis is that the data recorded with the OPM MEG system will allow to reconstruct maps of the brain activity. To test the main hypothesis, they will compare the signal to noise ratio of brain activities between a classical MEG system and the new OPM He4 MEG. The secondary hypothesis will be tested through a comparison of the maps of brain activity obtained thanks to the data recorded with a classical MEG system and the new OPM He4 MEG.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

OTHER

Masking

NONE

Enrollment

Conditions

Mild Concussion Healthy Volunteers

Interventions

Experiment 1: visual and auditory attention taskDEVICE

We will use the FYNA Research system on 20 healthy volunteers with a visual and auditory attention task to evaluate the system's performance in recording brain signals complex frequency content.

Experiment 2: language production and rest tasksDEVICE

We will use the FYNA Research system on 20 healthy healthy volunteers with a language production task to assess the system's functional mapping capabilities and a resting task to assess the system's ability to identify resting networks.

Experiment 3: visuo-motor taskDEVICE

We will use the FYNA Research system in 20 healthy volunteers with a visuo-motor task to evaluate the system's performance in recording brain signals when the subject moves, inducing perturbations that affect the classical system (loss of spatial precision) and the FYNA Research system (low-frequency artifacts).

Experiment 4: brain activity at restDEVICE

We will be using the FYNA Research system on 20 concussed male athletes volunteers to assess the system's ability to detect modulations in the frequency content of resting brain activity.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 YearsHealthy volunteers:

Medical Language ↔ Plain English

Healthy volunteers: Inclusion Criteria: * Age 18 to 70 * Strongly motivated to participate to the study * Signed informed consent for the study Exclusion Criteria: * major cognitive deficit and unable to understand the instructions * previous neurology or psychiatric or sleep pathologies * Woman with a positive pregnancy test during the inclusion. * Subjects under guardianship, curatorship or safeguard of justice protection * Subjects deprived of their liberty * Subject not affiliated to a social security system. * Subject with common contraindications to MEG and MRI examination : * Metal in the body incompatible with performance of the examination (pacemaker, implantable pump, neurostimulator, cochlear implant, auditory prothesis, metalic prothesis, intracerebral clip, implantable defibrillator, any metalic parts in the brain or upper part of the body, ventriculoperitoneal valve, dental appliance or steel pivot for root canal, ferromagnetic foreign body in the upper part of the upper part of the body) * Claustrophobia Subjects who suffered a mild concussion: Inclusion Criteria: * Male aged from 18 to 40 * Strongly motivated to participate to the study * Signed informed consent for the study * Mild concussion confirmed by the club doctor and a neurologist neurologist in the three weeks preceding the experiment Exclusion Criteria: * major cognitive deficit and unability to understand the instructions * previous neurology or psychiatric or sleep pathologies except mild concussion * Woman with a positive pregnancy test during the inclusion. * Subjects under guardianship, curatorship or safeguard of justice protection * Subjects deprived of their liberty * Subject not affiliated to a social security system * Subject with common contraindications to MEG and MRI examination : * Metal in the body incompatible with performance of the examination (pacemaker, implantable pump, neurostimulator, cochlear implant, auditory prothesis, metalic prothesis, intracerebral clip, implantable defibrillator, any metalic parts in the brain or upper part of the body, ventriculoperitoneal valve, dental appliance or steel pivot for root canal, ferromagnetic foreign body in the upper part of the upper part of the body) * Claustrophobia

Outcomes

Primary Outcomes

Signal to Noise Ratio comparison between classical MEG and FYNA Research for the visual stimulations

The signal to noise ratio of normal (SNR) brain activity following a visual stimulus will be computed with respect to the pre-stimulus baseline -100 milliseconds to -10 milliseconds. We will compare the SNRs obtained with the classical MEG system serving as a reference and the SNRs obtained with the new OPM He4 MEG through the group of healthy volunteers for this given stimulus.