Electroencephalography (EEG)

Electroencephalography (EEG) labs have been established within the Lawson arm of BIRC. The available systems also have been adapted to measure other electro-physiological measures such as electromyography (EMG) and electrocardiography (ECG). Non-physiological signals can be input into the amplifier and synchronized with the electrophysiological signals, both stand-alone, and as part of a simultaneous mMR-PET/EEG/EMG functional imaging system and within the Human Threshold Testing Facility.

The labs therefore focus on the use of high-density EEG systems (128 channel 3T MR compatible, with simultaneous mMRI/fMRI/PET/EEG/EMG/ECG and other capabilities) to perform recordings in a plethora of paradigms investigating the CNS pathways in health and disease. Researchers can perform simultaneous functional imaging, cortical source reconstruction, evoked potential and even spectral analysis to understand how the brain reacts to external stimuli, and which exact area in the brain is recruited for this purpose.

Example of pre- and post-processing electroencephalography (EEG) data acquired in the magnetic resonance imaging (MRI) scanner during exposure to 2-second blocks of 60 Hz magnetic field (MF) exposure. Top panel: raw data, in which artifacts are clearly visible and make the data unusable for further analysis. Bottom panel: post-processing EEG data, in which the MF exposure blocks have been corrected using principal component analysis (PCA). The EEG data acquired during MF exposure is now usable for analysis.

The EEG can be recorded inside the Siemens 3T mMR scanner as well as in a controlled laboratory environment, since a duplicate of the EEG system is set up in a Magneto-encephalography grade (MEG-grade) magnetic field shielded booth (a matching sham booth is also available).

The EEG lab has been chosen by the Canadian Department of National Defence to assess the use of EEG technology as a means to evaluate situational stress. A primary application is in assessing the readiness of soldiers who have endured a traumatic episode during combat operations. This platform is also used by CIHR industry-partnered projects investigating the functional impact of electric and magnetic stimuli acutely or chronically applied to the brain.

The integration of our new Transcranial Magnetic Stimulation system with neuro-navigation capability (awarded by the SJHC foundation to our scientists) to this EEG platform allowed us to initiate new translational collaborations, such as the one with Drs. Amer Burhan and Priya Subramanian on a project dealing with Alzheimer disease symptoms treated by TMS (ongoing project on conducted on this platform). Changes in brain activity are monitored simultaneously using EEG.

Investigators
Alexandre Legros, PhD, BEMS, Kinesiology
Frank Prato, PhD, Medical Imaging Physics
Robert Stodilka, PhD, Nuclear Medicine Physics
Jean Th├ęberge, PhD, Magnetic Resonance Physics
Alex Thomas, PhD, BEMS Group leader
Terry Thompson, PhD, MR Spectroscopy