title: The use of magnetic resonance spectroscopy as a tool for the measurement of bi-hemispheric transcranial electric stimulation effects on primary motor cortex metabolism.
abstract: Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of neurological and psychiatric disorders such as stroke and depression. Yet, the mechanisms underlying its ability to modulate brain excitability to improve clinical symptoms remains poorly understood. To help improve this understanding, proton magnetic resonance spectroscopy ((1)H-MRS) can be used as it allows the in vivo quantification of brain metabolites such as γ-aminobutyric acid (GABA) and glutamate in a region-specific manner. In fact, a recent study demonstrated that (1)H-MRS is indeed a powerful means to better understand the effects of tDCS on neurotransmitter concentration. This article aims to describe the complete protocol for combining tDCS (NeuroConn MR compatible stimulator) with (1)H-MRS at 3 T using a MEGA-PRESS sequence. We will describe the impact of a protocol that has shown great promise for the treatment of motor dysfunctions after stroke, which consists of bilateral stimulation of primary motor cortices. Methodological factors to consider and possible modifications to the protocol are also discussed.
authors.affiliation: Department of Psychology, University of Montréal.
authors.forename: Sara
authors.initials: S
authors.lastname: Tremblay
authors.affiliation: Department of Psychology, University of Montréal.
authors.forename: Vincent
authors.initials: V
authors.lastname: Beaulé
authors.affiliation: Montreal Neurological Institute, McGill University.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Proulx
authors.affiliation: Department of Psychology, University of Montréal.
authors.forename: Louis-Philippe
authors.initials: LP
authors.lastname: Lafleur
authors.affiliation: Department of Psychology, University of Montréal.
authors.forename: Julien
authors.initials: J
authors.lastname: Doyon
authors.affiliation: Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota; gosia@cmrr.umn.edu.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Marjańska
authors.affiliation: Department of Psychology, University of Montréal; hugo.theoret@umontreal.ca.
authors.forename: Hugo
authors.initials: H
authors.lastname: Théoret
mesh_terms: D004558:Electric Stimulation / Q000295:instrumentation / Q000379:methods; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D009044:Motor Cortex / Q000378:metabolism*; D066244:Proton Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid