title: Co-registration of magnetic resonance spectroscopy and transcranial magnetic stimulation.
abstract: Transcranial magnetic stimulation (TMS) is a widely used tool for noninvasive modulation of brain activity, that is thought to interact primarily with excitatory and inhibitory neurotransmitter systems. Neurotransmitters such as glutamate and GABA can be measured by magnetic resonance spectroscopy (MRS). An important prerequisite for studying the relationship between MRS neurotransmitter levels and responses to TMS is that both modalities should examine the same regions of brain tissue. However, co-registration of TMS and MRS has been little studied to date. This study reports on a procedure for the co-registration and co-visualization of MRS and TMS, successfully localizing the hand motor cortex, as subsequently determined by its functional identification using TMS. Sixteen healthy subjects took part in the study; in 14 of 16 subjects, the TMS determined location of motor activity intersected the (2.5cm)(3) voxel selected for MRS, centered on the so called 'hand knob' of the precentral gyrus. It is concluded that MRS voxels placed according to established anatomical landmarks in most cases agree well with functional determination of the motor cortex by TMS. Reasons for discrepancies are discussed.
authors.affiliation: Laboratory of Canada Research Chair in Cognitive Neuroscience, Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Faculty of Medicine, Laval University, QC, Canada. Electronic address: antoine.hone-blanchet.1@ulaval.ca.
authors.forename: Antoine
authors.initials: A
authors.lastname: Hone-Blanchet
authors.affiliation: Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Salas
authors.affiliation: Department of Physical Medicine and Rehabilitation, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Pablo
authors.initials: P
authors.lastname: Celnik
authors.affiliation: Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Aadi
authors.initials: A
authors.lastname: Kalloo
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Schar
authors.affiliation: FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Nicolaas A J
authors.initials: NA
authors.lastname: Puts
authors.affiliation: FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Ashley D
authors.initials: AD
authors.lastname: Harris
authors.affiliation: FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Barker
authors.affiliation: Laboratory of Canada Research Chair in Cognitive Neuroscience, Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Faculty of Medicine, Laval University, QC, Canada; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MS, USA.
authors.forename: Shirley
authors.initials: S
authors.lastname: Fecteau
authors.affiliation: Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Earley
authors.affiliation: Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Richard P
authors.initials: RP
authors.lastname: Allen
authors.affiliation: FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Edden
mesh_terms: D001931:Brain Mapping / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009044:Motor Cortex / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: Co-registration; Co-visualization; Magnetic resonance spectroscopy; Transcranial magnetic stimulation