title: A setup for administering TMS to medial and lateral cortical areas during whole-brain FMRI recording.
abstract: Stimulating brain areas with transcranial magnetic stimulation (TMS) while concurrently and noninvasively recording brain activity changes through functional MRI enables a new range of investigations about causal interregional interactions in the human brain. However, standard head-coil arrangements for current methods for concurrent TMS-functional MRI somewhat restrict the cortical brain regions that can be targeted with TMS because space in typical MR head coils is limited. Another limitation for concurrent TMS-functional MRI approaches concerns the estimation of the precise stimulation site, which can limit the interpretation of the activity changes induced by TMS and increase the variability of the stimulation effects. Here, we present a novel approach using flexible MR receiver coils, allowing for stimulation of a large part of the cortex including more lateral areas. Furthermore, we present a fast and economical method to determine the precise location of the stimulation coil during scanning. This point-based registration method can accurately compute, during scanning, where TMS pulses are delivered. We validated this approach by stimulating medial (M1) and more lateral (dorsal part of the supramarginal gyrus) brain areas concurrently with functional MRI. Activation close to but not directly at the stimulated location and in distal areas connected to the targeted site was observed. This study provides a proof of concept that TMS of medial and lateral brain areas is feasible without significantly compromising brain coverage and that one can precisely determine the exact coil location inside the bore to verify targeting of brain areas.
authors.affiliation: *Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center, Utrecht, the Netherlands; †Nuffield Department of Clinical Neurosciences, Oxford Centre for Functional MRI of the Brain (FMRIB), University of Oxford, Oxford, United Kingdom; ‡Department of Medical Technology and Clinical Physics, University Medical Center, Utrecht, the Netherlands; §Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands; ‖Imaging Science Institute, University Medical Center, Utrecht, the Netherlands; and ¶Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, United Kingdom.
authors.forename: Antoin D
authors.initials: AD
authors.lastname: de Weijer
authors.forename: Iris E C
authors.initials: IE
authors.lastname: Sommer
authors.forename: Erwin J
authors.initials: EJ
authors.lastname: Bakker
authors.forename: Mirjam
authors.initials: M
authors.lastname: Bloemendaal
authors.forename: Chris J G
authors.initials: CJ
authors.lastname: Bakker
authors.forename: Dennis W J
authors.initials: DW
authors.lastname: Klomp
authors.forename: Sven
authors.initials: S
authors.lastname: Bestmann
authors.forename: Sebastiaan F W
authors.initials: SF
authors.lastname: Neggers
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000098:blood supply*; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D050781:Transcranial Magnetic Stimulation / Q000295:instrumentation / Q000379:methods
chemical_list: D010100:Oxygen