Localization of cortical primary motor area of the hand using navigated transcranial magnetic stimulation, BOLD and arterial spin labeling fMRI.
Although the relationship between neuronavigated transcranial magnetic stimulation (nTMS) and functional magnetic resonance imaging (fMRI) has been widely studied in motor mapping, it is unknown how the motor response type or the choice of motor task affect this relationship.



Centers of gravity (CoGs) and response maxima were measured with blood-oxygen-level dependent (BOLD) and arterial spin labeling (ASL) fMRI during motor tasks against nTMS CoGs and response maxima, which were mapped with motor evoked potentials (MEPs) and silent periods (SPs).



No differences in motor representations (CoGs and response maxima) were observed in lateral-medial direction (p=0.265). fMRI methods localized the motor representation more posterior than nTMS (p<0.001). This was not affected by the BOLD fMRI motor task (p>0.999) nor nTMS response type (p>0.999). ASL fMRI maxima did not differ from the nTMS nor BOLD fMRI CoGs (p≥0.070), but the ASL CoG was deeper in comparison to other methods (p≤0.042). The BOLD fMRI motor task did not influence the depth of the motor representation (p≥0.745). The median Euclidean distances between the nTMS and fMRI motor representations varied between 7.7mm and 14.5mm and did not differ between the methods (F≤1.23, p≥0.318).



The relationship between fMRI and nTMS mapped excitatory (MEP) and inhibitory (SP) responses, and whether the choice of motor task affects this relationship, have not been studied before.



The congruence between fMRI and nTMS is good. The choice of nTMS motor response type nor BOLD fMRI motor task had no effect on this relationship.
Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Applied Physics, University of Eastern Finland, Kuopio, Finland. Electronic address: elisa.kallioniemi@kuh.fi.
Elisa
E
Kallioniemi
Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.
Minna
M
Pitkänen
Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland.
Mervi
M
Könönen
Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
Ritva
R
Vanninen
Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
Petro
P
Julkunen
D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006225:Hand / Q000294:innervation / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging*; D010100:Oxygen / Q000097:blood; D013113:Spin Labels; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
D013113:Spin Labels; D010100:Oxygen
Arterial spin labeling; Blood-oxygen-level dependent; Functional magnetic resonance imaging; Motor evoked potential; Neuronavigated transcranial magnetic stimulation; Silent period