Title
Concordance Between BeamF3 and MRI-neuronavigated Target Sites for Repetitive Transcranial Magnetic Stimulation of the Left Dorsolateral Prefrontal Cortex. Source Brain Stimulation. 8(5):965-73, 2015 Sep-Oct.
Authors:
Mir-Moghtadaei A; Caballero R; Fried P; Fox MD; Lee K; Giacobbe P; Daskalakis ZJ; Blumberger DM; Downar J. Institution Mir-Moghtadaei,Arsalan. Faculty of Arts and Sciences, University of Toronto, Canada. Caballero,Ruth. Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Bioengineering and Telemedicine Centre, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Spain. Fried,Peter. Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. Fox,Michael D. Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Department of Neurology, MassachusettsGeneral Hospital, Harvard Medical School, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Boston, MA, USA. Lee,Katherine. Faculty of Arts and Sciences, University of Toronto, Canada. Giacobbe,Peter. Department of Psychiatry, University of Toronto, Canada; MRI-Guided rTMS Clinic, University Health Network, Toronto, Canada. Daskalakis,Zafiris J. Institute of Medical Science, University of Toronto, Canada; Department of Psychiatry, University of Toronto, Canada; Temerty Centre for Therapeutic Brain Intervention at the Centre for Addiction and Mental Health, Toronto, Ontario, Canada. Blumberger,Daniel M. Institute of Medical Science, University of Toronto,Canada; Department of Psychiatry, University of Toronto, Canada; Temerty Centre for Therapeutic Brain Intervention at the Centre for Addiction and Mental Health, Toronto, Ontario, Canada. Downar,Jonathan. Institute of Medical Science, University of Toronto, Canada; Department of Psychiatry, University of Toronto, Canada; MRI-Guided rTMS Clinic, University Health Network, Toronto, Canada.
Electronic Address:
jonathan.downar@uhn.ca.
Abstract
Background:
The dorsolateral prefrontal cortex (DLPFC) is a common target for repetitive transcranial magnetic stimulation (rTMS) in major depression, but the conventional “5 cm rule” misses DLPFC in >1/3 cases. Another heuristic, BeamF3, locates the F3 EEG site from scalp measurements. MRI-guided neuronavigation is more onerous, but can target a specific DLPFC stereotaxic coordinate directly. The concordance between these two approaches has not previously been assessed.
Objective:
To quantify the discrepancy in scalp site between BeamF3 versus MRI-guided neuronavigation for left DLPFC. METHODS: Using 100 pre-treatment MRIs from subjects undergoing left DLPFC-rTMS, we localized the scalp site at minimum Euclidean distance from a target MNI coordinate (X – 38 Y + 44 Z + 26) derived from our previous work. We performed nasion-inion, tragus-tragus, and head-circumference measurements on the same subjects’ MRIs, and applied the BeamF3 heuristic. We then compared the distance between BeamF3 and MRI-guided scalp sites.
Results:
BeamF3-to-MRI-guided discrepancies were <0.65 cm in 50% of subjects, <0.99 cm in 75% of subjects, and <1.36 cm in 95% of subjects. The angle from midline to the scalp site did not differ significantly using MRI-guided versus BeamF3 methods. However, the length of the radial arc from vertex to target site was slightly but significantly longer (mean 0.35 cm) with MRI-guidance versus BeamF3.
Conclusion:
The BeamF3 heuristic may provide a reasonable approximation to MRI-guided neuronavigation for locating left DLPFC in a majority of subjects. A minor optimization of the heuristic may yield additionalconcordance.
Authors:
Karabanov AN; Raffin E; Siebner HR. Institution Karabanov,Anke Ninija. Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark. Electronic address: ankenk@drcmr.dk. Raffin,Estelle. Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Fonctions Cerebrals et Neuromodulation, Universite Joseph Fourier, Grenoble, France; Inserm, U836, Grenoble Institut des Neurosciences, Grenoble, France. Siebner,Hartwig Roman. Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark. Title
