Prefrontal rTMS for Treating Depression: Location and Intensity Results from the OPT-TMS Multi-Site Clinical Trial

• Type of Material: Article
• Authors: Kevin A. Johnson, Medical University of South Carolina; Mirza Baig, Medical University of South Carolina; Dave Ramsey, South Carolina Research Authority; Sarah H. Lisanby, Columbia University; David Avery, University of Washington; William McDonald, Emory University; Xingbao Li, Medical University of South Carolina; Elisabeth R. Bernhardt, Columbia University; David R. Haynor, University of Washington; Paul Holtzheimer, Emory University; Harold A. Sackeim, Columbia University; Mark S. George, Medical University of South Carolina; Ziad Nahas Nahas, Medical University of South Carolina
• Language: English
• Date: 2013-03-01
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2013 Elsevier Inc. All rights reserved.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.brs.2012.02.003
• Title of Journal or Parent Work: Brain Stimulation
• ISSN: 1935-861X
• Volume: 6
• Issue: 2
• Start Page: 108
• End Page: 117
• Grant/Funding Information: This study was supported by the National Institute of Mental Health as the Optimization of TMS for the Treatment of Depression Study (OPT-TMS) involving grants 5R01MH069929 (Dr Avery), 5R01MH069887 (Dr George), 5R01MH069896 (Dr. George), 5R01MH069895 (Dr Lisanby), and 5R01MH069886 (Dr McDonald).
• Keywords: Science & Technology; Clinical Neurology; CORTEX DISTANCE; Prefrontal cortex; RESISTANT DEPRESSION; TRANSCRANIAL MAGNETIC STIMULATION; ANTIDEPRESSANT RESPONSE; MOTOR-EVOKED-POTENTIALS; Psychiatry; HAND PREFERENCE; Transcranial magnetic stimulation (TMS); HUMAN-BRAIN; Motor cortex; Life Sciences & Biomedicine; Transcranial Magnetic Stimulation (TMS); Neurosciences; Depression; Neurosciences & Neurology; THRESHOLD; Imaging (MRI); RANDOMIZED-TRIAL; COIL PLACEMENT; Classifications
• Research Categories: Health Sciences, Medicine and Surgery

Abstract

Background: Motor cortex localization and motor threshold determination often guide Transcranial Magnetic Stimulation (TMS) placement and intensity settings for non-motor brain stimulation. However, anatomic variability results in variability of placement and effective intensity. Objective: Post-study analysis of the OPT-TMS Study reviewed both the final positioning and the effective intensity of stimulation (accounting for relative prefrontal scalp-cortex distances). Methods: We acquired MRI scans of 185 patients in a multi-site trial of left prefrontal TMS for depression. Scans had marked motor sites (localized with TMS) and marked prefrontal sites (5 cm anterior of motor cortex by the "5 cm rule"). Based on a visual determination made before the first treatment, TMS therapy occurred either at the 5 cm location or was adjusted 1 cm forward. Stimulation intensity was 120% of resting motor threshold. Results: The "5 cm rule" would have placed stimulation in premotor cortex for 9% of patients, which was reduced to 4% with adjustments. We did not find a statistically significant effect of positioning on remission, but no patients with premotor stimulation achieved remission (0/7). Effective stimulation ranged from 93 to 156% of motor threshold, and no seizures were induced across this range. Patients experienced remission with effective stimulation intensity ranging from 93 to 146% of motor threshold, and we did not find a significant effect of effective intensity on remission. Conclusions: Our data indicates that individualized positioning methods are useful to reduce variability in placement. Stimulation at 120% of motor threshold, unadjusted for scalp-cortex distances, appears safe for a broad range of patients.