MRI-guided dmPFC-rTMS as a Treatment for Treatment-resistant Major Depressive Disorder.
Here we outline the protocol for magnetic resonance imaging (MRI) guided repetitive transcranial magnetic stimulation (rTMS) to the dorsal medial prefrontal cortex (dmPFC) in patients with major depressive disorder (MDD). Technicians used a neuronavigation system to process patient MRIs to generate a 3-dimensional head model. The head model was subsequently used to identify patient-specific stimulatory targets. The dmPFC was stimulated daily for 20 sessions. Stimulation intensity was titrated to address scalp pain associated with rTMS. Weekly assessments were conducted on the patients using the Hamilton Rating Scale for Depression (HamD17) and Beck Depression Index II (BDI-II). Treatment-resistant MDD patients achieved significant improvements on both HAMD and BDI-II. Of note, angled, double-cone coil rTMS at 120% resting motor threshold allows for optimal stimulation of deeper midline prefrontal regions, which results in a possible therapeutic application for MDD. One major limitation of the rTMS field is the heterogeneity of treatment parameters across studies, including duty cycle, number of pulses per session and intensity. Further work should be done to clarify the effect of stimulation parameters on outcome. Future dmPFC-rTMS work should include sham-controlled studies to confirm its clinical efficacy in MDD.
Institute of Medical Sciences, University of Toronto.
Katharine
K
Dunlop
Faculty of Arts and Science, University of Toronto.
Pauline
P
Gaprielian
Department of Psychiatry, University of Toronto; Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health.
Daniel
D
Blumberger
Department of Psychiatry, University of Toronto; Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health.
Zafiris J
ZJ
Daskalakis
MRI-Guided rTMS Clinic, University Health Network; Department of Psychiatry, University Health Network; Department of Psychiatry, University of Toronto.
Sidney H
SH
Kennedy
MRI-Guided rTMS Clinic, University Health Network; Department of Psychiatry, University Health Network; Department of Psychiatry, University of Toronto.
Peter
P
Giacobbe
MRI-Guided rTMS Clinic, University Health Network; Department of Psychiatry, University Health Network; Toronto Western Research Institute, University Health Network; Department of Psychiatry, University of Toronto; jonathan.Downar@uhn.ca.
Jonathan
J
Downar
D003865:Major Depressive Disorder / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*