Resting state fMRI based target selection for personalized rTMS: stimulation over the left DLPFC temporarily alters the default mode network in healthy subjects
Aditya Singh, Tracy Erwin-Grabner, Grant Sutcliffe, Andrea Antal, Walter Paulus, Roberto Goya-Maldonado
bioRxiv June 12, 2018 preprint DOI: 10.1101/344390 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental neuroimaging study in healthy subjects |
|---|---|
| Sample size | 23 |
| Population | Healthy subjects |
| Dose | 3000 pulses |
| Duration | Single session; connectivity changes peaking at 27-32 minutes after stimulation |
| Measures | Temperament and Character Inventory (TCI), Positive and Negative Affect Schedule (PANAS) |
| Topics | Default mode network |
| Key findings | A new resting-state fMRI-based method for selecting the left DLPFC HF-rTMS target produced reproducible targets with more negative functional connectivity to the sgACC than standard MNI-coordinate targets, which the authors argue may improve antidepressant response. A single 3000-pulse HF-rTMS session decreased default mode network connectivity in sgACC and ventral striatum, peaking 27-32 minutes after stimulation; the right sgACC decrease correlated with harm avoidance scores, and the right nucleus accumbens decrease correlated with short-term reductions in self-rated negative emotions. |
Abstract
High frequency repetitive TMS (HF-rTMS) to the left dorsolateral prefrontal cortex (DLPFC) is an approved option for the treatment of depression, but there is also much variability in the resulting antidepressant response. This variability is believed to arise from various factors, an important one of which being the method by which rTMS is targeted to the optimal stimulation site in the left DLPFC. To more accurately target HF-rTMS at left DLPFC, we present a new method for target selection based on individual RS-fMRI data. We show in 23 healthy subjects that the new proposed method of target selection is reproducible and yields left DLPFC targets whose functional connectivity correlates more negatively with subgenual anterior cingulate cortex (sgACC) than targets based on standard MNI coordinates. Since previous work has highlighted higher negative connectivity with the sgACC as an important feature of targets for higher antidepressant effect of HF-rTMS, the targets selected by the new method can be expected to lead to a higher therapeutic response. Additionally, the mechanism of action of an entire single session of HF-rTMS (3000 pulses) in healthy subjects has not been reported. We show significant decreases in functional connectivity of the default mode network in sgACC and ventral striatum (vStr) regions, peaking at 27-32 minutes after stimulation. Also, we report a negative correlation between the magnitude of this decrease in the right sgACC and the harm avoidance domain measure from the Temperament and Character Inventory (TCI). This finding points towards the possibility of using the harm avoidance measure as a predictor of HF-rTMS response. In addition, the decreased functional connectivity of the default mode network in right nucleus accumbens (NAcc) correlates with a short-term decrease in self-rated negative emotions from the Positive and Negative Affect Schedule (PANAS) i.e. the lower the functional connectivity of right NAcc with the default mode network, the lower the reported perception of negative mood by the subjects. This suggests a mechanism by which changes induced by rTMS influence the perception of negative mood in recipients.
Comparable studies
Other experimental studies on default mode network, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Functional connectivity of default mode network components: Correlation, anticorrelation, and causality Healthy subjects | 2008 | Observational study using resting-state fMRI and seed correlation analysis | |
| Patterns of Brain Activity Supporting Autobiographical Memory, Prospection, and Theory of Mind, and Their Relationship to the Default Mode Network Healthy subjects | 2009 | Experimental study using fMRI | |
| Dynamic reconfiguration of the default mode network during narrative comprehension Human subjects | 2016 | Experimental study | |
| Broadband Cortical Desynchronization Underlies the Human Psychedelic State Healthy human participants | 2013 | Experimental study | |
| The brain on art: intense aesthetic experience activates the default mode network Human observers | 2012 | Observational study with fMRI and behavioral analysis |