Targeting Symptom-Specific Networks With Transcranial Magnetic Stimulation

Siddiqi, Shan H.; Fox, Michael D.

doi:10.1016/j.biopsych.2023.11.011

Cited by 10 publications

(4 citation statements)

References 87 publications

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“…Previous investigations have revealed that the FC between these targets is characterized by a relatively large number of NCs, suggesting that stimulation of these regions may influence a shared, disease-specific neural network. For example, multiple studies have shown that the NC between the dlPFC and SGC can predict the outcomes of rTMS, with a more negative relationship between these regions leading to a better outcome in patients following rTMS treatment [10,11,33]. Alternatively, brain stimulation has also been shown to induce NCs between brain regions.…”

Section: Implications For the Use Of Negative Correlations In Clinica...mentioning

confidence: 99%

The role of inhibition in resting-state fMRI negative correlations

Harita,

Momi,

Wang

et al. 2024

Preprint

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Resting-state brain activity, as observed via functional magnetic resonance imaging (fMRI), displays non-random fluctuations whose covariance structure (aka functional connectivity; FC) is commonly parsed into spatial patterns of positive and negative correlations (PCs and NCs). Mapping NC patterns for certain key seed regions has shown considerable promise in recent years as a tool for enhancing neuro-navigated targeting and clinical outcomes of repetitive transcranial magnetic stimulation (rTMS) therapies in psychiatry. These successes bring to the fore several major outstanding questions around the neurophysiological origins of fMRI NCs, the answers to which should prove useful for future therapeutic protocol development. In this work, we studied candidate mechanisms for the emergence of fMRI NCs using connectome-based computational modeling. Simulations of fMRI data under manipulation of inhibitory parameters WI and λ, representing local and network-mediated inhibition respectively, were explored, focusing on the impact of inhibition levels on the emergence of NCs. Despite the considerable difference in time scales between GABAergic neuronal inhibition (tens of ms) and fMRI FC (dozens of seconds), a clear relationship was observed, whereby the greater levels of overall inhibition led to significantly greater magnitude and spatial extent of NCs. We show that this effect is due to a leftward shift in the FC correlation distribution, leading to a reduction in the number of PCs and a concomitant increase in the number of NCs. Relatedly, we observed that those connections available for recruitment as NCs were precisely those with the weakest corresponding structural connectivity. Relative to nominally default values for the models used, greater levels of inhibition also improved, quantitatively and qualitatively, single-subject fits of simulated to empirical FC matrices. Our results provide new insights into how individual variability in anatomical connectivity strengths and neuronal inhibition levels may determine individualized expression of NCs in fMRI data. These, in turn, may offer new directions for optimization and personalization of rTMS therapies and other clinical applications of fMRI NC patterns.

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Section: Implications For the Use Of Negative Correlations In Clinica...mentioning

confidence: 99%

The role of inhibition in resting-state fMRI negative correlations

Harita,

Momi,

Wang

et al. 2024

Preprint

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“…A potential approach to overcome these limitations could be to rely on information from causally derived targets beyond the causal evidence provided by earlier TMS studies [5,6]. For instance, studies have demonstrated that selecting targets from brain lesions or deep brain stimulation studies could potentially serve as effective TMS targets (see [33] for a review). While most causal targets have been derived from psychiatric symptoms such as depression or anxiety, examining behavioral deficits associated with focal brain injuries or deep brain stimulation can help selecting a TMS target for this specific executive function.…”

Section: Plos Onementioning

confidence: 99%

Lessons learned from an fMRI-guided rTMS study on performance in a numerical Stroop task

Beynel,

Gura,

Rezaee

et al. 2024

PLoS ONE

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The Stroop task is a well-established tool to investigate the influence of competing visual categories on decision making. Neuroimaging as well as rTMS studies have demonstrated the involvement of parietal structures, particularly the intraparietal sulcus (IPS), in this task. Given its reliability, the numerical Stroop task was used to compare the effects of different TMS targeting approaches by Sack and colleagues (Sack AT 2009), who elegantly demonstrated the superiority of individualized fMRI targeting. We performed the present study to test whether fMRI-guided rTMS effects on numerical Stroop task performance could still be observed while using more advanced techniques that have emerged in the last decade (e.g., electrical sham, robotic coil holder system, etc.). To do so we used a traditional reaction time analysis and we performed, post-hoc, a more advanced comprehensive drift diffusion modeling approach. Fifteen participants performed the numerical Stroop task while active or sham 10 Hz rTMS was applied over the region of the right intraparietal sulcus (IPS) showing the strongest functional activation in the Incongruent > Congruent contrast. This target was determined based on individualized fMRI data collected during a separate session. Contrary to our assumption, the classical reaction time analysis did not show any superiority of active rTMS over sham, probably due to confounds such as potential cumulative rTMS effects, and the effect of practice. However, the modeling approach revealed a robust effect of rTMS on the drift rate variable, suggesting differential processing of congruent and incongruent properties in perceptual decision-making, and more generally, illustrating that more advanced computational analysis of performance can elucidate the effects of rTMS on the brain where simpler methods may not.

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“…Currently, TMS has the potential to be applied to the diagnosis and treatment of types of neuronal diseases, such as depression [81][82][83], stroke [84,85], multiple sclerosis [86][87][88], and limb paralysis [89,90], without the disadvantages of electrical stimulation therapies. Eddy currents not only have been used in the development of new therapies, but also complement currently available ones.…”

Section: Medical Applicationsmentioning

confidence: 99%

“…Sekino et al [78] observed that the current distributions in the brain using TMS depend on the characteristics of the coil used. The results showed that the neurons present in the cerebellum could be activated by inducing a magnetic field of 0.56 T. Currently, TMS has the potential to be applied to the diagnosis and treatment of types of neuronal diseases, such as depression [81][82][83], stroke [84,85], multiple sclerosis [86][87][88], and limb paralysis [89,90], without the disadvantages of electrical stimulation therapies. Eddy currents not only have been used in the development of new therapies, but also complement currently available ones.…”

Section: Medical Applicationsmentioning

confidence: 99%

Past, Present, and Future of New Applications in Utilization of Eddy Currents

Romero-Arismendi,

Olivares-Galvan,

Hernandez-Avila

et al. 2024

Technologies

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Eddy currents are an electromagnetic phenomenon that represent an inexhaustible source of inspiration for technological innovations in the 21st century. Throughout history, these currents have been a subject of research and technological development in multiple fields. This article delves into the fascinating world of eddy currents, revealing their physical foundations and highlighting their impact on a wide range of applications, ranging from non-destructive evaluation of materials to levitation phenomena, as well as their influence on fields as diverse as medicine, the automotive industry, and aerospace. The nature of eddy currents has stimulated the imaginations of scientists and engineers, driving the creation of revolutionary technologies that are transforming our society. As we progress through this article, we will cover the main aspects of eddy currents, their practical applications, and challenges for future works.

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Targeting Symptom-Specific Networks With Transcranial Magnetic Stimulation

Cited by 10 publications

References 87 publications

The role of inhibition in resting-state fMRI negative correlations

The role of inhibition in resting-state fMRI negative correlations

Lessons learned from an fMRI-guided rTMS study on performance in a numerical Stroop task

Past, Present, and Future of New Applications in Utilization of Eddy Currents

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