Theta-burst transcranial magnetic stimulation induced cognitive task-related decrease in activity of default mode network: An exploratory study

Background: Default mode network (DMN) dysfunction is well established in Alzheimer’s disease (AD) and documented in both preclinical stages and at-risk subjects, thus representing a potential disease target. Multi-sessions of repetitive transcranial magnetic stimulation (rTMS) seem capable of modulating DMN dynamics and memory in healthy individuals and AD patients; however, the potential of this approach in at-risk subjects has yet to be tested. Objective: This study will test the effect of rTMS on the DMN in healthy older individuals carrying the strongest genetic risk factor for AD, the Apolipoprotein E (APOE) ɛ4 allele. Methods: We will recruit 64 older participants without cognitive deficits, 32 APOE ɛ4 allele carriers and 32 non-carriers as a reference group. Participants will undergo four rTMS sessions of active (high frequency) or sham DMN stimulation. Multimodal imaging exam (including structural, resting-state, and task functional MRI, and diffusion tensor imaging), TMS with concurrent electroencephalography (TMS-EEG), and cognitive assessment will be performed at baseline and after the stimulation sessions. Results: We will assess changes in DMN connectivity with resting-state functional MRI and TMS-EEG, as well as changes in memory performance in APOE ɛ4 carriers. We will also investigate the mechanisms underlying DMN modulation through the assessment of correlations with measures of neuronal activity, excitability, and structural connectivity with multimodal imaging. Conclusion: The results of this study will inform on the physiological and cognitive outcomes of DMN stimulation in subjects at risk for AD and on the possible mechanisms. These results may outline the design of future non-pharmacological preventive interventions for AD.

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Personalized repetitive transcranial magnetic stimulation temporarily alters default mode network in healthy subjects

Scientific Reports ◽

10.1038/s41598-019-42067-3 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 8

Author(s):

Aditya Singh ◽

Tracy Erwin-Grabner ◽

Grant Sutcliffe ◽

Andrea Antal ◽

Walter Paulus ◽

...

Keyword(s):

Transcranial Magnetic Stimulation ◽

Default Mode Network ◽

Healthy Subjects ◽

Magnetic Stimulation ◽

Repetitive Transcranial Magnetic Stimulation ◽

Default Mode

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Ruminative reflection is associated with anticorrelations between the orbitofrontal cortex and the default mode network in depression: implications for repetitive transcranial magnetic stimulation

Brain Imaging and Behavior ◽

10.1007/s11682-021-00596-4 ◽

2021 ◽

Author(s):

Tobin J. Ehrlich ◽

Jyoti Bhat ◽

Andrea M. Horwege ◽

Daniel H. Mathalon ◽

Gary H. Glover ◽

...

Keyword(s):

Prefrontal Cortex ◽

Transcranial Magnetic Stimulation ◽

Functional Connectivity ◽

Default Mode Network ◽

Orbitofrontal Cortex ◽

Magnetic Stimulation ◽

Repetitive Transcranial Magnetic Stimulation ◽

Mechanistic Model ◽

Response Scale ◽

Default Mode

AbstractPatients with depression who ruminate repeatedly focus on depressive thoughts; however, there are two cognitive subtypes of rumination, reflection and brooding, each associated with different prognoses. Reflection involves problem-solving and is associated with positive outcomes, whereas brooding involves passive, negative, comparison with other people and is associated with poor outcomes. Rumination has also been related to atypical functional hyperconnectivity between the default mode network and subgenual prefrontal cortex. Repetitive pulse transcranial magnetic stimulation of the prefrontal cortex has been shown to alter functional connectivity, suggesting that the abnormal connectivity associated with rumination could potentially be altered. This study examined potential repetitive pulse transcranial magnetic stimulation prefrontal cortical targets that could modulate one or both of these rumination subtypes. Forty-three patients who took part in a trial of repetitive pulse transcranial magnetic stimulation completed the Rumination Response Scale questionnaire and resting-state functional magnetic resonance imaging. Seed to voxel functional connectivity analyses identified an anticorrelation between the left lateral orbitofrontal cortex (−44, 26, −8; k = 172) with the default mode network-subgenual region in relation to higher levels of reflection. Parallel analyses were not significant for brooding or the RRS total score. These findings extend previous studies of rumination and identify a potential mechanistic model for symptom-based neuromodulation of rumination.

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Intermittent theta burst stimulation at personalized targets reduces the functional connectivity of the default mode network in healthy subjects

10.1101/646265 ◽

2019 ◽

Cited By ~ 1

Author(s):

Aditya Singh ◽

Tracy Erwin-Grabner ◽

Grant Sutcliffe ◽

Walter Paulus ◽

Peter Dechent ◽

...

Keyword(s):

Transcranial Magnetic Stimulation ◽

Functional Connectivity ◽

Default Mode Network ◽

Healthy Subjects ◽

Magnetic Stimulation ◽

Anterior Cingulate ◽

Single Session ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

Theta Burst

AbstractUnderstanding the mechanisms by which transcranial magnetic stimulation protocols exert changes in the default mode network (DMN) is paramount to develop therapeutically more effective approaches in the future. A full session (3000 pulses) of 10 Hz repetitive transcranial magnetic stimulation (HF-rTMS) reduces the functional connectivity (FC) of the DMN and the subgenual anterior cingulate cortex but current understanding of the effects of a single session of intermittent theta burst stimulation (iTBS) on the DMN in healthy subjects is limited. To reduce the effects of inter-individual variability in functional architectures, we used a novel personalized target selection approach based on each subject’s resting state fMRI for an unprecedented investigation into the effects of a single session (1800 pulses) of iTBS over the DMN in healthy controls. 26 healthy subjects participated in a double-blind, crossover, sham-controlled study. After iTBS to the personalized left dorsolateral prefrontal cortex (DLPFC) targets, we investigated the time lapse of effects in the DMN and its relationship to the harm avoidance (HA) personality trait measure (Temperament and Character Inventory/TCI). Approx. 25-30 minutes after stimulation, we observed reduced FC between the DMN and the rostral anterior cingulate cortex (rACC). About 45 minutes after stimulation the FC of rACC strongly decreased further, as did the FC of right anterior insula (rAI) with the DMN. We also report a positive correlation between the FC decrease in the rACC and the HA domain of TCI. Our results show how iTBS at personalized left-DLPFC targets reduces the FC between DMN and the rACC and rAI, regions typically described as nodes of the salience network. We find that HA scores can potentially predict iTBS response, as has been observed for HF-rTMS.

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