scholarly journals Cortical-subcortical structural connections support transcranial magnetic stimulation engagement of the amygdala

2021 ◽  
Author(s):  
Valerie J Sydnor ◽  
Matthew Cieslak ◽  
Romain Duprat ◽  
Joseph Deluisi ◽  
Matthew W Flounders ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Affect Regulation ◽  
Magnetic Stimulation ◽  
Affective States ◽  
Fiber Density ◽  
Affective Symptoms ◽  
Amygdala Activity ◽  
Structural Connections ◽  
The Impact ◽  
Dose Dependent

The amygdala processes valenced stimuli, influences affective states, and exhibits aberrant activity across anxiety disorders, depression, and PTSD. Interventions that modulate amygdala activity hold promise for treating transdiagnostic affective symptoms. We investigated (N=45) whether transcranial magnetic stimulation (TMS) elicits indirect changes in amygdala activity when applied to ventrolateral prefrontal cortex (vlPFC), a region important for affect regulation. Harnessing in-scanner interleaved TMS/functional MRI (fMRI), we reveal that vlPFC neurostimulation evoked acute, dose-dependent modulations of amygdala fMRI BOLD signal. Larger TMS-evoked changes in amygdala fMRI signal were associated with higher fiber density in a vlPFC-amygdala white matter pathway, suggesting this pathway facilitated stimulation-induced communication between cortex and subcortex. This work provides evidence of amygdala engagement by TMS, highlighting stimulation of vlPFC-amygdala circuits as a candidate treatment for affective psychopathology. More broadly, it indicates that targeting cortical-subcortical connections may enhance the impact of TMS on subcortical neural activity and, by extension, subcortex-subserved behaviors.

scholarly journals Transcranial Magnetic Stimulation as a Tool to Investigate Motor Cortex Excitability in Sport

2021 ◽  
Vol 11 (4) ◽  
pp. 432
Author(s):  
Fiorenzo Moscatelli ◽  
Antonietta Messina ◽  
Anna Valenzano ◽  
Vincenzo Monda ◽  
Monica Salerno ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Motor Coordination ◽  
Cortical Excitability ◽  
Non Invasive ◽  
Motor Cortex Excitability ◽  
Invasive Method ◽  
And Control ◽  
The Impact

Transcranial magnetic stimulation, since its introduction in 1985, has brought important innovations to the study of cortical excitability as it is a non-invasive method and, therefore, can be used both in healthy and sick subjects. Since the introduction of this cortical stimulation technique, it has been possible to deepen the neurophysiological aspects of motor activation and control. In this narrative review, we want to provide a brief overview regarding TMS as a tool to investigate changes in cortex excitability in athletes and highlight how this tool can be used to investigate the acute and chronic responses of the motor cortex in sport science. The parameters that could be used for the evaluation of cortical excitability and the relative relationship with motor coordination and muscle fatigue, will be also analyzed. Repetitive physical training is generally considered as a principal strategy for acquiring a motor skill, and this process can elicit cortical motor representational changes referred to as use-dependent plasticity. In training settings, physical practice combined with the observation of target movements can enhance cortical excitability and facilitate the process of learning. The data to date suggest that TMS is a valid technique to investigate the changes in motor cortex excitability in trained and untrained subjects. Recently, interest in the possible ergogenic effect of non-invasive brain stimulation in sport is growing and therefore in the future it could be useful to conduct new experiments to evaluate the impact on learning and motor performance of these techniques.

scholarly journals Antiepileptic Efficacy and Network Connectivity Modulation of Repetitive Transcranial Magnetic Stimulation by Vertex Suppression

2021 ◽  
Vol 15 ◽  
Author(s):  
Cong Fu ◽  
Aikedan Aisikaer ◽  
Zhijuan Chen ◽  
Qing Yu ◽  
Jianzhong Yin ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Seizure Frequency ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Reduction Rate ◽  
Network Connectivity ◽  
Hamilton Depression Scale ◽  
Depression And Anxiety ◽  
Epileptiform Discharges ◽  
The Impact

A core feature of drug-resistant epilepsy is hyperexcitability in the motor cortex, and low-frequency repetitive transcranial magnetic stimulation (rTMS) is a suitable treatment for seizures. However, the antiepileptic effect causing network reorganization has rarely been studied. Here, we assessed the impact of rTMS on functional network connectivity (FNC) in resting functional networks (RSNs) and their relation to treatment response. Fourteen patients with medically intractable epilepsy received inhibitive rTMS with a figure-of-eight coil over the vertex for 10 days spread across two weeks. We designed a 6-week follow-up phase divided into four time points to investigate FNC and rTMS-induced timing-dependent plasticity, such as seizure frequency and abnormal interictal discharges on electroencephalography (EEG). For psychiatric comorbidities, the Hamilton Depression Scale (HAM-D) and the Hamilton Anxiety Scale (HAM-A) were applied to measure depression and anxiety before and after rTMS. FNC was also compared to that of a cohort of 17 healthy control subjects. The after-effects of rTMS included all subjects that achieved the significant decrease rate of more than 50% in interictal epileptiform discharges and seizure frequency, 12 (14) patients with the reduction rate above 50% compared to the baseline, as well as emotional improvements in depression and anxiety (p < 0.05). In the analysis of RSNs, we found a higher synchronization between the sensorimotor network (SMN) and posterior default-mode network (pDMN) in epileptic patients than in healthy controls. In contrast to pre-rTMS, the results demonstrated a weaker FNC between the anterior DMN (aDMN) and SMN after rTMS, while the FNC between the aDMN and dorsal attention network (DAN) was greater (p < 0.05, FDR corrected). Importantly, the depressive score was anticorrelated with the FNC of the aDMN-SMN (r = −0.67, p = 0.0022), which was markedly different in the good and bad response groups treated with rTMS (p = 0.0115). Based on the vertex suppression by rTMS, it is possible to achieve temporary clinical efficacy by modulating network reorganization in the DMN and SMN for patients with refractory epilepsy.

scholarly journals The impact of transcranial magnetic stimulation on diagnostic confidence in patients with Alzheimer disease

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Alberto Benussi ◽  
Antonella Alberici ◽  
Clarissa Ferrari ◽  
Valentina Cantoni ◽  
Valentina Dell’Era ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Alzheimer Disease ◽  
Magnetic Stimulation ◽  
Diagnostic Confidence ◽  
The Impact

Role of d-serine in the beneficial effects of repetitive transcranial magnetic stimulation in post-stroke patients

2020 ◽  
Vol 32 (3) ◽  
pp. 128-134 ◽  
Author(s):  
Masachika Niimi ◽  
Yuko Fujita ◽  
Tamaki Ishima ◽  
Kenji Hashimoto ◽  
Nobuyuki Sasaki ◽  
...  
Keyword(s):  
Amino Acids ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Stroke Patients ◽  
Post Stroke ◽  
Beneficial Effects ◽  
Depressed Patients ◽  
Before And After ◽  
The Impact

AbstractObjective:Abnormalities in neurotransmission via N-methyl-d-aspartic acid receptor (NMDAR) play a role in the pathophysiology of neuropsychiatric disorders. The impact of repetitive transcranial magnetic stimulation (rTMS) on NMDAR-related amino acids remains unknown. We aim to investigate the effects of rTMS on NMDAR-related amino acids in serum of post-stroke patients.Methods:Ninety-five consecutive post-stroke patients with upper limb hemiparesis were recruited. In 27 patients, the Beck Depression Inventory (BDI) score was 10 or higher. Twelve depressed patients underwent rehabilitation in combination with rTMS and 15 non-depressed patients underwent rehabilitation only without rTMS for 14 days. 1 Hz rTMS was applied to the primary motor area in the non-lesional hemisphere. BDI was conducted before and after treatment. Serum glutamine, glutamate, glycine, l-serine, and d-serine levels were measured before and after treatment.Results:There were no differences between depressed patients and non-depressed patients in clinical characteristics, levels of the five amino acids in serum, and the ratio of amino acids. However, in 27 depressed patients, there was a significant correlation between levels of glutamate in serum and BDI (ρ = 0.428, p = 0.026). BDI decreased significantly in depressed patients after treatment with or without rTMS. d-serine decreased in the rehabilitation with rTMS group, but increased in the rehabilitation without rTMS group. l-serine increased in the rehabilitation with rTMS group, but decreased in the rehabilitation without rTMS group.Conclusion:The results suggest that rTMS can modulate NMDAR-related amino acids in blood, producing beneficial effects.

Impact of Low-Frequency Transcranial Magnetic Stimulation on Brain Automatic Information Processing

2006 ◽  
Vol 20 (4) ◽  
pp. 267-275 ◽  
Author(s):  
O. Laloyaux ◽  
M. Ansseau ◽  
M. Hansenne
Keyword(s):  
Information Processing ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Low Frequency ◽  
Automatic Information Processing ◽  
Automatic Information ◽  
Before And After ◽  
Left And Right ◽  
The Impact

Repetitive transcranial magnetic stimulation (rTMS) is considered a powerful method for the study of the relationships between cortical activity and cognitive processes. Previous ERPs studies that focused on P300 response have shown that inhibitory/excitatory effects on prefrontal cortex (PFC), induced by low- and high-frequency rTMS, were able to modulate controlled but not automatic information processing. The present study assessed the impact of inhibition over left and right PFC induced by rTMS on mismatch negativity (MMN), which is known to represent automatic cerebral processes for detecting change. Auditory MMN was recorded in 20 subjects before and after application of left and right PFC 1-Hz rTMS for 15 min. MMN was also recorded before and after a sham-occipital 1-Hz rTMS as control condition. Results showed that 1-Hz rTMS induced no modification to either MMN latency or amplitude. In addition, N100 and P200 components to the frequent tones were not affected by rTMS. These results are consistent with previous findings showing that rTMS over both PFC is unable to disrupt automatic information processing. However, since two sites were stimulated in the present study, no definite conclusions about the inability of rTMS to disrupt automatic processing can be made.

The impact of ‘cluster maintenance TMS’ on irritability occurring in major depressive disorder

2020 ◽  
pp. 103985622094303 ◽  
Author(s):  
Saxby Pridmore ◽  
Yvonne Turnier-Shea ◽  
Sheila Erger ◽  
Tamara May
Keyword(s):  
Major Depressive Disorder ◽  
Transcranial Magnetic Stimulation ◽  
Depressive Disorder ◽  
Magnetic Stimulation ◽  
Subjective Measure ◽  
Naturalistic Study ◽  
Treatment Resistant ◽  
Major Depressive ◽  
The Impact ◽  
Cluster Maintenance

Objective: To determine the impact of clustered maintenance transcranial magnetic stimulation (TMS) on irritability occurring in treatment-resistant major depressive disorder (MDD). Method: A naturalistic study of 106 courses that includes pre- and posttreatment assessments of subjective and objective depression and a subjective measure of irritability developed for this study. Results: Forty-six participants (35 females), mean age 43.2 years (14.3), completed 106 courses. There was a significant reduction in irritability and depression scores ( p < .001). The change in irritability scores was significantly correlated with the change in depression scores, r = .40, p < .001. Conclusion: TMS has the capacity to reduce the irritability co-occurring with treatment-resistant MDD, known to be responsive to TMS. This increases the possibility of using TMS in the treatment of irritability co-occurring with other disorders or standing alone (should irritability be categorized as a stand-alone disorder).

scholarly journals Motor threshold in transcranial magnetic stimulation: The impact of white matter fiber orientation and skull-to-cortex distance

2009 ◽  
Vol 30 (7) ◽  
pp. 2044-2055 ◽  
Author(s):  
Tal Herbsman ◽  
Lauren Forster ◽  
Christine Molnar ◽  
Robert Dougherty ◽  
Doug Christie ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
White Matter ◽  
Fiber Orientation ◽  
Magnetic Stimulation ◽  
Motor Threshold ◽  
The Impact
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