scholarly journals Mapping causal circuit dynamics in stroke using simultaneous electroencephalography and transcranial magnetic stimulation

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Camarin E. Rolle ◽  
Fiona M. Baumer ◽  
Joshua T. Jordan ◽  
Ketura Berry ◽  
Madelleine Garcia ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Hand Movement ◽  
Tissue Loss ◽  
Dominant Hand ◽  
Motor Tasks ◽  
Stroke Patients ◽  
Motor Network ◽  
Arm Function ◽  
The Impact

Abstract Background Motor impairment after stroke is due not only to direct tissue loss but also to disrupted connectivity within the motor network. Mixed results from studies attempting to enhance motor recovery with Transcranial Magnetic Stimulation (TMS) highlight the need for a better understanding of both connectivity after stroke and the impact of TMS on this connectivity. This study used TMS-EEG to map the causal information flow in the motor network of healthy adult subjects and define how stroke alters these circuits. Methods Fourteen stroke patients and 12 controls received TMS to two sites (bilateral primary motor cortices) during two motor tasks (paretic/dominant hand movement vs. rest) while EEG measured the cortical response to TMS pulses. TMS-EEG based connectivity measurements were derived for each hemisphere and the change in connectivity (ΔC) between the two motor tasks was calculated. We analyzed if ΔC for each hemisphere differed between the stroke and control groups or across TMS sites, and whether ΔC correlated with arm function in stroke patients. Results Right hand movement increased connectivity in the left compared to the right hemisphere in controls, while hand movement did not significantly change connectivity in either hemisphere in stroke. Stroke patients with the largest increase in healthy hemisphere connectivity during paretic hand movement had the best arm function. Conclusions TMS-EEG measurements are sensitive to movement-induced changes in brain connectivity. These measurements may characterize clinically meaningful changes in circuit dynamics after stroke, thus providing specific targets for trials of TMS in post-stroke rehabilitation.

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.

scholarly journals Distinction of High- and Low-Frequency Repetitive Transcranial Magnetic Stimulation on the Functional Reorganization of the Motor Network in Stroke Patients

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhiwei Guo ◽  
Yu Jin ◽  
Xi Bai ◽  
Binghu Jiang ◽  
Lin He ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Functional Connectivity ◽  
Magnetic Stimulation ◽  
Sham Group ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Low Frequency ◽  
Stroke Patients ◽  
Functional Reorganization ◽  
Motor Network ◽  
Motor Improvement

Objective. To investigate the functional reorganization of the motor network after repetitive transcranial magnetic stimulation (rTMS) in stroke patients with motor dysfunction and the distinction between high-frequency rTMS (HF-rTMS) and low-frequency rTMS (LF-rTMS). Methods. Thirty-three subcortical stroke patients were enrolled and assigned to the HF-rTMS group, LF-rTMS group, and sham group. Each patient of rTMS groups received either 10.0 Hz rTMS over the ipsilesional primary motor cortex (M1) or 1.0 Hz rTMS over the contralesional M1 for 10 consecutive days. A resting-state functional magnetic resonance imaging (fMRI) scan and neurological examinations were performed at baseline and after rTMS. The motor network and functional connectivities intramotor network with the core brain regions including the bilateral M1, premotor area (PMA), and supplementary motor area (SMA) were calculated. Comparisons of functional connectivities and Pearson correlation analysis between functional connectivity changes and behavioral improvement were calculated. Results. Significant motor improvement was found after rTMS in all groups which was larger in two rTMS groups than in the sham group. The functional connectivities of the motor network were significantly increased in bilateral M1, SMA, and contralesional PMA after real rTMS. These changes were only detected in the regions of the ipsilesional hemisphere in the HF-rTMS group and in the regions of the contralesional hemisphere in the LF-rTMS group. Significantly changed functional connectivities of the intramotor network were found between the ipsilesional M1 and SMA and contralesional PMA, between contralesional M1 and contralesional SMA, between contralesional SMA and ipsilesional SMA and contralesional PMA in the HF-rTMS group in which the changed connectivity between ipsilesional M1 and contralesional PMA was obviously correlated with the motor improvement. In addition, the functional connectivity of the intramotor network between ipsilesional M1 and contralesional PMA was significantly higher in the HF-rTMS group than in the LF-rTMS group. Conclusion. Both HF-rTMS and LF-rTMS have a positive effect on motor recovery in patients with subcortical stroke and could promote the reorganization of the motor network. HF-rTMS may contribute more to the functional connectivity reorganization of the ipsilesional motor network and realize greater benefit to the motor recovery.

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 Efficacy of repetitive transcranial magnetic stimulation combined with visual scanning treatment on cognitive and behavioral symptoms of left hemispatial neglect in right hemispheric stroke patients: study protocol for a randomized controlled trial

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Francesco Di Gregorio ◽  
Fabio La Porta ◽  
Emanuela Casanova ◽  
Elisabetta Magni ◽  
Roberta Bonora ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Controlled Trial ◽  
Hemispatial Neglect ◽  
Visual Scanning ◽  
Stroke Patients ◽  
Rehabilitation Protocol ◽  
Randomized Controlled

Abstract Background Left hemispatial neglect (LHN) is a neuropsychological syndrome often associated with right hemispheric stroke. Patients with LHN have difficulties in attending, responding, and consciously representing the right side of space. Various rehabilitation protocols have been proposed to reduce clinical symptoms related to LHN, using cognitive treatments, or on non-invasive brain stimulation. However, evidence of their benefit is still lacking; in particular, only a few studies focused on the efficacy of combining different approaches in the same patient. Methods In the present study, we present the SMART ATLAS trial (Stimolazione MAgnetica Ripetitiva Transcranica nell’ATtenzione LAteralizzata dopo Stroke), a multicenter, randomized, controlled trial with pre-test (baseline), post-test, and 12 weeks follow-up assessments based on a novel rehabilitation protocol based on the combination of brain stimulation and standard cognitive treatment. In particular, we will compare the efficacy of inhibitory repetitive-transcranial magnetic stimulation (r-TMS), applied over the left intact parietal cortex of LHN patients, followed by visual scanning treatment, in comparison with a placebo stimulation (SHAM control) followed by the same visual scanning treatment, on visuospatial symptoms and neurophysiological parameters of LHN in a population of stroke patients. Discussion Our trial results may provide scientific evidence of a new, relatively low-cost rehabilitation protocol for the treatment of LHN. Trial registration ClinicalTrials.gov NCT04080999. Registered on September 2019.

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