How different priming stimulations affect the corticospinal excitability induced by noninvasive brain stimulation techniques: a systematic review and meta-analysis

2018 ◽  
Vol 29 (8) ◽  
pp. 883-899 ◽  
Author(s):  
Maryam Hassanzahraee ◽  
Maryam Zoghi ◽  
Shapour Jaberzadeh

Abstract Noninvasive brain stimulation (NIBS) techniques could induce changes in corticospinal excitability (CSE) and neuroplasticity. These changes could be affected by different factors, including having a session of stimulation called the ‘priming’ protocol before the main stimulation session called the ‘test’ protocol. Literature indicates that a priming protocol could affect the activity of postsynaptic neurons, form a neuronal history, and then modify the expected effects of the test protocol on CSE indicated by the amplitude of transcranial magnetic stimulation-induced motor-evoked potentials. This prior history affects a threshold to activate the necessary mechanism stabilizing the neuronal activity within a useful dynamic range. For studying the effects of this history and related metaplasticity mechanisms in the human primary motor cortex (M1), priming-test protocols are successfully employed. Thirty-two studies were included in this review to investigate how different priming protocols could affect the induced effects of a test protocol on CSE in healthy individuals. The results showed that if the history of synaptic activity were high or low enough to displace the threshold, the expected effects of the test protocol would be the reverse. This effect reversal is regulated by homeostatic mechanisms. On the contrary, the effects of the test protocol would not be the reverse, and at most we experience a prolongation of the lasting effects if the aforementioned history is not enough to displace the threshold. This effect prolongation is mediated by nonhomeostatic mechanisms. Therefore, based on the characteristics of priming-test protocols and the interval between them, the expected results of priming-test protocols would be different. Moreover, these findings could shed light on the different mechanisms of metaplasticity involved in NIBS. It helps us understand how we can improve the expected outcomes of these techniques in clinical approaches.

2018 ◽  
Vol 29 (2) ◽  
pp. 199-222 ◽  
Author(s):  
Michael Pellegrini ◽  
Maryam Zoghi ◽  
Shapour Jaberzadeh

AbstractNoninvasive brain stimulation (NIBS) modifies corticospinal excitability (CSE) historically in a predictable manner dependent on stimulation parameters. Researchers, however, discuss high degrees of variability between individuals, either responding as expected or not responding as expected. The explanation for this interindividual variability remains unknown with suggested interplay between stimulation parameters and variations in biological, anatomical, and physiological factors. This systematic review and meta-analysis aimed to investigate the effect of variation in inherent factors within an individual (biological and anatomical factors) on CSE in response to NIBS of the primary motor cortex. Twenty-two studies were included investigating genetic variation (n=7), age variation (n=4), gender variation (n=7), and anatomical variation (n=5). The results indicate that variation in brain-derived neurotrophic factor genotypes may have an effect on CSE after NIBS. Variation between younger and older adults also affects CSE after NIBS. Variation between age-matched males and females does not affect CSE after NIBS, but variation across the menstrual cycle does. Variation between skull thickness and brain tissue morphology influences the electric field magnitude that ultimately reaches the primary motor cortex. These findings indicate that biological and anatomical variations may in part account for interindividual variability in CSE in response to NIBS of the primary motor cortex, categorizing individuals as responding as expected (responders) or not responding as expected (nonresponders).


2020 ◽  
Vol 20 (4) ◽  
pp. 401-412
Author(s):  
Alejandra Cardenas-Rojas ◽  
Kevin Pacheco-Barrios ◽  
Stefano Giannoni-Luza ◽  
Oscar Rivera-Torrejon ◽  
Felipe Fregni

2020 ◽  
Vol 31 (8) ◽  
pp. 905-914 ◽  
Author(s):  
Yali Feng ◽  
Jiaqi Zhang ◽  
Yi Zhou ◽  
Zhongfei Bai ◽  
Ying Yin

AbstractNoninvasive brain stimulation (NIBS) techniques have been used to facilitate the recovery from prolonged unconsciousness as a result of brain injury. The aim of this study is to systematically assess the effects of NIBS in patients with a disorder of consciousness (DOC). We searched four databases for any randomized controlled trials on the effect of NIBS in patients with a DOC, which used the JFK Coma Recovery Scale-Revised (CRS-R) as the primary outcome measure. A random-effects meta-analysis was conducted to pool effect sizes. Fourteen studies with 273 participants were included in this review, of which 12 studies with sufficient data were included in the meta-analysis. Our meta-analysis showed a significant effect on increasing CRS-R scores in favor of real stimulation as compared to sham (Hedges’ g = 0.522; 95% confidence interval [CI], 0.318–0.726; P < 0.0001, I2 = 0.00%). Subgroup analysis demonstrated that only anodal transcranial direct current stimulation (tDCS) of the left dorsolateral prefrontal cortex (DLPFC) significantly enhances the CRS-R scores in patients with a DOC, as compared to sham (Hedges’ g = 0.703; 95% CI, 0.419–0.986; P < 0.001), and this effect was predominant in patients in a minimally conscious state (MCS) (Hedges’ g = 0.815; 95% CI, 0.429–1.200; P < 0.001). Anodal tDCS of the left DLPFC appears to be an effective approach for patients with MCS.


2018 ◽  
Vol 34 (9) ◽  
pp. 1336-1345 ◽  
Author(s):  
Sara M. Vacas ◽  
Florindo Stella ◽  
Julia C. Loureiro ◽  
Frederico Simões do Couto ◽  
Albino J. Oliveira-Maia ◽  
...  

2019 ◽  
Vol 98 (4) ◽  
pp. 279-289
Author(s):  
Paulo J. C. Suen ◽  
Andre R. Brunoni

Noninvasive brain stimulation therapies are a promising field for the development of new protocols for the treatment of neuropsychiatric disorders. They are based on the stimulation of neural networks with the intent of modeling their synaptic activity to adequate levels. For this, it is necessary to precisely determine which networks are related to which brain functions, and the normal activation level of each of these networks, so that it is possible to direct the stimulation to the affected networks in order to induce the desired effects. These relationships are under intense investigation by the scientific community, and will contribute to the advancement of treatments by neurostimulation, with the emergence of increasingly accurate and effective protocols for different disorders. Currently, the most used techniques are Transcranial Direct Current Stimulation and Transcranial Magnetic Stimulation, with the most common applications being for treating Major Depressive Disorder. The advancement of research in this field may determine new target networks for stimulation in the treatment of other disorders, extending the application of these techniques and also our knowledge about brain functioning.


2018 ◽  
Vol 99 (2) ◽  
pp. 355-366.e1 ◽  
Author(s):  
Ana Paula S. Salazar ◽  
Patrícia G. Vaz ◽  
Ritchele R. Marchese ◽  
Cinara Stein ◽  
Camila Pinto ◽  
...  

2013 ◽  
Vol 109 (1) ◽  
pp. 124-136 ◽  
Author(s):  
Jean-Jacques Orban de Xivry ◽  
Mohammad Ali Ahmadi-Pajouh ◽  
Michelle D. Harran ◽  
Yousef Salimpour ◽  
Reza Shadmehr

Both abrupt and gradually imposed perturbations produce adaptive changes in motor output, but the neural basis of adaptation may be distinct. Here, we measured the state of the primary motor cortex (M1) and the corticospinal network during adaptation by measuring motor-evoked potentials (MEPs) before reach onset using transcranial magnetic stimulation of M1. Subjects reached in a force field in a schedule in which the field was introduced either abruptly or gradually over many trials. In both groups, by end of the training, muscles that countered the perturbation in a given direction increased their activity during the reach (labeled as the on direction for each muscle). In the abrupt group, in the period before the reach toward the on direction, MEPs in these muscles also increased, suggesting a direction-specific increase in the excitability of the corticospinal network. However, in the gradual group, these MEP changes were missing. After training, there was a period of washout. The MEPs did not return to baseline. Rather, in the abrupt group, off direction MEPs increased to match on direction MEPs. Therefore, we observed changes in corticospinal excitability in the abrupt but not gradual condition. Abrupt training includes the repetition of motor commands, and repetition may be the key factor that produces this plasticity. Furthermore, washout did not return MEPs to baseline, suggesting that washout engaged a new network that masked but did not erase the effects of previous adaptation. Abrupt but not gradual training appears to induce changes in M1 and/or corticospinal networks.


2020 ◽  
Vol 54 (6) ◽  
pp. 582-590 ◽  
Author(s):  
Binlong Zhang ◽  
Jiao Liu ◽  
Tuya Bao ◽  
Georgia Wilson ◽  
Joel Park ◽  
...  

Objective: Many noninvasive brain stimulation techniques have been applied to treat depressive disorders. However, the target brain region in most noninvasive brain stimulation studies is the dorsolateral prefrontal cortex. Exploring new stimulation locations may improve the efficacy of noninvasive brain stimulation for depressive disorders. We aimed to explore potential noninvasive brain stimulation locations for depressive disorders through a meta-analysis and a functional connectivity approach. Methods: We conducted a meta-analysis of 395 functional magnetic resonance imaging studies to identify depressive disorder–associated brain regions as regions of interest. Then, we ran resting-state functional connectivity analysis with three different pipelines in 40 depression patients to find brain surface regions correlated with these regions of interest. The 10–20 system coordinates corresponding to these brain surface regions were considered as potential locations for noninvasive brain stimulation. Results: The 10–20 system coordinates corresponding to the bilateral dorsolateral prefrontal cortex, bilateral inferior frontal gyrus, medial prefrontal cortex, supplementary motor area, bilateral supramarginal gyrus, bilateral primary motor cortex, bilateral operculum, left angular gyrus and right middle temporal gyrus were identified as potential locations for noninvasive brain stimulation in depressive disorders. The coordinates were: posterior to F3, posterior to F4, superior to F3, posterior to F7, anterior to C4, P3, midpoint of F7–T3, posterior to F8, anterior to C3, midpoint of Fz–Cz, midpoint of Fz–Fp1, anterior to T4, midpoint of C3–P3, and anterior to C4. Conclusion: Our study identified several potential noninvasive brain stimulation locations for depressive disorders, which may serve as a basis for future clinical investigations.


Author(s):  
Joseph Classen ◽  
Ying-Zu Huang ◽  
Christoph Zrenner

Commonly used repetitive transcranial magnetic stimulation (rTMS) protocols, including regular rTMS, intermittent and continuous theta-burst stimulation (TBS) and quadripulse stimulation (QPS) are presented with respect to their induced neuromodulatory after-effects and the underlying cellular and synaptic neurophysiological mechanisms. The anatomical target is typically primary motor cortex since motor evoked potentials (MEPs) before and after the intervention can be used to assess effects of the respective rTMS protocol. High-frequency regular rTMS and intermittent TBS protocols tend to increase corticospinal excitability as indexed by MEP amplitude, whereas low-frequency regular rTMS and continuous TBS protocols tend to reduce corticospinal excitability. These effects are primarily due to LTP-like and LTD-like synaptic changes mediated by GABA and NMDA receptors. Changes in the balance between excitatory and inhibitory cortical microcircuits play a secondary role, with inconsistent effects as determined by paired-pulse TMS protocols. Finally, the challenge of large inter-subject response variability, and current directions of research to optimize rTMS effects through EEG-dependent personalized TMS are discussed.


Sign in / Sign up

Export Citation Format

Share Document