J Vis Exp. 2022 Apr 20;(182). doi: 10.3791/62773.

ABSTRACT

Neuroimaging is typically perceived as a resource demanding discipline. While this is the case in certain circumstances, institutions with limited resources have historically contributed significantly to the field of neuroscience, including neuroimaging. In the study of self-deception, we have successfully employed single-pulse TMS to determine the brain correlates of abilities including overclaiming and self-enhancement. Even without the use of neuro-navigation, methods provided here lead to successful outcomes. For example, it was discovered that decreases in self-deceptive responding lead to a decrease in affect. These methods provide data that are reliable and valid, and such methods provide research opportunities otherwise unavailable. Through the use of these methods, the overall knowledge base in the field of neuroscience is expanded, providing research opportunities to students such as those at our institution (Montclair State University is a Hispanic-Serving Institute) who are often denied such research experiences.

PMID:35532269 | DOI:10.3791/62773

Front Psychiatry. 2022 Apr 21;13:825205. doi: 10.3389/fpsyt.2022.825205. eCollection 2022.

ABSTRACT

Transcranial magnetic stimulation (TMS) is a promising treatment modality for psychiatric and neurological disorders. Repetitive TMS (rTMS) is widely used for the treatment of psychiatric and neurological diseases, such as depression, motor stroke, and neuropathic pain. However, the underlying mechanisms of rTMS-mediated neuronal modulation are not fully understood. In this respect, concurrent or simultaneous TMS-fMRI, in which TMS is applied during functional magnetic resonance imaging (fMRI), is a viable tool to gain insights, as it enables an investigation of the immediate effects of TMS. Concurrent application of TMS during neuroimaging usually causes severe artifacts due to magnetic field inhomogeneities induced by TMS. However, by carefully interleaving the TMS pulses with MR signal acquisition in the way that these are far enough apart, we can avoid any image distortions. While the very first feasibility studies date back to the 1990s, recent developments in coil hardware and acquisition techniques have boosted the number of TMS-fMRI applications. As such, a concurrent application requires expertise in both TMS and MRI mechanisms and sequencing, and the hurdle of initial technical set up and maintenance remains high. This review gives a comprehensive overview of concurrent TMS-fMRI techniques by collecting (1) basic information, (2) technical challenges and developments, (3) an overview of findings reported so far using concurrent TMS-fMRI, and (4) current limitations and our suggestions for improvement. By sharing this review, we hope to attract the interest of researchers from various backgrounds and create an educational knowledge base.

PMID:35530029 | PMC:PMC9069063 | DOI:10.3389/fpsyt.2022.825205

Front Psychiatry. 2022 Apr 21;13:875722. doi: 10.3389/fpsyt.2022.875722. eCollection 2022.

ABSTRACT

In the last decade, the market for new psychoactive substances has been enriched by numerous psychedelic phenethylamines, which mimic the psychoactive effect of lysergic acid diethylamide (LSD). In particular, the -NBOMe series, which are more potent than their 2C compounds analogs, are considered worthy substitutes for LSD by users. The purpose of this study was to assess the effects of 25H-NBOMe and its halogenated derivatives (25I-NBOMe and 25B-NBOMe) in comparison to their 2C compounds analogs and LSD on the sensorimotor (visual, acoustic, and overall tactile), reaction time, spontaneous (total distance traveled) and stimulated (drag, accelerod test) motor activity, grip strength test, and prepulse inhibition (PPI) responses in mice. Systemic administration of -NBOMe, 2C compounds analogs, and LSD (0.001-10 mg/kg) differently impaired the sensorimotor, reaction time, motor, and PPI responses in mice. In particular, halogenated (25I and 25B)-NBOMe derivatives appear to be more effective than the entire class of 2C compounds analogs in altering visual and acoustic responses, affecting reaction time, and motor and sensory gating in PPI test. In fact, the specific rank order of compounds potency for nearly all of the experiments showed that (25I and 25B)-NBOMe were more potent than 2C compounds analogs and LSD. -NBOMe and 2C compounds analogs impaired not only the reception of incoming sensory stimuli (visual and acoustic), but their correct brain processing (PPI) in an equal and sometimes stronger way than LSD. This sensory impairment directly affected the spontaneous motor response and reaction time of mice, with no change in performance in stimulated motor activity tests. These aspects should be carefully considered to better understand the potential danger that psychedelic phenethylamines, in particular -NBOMe, may pose to public health, with particular reference to decreased performance in driving and hazardous works that require special sensorimotor skills.

PMID:35530025 | PMC:PMC9069068 | DOI:10.3389/fpsyt.2022.875722

Neural Plast. 2022 Apr 29;2022:3593262. doi: 10.1155/2022/3593262. eCollection 2022.

ABSTRACT

BACKGROUND: Various forms of theta-burst stimulation (TBS) such as intermittent TBS (iTBS) and continuous TBS (cTBS) have been introduced as novel facilitation/suppression schemes during repetitive transcranial magnetic stimulation (rTMS), demonstrating a better efficacy than conventional paradigms. Herein, we extended the rTMS-TBS schemes to electrical stimulation of high-definition montage (HD-TBS) and investigated its neural effects on the human brain.

METHODS: In a within-subject design, fifteen right-handed healthy adults randomly participated in 10 min and 2 mA HD-TBS sessions: unilateral (Uni)-iTBS, bilateral (Bi)-cTBS/iTBS, and sham stimulation over primary motor cortex regions. A 20-channel near-infrared spectroscopy (NIRS) system was covered on the bilateral prefrontal cortex (PFC), sensory motor cortex (SMC), and parietal lobe (PL) for observing cerebral hemodynamic responses in the resting-state and during fast finger-tapping tasks at pre-, during, and poststimulation. Interhemispheric correlation coefficient (IHCC) and wavelet phase coherence (WPCO) from resting-state NIRS and concentration of oxyhemoglobin during fast finger-tapping tasks were explored to reflect the symmetry between the two hemispheres and cortical activity, respectively.

RESULTS: The IHCC and WPCO of NIRS data in the SMC region under Bi-cTBS/iTBS showed relatively small values at low-frequency bands III (0.06-0.15 Hz) and IV (0.02-0.06), indicating a significant desynchronization in both time and frequency domains. In addition, the SMC activation induced by fast finger-tapping exercise was significantly greater during Uni-iTBS as well as during and post Bi-cTBS/iTBS sessions.

CONCLUSIONS: It appears that a 10 min and 2 mA Bi-cTBS/iTBS applied over two hemispheres within the primary motor cortex region could effectively modulate the interhemispheric synchronization and cortical activation in the SMC of healthy subjects. Our study demonstrated that bilateral HD-TBS approaches is an effective noninvasive brain stimulation scheme which could be a novel therapeutic for inducing effects of neuromodulation on various neurological disorders caused by ischemic stroke or traumatic brain injuries.

PMID:35529454 | PMC:PMC9076342 | DOI:10.1155/2022/3593262

Front Neurosci. 2022 Apr 22;16:854219. doi: 10.3389/fnins.2022.854219. eCollection 2022.

ABSTRACT

BACKGROUND: Rehabilitation of post-stroke dysphagia is an urgent clinical problem, and repetitive transcranial magnetic stimulation (rTMS) has been widely used in the study of post-stroke function. However, there is no reliable evidence-based medicine to support the effect of rTMS on post-stroke dysphagia. This review aims to evaluate the effectiveness and safety of rTMS on post-stroke dysphagia.

METHODS: English-language literature published before December 20, 2021, were searched in six electronic databases. Identified articles were screened, data were extracted, and the methodological quality of included trials was assessed. Meta-analysis was performed using RevMan 5.3 software. The GRADE method was used to assess the quality of the evidence.

RESULTS: A total of 10 studies with 246 patients were included. Meta-analysis showed that rTMS significantly improved overall swallowing function (standardized mean difference [SMD]-0.76, 95% confidence interval (CI)-1.07 to-0.46, p < 0.0001, n = 206; moderate-quality evidence), Penetration Aspiration Scale (PAS) (mean difference [MD]-1.03, 95% CI-1.51 to-0.55, p < 0.0001, n = 161; low-quality evidence) and Barthel index scale (BI) (MD 23.86, 95% CI 12.73 to 34.99, p < 0.0001, n = 136; moderate-quality evidence). Subgroup analyses revealed that (1) rTMS targeting the affected hemisphere and targeting both hemispheres significantly enhanced overall swallowing function and reduced aspiration. (2) Low-frequency rTMS significantly enhanced overall swallowing function and reduced aspiration, and there was no significant difference between high-frequency rTMS and control group in reducing aspiration (p = 0.09). (3) There was no statistical difference in the dropout rate (low-quality evidence) and adverse effects (moderate-quality evidence) between the rTMS group and the control group.

CONCLUSION: rTMS improved overall swallowing function and activity of daily living ability and reduced aspiration in post-stroke patients with good acceptability and mild adverse effects.

PMID:35527818 | PMC:PMC9072781 | DOI:10.3389/fnins.2022.854219

Front Neurosci. 2022 Mar 23;16:832280. doi: 10.3389/fnins.2022.832280. eCollection 2022.

NO ABSTRACT

PMID:35527813 | PMC:PMC9074385 | DOI:10.3389/fnins.2022.832280

Exp Neurol. 2022 May 5:114106. doi: 10.1016/j.expneurol.2022.114106. Online ahead of print.

ABSTRACT

Dopamine modulation is thought to underpin some of the therapeutic effects associated with repetitive transcranial magnetic stimulation (rTMS). However, patient studies have failed to demonstrate consistent changes in the dopamine system in vivo after a therapeutic course of rTMS. Here, we evaluated acute and chronic changes in striatal dopamine release elicited by a clinically relevant course of theta burst (TBS) or sham stimulation using [¹¹C]raclopride in healthy non-human primates (n = 11). Subjects were scanned immediately after the first session of TBS and the day after a 3 week course of daily TBS delivery. After experiment completion, animals were euthanized, and immunofluorescence staining was carried out using antibodies targeting D₂ receptors (D₂R). Continuous TBS (cTBS, an inhibitory form of rTMS) over the left primary motor cortex acutely decreased dopamine release bilaterally in the putamen. However, no significant changes in dopamine receptors nor D₂R immunoreactivity were noted 24 h after the last stimulation, while a decrease in cortical excitability, as measured by an increase in resting motor threshold, could still be quantified. On the opposite, intermittent TBS (iTBS, an excitatory form of rTMS) did not affect dopamine release, acutely or chronically, D₂R immunoreactivity or cortical excitability. These findings suggest that the long-term therapeutic effects of TBS might be facilitated through the modulation of different neurotransmission systems beyond the dopamine system. However, given the small sample size, these results should me interpreted with caution.

PMID:35526596 | DOI:10.1016/j.expneurol.2022.114106

Psychiatry Res. 2022 May 1;313:114592. doi: 10.1016/j.psychres.2022.114592. Online ahead of print.

ABSTRACT

This meta-analysis examined the effects of noninvasive brain stimulation (NIBS) for treating eating disorders (EDs), evaluating the difference between repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). We identified 15 studies on EDs, including 9 RCTs (266 participants) and 6 one-arm trials (59 participants). The pooled effect sizes indicated that NIBS plays a positive role in improving the eating symptoms of ED patients. Although its long-term effects need to be further explored, this treatment has the potential to be an important supplement to conventional ED therapy.

PMID:35526422 | DOI:10.1016/j.psychres.2022.114592

Brain Stimul. 2022 May 4:S1935-861X(22)00078-X. doi: 10.1016/j.brs.2022.04.018. Online ahead of print.

ABSTRACT

BACKGROUND: The human primary sensory (S1) and primary motor (M1) hand areas feature high-frequency neuronal responses. Electrical nerve stimulation evokes high-frequency oscillations (HFO) at around 650 Hz in the contralateral S1. Likewise, transcranial magnetic stimulation (TMS) of M1 can evoke a series of descending volleys in the corticospinal pathway that can be detected non-invasively with a paired-pulse TMS protocol, called short interval intracortical facilitation (SICF). SICF features several peaks of facilitation of motor evoked potentials in contralateral hand muscles, which are separated by inter-peak intervals resembling HFO rhythmicity.

HYPOTHESIS: In this study, we tested the hypothesis that the individual expressions of HFO and SICF are tightly related to each other and to the regional myelin content in the sensorimotor cortex.

METHODS: In 24 healthy volunteers, we recorded HFO and SICF, and, in a subgroup of 20 participants, we mapped the cortical myelin content using the ratio between the T1- and T2-weighted MRI signal as read-out.

RESULTS: The individual frequencies and magnitudes of HFO and SICF curves were tightly correlated: the intervals between the first and second peak of cortical HFO and SICF showed a positive linear relationship (r = 0.703, p < 0.001), while their amplitudes were inversely related (r = -0.613, p = 0.001). The rhythmicity, but not the magnitude of the high-frequency responses, was related to the cortical myelin content: the higher the cortical myelin content, the shorter the inter-peak intervals of HFO and SICF.

CONCLUSION: The results confirm a tight functional relationship between high-frequency responses in S1 (i.e., HFO) and M1 (i.e., as measured with SICF). They also establish a link between the degree of regional cortical myelination and the expression of high-frequency responses in the human sensorimotor cortex, giving further the opportunity to infer their generators.

PMID:35525389 | DOI:10.1016/j.brs.2022.04.018

J Neural Eng. 2022 May 7. doi: 10.1088/1741-2552/ac6dc4. Online ahead of print.

ABSTRACT

OBJECTIVE: Evaluating ipsilateral motor-evoked potentials (iMEP) induced by transcranial magnetic stimulation (TMS) is challenging. In healthy adults, isometric contraction is necessary to facilitate iMEP induction; therefore, the signal may be masked by the concurrent muscle activity. Signal analysis algorithms for iMEP evaluation need to be benchmarked and evaluated.

APPROACH: An open analysis toolbox for iMEP evaluation was implemented on the basis of eleven previously reported algorithms, which were all threshold based, and a new template-based method based on data-driven signal decomposition. The reliability and validity of these algorithms were evaluated with a dataset of 4244 iMEP from 55 healthy adults.

MAIN RESULTS: iMEP estimation varies drastically between algorithms. Several algorithms exhibit high reliability, but some appear to be influenced by background activity of muscle preactivation. Especially in healthy subjects, template-based approaches might be more valid than threshold-based ones. Measurement of iMEP persistence requires algorithms that reject some trials as MEP negative. The stricter the algorithms reject trials, the less reliable they generally are. Our evaluation identifies an optimally strict and reliable algorithm.

SIGNIFICANCE: We show different benchmarks and propose application for different use cases.

PMID:35525187 | DOI:10.1088/1741-2552/ac6dc4

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2022 Apr 25;39(2):267-275. doi: 10.7507/1001-5515.202108036.

ABSTRACT

Transcranial magneto-acoustic-electrical stimulation is a new non-invasive neuromodulation technology, in which the induced electric field generated by the coupling effect of ultrasound and static magnetic field are used to regulate the neural rhythm oscillation activity in the corresponding brain region. The purpose of this paper is to investigate the effects of transcranial magneto-acoustic-electrical stimulation on the information transfer and communication in neuronal clusters during memory. In the experiment, twenty healthy adult Wistar rats were randomly divided into a control group (five rats) and stimulation groups (fifteen rats). Transcranial magneto-acoustic-electrical stimulation of 0.05~0.15 T and 2.66~13.33 W/cm ² was applied to the rats in stimulation groups, and no stimulation was applied to the rats in the control group. The local field potentials signals in the prefrontal cortex of rats during the T-maze working memory tasks were acquired. Then the coupling differences between delta rhythm phase, theta rhythm phase and gamma rhythm amplitude of rats in different parameter stimulation groups and control group were compared. The experimental results showed that the coupling intensity of delta and gamma rhythm in stimulation groups was significantly lower than that in the control group ( P<0.05), while the coupling intensity of theta and gamma rhythm was significantly higher than that in the control group ( P<0.05). With the increase of stimulation parameters, the degree of coupling between delta and gamma rhythm showed a decreasing trend, while the degree of coupling between theta and gamma rhythm tended to increase. The preliminary results of this paper indicated that transcranial magneto-acoustic-electrical stimulation inhibited delta rhythmic neuronal activity and enhanced the oscillation of theta and gamma rhythm in the prefrontal cortex, thus promoted the exchange and transmission of information between neuronal clusters in different spatial scales. This lays the foundation for further exploring the mechanism of transcranial magneto-acoustic-electrical stimulation in regulating brain memory function.

PMID:35523547 | DOI:10.7507/1001-5515.202108036

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2022 Apr 25;39(2):237-247. doi: 10.7507/1001-5515.202103079.

ABSTRACT

Brain functional network changes over time along with the process of brain development, disease, and aging. However, most of the available measurements for evaluation of the difference (or similarity) between the individual brain functional networks are for charactering static networks, which do not work with the dynamic characteristics of the brain networks that typically involve a long-span and large-scale evolution over the time. The current study proposes an index for measuring the similarity of dynamic brain networks, named as dynamic network similarity (DNS). It measures the similarity by combining the "evolutional" and "structural" properties of the dynamic network. Four sets of simulated dynamic networks with different evolutional and structural properties (varying amplitude of changes, trend of changes, distribution of connectivity strength, range of connectivity strength) were generated to validate the performance of DNS. In addition, real world imaging datasets, acquired from 13 stroke patients who were treated by transcranial direct current stimulation (tDCS), were used to further validate the proposed method and compared with the traditional similarity measurements that were developed for static network similarity. The results showed that DNS was significantly correlated with the varying amplitude of changes, trend of changes, distribution of connectivity strength and range of connectivity strength of the dynamic networks. DNS was able to appropriately measure the significant similarity of the dynamics of network changes over the time for the patients before and after the tDCS treatments. However, the traditional methods failed, which showed significantly differences between the data before and after the tDCS treatments. The experiment results demonstrate that DNS may robustly measure the similarity of evolutional and structural properties of dynamic networks. The new method appears to be superior to the traditional methods in that the new one is capable of assessing the temporal similarity of dynamic functional imaging data.

PMID:35523544 | DOI:10.7507/1001-5515.202103079

Exp Brain Res. 2022 May 6. doi: 10.1007/s00221-022-06375-x. Online ahead of print.

ABSTRACT

Neurorecovery from locomotor training is well established in human spinal cord injury (SCI). However, neurorecovery resulting from combined interventions has not been widely studied. In this randomized clinical trial, we established the tibialis anterior (TA) flexion reflex modulation pattern when transcranial magnetic stimulation (TMS) of the primary motor cortex was paired with transcutaneous spinal cord (transspinal) stimulation over the thoracolumbar region during assisted step training. Single pulses of TMS were delivered either before (TMS-transspinal) or after (transspinal-TMS) transspinal stimulation during the stance phase of the less impaired leg. Eight individuals with chronic incomplete or complete SCI received at least 20 sessions of paired stimulation during assisted step training. Each session consisted of 240 paired stimuli delivered over 10-min blocks for 1 h during robotic-assisted step training with the Lokomat6 Pro^®. Body weight support, leg guidance force and treadmill speed were adjusted based on each participant's ability to step without knee buckling or toe dragging. Both the early and late TA flexion reflex remained unaltered after TMS-transspinal and locomotor training. In contrast, the early and late TA flexion reflexes were significantly depressed during stepping after transspinal-TMS and locomotor training. Reflex changes occurred at similar slopes and intercepts before and after training. Our findings support that targeted brain and spinal cord stimulation coupled with locomotor training reorganizes the function of flexion reflex pathways, which are a part of locomotor networks, in humans with varying levels of sensorimotor function after SCI.Trial registration number NCT04624607; Registered on November 12, 2020.

PMID:35513720 | DOI:10.1007/s00221-022-06375-x

Neurochem Int. 2022 May 2:105356. doi: 10.1016/j.neuint.2022.105356. Online ahead of print.

ABSTRACT

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulation technique. Recently, rTMS has shown promising therapeutic potential in multiple neurological conditions. Nevertheless, challenges remain in the clinical application of rTMS, which mainly due to the lack of consensus on optimal stimulation protocols and poor understanding of the exact targets driving its action. Experimental animal research with more controllable factors may contribute to fill our knowledge gap in this area, and to accelerate the development of clinical translation studies. Therefore, the current study was designed to systematically review the effects of rTMS on animal models of certain diseases and evaluate its potential mechanisms of action, which may guide future studies aiming to improve the therapeutic utilization for these diseases.

METHODS: A systematic literature search was conducted through the PubMed online database on August 19, 2021. The search strategy consisted of two main components: rTMS and stroke, Alzheimer's disease (AD), vascular dementia (VaD), and Parkinson's disease (PD), with results limited to animal studies.

RESULTS: We identified 41 animal studies, 21 that examined stroke, 8 that investigated Alzheimer's disease, 5 that studied vascular dementia, and 7 that examined Parkinson's disease, all of these studies were conducted in rodents (rat and mice). Despite variations in study design and research methods, the therapeutic benefits of rTMS, as reflected in the alleviation of disease-related symptoms and pathological improvements, have been reported in these studies. rTMS induces multi-directional changes at the cellular and molecular levels, including a significant contribution to synaptic plasticity. Furthermore, the curative effects of rTMS are related to stimulation parameters, with high-frequency rTMS reported has better therapeutic efficacy in several studies. In terms of safety, one study involving combination therapy reported the adverse effects of rTMS administration.

CONCLUSIONS: rTMS have shown encouraging therapeutic value in rodent models of stroke, AD, VaD, and PD. Nonetheless, the optimal protocols and exact target of action for this therapy remain to be determined. Correspondingly, further research is still needed to bridge the translation gap between rodent experiments and clinical application, which might lead to new directions in the treatment of multiple neurological disorders.

PMID:35513205 | DOI:10.1016/j.neuint.2022.105356

Indian J Psychol Med. 2022 Jan;44(1):74-77. doi: 10.1177/0253717620959257. Epub 2020 Oct 21.

NO ABSTRACT

PMID:35509648 | PMC:PMC9022911 | DOI:10.1177/0253717620959257

Int Immunopharmacol. 2022 Apr 30;109:108788. doi: 10.1016/j.intimp.2022.108788. Online ahead of print.

ABSTRACT

AIMS: Recently numerous studies have demonstrated that neuroinflammation plays a critical role in the pathogenesis of depression. Repetitive transcranial magnetic stimulation (rTMS) has been used to treat depression for years but its mechanism is not fully elucidated. The present study was designed to investigate whether rTMS could alleviate neuroglia-associated neuro-inflammatory process in mice models of depression.

METHODS: Mice were treated with chronic unpredictable mild stress (CUMS) to induce depression models and received four weeks of 15 Hz rTMS. Then the depression-like behaviors, microglia activation, the level of astrocytes, pro-inflammatory cytokines and inflammation-related signaling pathways were evaluated.

RESULTS: rTMS ameliorated depression-like behaviors in CUMS-treated mice. rTMS not only markedly alleviated the activation of microglia but induced a switch of microglia polarization from pro-inflammatory M1 phenotype to anti-inflammatory M2 phenotype in the hippocampus and prefrontal cortex. Meanwhile, rTMS reversed the down-regulation of astrocytes and inhibited high levels of interleukin (IL)-6, IL-1β and tumor necrosis factor-alpha (TNF-α) caused by CUMS in above regions. Moreover, we found that anti-inflammatory actions by rTMS were associated with the TLR4/NF-κB/NLRP3 signaling pathway.

CONCLUSION: Collectively, our findings indicate that rTMS can exert anti-inflammatory actions in depression and provide new insights into the mechanism of rTMS in the treatment of depression.

PMID:35504201 | DOI:10.1016/j.intimp.2022.108788

Development. 2022 Apr 15;149(8):dev200270. doi: 10.1242/dev.200270. Epub 2022 May 3.

ABSTRACT

Although best known for their phagocytic and immunological functions, macrophages have increasingly been recognised as key players in the development, homeostasis and regeneration of their host tissues. Early during development, macrophages infiltrate and colonise all tissues within the body, developing symbiotically with their host tissues and acquiring unique functional adaptations based on the tissue microenvironment. These embryonic resident tissue macrophages (RTMs) are ontogenically distinct from the later adult bone marrow-derived monocytes, and in some tissues are self-maintained independently of general circulation at a steady state. In this article, we briefly discuss the ontogeny, maintenance and unique tissue adaptions of RTMs focusing on microglia, Kupffer cells, Langerhans cells, intestinal macrophages, cardiac macrophages and tumour-associated macrophages, and highlight their role in development, homeostasis and dysfunction.

PMID:35502781 | DOI:10.1242/dev.200270

BMC Neurosci. 2022 May 2;23(1):26. doi: 10.1186/s12868-022-00709-9.

ABSTRACT

BACKGROUND: Transcranial magneto-acoustical stimulation (TMAS) is a noninvasive technique that has advantages in spatial resolution and penetration depth. It changes the firing properties of neurons through the current generated by focused ultrasound and a static magnetic field. Spike-frequency adaptation is an important dynamic characteristic of neural information processing.

METHODS: To address the effects of TMAS on neural spike-frequency adaptation, this study employs some ultrasound and magnetic field parameters, such as magnetic flux density, ultrasonic intensity, fundamental ultrasonic frequency, modulation frequency, and duty cycle. Using these different ultrasound and magnetic field parameters, membrane potential curves, spike-frequency curves, and adapted onset spike-frequency curves are exhibited and analyzed.

RESULTS: The results show that spike-frequency adaptation is strongly dependent on ultrasonic intensity and magnetic flux density and is rarely affected by other parameters. However, modulation frequency and duty cycle influence membrane potentials and spike frequencies to some degree.

CONCLUSIONS: This study reveals the mechanism of the effects of TMAS on neural spike-frequency adaptation and serves as theoretical guidance for TMAS experiments.

PMID:35501687 | PMC:PMC9063290 | DOI:10.1186/s12868-022-00709-9

Neurotherapeutics. 2022 May 2:1-14. doi: 10.1007/s13311-022-01231-w. Online ahead of print.

ABSTRACT

Repeated sessions of cerebellar anodal transcranial direct current stimulation (tDCS) have been suggested to modulate cerebellar-motor cortex (M1) connectivity and decrease ataxia severity. However, therapeutic trials involving etiologically homogeneous groups of ataxia patients are lacking. The objective of this study was to investigate if a two-week regimen of daily cerebellar tDCS sessions diminishes ataxia and non-motor symptom severity and alters cerebellar-M1 connectivity in individuals with spinocerebellar ataxia type 3 (SCA3). We conducted a randomized, double-blind, sham-controlled trial in which twenty mildly to moderately affected SCA3 patients received ten sessions of real or sham cerebellar tDCS (i.e., five days per week for two consecutive weeks). Effects were evaluated after two weeks, three months, six months, and twelve months. Change in Scale for the Assessment and Rating of Ataxia (SARA) score after two weeks was defined as the primary endpoint. Static posturography, SCA Functional Index tests, various patient-reported outcome measures, the cerebellar cognitive affective syndrome scale, and paired-pulse transcranial magnetic stimulation to examine cerebellar brain inhibition (CBI) served as secondary endpoints. Absolute change in SARA score did not differ between both trial arms at any of the time points. We observed significant short-term improvements in several motor, cognitive, and patient-reported outcomes after the last stimulation session in both groups but no treatment effects in favor of real tDCS. Nonetheless, some of the patients in the intervention arm showed a sustained reduction in SARA score lasting six or even twelve months, indicating interindividual variability in treatment response. CBI, which reflects the functional integrity of the cerebellothalamocortical tract, remained unchanged after ten tDCS sessions. Albeit exploratory, there was some indication for between-group differences in SARA speech score after six and twelve months and in the number of extracerebellar signs after three and six months. Taken together, our study does not provide evidence that a two-week treatment with daily cerebellar tDCS sessions reduces ataxia severity or restores cerebellar-M1 connectivity in early-to-middle-stage SCA3 patients at the group level. In order to potentially increase therapeutic efficacy, further research is warranted to identify individual predictors of symptomatic improvement.

PMID:35501469 | PMC:PMC9059914 | DOI:10.1007/s13311-022-01231-w

Eur J Neurosci. 2022 May 2. doi: 10.1111/ejn.15683. Online ahead of print.

ABSTRACT

Evidence suggests excitability of the motor cortex (M1) changes in response to motor skill learning of the upper limb. Few studies have examined immediate changes in corticospinal excitability and intra-cortical mechanisms following motor learning in the lower back. Further, it is unknown which transcranial magnetic stimulation (TMS) paradigms are likely to reveal changes in cortical function in this region. This study aimed to: (1) compare corticospinal excitability and intra-cortical mechanisms in the lower back region of M1 before and after a single session of lumbopelvic tilt motor learning task in healthy people; and (2) compare these measures between two TMS coils and two methods of recruitment curve (RC) acquisition. Twenty-eight young participants (23.6±4.6 years) completed a lumbopelvic tilting task involving three 5-minute blocks. Single-pulse (RC from 70%-150% of active motor threshold) and paired-pulse TMS measures (ICF, SICF, and SICI) were undertaken before (using 2 coils: figure-of-8 and double cone) and after (using double cone coil only) training. RCs were also acquired using a traditional and rapid method. A significant increase in corticospinal excitability was found after training as measured by RC intensities, but this was not related to the RC slope. No significant differences were found for paired-pulse measures after training. Finally, there was good agreement between RC parameters when measured with the two different TMS coils or different acquisition methods (traditional vs. rapid). Changes in corticospinal excitability after a single session of lumbopelvic motor learning task are seen, but these changes are not explained by changes in intra-cortical mechanisms.

PMID:35501123 | DOI:10.1111/ejn.15683

Neurol Sci. 2022 May 2. doi: 10.1007/s10072-022-06092-x. Online ahead of print.

ABSTRACT

PURPOSE: Aphasia-acquired loss of the ability to understand or express language-is a common and debilitating neurological consequence of stroke. Evidence suggests that transcranial magnetic stimulation (TMS) can significantly improve language outcomes in patients with aphasia. Repetitive transcranial magnetic stimulation (rTMS) has been reported to improve naming in chronic stroke patients with nonfluent aphasia since 2005.

METHODS: We conducted a systematic review and meta-analyses of TMS treatment studies in patients with aphasia. Eight electronic databases (PubMed, Medline, Embase, Scopus, ScienceDirect, Cochrane Central Register of Controlled Trials, Journals@Ovid, and clinicaltrials.gov) were searched for articles. Relevant studies were further evaluated, and studies that met inclusion criteria were reviewed. The searches were limited to human studies written in English and published between January 1960 and January 2020. In keeping with the main objective of this review, we included all studies that carried out treatment using rTMS in stroke patients with aphasia, regardless of the trial (or experimental) design of the study. Studies that implemented between-subject or randomized controlled (RCT) design, cross-over trials, and within-subject or pre-post trials were all included. Standard mean difference (SMD) for changes in picture naming accuracy was estimated.

RESULTS: The literature search yielded 423 studies. Fifty articles were further evaluated to be included. Eleven met all inclusion criteria and were chosen for review. Eleven eligible studies involving 242 stroke patients were identified in this meta-analysis. Further analyses demonstrated prominent effects for the naming subtest (SMD = 1.26, 95% CI = 0.80 to 1.71, p = 0.01), with heterogeneity (I² = 69.101%). The meta-analysis continued to show that there was a statistically significant effect of rTMS compared with sham rTMS on the severity of aphasia. None of the patients from the 11 included articles reported adverse effects from rTMS.

CONCLUSIONS: There are some strong studies evaluating the efficacy of rTMS in stroke patients but further research is required to fully establish the usefulness of this treatment. This meta-analysis indicates a clinically positive effect of rTMS with or without speech and language therapy (SLT) for patients with aphasia following stroke in overall language function and expressive language, including naming, repetition, writing, and comprehension. Low-frequency (1 Hz) rTMS over the unaffected hemisphere is effective and compatible with the concept of interhemispheric inhibition. Moreover, the treatment of 1 Hz rTMS for patients with aphasia after stroke was safe.

PMID:35499630 | DOI:10.1007/s10072-022-06092-x

Front Cell Neurosci. 2022 Apr 12;16:878345. doi: 10.3389/fncel.2022.878345. eCollection 2022.

ABSTRACT

Ischemic stroke (IS) is a severe neurological disease that is difficult to recovery. Previous studies have shown that repetitive transcranial magnetic stimulation (rTMS) is a promising therapeutic approach, while the exact therapy mechanisms of rTMS in improving neural functional recovery remain unclear. Furthermore, the inflammatory environment may influence the rehabilitation efficacy. Our study shows that long-term rTMS stimulation will significantly promote neurogenesis, inhibit apoptosis, and control inflammation. rTMS inhibits the activation of transcription factors nuclear factor kappa b (NF-κB) and signal transducer and activator of transcription 6 (STAT6) and promotes the anti-inflammatory polarization of microglia. Obvious promotion of anti-inflammatory cytokines production is observed both in vitro and in vivo through rTMS stimulation on microglia. In addition, neural stem cells (NSCs) cultured in conditioned medium (CM) from microglia treated with rTMS showed downregulation of apoptosis and upregulation of neuronal differentiation. Overall, our results illustrate that rTMS can modulate microglia with anti-inflammatory polarization variation, promote neurogenesis, and improve neural function recovery.

PMID:35496902 | PMC:PMC9039226 | DOI:10.3389/fncel.2022.878345

Front Neurosci. 2022 Apr 12;16:866245. doi: 10.3389/fnins.2022.866245. eCollection 2022.

ABSTRACT

Understanding the operation of cortical circuits is an important and necessary task in both neuroscience and neurorehabilitation. The functioning of the neocortex results from integrative neuronal activity, which can be probed non-invasively by transcranial magnetic stimulation (TMS). Despite a clear indication of the direct involvement of cortical neurons in TMS, no explicit connection model has been made between the microscopic neuronal landscape and the macroscopic TMS outcome. Here we have performed an integrative review of multidisciplinary evidence regarding motor cortex neurocytology and TMS-related neurophysiology with the aim of elucidating the micro-macro connections underlying TMS. Neurocytological evidence from animal and human studies has been reviewed to describe the landscape of the cortical neurons covering the taxonomy, morphology, circuit wiring, and excitatory-inhibitory balance. Evidence from TMS studies in healthy humans is discussed, with emphasis on the TMS pulse and paradigm selectivity that reflect the underlying neural circuitry constitution. As a result, we propose a preliminary neuronal model of the human motor cortex and then link the TMS mechanisms with the neuronal model by stimulus intensity, direction of induced current, and paired-pulse timing. As TMS bears great developmental potential for both a probe and modulator of neural network activity and neurotransmission, the connection model will act as a foundation for future combined studies of neurocytology and neurophysiology, as well as the technical advances and application of TMS.

PMID:35495053 | PMC:PMC9039343 | DOI:10.3389/fnins.2022.866245

Front Neurol. 2022 Apr 13;13:843975. doi: 10.3389/fneur.2022.843975. eCollection 2022.

ABSTRACT

BACKGROUND: Dravet syndrome (DS) is a refractory developmental and epileptic encephalopathy (EE) with a variety of comorbidities, including cognitive impairment, autism-like behavior, speech dysfunction, and ataxia, which can seriously affect the quality of life of patients and impose a great burden on society and their families. Currently, the pharmacological therapy is patient dependent and may work or not. Neuromodulation techniques, including vagus nerve stimulation (VNS), deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), responsive neurostimulation (RNS), and chronic subthreshold cortical stimulation (CSCS), have become common adjuvant therapies for neurological diseases, but their efficacy in the treatment of DS is unknown.

METHODS: We searched Web of Science, PubMed, and SpringerLink for all published cases related to the neuromodulation techniques of DS until January 15, 2022. The systematic review was supplemented with relevant articles from the references. The results reported by each study were summarized narratively.

RESULTS: The Web of science, PubMed and SpringerLink search yielded 258 items. A total of 16 studies published between 2016 and 2021 met the final inclusion criteria. Overall, 16 articles (109 cases) were included in this study, among which fifteen (107 patients) were involved VNS, and one (2 patients) was involved DBS. After VNS implantation, seizures were reduced to ≥50% in 60 cases (56%), seizure free were found in 8 cases (7.5%). Only two DS patients received DBS treatment, and the initial outcomes of DBS implantation were unsatisfactory. The seizures significantly improved over time for both DBS patients after the addition of antiepileptic drugs.

CONCLUSION: More than half of the DS patients benefited from VNS, and VNS may be effective in the treatment of DS. However, it is important to note that VNS does not guarantee improvement of seizures, and there is a risk of infection and subsequent device failure. Although DBS is a safe and effective strategy for the treatment of refractory epilepsy, the role of DBS in DS needs further study, as the sample size was small. Thus far, there is no strong evidence for the role of DBS in DS.

PMID:35493838 | PMC:PMC9044920 | DOI:10.3389/fneur.2022.843975

Front Neurol. 2022 Apr 15;13:844606. doi: 10.3389/fneur.2022.844606. eCollection 2022.

ABSTRACT

OBJECTIVES: To reveal the effects of repetitive transcranial magnetic stimulation (rTMS) on the improvement of cognitive function in patients with stress-related depression, and to enrich the neural mechanism(s) underlying rTMS so as to improve cognitive function in patients with stress-related depression.

METHODS: We conducted a randomized, double-blind, placebo-controlled study of rTMS in patients with stress-related depression who were 18-40 years of age. Patients were randomly allocated to either a sham or experimental group in a 1:1 ratio. A 10-session rTMS protocol was used with 10-Hz stimulation over the left dorsolateral prefrontal cortex (DLPFC). Clinical assessments (HAMD, HAMA, DASS, MoCA), neuropsychologic (Stroop, WCST), and resting state fMRI and ¹H-MRS assessments were executed at two time points-baseline and after the 10th rTMS session.

RESULTS: rTMS relieved the mental symptoms of patients in both groups. The MoCA score of patients in the experimental group increased; the number of correct answers increased significantly in Stroop testing, and the number of errors and omissions decreased significantly; the number of persistent errors decreased significantly; and the time used to complete the test decreased to an even greater extent in the WCST experimental group. The ReHo value in the lingual gyrus of the right hemisphere and the cuneus of the left and right hemispheres in the experimental group decreased after treatment. The DC value in the left and right hemispheric cuneus and postcentral gyrus of the left hemisphere in the experimental group diminished after treatment. The functional connections of these brain regions also changed as the Cho and NAA/Cr of the left DLPFC changed, with alterations related to the improvement in cognitive function. The level of choline (Cho) in the left DLPFC of the experimental group was significantly lower than that of the control group, and the level of N-acetylaspartate/creatine (NAA/Cr) in the left DLPFC of the control group was significantly higher than that of the experimental group. These changes were related to the overall improvement in cognitive function.

CONCLUSIONS: Ten-Hz rTMS over the left DLPFC improved the cognitive function of patients with stress-related depression. The governing mechanism for this phenomenon may be via rTMS effects on multiple visual-related brain regions and their functional connections, and on the somatosensory cortex and its functional connection with visual and auditory cortex, reducing the level of Cho and stabilizing the level of NAA/Cr in the left DLPFC.

PMID:35493813 | PMC:PMC9051398 | DOI:10.3389/fneur.2022.844606

Front Mol Neurosci. 2022 Apr 12;15:887426. doi: 10.3389/fnmol.2022.887426. eCollection 2022.

ABSTRACT

OBJECTIVE: High-frequency repetitive transcranial magnetic stimulation (rTMS) induces analgesic effects in both experimental pain and clinical pain conditions. However, whether rTMS can modulate sensory and pain thresholds on sensory fibers is still unclear. Here, we compared the effects of three rTMS paradigms on sensory and pain thresholds conducted by different sensory fibers (Aβ, Aδ, and C fibers) with sham stimulation and investigate the potential brain activation using functional near-infrared spectroscopy (fNIRS).

METHODS: Forty right-handed healthy subjects were randomly allocated into one of four groups. Each subject received one session rTMS [prolonged continuous theta-burst stimulation (pcTBS), intermittent theta-burst stimulation (iTBS), 10 Hz rTMS or sham]. Current perception threshold (CPT), pain tolerance threshold (PTT), and fNIRS were measured at baseline, immediately after stimulation, and 1 h after stimulation, respectively.

RESULTS: Significant differences between treatments were observed for changes for CPT 2,000 Hz between baseline and 1 h after rTMS (F = 6.551, P < 0.001): pcTBS versus sham (P = 0.004) and pcTBS versus 10 Hz rTMS (P = 0.007). There were significant difference in average HbO μm in the right frontopolar cortex (FPC) [channel 23: P = 0.030 (pcTBS versus sham: P = 0.036)], left dorsolateral prefrontal cortex (DLPFC) [channel 7: P = 0.006 (pcTBS versus sham: P = 0.004)], left FPC [channel 17: P = 0.014 (pcTBS versus sham: P = 0.046), channel 22: P = 0.004 (pcTBS versus sham: P = 0.004)] comparing four group in 1 h after stimulation in PTT 2000 Hz (Aβ-fiber).

CONCLUSION: Prolonged continuous theta-burst stimulation can regulate sensitivity on Aβ fibers. In addition, single-session pcTBS placed on left M1 can increase the excitability of DLPFC and FPC, indicating the interaction between M1 and prefrontal cortex may be a potential mechanism of analgesic effect of rTMS. Studies in patients with central post-stroke pain are required to confirm the potential clinical applications of pcTBS.

PMID:35493324 | PMC:PMC9039327 | DOI:10.3389/fnmol.2022.887426

Front Psychiatry. 2022 Apr 14;13:860448. doi: 10.3389/fpsyt.2022.860448. eCollection 2022.

ABSTRACT

Excitatory/inhibitory imbalance has been suggested as a neurobiological substrate of the cognitive symptomatology in Autism Spectrum Disorder (ASD). Studies using magnetic resonance spectroscopy (MRS) attempted to characterize GABA and Glutamate brain levels in ASD. However mixed findings have been reported. Here, we characterize both neurochemical and physiological aspects of GABA system in ASD by implementing a more comprehensive approach combining MRS and transcranial magnetic stimulation (TMS). A group of 16 young ASD adults and a group of 17 controls participated in this study. We employed one MRS session to assess motor cortex GABA+ and Glutamate+Glutamine (Glx) levels using MEGAPRESS and PRESS sequences, respectively. Additionally, a TMS experiment was implemented including paired-pulse (SICI, ICF and LICI), input-output curve and cortical silent period to probe cortical excitability. Our results showed a significantly increased Glx, with unchanged GABA+ levels in the ASD group compared with controls. Single TMS measures did not differ between groups, although exploratory within-group analysis showed impaired inhibition in SICI5ms, in ASD. Importantly, we observed a correlation between GABA levels and measures of the input-output TMS recruitment curve (slope and MEP amplitude) in the control group but not in ASD, as further demonstrated by direct between group comparisons. In this exploratory study, we found evidence of increased Glx levels which may contribute to ASD excitatory/inhibitory imbalance while highlighting the relevance of conducting further larger-scale studies to investigate the GABA system from complementary perspectives, using both MRS and TMS techniques.

PMID:35492696 | PMC:PMC9046777 | DOI:10.3389/fpsyt.2022.860448

Front Psychiatry. 2022 Apr 14;13:886918. doi: 10.3389/fpsyt.2022.886918. eCollection 2022.

ABSTRACT

Depressive disorders are among the most common psychiatric conditions and contribute to significant morbidity. Even though the use of antidepressants revolutionized the management of depression and had a tremendous positive impact on the patient's outcome, a significant proportion of patients with major depressive disorder (MDD) show no or partial or response even with adequate treatment. Given the limitations of the prevailing monoamine hypothesis-based pharmacotherapy, glutamate and glutamatergic related pathways may offer an alternative and a complementary option for designing novel intervention strategies. Over the past few decades, there has been a growing interest in understanding the neurobiological underpinnings of glutamatergic dysfunctions in the pathogenesis of depressive disorders and the development of new pharmacological and non-pharmacological treatment options. There is a growing body of evidence for the efficacy of neuromodulation techniques, including transcranial magnetic stimulation, transcutaneous direct current stimulation, transcranial alternating current stimulation, and photo-biomodulation on improving connectivity and neuroplasticity associated with depression. This review attempts to revisit the role of glutamatergic neurotransmission in the etiopathogenesis of depressive disorders and review the current neuroimaging, neurophysiological and clinical evidence of these neuromodulation techniques in the pathophysiology and treatment of depression.

PMID:35492692 | PMC:PMC9047946 | DOI:10.3389/fpsyt.2022.886918

Brain Stimul. 2022 Apr 28;15(3):697-706. doi: 10.1016/j.brs.2022.04.017. Online ahead of print.

ABSTRACT

BACKGROUND: The effects of transcranial magnetic stimulation (TMS) on brain activity depend on the design of the stimulation coil. A wide range of coils from different vendors are currently used with different stimulation properties. This decreases the comparability of study results.

OBJECTIVE: To systematically compare widely used commercial TMS coils concerning their focality, stimulation depth and efficacy. To provide validated models and data of these coils for accurate simulations of the induced electric fields.

METHODS: We reconstructed the magnetic vector potential of 25 commercially available TMS coils of different vendors from measurements of their magnetic fields. Most coils had a figure-of-eight configuration. We employed the reconstructed magnetic vector potential in simulations of the electric field in a spherical head model. We estimated the motor thresholds of the coil-stimulator combinations using the calculated fields, the pulse waveforms and a leaky integrator model of the neural membrane.

RESULTS: Our results confirm a previously reported systematic trade-off between focality and relative depth of stimulation. However, neither the peak field strength in the "cortex" of the sphere model nor the estimated motor thresholds were strongly related to the two former measures and need to be additionally determined.

CONCLUSION: Our comprehensive coil characterization facilitates objective comparisons of coils of different sizes and from different vendors. The models and auxiliary data will be made available for electric field simulations in SimNIBS. Our work will support TMS users making an informed selection of a suited coil for a specific application and will help to reduce uncertainty regarding the TMS-induced electric field in the brain target region.

PMID:35490970 | DOI:10.1016/j.brs.2022.04.017

Clin Neurophysiol. 2022 Apr 20;139:28-42. doi: 10.1016/j.clinph.2022.04.004. Online ahead of print.

ABSTRACT

OBJECTIVE: Migraine is a primary headache disorder with a well-known association with insufficient sleep. However, both the underlying pathophysiology of the disease and the relationship with sleep is still unexplained. In this study, we apply transcranial magnetic stimulation to investigate possible mechanisms of insufficient sleep in migraine.

METHODS: We used a randomised, blinded crossover design to examine 46 subjects with migraine during the interictal period and 29 healthy controls. Each subject underwent recordings of cortical silent period, short- and long-interval intracortical inhibition, intracortical facilitation and short-latency afferent inhibition after both two nights of habitual eight-hour sleep and two nights of restricted four-hour sleep.

RESULTS: We found reduced cortical silent period duration after sleep restriction in interictal migraineurs compared to controls (p = 0.046). This effect was more pronounced for non-sleep related migraine (p = 0.002) and migraine with aura (p = 0.017). The sleep restriction effect was associated with ictal symptoms of hypersensitivity such as photophobia (p = 0.017) and overall silent period was associated with premonitory dopaminergic symptoms such as yawning (p = 0.034).

CONCLUSIONS: Sleep restriction reduces GABAergic cortical inhibition during the interictal period in individuals with migraine.

SIGNIFICANCE: Sleep related mechanisms appear to affect the pathophysiology of migraine and may differentiate between migraine subgroups.

PMID:35490438 | DOI:10.1016/j.clinph.2022.04.004

Ann Clin Transl Neurol. 2022 May;9(5):722-733. doi: 10.1002/acn3.51551. Epub 2022 Apr 30.

ABSTRACT

OBJECTIVE: We propose a novel cue-based asynchronous brain-computer interface(BCI) for neuromodulation via the pairing of endogenous motor cortical activity with the activation of somatosensory pathways.

METHODS: The proposed BCI detects the intention to move from single-trial EEG signals in real time, but, contrary to classic asynchronous-BCI systems, the detection occurs only during time intervals when the patient is cued to move. This cue-based asynchronous-BCI was compared with two traditional BCI modes (asynchronous-BCI and offline synchronous-BCI) and a control intervention in chronic stroke patients. The patients performed ankle dorsiflexion movements of the paretic limb in each intervention while their brain signals were recorded. BCI interventions decoded the movement attempt and activated afferent pathways via electrical stimulation. Corticomotor excitability was assessed using motor-evoked potentials in the tibialis-anterior muscle induced by transcranial magnetic stimulation before, immediately after, and 30 min after the intervention.

RESULTS: The proposed cue-based asynchronous-BCI had significantly fewer false positives/min and false positives/true positives (%) as compared to the previously developed asynchronous-BCI. Linear-mixed-models showed that motor-evoked potential amplitudes increased following all BCI modes immediately after the intervention compared to the control condition (p <0.05). The proposed cue-based asynchronous-BCI resulted in the largest relative increase in peak-to-peak motor-evoked potential amplitudes(141% ± 33%) among all interventions and sustained it for 30 min(111% ± 33%).

INTERPRETATION: These findings prove the high performance of a newly proposed cue-based asynchronous-BCI intervention. In this paradigm, individuals receive precise instructions (cue) to promote engagement, while the timing of brain activity is accurately detected to establish a precise association with the delivery of sensory input for plasticity induction.

PMID:35488791 | DOI:10.1002/acn3.51551

Top Stroke Rehabil. 2022 Apr 29:1-8. doi: 10.1080/10749357.2022.2070364. Online ahead of print.

ABSTRACT

INTRODUCTION: Standardization of first principles has transformed stroke rehabilitation in developed countries and helped guide the appropriate allocation of resources to ensure better outcomes for patients. There have been challenges in incorporating new evidence into stroke rehabilitation practices. The sheer number of RCTs can be daunting to the average clinician, made worse by the lack of a framework for their application.

OBJECTIVES: To develop a framework for the introduction of adjunct practices for the motor recovery of the upper extremity post stroke into clinical practice.

METHODOLOGY: A literature search following PRISMA guidelines revealed 1,307 RCTs involving rehabilitation interventions for the hemiparetic upper extremity post stroke.

RESULTS: Therapies were divided into three categories of therapies: (1) Basic Conventional Therapy Approaches (<15% of interventions), (2) Adjunct Therapies Designed to Enhance Conventional Therapies (>85% of interventions), and (3) Treatment to Manage Complications (~9% of interventions). Adjunct Therapies, despite having a spectacular evidence base, are often not employed clinically. To encourage their clinical use, we have developed a framework that divides adjunct therapies into two categories: (1) Treatments that Stimulate the Brain (i.e. rTMS, mental practice, and virtual reality) and (2) Treatments that Peripherally Facilitate the Hemiparetic Upper Extremity (i.e. robotics, EMG Biofeedback, and Constraint-induced Movement Therapy).

CONCLUSION: To allow stroke rehabilitation to continue to improve upper extremity recovery and outcomes, we propose a new intuitive framework that is based on a strong evidence base to guide clinicians and improve stroke rehabilitation.

PMID:35488362 | DOI:10.1080/10749357.2022.2070364

Exp Brain Res. 2022 Apr 29:1-10. doi: 10.1007/s00221-022-06370-2. Online ahead of print.

ABSTRACT

Muscle weakness is a critical problem facing many older adults. Interventions targeting nervous system plasticity may show promise in enhancing strength. The purpose of this study was to examine the acute effects of action observation on muscular strength characteristics and corticospinal excitability in older adults. Isometric wrist flexion strength characteristics and corticospinal excitability of the first dorsal interosseous (FDI) were measured in 14 older adults (mean age = 73 years) in response to observation of (1) STRONG contractions of the hand/wrist, (2) WEAK contractions of the hand/wrist, and (3) a CONTROL condition. Results from repeated measures analyses of variance (ANOVAs) indicated that rate of torque development at 200 ms (RTD200) significantly decreased from PRE to POST observation for CONTROL and WEAK, but not STRONG. No other ANOVAs were significant. However, effect sizes indicated that maximal voluntary contraction (MVC) peak torque showed moderate declines following WEAK (d = - 0.571) and CONTROL (d = - 0.636), but not STRONG (d = 0.024). Similarly, rate of torque development at 30 (RTD30), 50 (RTD50), and 200 (RTD200) ms showed large declines from PRE to POST after WEAK and CONTROL, but small changes following STRONG. FDI motor-evoked potential (MEP) amplitude tended to increase over time, but these results were variable. There was a pronounced effect from PRE to 8MIN (d = 0.954) during all conditions. Action observation of strong contractions may exert a preservatory effect on muscular strength. More work is needed to determine whether this is modulated by increased corticospinal excitability. The study was prospectively registered (ClinicalTrials.gov Identifier: NCT03946709).

PMID:35488129 | PMC:PMC9053563 | DOI:10.1007/s00221-022-06370-2

Sci Rep. 2022 Apr 29;12(1):6998. doi: 10.1038/s41598-022-10981-8.

ABSTRACT

Visual processing of emotional stimuli has been shown to engage complex cortical and subcortical networks, but it is still unclear how it affects sensorimotor integration processes. To fill this gap, here, we used a TMS protocol named short-latency afferent inhibition (SAI), capturing sensorimotor interactions, while healthy participants were observing emotional body language (EBL) and International Affective Picture System (IAPS) stimuli. Participants were presented with emotional (fear- and happiness-related) or non-emotional (neutral) EBL and IAPS stimuli while SAI was tested at 120 ms and 300 ms after pictures presentation. At the earlier time point (120 ms), we found that fear-related EBL and IAPS stimuli selectively enhanced SAI as indexed by the greater inhibitory effect of somatosensory afferents on motor excitability. Larger early SAI enhancement was associated with lower scores at the Behavioural Inhibition Scale (BIS). At the later time point (300 ms), we found a generalized SAI decrease for all kind of stimuli (fear, happiness or neutral). Because the SAI index reflects integrative activity of cholinergic sensorimotor circuits, our findings suggest greater sensitivity of such circuits during early (120 ms) processing of threat-related information. Moreover, the correlation with BIS score may suggest increased attention and sensory vigilance in participants with greater anxiety-related dispositions. In conclusion, the results of this study show that sensorimotor inhibition is rapidly enhanced while processing threatening stimuli and that SAI protocol might be a valuable option in evaluating emotional-motor interactions in physiological and pathological conditions.

PMID:35488018 | PMC:PMC9054825 | DOI:10.1038/s41598-022-10981-8

Neuroimage Clin. 2022 Apr 16;34:103011. doi: 10.1016/j.nicl.2022.103011. Online ahead of print.

ABSTRACT

INTRODUCTION: Prefrontal cortex (PFC) regions are promising targets for therapeutic applications of non-invasive brain stimulation, e.g. transcranial direct current stimulation (tDCS), which has been proposed as a novel intervention for major depressive disorder (MDD) and negative symptoms of schizophrenia (SCZ). However, the effects of tDCS vary inter-individually, and dose-response relationships have not been established. Stimulation parameters are often tested in healthy subjects and transferred to clinical populations. The current study investigates the variability of individual MRI-based electric fields (e-fields) of standard bifrontal tDCS across individual subjects and diagnoses.

METHOD: The study included 74 subjects, i.e. 25 patients with MDD, 24 patients with SCZ, and 25 healthy controls (HC). Individual e-fields of a common tDCS protocol (i.e. 2 mA stimulation intensity, bifrontal anode-F3/cathode-F4 montage) were modeled by two investigators using SimNIBS (2.0.1) based on structural MRI scans.

RESULT: On a whole-brain level, the average e-field strength was significantly reduced in MDD and SCZ compared to HC, but MDD and SCZ did not differ significantly. Regions of interest (ROI) analysis for PFC subregions showed reduced e-fields in Sallet areas 8B and 9 for MDD and SCZ compared to HC, whereas there was again no difference between MDD and SCZ. Within groups, we generally observed high inter-individual variability of e-field intensities at a higher percentile of voxels.

CONCLUSION: MRI-based e-field modeling revealed significant differences in e-field strengths between clinical and non-clinical populations in addition to a general inter-individual variability. These findings support the notion that dose-response relationships for tDCS cannot be simply transferred from healthy to clinical cohorts and need to be individually established for clinical groups. In this respect, MRI-based e-field modeling may serve as a proxy for individualized dosing.

PMID:35487132 | DOI:10.1016/j.nicl.2022.103011

Drug Alcohol Depend. 2022 Apr 9;235:109450. doi: 10.1016/j.drugalcdep.2022.109450. Online ahead of print.

ABSTRACT

BACKGROUND: Although left frontal pole (LFP) repetitive transcranial magnetic stimulation (rTMS) has been recently investigated for the treatment of different substance use disorders, there is no current evidence that it can effectively influence craving or clinical outcomes in smokers. A single session of 1 Hz rTMS over LFP is proposed to explore short-term effects of this protocol in tobacco use disorder.

METHODS: A pilot randomized trial compared 1 Hz rTMS of the LFP (n = 12) and primary motor cortex (n = 12) in a high-craving, severe nicotine dependence population (9 females, 15 males). A cigarette cue-reactivity paradigm with smoking-related and neutral visual stimuli was used for primary outcome measures. Chronic craving, dependence severity, impulsivity and cognitive measures were also obtained.

RESULTS: Compared to baseline, LFP rTMS significantly reduced cue-reactivity to both smoking-related and neutral cue types, while no change occurred in the motor cortex group. Reactivity to affectively neutral pictures was significantly reduced in the LFP vs. motor cortex analysis. There was one robust correlation between verbal memory recall score and reduction of neutral cue-reactivity.

CONCLUSIONS: LFP 1 Hz rTMS significantly reduced cigarette cue-reactivity. Association of change in cue-reactivity with verbal memory performance suggests a relationship between craving experiences and declarative memory systems that seems relevant to rTMS effects.

PMID:35487078 | DOI:10.1016/j.drugalcdep.2022.109450

Brain. 2022 Apr 29:awac157. doi: 10.1093/brain/awac157. Online ahead of print.

ABSTRACT

Activity changes in the ipsi- and contralesional parietal cortex and abnormal interhemispheric connectivity between these regions are commonly observed after stroke, however, their significance for motor recovery remains poorly understood. We here assessed the contribution of ipsilesional and contralesional anterior intraparietal cortex (aIPS) for hand motor function in eighteen recovered chronic stroke patients and eighteen healthy controls using a multimodal assessment consisting of resting-state fMRI, motor task fMRI, online-rTMS interference, and 3-D movement kinematics. Effects were compared against two control stimulation sites, i.e., contralesional M1 and a sham stimulation condition. We found that patients with good motor outcome compared to patients with more substantial residual deficits featured increased resting-state connectivity between ipsilesional aIPS and contralesional aIPS as well as between ipsilesional aIPS and dorsal premotor cortex. Moreover, interhemispheric connectivity between ipsilesional M1 and contralesional M1 as well as ipsilesional aIPS and contralesional M1 correlated with better motor performance across tasks. TMS interference at individual aIPS and M1 coordinates led to differential effects depending on the motor task that was tested, i.e., index finger-tapping, rapid pointing movements, or a reach-grasp-lift task. Interfering with contralesional aIPS deteriorated the accuracy of grasping, especially in patients featuring higher connectivity between ipsi- and contralesional aIPS. In contrast, interference with the contralesional M1 led to impaired grasping speed in patients featuring higher connectivity between bilateral M1. These findings suggest differential roles of contralesional M1 and aIPS for distinct aspects of recovered hand motor function, depending on the reorganization of interhemispheric connectivity.

PMID:35485480 | DOI:10.1093/brain/awac157

Clin Exp Rheumatol. 2022 Apr 27. doi: 10.55563/clinexprheumatol/6qb8e4. Online ahead of print.

ABSTRACT

OBJECTIVES: Fibromyalgia is a disease of unknown origin in which sleep involvement is very prevalent, and one of the main symptoms, even as prevalent as pain. In fact, one condition has been linked to the other, and the two may feedback on each other. We investigated what happens if by applying low-field magnetic stimulation in patients with fibromyalgia, it could improve sleep variables, and if this would be related to an improvement in the pain of the patients.

METHODS: We compared the results of a group of female patients with fibromyalgia, who underwent treatment for 6 weeks, with another group of patients with similar characteristics, who were not treated. The results were also compared with a group of healthy women, who served as a second control group. The Pittsburgh sleep scale was used as a sleep scale and a global clinical scale was used to assess general state.

RESULTS: A significant improvement was observed in the different items of the sleep scale applied, from the four weeks of treatment, being even more evident at the end of treatment at six weeks. A total of 82% of patients improved at the end of treatment. There was a correlation of this improvement with the overall pain situation of the patients. In addition, there was a trend towards equal sleep outcomes between treated patients and healthy subjects.

CONCLUSIONS: Treatment with low intensity magnetic stimulation could improve the sleep of fibromyalgia patients, as well as their overall clinical situation, and both processes could be interrelated.

PMID:35485408 | DOI:10.55563/clinexprheumatol/6qb8e4

Exp Brain Res. 2022 Apr 28. doi: 10.1007/s00221-022-06374-y. Online ahead of print.

ABSTRACT

The posterior parietal, premotor and motor cortices are brain regions relevant in the planning of movement. Previous transcranial magnetic stimulation (TMS) studies have shown ipsilateral premotor-to-motor inhibition in healthy subjects at rest. This premotor-to-motor inhibition has been found to be altered in patients with writer's cramp (WC), a common type of focal hand dystonia. We aimed to investigate the influence of the posterior parietal cortex on the ipsilateral ventral premotor cortex using a three single-pulse TMS paradigm. Nineteen right-handed subjects (eleven healthy volunteers and eight WC patients) completed the study. A three single-pulse TMS paradigm (preconditioning, conditioning, and test stimuli) was used to sequentially stimulate the left posterior parietal, ventral premotor, and primary motor cortices. We found that in both healthy subjects and patients, stimulating the ipsilateral posterior parietal cortex resulted in reversal of the resting premotor-to-motor inhibition. Resting premotor-to-motor inhibition was also found, with no statistically significant group difference. Furthermore, a facilitatory effect of the posterior parietal cortex on the primary motor cortex was found in both groups. Our results suggest that in the resting state, the inhibitory effect of the left posterior parietal cortex on the ipsilateral ventral premotor cortex found in healthy subjects is also intact in WC patients. While we are unable to identify any parietal-to-premotor connectivity abnormality in the resting state, an abnormality during a specific task cannot be excluded. Previously reported conductivity abnormalities in resting fMRI do not appear to translate into a TMS physiological abnormality.

PMID:35484336 | DOI:10.1007/s00221-022-06374-y

Fortschr Neurol Psychiatr. 2022 Apr 28. doi: 10.1055/a-1787-0335. Online ahead of print.

ABSTRACT

Due to the increasing number of cases of Alzheimer's disease and the relatively moderate success with the available symptomatic and causal pharmacological therapies, there is a considerable need to explore non-pharmacological treatment options. In the field of non-invasive brain stimulation (NIBS), various methods have been investigated, particularly transcranial magnetic stimulation and transcranial electrical stimulation. In addition, deep brain stimulation (DBS) is currently being researched as an innovative method for targeted neuromodulation. Both non-invasive and invasive approaches aim to modulate neuronal activity and improve cognitive-mnestic functions. Secondary mechanisms such as long-term potentiation in NIBS or neurogenesis in DBS could also achieve long-term positive effects. Preclinical and clinical studies have already shown promising results in patients in early stages of Alzheimer's disease. However, inconsistent study and stimulation protocols and small sample sizes make it difficult to assess efficacy. Further research is warranted to enable the use of non-invasive or invasive neuromodulatory approaches in clinical practice in the near future.

PMID:35483888 | DOI:10.1055/a-1787-0335

Front Hum Neurosci. 2022 Apr 11;16:860965. doi: 10.3389/fnhum.2022.860965. eCollection 2022.

ABSTRACT

BACKGROUND: We investigated whether transcranial magnetic stimulation (rTMS) over the primary somatosensory cortex (S1) and sensory stimulation (SS) could promote upper limb recovery in participants with subacute stroke.

METHODS: Participants were randomized into four groups: rTMS/Sham SS, Sham rTMS/SS, rTMS/SS, and control group (Sham rTMS/Sham SS). Participants underwent ten sessions of sham or active rTMS over S1 (10 Hz, 1,500 pulses, 120% of resting motor threshold, 20 min), followed by sham or active SS. The SS involved active sensory training (exploring features of objects and graphesthesia, proprioception exercises), mirror therapy, and Transcutaneous electrical nerve stimulation (TENS) in the region of the median nerve in the wrist (stimulation intensity as the minimum intensity at which the participants reported paresthesia; five electrical pulses of 1 ms duration each at 10 Hz were delivered every second over 45 min). Sham stimulations occurred as follows: Sham rTMS, coil was held while disconnected from the stimulator, and rTMS noise was presented with computer loudspeakers with recorded sound from a real stimulation. The Sham SS received therapy in the unaffected upper limb, did not use the mirror and received TENS stimulation for only 60 seconds. The primary outcome was the Body Structure/Function: Fugl-Meyer Assessment (FMA) and Nottingham Sensory Assessment (NSA); the secondary outcome was the Activity/Participation domains, assessed with Box and Block Test, Motor Activity Log scale, Jebsen-Taylor Test, and Functional Independence Measure.

RESULTS: Forty participants with stroke ischemic (n = 38) and hemorrhagic (n = 2), men (n = 19) and women (n = 21), in the subacute stage (10.6 ± 6 weeks) had a mean age of 62.2 ± 9.6 years, were equally divided into four groups (10 participants in each group). Significant somatosensory improvements were found in participants receiving active rTMS and active SS, compared with those in the control group (sham rTMS with sham SS). Motor function improved only in participants who received active rTMS, with greater effects when active rTMS was combined with active SS.

CONCLUSION: The combined use of SS with rTMS over S1 represents a more effective therapy for increasing sensory and motor recovery, as well as functional independence, in participants with subacute stroke.

CLINICAL TRIAL REGISTRATION: [clinicaltrials.gov], identifier [NCT03329807].

PMID:35479184 | PMC:PMC9036089 | DOI:10.3389/fnhum.2022.860965

Eur J Neurosci. 2022 Apr 28. doi: 10.1111/ejn.15677. Online ahead of print.

ABSTRACT

Somatosensory feedback to the central nervous system is essential to plan, perform and refine spine motor control. However, the influence of somatosensory afferent input from the trunk on the motor output to trunk muscles has received little attention. The objective was to compare the effects of distinct modalities of afferent stimulation on the net motoneuron and corticomotor excitability of paravertebral muscles. Fourteen individuals were recruited. Modulation of corticospinal excitability (motor-evoked potential [MEP]) of paravertebral muscles was measured when afferent stimuli (cutaneous noxious and non-noxious, muscle contraction) were delivered to the trunk at 10 intervals prior to transcranial magnetic stimulation. Each peripheral stimulation was applied alone, and subsequent electromyography (EMG) modulation was measured to control for net motoneuron excitability. MEP modulation and MEP/EMG ratio were used as measures of corticospinal excitability with and without control of net motoneuron excitability, respectively. MEP and EMG modulation were smaller after evoked muscle contraction than after cutaneous noxious and non-noxious stimuli. MEP/EMG ratio was not different between stimulation types. Both MEP and EMG amplitudes were reduced after evoked muscle contraction, but not when expressed as MEP/EMG ratio. Noxious and non-noxious stimulation had limited impact on all variables. Distinct modalities of peripheral afferent stimulation of the lumbo-sacral area differently modulated responses of paravertebral muscles, but without an influence on corticospinal excitability with control of net motoneuron excitability. Muscle stimulation reduced paravertebral activity and was best explained by spinal mechanisms. The impact of afferent stimulation on back muscles differs from the effects reported for limb muscles.

PMID:35478204 | DOI:10.1111/ejn.15677

Aging (Albany NY). 2022 Apr 27;undefined(undefined). doi: 10.18632/aging.204044. Online ahead of print.

NO ABSTRACT

PMID:35478169 | DOI:10.18632/aging.204044

J Psychiatry Neurosci. 2022 Apr 27;47(2):E153-E161. doi: 10.1503/jpn.210201. Print 2022 Mar-Apr.

ABSTRACT

BACKGROUND: At present, the use of repetitive transcranial magnetic stimulation (rTMS) for generalized anxiety disorder (GAD) is limited to single-site interventions. We investigated whether dual-site frontoparietal stimulation delivered using cortical-cortical paired associative stimulation (ccPAS) had stronger clinical efficacy than single-site stimulation in patients with GAD.

METHODS: We randomized 50 patients with GAD to 1 Hz rTMS (10 sessions) using 1 of the following protocols: single-site stimulation over the right dorsolateral prefrontal cortex (dlPFC; 1500 pulses per session); single-site stimulation over the right posterior parietal cortex (PPC; 1500 pulses per session); repetitive dual-site ccPAS (rds-ccPAS) over the right dlPFC and right PPC with 1500 pulses per session (rd-ccPAS-1500); or rds-ccPAS over the right dlPFC and right PPC with 750 pulses per session (rd-ccPAS-750). Both rds-ccPAS treatments used a between-site interval of 100 ms.

RESULTS: Clinical scores for anxiety, depression and insomnia were reduced in all 4 groups after treatment. We found greater improvements in anxiety symptoms in the rds-ccPAS-1500 group compared to the rds-ccPAS-750 and single-site groups. We found greater improvements in depression symptoms and insomnia in the rds-PAS-1500 group compared to the single-site groups. The rds-ccPAS-1500 group also showed significant or trend-level improvements in anxiety symptoms and insomnia at 10-day and 1-month followup. More patients responded to treatment with rds-ccPAS-1500 than with single-site stimulation. The between-group differences in response rates persisted to the 3-month follow-up. Treatment using rds-ccPAS with a between-site interval of 100 ms induced a more significant improvement than the between-site interval of 50 ms we evaluated in a previous study.

LIMITATIONS: These results need to be replicated in a larger sample using sham control and equal-pulse single-site stimulation.

CONCLUSION: Frontoparietal rds-ccPAS may be a better treatment option for GAD.

PMID:35477683 | DOI:10.1503/jpn.210201

J Psychopharmacol. 2022 Apr;36(4):479-488. doi: 10.1177/02698811221078751. Epub 2022 Apr 27.

ABSTRACT

BACKGROUND: Although numerous studies reported some changes of cortical silent period (CSP), an indicator of gamma-aminobutyric acid (GABA) function in central nervous system, in schizophrenia patients, it has been unknown how the disease stage and antipsychotic medication affect CSP values.

METHODS: The present study conducted a systematic review of previous literature comparing CSP between schizophrenia patients and healthy subjects, and then performed meta-analysis on the effects of (1) the disease stage and (2) antipsychotics on CSP.

RESULTS: (1) In the comparison of the disease stage comprising a total of 17 reports, there was no significant difference in CSP between patients under drug-naïve first-episode psychoses and healthy controls, or between patients with antipsychotic medication and healthy controls. (2) In the comparison of the antipsychotic class, patients treated with clozapine were longer in CSP compared to healthy controls. Patients treated with olanzapine/quetiapine or with other type of antipsychotics were not different from healthy controls. Regarding other type of antipsychotics, the iteration analysis after leaving out one literature showed that patients were shorter in CSP than healthy controls.

CONCLUSION: The results showed that clozapine seems to surely prolong CSP, indicating the enhancement of GABA transmission via GABA_B receptors, suggesting the possible relationship between the CSP prolongation by clozapine and its high efficacy in psychopathology. The finding of shorter CSP in patients with other type of antipsychotics was distinct from clozapine/olanzapine/quetiapine, but was difficult to interpret since this group included a variety of transcranial magnetic stimulation (TMS) methodologies and patients' background.

PMID:35475374 | DOI:10.1177/02698811221078751

Brain Stimul. 2022 Apr 26;15(3):695-696. doi: 10.1016/j.brs.2022.04.013. Online ahead of print.

NO ABSTRACT

PMID:35472600 | DOI:10.1016/j.brs.2022.04.013

Addiction. 2022 Apr 25. doi: 10.1111/add.15889. Online ahead of print.

ABSTRACT

BACKGROUND AND AIMS: Non-invasive brain stimulation (NIBS) methods have showed promising results for the treatment of tobacco use disorder, but little is known about the efficacy of NIBS on sustained tobacco abstinence. We aimed to assess its effectiveness for long-term smoking cessation.

METHODS: Systematic review and meta-analysis of randomized controlled trials (RCT). PubMed, Cochrane library, Embase, PsycINFO and clinical trials registries were systematically searched for relevant studies up to May 2021. Relevant studies included adult smokers seeking smoking cessation, included in an RCT using NIBS [specifically repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS)], and with follow-up of more than 4 weeks. There were no restrictions on location. Abstinence rates in the active NIBS groups were compared with abstinence rates in sham NIBS or in usual treatment groups, from 4 weeks to 12 months following the quit attempt. Smoking abstinence was measured on an intention-to-treat basis and we used risk ratios (RRs) as measures of effect size.

RESULTS: Seven studies were included (n = 699 patients). In all included studies, the control groups were receiving sham NIBS and only data from 3 to 6 months were analysable. By pooling the seven included studies, the RR of sustained abstinence of any form of NIBS relative to sham NIBS was 2.39 [95% confidence interval (CI) = 1.26-4.55; I² = 40%]. Subgroup analyses found that the RR was even higher when excitatory rTMS was used on the left dorsolateral prefrontal cortex (RR = 4.34; 95% CI = 1.69-11.18; I² = 0%) or when using deep rTMS targeting the lateral prefrontal cortex and insula bilaterally (RR = 4.64; 95% CI = 1.61-13.39; I² = 0%). A high risk of bias was found in four included studies. We also determined, using grades of recommendation, assessment, development and evaluation, that overall there was a low level of confidence in the results.

CONCLUSION: Non-invasive brain stimulation (NIBS) may improve smoking abstinence rates from 3 to 6 months after quitting smoking, compared with sham NIBS or usual treatment.

PMID:35470522 | DOI:10.1111/add.15889

Neurosci Lett. 2022 May 29;780:136653. doi: 10.1016/j.neulet.2022.136653. Epub 2022 Apr 22.

ABSTRACT

Previous reports indicate that the right ventrolateral prefrontal cortex (VLPFC) is involved in emotional regulation. However, most such studies were performed under unphysiological conditions, like the administration of transcranial direct current or repetitive transcranial magnetic stimulation. We have shown that the right VLPFC is stimulated by an acute bout of daily activity, such as cleaning. Here, we investigated the relationship between the right VLPFC and mood changes using this system. Fourteen young adults vacuumed a floor as a cleaning task and kept a standing position as a control task on separate days. The oxyhemoglobin (oxy-Hb) and deoxy-hemoglobin (deoxy-Hb) signals of the prefrontal cortex were measured during the tasks. The mood scale scores of Profile of Mood States 2nd edition (POMS) and Two-Dimensional Mood Scale (TDMS) were measured before and after both tasks. The differences in subscale scores between pre- and post-tasks in both scales were calculated as ΔPOMS and ΔTDMS. The cleaning task significantly increased the oxy-Hb signal in the bilateral VLPFC and right frontopolar, but did not affect the deoxy-Hb signals. The control task significantly decreased the oxy-Hb signal in some brain regions. The Confusion-Bewilderment score in POMS changed after the cleaning task. Importantly, the oxy-Hb signal in the right VLPFC was negatively correlated with the ΔPOMS Confusion-Bewilderment score. The activity of the right VLPFC stimulated by the cleaning task might have a correlation with the Confusion-Bewilderment mood state.

PMID:35469825 | DOI:10.1016/j.neulet.2022.136653

Neurologia (Engl Ed). 2022 Apr;37(3):199-215. doi: 10.1016/j.nrleng.2020.05.004. Epub 2020 May 24.

ABSTRACT

INTRODUCTION: A growing number of studies have evaluated the effects of transcranial magnetic stimulation (TMS) for the symptomatic treatment of multiple sclerosis (MS).

METHODS: We performed a PubMed search for articles, recent books, and recommendations from the most relevant clinical practice guidelines and scientific societies regarding the use of TMS as symptomatic treatment in MS.

CONCLUSIONS: Excitatory electromagnetic pulses applied to the affected cerebral hemisphere allow us to optimise functional brain activity, including the transmission of nerve impulses through the demyelinated corticospinal pathway. Various studies into TMS have safely shown statistically significant improvements in spasticity, fatigue, lower urinary tract dysfunction, manual dexterity, gait, and cognitive deficits related to working memory in patients with MS; however, the exact level of evidence has not been defined as the results have not been replicated in a sufficient number of controlled studies. Further well-designed, randomised, controlled clinical trials involving a greater number of patients are warranted to attain a higher level of evidence in order to recommend the appropriate use of TMS in MS patients across the board. TMS acts as an adjuvant with other symptomatic and immunomodulatory treatments. Additional studies should specifically investigate the effect of conventional repetitive TMS on fatigue in these patients, something that has yet to see the light of day.

PMID:35465914 | DOI:10.1016/j.nrleng.2020.05.004

Front Hum Neurosci. 2022 Apr 8;16:790678. doi: 10.3389/fnhum.2022.790678. eCollection 2022.

ABSTRACT

OBJECTIVE: Previous studies have demonstrated altered brain activity in strabismic amblyopia (SA). In this study, low-frequency repetitive transcranial magnetic stimulation (rTMS) was applied in children with strabismic amblyopia after they had undergone strabismus surgery. The effect of rTMS was investigated by measuring the changes of brain features using the amplitude of low-frequency fluctuation (ALFF).

MATERIALS AND METHODS: In this study, 21 SA patients (12 males and 9 females) were recruited based on their age (7-13 years old), weight, and sex. They all had SA in their left eyes and they received rTMS treatment one month after strabismus surgery. Their vision before and after surgery were categorized as pre-rTMS (PRT) and post-rTMS (POT). All participants received rTMS treatment, underwent magnetic resonance imaging (MRI), and their data were analyzed using the repeated measures t-test. The team used correlation analysis to explore the relationship between logMAR visual acuity and ALFF.

RESULTS: Pre- versus post-rTMS values of ALFF were significantly different within individuals. In the POT group, ALFF values were significantly decreased in the Angular_R (AR), Parietal_Inf_L (PIL), and Cingulum_Mid_R (CMR) while ALFF values were significantly increased in the Fusiform_R (FR) and Frontal_Inf_Orb_L(FIL) compared to the PRT stage.

CONCLUSION: Our data showed that ALFF recorded from some brain regions was changed significantly after rTMS in strabismic amblyopes. The results may infer the pathological basis of SA and demonstrate that visual function may be improved using rTMS in strabismic amblyopic patients.

PMID:35463933 | PMC:PMC9027809 | DOI:10.3389/fnhum.2022.790678