Neuromodulation for brain disorders: challenges and opportunities

Supracortical Microstimulation: Advances in Microelectrode Design and In Vivo Validation

Electrical stimulation of the brain is being developed as a treatment for an increasing number of neurological disorders. Technologies for delivering electrical stimulation are advancing rapidly and vary in specificity, coverage, and invasiveness. Supracortical microstimulation (SCMS), characterized by microelectrode contacts placed on the epidural or subdural cortical surface, achieves a balance between the advantages and limitations of other electrical stimulation technologies by delivering spatially precise activation without disrupting the integrity of the cortex. However, in vivo experiments involving SCMS have not been comprehensively summarized. Here, we review the field of SCMS, focusing on recent advances, to guide the development of clinically translatable supracortical microelectrodes. We also highlight the gaps in our understanding of the biophysical effects of this technology. Future work investigating the unique electrochemical properties of supracortical microelectrodes and validating SCMS in nonhuman primate preclinical studies can enable rapid clinical translation of innovative treatments for humans with neurological disorders.

Cellular Activity Modulation Mediated by Near Infrared-Irradiated Polydopamine Nanoparticles: In Vitro and Ex Vivo Investigation

The precise control of cell activity is crucial for understanding and potentially treating many disorders. Focusing on neurons and myotubes, recent advancements in nanotechnology have introduced photoresponsive nanoparticles as an alternative tool for modulating cell function with high spatial and temporal resolution. This approach offers a noninvasive alternative to traditional stimulation techniques, reducing potential tissue damage and improving the specificity of cell activation. Here, we introduce an approach envisioning fully organic polydopamine nanoparticles (PDNPs) to remotely modulate the activity of differentiated SH-SY5Y cells and differentiated C2C12 cells, via near-infrared (NIR) laser stimulation. Confocal microscopy imaging revealed the possibility of thermally activating individual neuron-like cells, eliciting a significant cellular response characterized by the generation of calcium transients and the subsequent release of the neurotransmitter acetylcholine. Similarly, we demonstrated the possibility of precisely triggering the muscle contraction of single myotubes. Additionally, we investigated the antioxidant properties of PDNPs, demonstrating their capacity to prevent an increase in oxidative stress levels related to an increase in intracellular temperature. Moreover, proteomic analysis revealed that a PDNP treatment could positively affect neuronal plasticity and nervous system maturation, besides promoting muscle growth and preserving its functional integrity, underscoring its potential to support both neural and musculoskeletal development. Eventually, the effect of the NIR laser irradiation in the presence of PDNPs in neuron-like cells was successfully evaluated ex vivo on brains of Drosophila melanogaster, genetically modified to express the fluorescent calcium indicator jGCaMP7c.

Trigeminal nerve stimulation in drug-resistant epilepsy: A systematic review

INTRODUCTION

Trigeminal Nerve Stimulation (TNS) is a technique that may be useful to reduce seizure burden in drug-resistant epilepsy (DRE), but its efficacy is not well characterized. This study sought to understand the application of TNS in DRE by providing a comprehensive overview of the current use and efficacy of TNS for neuromodulation in DRE.

METHODS

A systematic review examining the use of TNS for DRE was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Scopus, and Embase databases were queried; studies were included if they examined TNS for treatment of DRE in human patients and reported seizure outcomes. Demographic, clinical, TNS neurostimulation parameters, and outcome data were collected. Primary outcome measures included efficacy, measured by change in seizure frequency, and adverse events (AEs). Secondary outcomes included patient-reported metrics assessing quality of life (QoL).

RESULTS

A total of 234 studies were identified; seven met inclusion criteria, comprising a total of 148 patients. Seizure history and epilepsy characteristics varied. Mean age ranged 28.8-44.3 years, with percent male ranging 7-24 %. All studies reporting seizure frequency showed a significant reduction in seizure frequency following TNS, though follow-up time varied. Adverse events included skin irritation and headache most commonly, reported at 12 % and 11 %, respectively. No serious or life-threatening adverse effects were reported. Multiple studies reported positive changes in Beck Depression Inventory (BDI) and Quality of Life in Epilepsy (QOLIE) scores indicating an increase in quality of life and mood throughout treatment periods.

CONCLUSION

TNS is a neuromodulatory therapy for DRE. Our review suggests it is well-tolerated and can reduce seizure frequency, while improving mental health and well-being, with minimal AEs. Larger comparative studies are needed to better explore the use of TNS for treatment of DRE.

Parameter-dependent cell-type specific effects of transcranial focused ultrasound stimulation in an awake head-fixed rodent model

Objective.Transcranial focused ultrasound (tFUS) is a promising neuromodulation technique able to target shallow and deep brain structures with high precision. Previous studies have demonstrated that tFUS stimulation responses are cell-type specific, and specifically tFUS can elicit time-locked neural activity in regular spiking units (RSUs) that is sensitive to increases in pulse repetition frequency (PRF), while time-locked responses are not seen in fast spiking units (FSUs). These findings suggest a unique capability of tFUS to alter circuit network dynamics with cell-type specificity; however, these results could be biased by the use of anesthesia, which significantly modulates neural activities.Approach.In this study, we developed an awake head-fixed rat model specifically designed for simultaneous tFUS stimulation using a customized 128-element ultrasound array transducer, and recording of spiking data. Using this novel animal model, we examined a series of PRFs and burst duty cycles (DCs) to determine their effects on neuronal subpopulations without anesthesia.Main results.We observed cell type specific responses to varying PRF and DC in the awake setting as well as the anesthetized setting, with time locked responses observed in RSU and delayed responses in FSU. Anesthesia broadly was found to dampen responses to tFUS, and affected the latency of delayed responses. Preferred parameters for inducing time-locked responses appear to be 1500 Hz PRF and 60% DC.Significance.We conclude that despite some differences in response, isoflurane anesthesia is not a major confound in studying the cell-type specificity of ultrasound neuromodulation, but may affect studies of circuit dynamics and FSU. Our developed awake model will allow for future investigations without this confound.

Implantable hydrogels as pioneering materials for next-generation brain-computer interfaces

Use of brain-computer interfaces (BCIs) is rapidly becoming a transformative approach for diagnosing and treating various brain disorders. By facilitating direct communication between the brain and external devices, BCIs have the potential to revolutionize neural activity monitoring, targeted neuromodulation strategies, and the restoration of brain functions. However, BCI technology faces significant challenges in achieving long-term, stable, high-quality recordings and accurately modulating neural activity. Traditional implantable electrodes, primarily made from rigid materials like metal, silicon, and carbon, provide excellent conductivity but encounter serious issues such as foreign body rejection, neural signal attenuation, and micromotion with brain tissue. To address these limitations, hydrogels are emerging as promising candidates for BCIs, given their mechanical and chemical similarities to brain tissues. These hydrogels are particularly suitable for implantable neural electrodes due to their three-dimensional water-rich structures, soft elastomeric properties, biocompatibility, and enhanced electrochemical characteristics. These exceptional features make them ideal for signal recording, neural modulation, and effective therapies for neurological conditions. This review highlights the current advancements in implantable hydrogel electrodes, focusing on their unique properties for neural signal recording and neuromodulation technologies, with the ultimate aim of treating brain disorders. A comprehensive overview is provided to encourage future progress in this field. Implantable hydrogel electrodes for BCIs have enormous potential to influence the broader scientific landscape and drive groundbreaking innovations across various sectors.

Analgesic effect of simultaneously targeting multiple pain processing brain circuits in an aged humanized mouse model of chronic pain by transcranial focused ultrasound

Low-intensity transcranial focused ultrasound (tFUS) has recently been shown to noninvasively and non-pharmacologically modulate pain hypersensitivity with high spatial specificity and deep brain penetration. However, the lack of knowledge about its effectiveness for pain management in older subjects vulnerable to severe pain who are also at increased risk of cognitive impairment, presents significant challenges. Additionally, current opioid pain treatments require hospital visits, limiting unwanted serious side effects with multiple liabilities, and device-based pain treatments are typically administered at medical facilities with bulky and expensive equipment, limiting accessibility and thus highlighting the need for at-home non-pharmacological treatment options. Here, we present a more accessible, noninvasive tFUS pain treatment strategy for senior subjects. This approach involves simultaneously targeting multiple pain-processing circuits using a battery-powered, compact, and low-cost ultrasound analog front end (UAFE). We developed and evaluated the performance of the UAFE capable of generating sufficiently high-amplitude output with significantly lower noise levels compared to a commercial transmitter. Using a humanized sickle mouse model of chronic hyperalgesia, we found that tFUS stimulation targeting multiple pain-processing circuits effectively reduces heat hyperalgesia in aged female mice. In addition to its efficacy, our behavioral-based safety assessment revealed no adverse effects on motor functions. These results suggest that using a battery-powered, compact UAFE to simultaneously target multiple pain-processing circuits can effectively suppress heat pain-related behaviors in aged female sickle mice without negatively impacting motor coordination and balance. This highlights the potential for further development of fully home-based tFUS pain treatment for seniors.

Safety of non-invasive brain stimulation in patients with implants: a computational risk assessment

Objective.Non-invasive brain stimulation (NIBS) methodologies, such as transcranial electric stimulation (tES) are increasingly employed for therapeutic, diagnostic, or research purposes. The concurrent presence of active/passive implants can pose safety risks, affect the NIBS delivery, or generate confounding signals. A systematic investigation is required to understand the interaction mechanisms, quantify exposure, assess risks, and establish guidance for NIBS applications.Approach.We used measurements, simplified generic, and detailed anatomical modeling to: (i) systematically analyze exposure conditions with passive and active implants, considering local field enhancement, exposure dosimetry, tissue heating and neuromodulation, capacitive lead current injection, low-impedance pathways between electrode contacts, and insulation damage; (ii) identify risk metrics and efficient prediction strategies; (iii) quantify these metrics in relevant exposure cases and (iv) identify worst case conditions. Various aspects including implant design, positioning, scar tissue formation, anisotropy, and frequency were investigated.Main results.At typical tES frequencies, local enhancement of dosimetric exposure quantities can reach up to one order of magnitude for deep brain stimulation (DBS) and stereoelectroencephalography implants (more for elongated passive implants), potentially resulting in unwanted neuromodulation that can confound results but is still 2-3 orders of magnitude lower than active DBS. Under worst-case conditions, capacitive current injection in the active implants' lead can produce local exposures of similar magnitude as the passive field enhancement, while capacitive pathways between contacts are negligible. Above 10 kHz, applied current magnitudes increase, necessitating consideration of tissue heating. Furthermore, capacitive effects become more prominent, leading to current injection that can reach DBS-like levels. Adverse effects from abandoned/damaged leads in direct electrode vicinity cannot be excluded.Significance.Safety related concerns of tES application in the presence of implants are systematically identified and explored, resulting in specific and quantitative guidance and establishing basis for safety standards. Furthermore, several methods for reducing risks are suggested while acknowledging the limitations (see section4.5).

Significant reduction of seizure frequency in patients with drug-resistant epilepsy by vagus nerve stimulation: Systematic review and meta-analysis

BACKGROUND

Epilepsy is a major neurological disorder, typically managed with Anti-Seizure Medication (ASM). Nevertheless, a substantial 30 % of patients did not respond satisfactorily to ASMs, classifying their condition as Drug-Resistant Epilepsy (DRE). Vagus Nerve Stimulation (VNS) was recommended as a potential solution.

OBJECTIVE

To evaluate clinical efficacy of VNS on patients with DRE in reduction of seizures through a systematic review and meta-analysis using a random effects model.

METHODS

A systematic search was done from PubMed, ScienceDirect, Cochrane Library and Google Scholar databases on observational studies and randomized controlled trials (RCTs) for the clinical effectiveness of VNS among DRE patients. A meta-analysis was performed to obtain the pooled estimate of the clinical effectiveness of VNS in terms of seizure reduction and the odds ratio (OR) for patients achieving > 50 % seizure reduction. Heterogeneity was assessed using visual inspection of forest plots and I2 statistic.

RESULTS

A total of 1023 articles were retrieved from the electronic search. After removing duplicates, non-relevance and non-availability of efficacy data, 28 articles were included in the final analysis. Of these, 9 are RCTs and 19 are observational studies. The pooled estimate of > 50 % seizure reduction was 0.46 (95 % CI: 0.40-0.51) and the pooled estimate of the OR comparing > 50 % vs ≤ 50 % seizure reduction was 0.76 (95 % CI: 0.44-1.29).

CONCLUSION

Our meta-analysis showed that 46 % of DRE patients have experienced ≥ 50 % seizure reduction with VNS treatment. It should be considered in patients in whom ASM has failed or who continue to experience seizures after medication.

Noradrenergic and Dopaminergic modulation of meta-cognition and meta-control

Humans and animals use multiple control systems for decision-making. This involvement is subject to meta-cognitive regulation - as a form of control over control or meta-control. However, the nature of this meta-control is unclear. For instance, Model-based (MB) control may be boosted when decision-makers generally lack confidence as it is more statistically efficient; or it may be suppressed, since the MB controller can correctly assess its own unreliability. Since control and metacontrol are themselves subject to the influence of neuromodulators, we examined the effects of perturbing the noradrenergic (NE) and dopaminergic (DA) systems with propranolol and L-DOPA, respectively. We first administered a simple perceptual task to examine the effects of the manipulations on meta-cognitive ability. Using Bayesian analyses, we found that 81% of group M-ratio samples were lower under propranolol relative to placebo, suggesting a decrease of meta-cognitive ability; and 60% of group M-ratio samples were higher under L-DOPA relative to placebo, considered as no effect of L-DOPA on meta-cognitive ability . We then asked subjects to provide choices and confidence ratings in a two-outcome decision-making task that has been used to dissociate Model-free (MF) and MB control. MB behavior was enhanced by propranolol, while MF behavior was not significantly affected by either drug. The interaction between confidence and MF/MB behavior was highly variable under propranolol, but under L-DOPA, the interaction was significantly lower/higher relative to placebo. Our results suggest a decrease in metacognitive ability under the influence of propranolol and an enhancement of MB behavior and meta-control under the influence of propranolol and L-DOPA, respectively. These findings shed light on the role of NE and DA in different aspects of control and meta-control and suggest potential avenues for mitigating dysfunction.

Intracranial closed-loop neuromodulation as an intervention for neuropsychiatric disorders: an overview

Recent technological advances in intracranial brain stimulation have enhanced the potential of neuromodulation for addressing neuropsychiatric disorders. We present a review of the methodology and the preliminary outcomes of the pioneering studies exploring intracranial biomarker detection and closed-loop neuromodulation to modulate high-symptom severity states in neuropsychiatric disorders. We searched PubMed, Scopus, Web of Science, Embase, and PsycINFO/PsycNet, followed by the reference and citation lists of retrieved articles. This search strategy yielded a total of 583 articles, of which 5 articles met the inclusion criteria, focusing on depression, obsessive-compulsive disorder, post-traumatic stress disorder, and binge eating disorder. We discuss the methodology of biomarker identification, the biomarkers identified, and the preliminary treatment outcomes for closed-loop neuromodulation. Successful biomarker identification hinges on investigating across various setting. Targeted neuromodulation, either directed at the biomarker or within its associated neural network, offers a promising treatment approach. Future research should seek to understand the mechanisms underlying the effects of neuromodulation as well as the long-term viability of these treatment effects across different neuropsychiatric conditions.

Advancing Neuroscience and Therapy: Insights into Genetic and Non-Genetic Neuromodulation Approaches

Neuromodulation stands as a cutting-edge approach in the fields of neuroscience and therapeutic intervention typically involving the regulation of neural activity through physical and chemical stimuli. The purpose of this review is to provide an overview and evaluation of different neuromodulation techniques, anticipating a clearer understanding of the future developmental trajectories and the challenges faced within the domain of neuromodulation that can be achieved. This review categorizes neuromodulation techniques into genetic neuromodulation methods (including optogenetics, chemogenetics, sonogenetics, and magnetogenetics) and non-genetic neuromodulation methods (including deep brain stimulation, transcranial magnetic stimulation, transcranial direct current stimulation, transcranial ultrasound stimulation, photobiomodulation therapy, infrared neuromodulation, electromagnetic stimulation, sensory stimulation therapy, and multi-physical-factor stimulation techniques). By systematically evaluating the principles, mechanisms, advantages, limitations, and efficacy in modulating neuronal activity and the potential applications in interventions of neurological disorders of these neuromodulation techniques, a comprehensive picture is gradually emerging regarding the advantages and challenges of neuromodulation techniques, their developmental trajectory, and their potential clinical applications. This review highlights significant advancements in applying these techniques to treat neurological and psychiatric disorders. Genetic methods, such as sonogenetics and magnetogenetics, have demonstrated high specificity and temporal precision in targeting neuronal populations, while non-genetic methods, such as transcranial magnetic stimulation and photobiomodulation therapy, offer noninvasive and versatile clinical intervention options. The transformative potential of these neuromodulation techniques in neuroscience research and clinical practice is underscored, emphasizing the need for integration and innovation in technologies, the optimization of delivery methods, the improvement of mediums, and the evaluation of toxicity to fully harness their therapeutic potential.

Immediate effects of Vojta Therapy on gait ability in down syndrome patients: a pilot study

Background

Vojta Therapy (VT) is a neurorehabilitation approach that targets ontogenetic postural function and automatic body posture control. Research has shown its potential to enhance gait ability. However, limited evidence exists regarding its immediate effects on individuals with Down syndrome (DS).

Objectives

This study aimed to assess the immediate effects of one session VT on spatiotemporal gait parameters in individuals with DS.

Design

A non-randomized pilot study was conducted.

Methods

Sixteen individuals with DS (mean age: 17.88 ± 4.57 years, 8 males) participated in this study. Each received a single VT session administered by an experienced physiotherapist. Spatiotemporal gait parameters before and after VT were analyzed using the Vicon motion capture system.

Results

Significant improvements were observed in walking speed (m/s), cadence (steps/min), right step time (s), step length (cm), stride length (cm), and double support time (%GC) following the VT session (P < 0.05). These findings suggest that VT may offer immediate benefits in improving gait parameters for individuals with DS.

Conclusions

Future large-scale studies with more robust designs are necessary to explore the long-term effects of extended VT programs.

Interdisciplinary Approaches in Psychiatric Research: From Neural Dynamics to Clinical Applications in Schizophrenia

This editorial explores the dynamic psychiatric research field by focusing on interdisciplinary approaches to understand the complexity of mental disorders by placing particular emphasis on schizophrenia. It highlights the need to integrate findings from diverse scientific disciplines, such as neuroscience, computational modeling and genomics, to unravel the multifaceted nature of these conditions. The potential of interdisciplinary research to transform our knowledge and the treatment of psychiatric disorders is underscored by moving beyond traditional models and developing more nuanced frameworks to more effectively address these complexities. Thus by combining perspectives from different fields, significant advancements are expected in the diagnosis, treatment and prevention of mental disorders like schizophrenia, and will open new research and clinical practice avenues in psychiatry.

Evidence of compensatory neural hyperactivity in a subgroup of breast cancer survivors treated with chemotherapy and its association with brain aging

Introduction

Chemotherapy-related cognitive impairment (CRCI) remains poorly understood in terms of the mechanisms of cognitive decline. Neural hyperactivity has been reported on average in cancer survivors, but it is unclear which patients demonstrate this neurophenotype, limiting precision medicine in this population.

Methods

We evaluated a retrospective sample of 80 breast cancer survivors and 80 non-cancer controls, aged 35-73, for which we had previously identified and validated three data-driven, biological subgroups (biotypes) of CRCI. We measured neural activity using the z-normalized percent amplitude of fluctuation from resting-state functional magnetic resonance imaging (MRI). We tested established, quantitative criteria to determine whether hyperactivity can accurately be considered compensatory. We also calculated the brain age gap by applying a previously validated algorithm to anatomic MRI.

Results

We found that neural activity differed across the three CRCI biotypes and controls (F = 13.5, p < 0.001), with Biotype 2 demonstrating significant hyperactivity compared to the other groups (p < 0.004, corrected), primarily in prefrontal regions. Alternatively, Biotypes 1 and 3 demonstrated significant hypoactivity (p < 0.02, corrected). Hyperactivity in Biotype 2 met several of the criteria to be considered compensatory. However, we also found a positive relationship between neural activity and the brain age gap in these patients (r = 0.45, p = 0.042).

Discussion

Our results indicated that neural hyperactivity is specific to a subgroup of breast cancer survivors and, while it seems to support preserved cognitive function, it could also increase the risk of accelerated brain aging. These findings could inform future neuromodulatory interventions with respect to the risks and benefits of upregulation or downregulation of neural activity.

Highly accurate calculation of electric field for transcranial magnetic stimulation using hybridizable discontinuous galerkin method

The computation of electric field in transcranial magnetic stimulation (TMS) is essentially a problem of gradient calculation for thin layers. This paper introduces a hybrid-order hybridizable discontinuous Galerkin finite element method (HDG-FEM) and systematically demonstrates its superiority in TMS computations. The discrete format of HDG-FEM employing hybrid orders for TMS is derived and, from a fundamental numerical principle perspective, this study provides the elucidation of why HDG-FEM exhibits superior gradient computation capabilities compared to the widely used CG-FEM. Furthermore, the exceptional performance of HDG-FEM in thin layer calculation is demonstrated on both modified head models and realistic head models, focusing on three aspects: calculation errors, utilization of hybrid order, and computational cost. For the calculation of E-field in thin-layer regions with parameter mutation, the L∞ norm error of the first-order HDG-FEM with the same tetrahedral mesh is comparable to the L∞ norm error of the second-order CG-FEM. The L2 norm error of the same-order HDG-FEM is smaller than that of the same-order CG-FEM. By utilizing the hybrid order, HDG-FEM achieves a rapid reduction in errors of thin layers without a significant increase in the computational cost. This study transforms the three-dimensional TMS problem into a special two-dimensional problem for computation, reducing computational complexity from p3 in three dimensions to p2 in two dimensions, while achieving significantly higher accuracy compared to the commonly used CG-FEM. The utilization of hybrid orders in thin layers of the head demonstrates significant flexibility, making HDG-FEM a new alternative choice for TMS computations.

Effects of online and offline trigeminal nerve stimulation on visuomotor learning

Introduction

A current thrust in neurology involves using exogenous neuromodulation of cranial nerves (e.g, vagus, trigeminal) to treat the signs and symptoms of various neurological disorders. These techniques also have the potential to augment cognitive and/or sensorimotor functions in healthy individuals. Although much is known about the clinical effects of trigeminal nerve stimulation (TNS), effects on sensorimotor and cognitive functions such as learning have received less attention, despite their potential impact on neurorehabilitation. Here we describe the results of experiments aimed at assessing the effects of TNS on motor learning, which was behaviorally characterized using an upper extremity visuomotor adaptation paradigm.

Objective

Assessing the effects of TNS on motor learning.

Methods

Motor learning was behaviorally characterized using an upper extremity visuomotor adaptation paradigm. In Experiment 1, effects of offline TNS using clinically tested frequencies (120 and 60 Hz) were characterized. Sixty-three healthy young adults received TNS before performing a task that involved reaching with perturbed hand visual feedback. In Experiment 2, the effects of 120 and 60 Hz online TNS were characterized with the same task. Sixty-three new participants received either TNS or sham stimulation concurrently with perturbed visual feedback.

Results

Experiment 1 results showed that 60 Hz stimulation was associated with slower rates of learning than both sham and 120 Hz stimulation, indicating frequency-dependent effects of TNS. Experiment 2 however showed no significant differences among stimulation groups. A post-hoc, cross-study comparison of the 60 Hz offline and online TNS results showed a statistically significant improvement in learning rates with online stimulation relative to offline, pointing to timing-dependent effects of TNS on visuomotor learning.

Discussion

The results indicate that both the frequency and timing of TNS can influence rates of motor learning in healthy adults. This suggests that optimization of one or both parameters could potentially increase learning rates, which would provide new avenues for enhancing performance in healthy individuals and augmenting rehabilitation in patients with sensorimotor dysfunction resulting from stroke or other neurological disorders.

Advancements in Modern Treatment Approaches for Central Post-Stroke Pain: A Narrative Review

PURPOSE OF REVIEW

Central post-stroke pain (CPSP) poses a multifaceted challenge in medical practice, necessitating a thorough and multidisciplinary approach for its diagnosis and treatment. This review examines current methods for addressing CPSP, highlighting both pharmacological and non-pharmacological therapies. It covers the mechanisms and clinical effectiveness of these treatments in managing CPSP and emphasizes the importance of personalized treatment plans, given the varied causes of CPSP.

RECENT FINDINGS

Recent advancements have illuminated diverse treatment modalities for CPSP. Pharmacotherapy spans from conventional analgesics to anticonvulsants and antidepressants, tailored to mitigate the neuropathic characteristics of CPSP. Non-pharmacological interventions, including physical therapy and psychological strategies, are pivotal in managing CPSP's chronic nature. For cases resistant to standard treatments, advanced interventions such as nerve blocks and surgical procedures like deep brain stimulation (DBS) or motor cortex stimulation (MCS) are considered. Additionally, innovative technologies such as neuromodulation techniques and personalized medicine are emerging as promising avenues to enhance therapeutic outcomes and improve quality of life for individuals grappling with CPSP.

SUMMARY

Modern approaches in managing CPSP require an interdisciplinary and patient-centric approach. Customizing treatment plans to address the specific etiology and symptoms of CPSP is crucial. Pharmacotherapy remains fundamental, encompassing medications such as anticonvulsants and antidepressants tailored to manage neuropathic pain. Integrating non-pharmacological interventions is crucial for providing comprehensive care. Additionally, investigating innovative technologies and personalized medicine presents promising opportunities to enhance treatment results and elevate the quality of life for those suffering from CPSP. Ultimately, an integrated approach that acknowledges the multifaceted nature of CPSP is essential for effective management and patient well-being.

Navigating the Neuroimmunomodulation Frontier: Pioneering Approaches and Promising Horizons-A Comprehensive Review

The research in neuroimmunomodulation aims to shed light on the complex relationships that exist between the immune and neurological systems and how they affect the human body. This multidisciplinary field focuses on the way immune responses are influenced by brain activity and how neural function is impacted by immunological signaling. This provides important insights into a range of medical disorders. Targeting both brain and immunological pathways, neuroimmunomodulatory approaches are used in clinical pain management to address chronic pain. Pharmacological therapies aim to modulate neuroimmune interactions and reduce inflammation. Furthermore, bioelectronic techniques like vagus nerve stimulation offer non-invasive control of these systems, while neuromodulation techniques like transcranial magnetic stimulation modify immunological and neuronal responses to reduce pain. Within the context of aging, neuroimmunomodulation analyzes the ways in which immunological and neurological alterations brought on by aging contribute to cognitive decline and neurodegenerative illnesses. Restoring neuroimmune homeostasis through strategies shows promise in reducing age-related cognitive decline. Research into mood disorders focuses on how immunological dysregulation relates to illnesses including anxiety and depression. Immune system fluctuations are increasingly recognized for their impact on brain function, leading to novel treatments that target these interactions. This review emphasizes how interdisciplinary cooperation and continuous research are necessary to better understand the complex relationship between the neurological and immune systems.

Optimizing neuroscience data management by combining REDCap, BIDS and SQLite: a case study in Deep Brain Stimulation

Neuroscience studies entail the generation of massive collections of heterogeneous data (e.g. demographics, clinical records, medical images). Integration and analysis of such data in research centers is pivotal for elucidating disease mechanisms and improving clinical outcomes. However, data collection in clinics often relies on non-standardized methods, such as paper-based documentation. Moreover, diverse data types are collected in different departments hindering efficient data organization, secure sharing and compliance to the FAIR (Findable, Accessible, Interoperable, Reusable) principles. Henceforth, in this manuscript we present a specialized data management system designed to enhance research workflows in Deep Brain Stimulation (DBS), a state-of-the-art neurosurgical procedure employed to treat symptoms of movement and psychiatric disorders. The system leverages REDCap to promote accurate data capture in hospital settings and secure sharing with research institutes, Brain Imaging Data Structure (BIDS) as image storing standard and a DBS-specific SQLite database as comprehensive data store and unified interface to all data types. A self-developed Python tool automates the data flow between these three components, ensuring their full interoperability. The proposed framework has already been successfully employed for capturing and analyzing data of 107 patients from 2 medical institutions. It effectively addresses the challenges of managing, sharing and retrieving diverse data types, fostering advancements in data quality, organization, analysis, and collaboration among medical and research institutions.

Low-intensity transcranial focused ultrasound suppresses pain by modulating pain-processing brain circuits

ABSTRACT

There is an urgent and unmet clinical need to develop nonpharmacological interventions for chronic pain management because of the critical side effects of opioids. Low-intensity transcranial focused ultrasound (tFUS) is an emerging noninvasive neuromodulation technology with high spatial specificity and deep brain penetration. Here, we developed a tightly focused 128-element ultrasound transducer to specifically target small mouse brains using dynamic focus steering. We demonstrate that tFUS stimulation at pain-processing brain circuits can significantly alter pain-associated behaviors in mouse models in vivo. Our findings indicate that a single-session focused ultrasound stimulation to the primary somatosensory cortex (S1) significantly attenuates heat pain sensitivity in wild-type mice and modulates heat and mechanical hyperalgesia in a humanized mouse model of chronic pain in sickle cell disease. Results further revealed a sustained behavioral change associated with heat hypersensitivity by targeting deeper cortical structures (eg, insula) and multisession focused ultrasound stimulation to S1 and insula. Analyses of brain electrical rhythms through electroencephalography demonstrated a significant change in noxious heat hypersensitivity-related and chronic hyperalgesia-associated neural signals after focused ultrasound treatment. Validation of efficacy was carried out through control experiments, tuning ultrasound parameters, adjusting interexperiment intervals, and investigating effects on age, sex, and genotype in a head-fixed awake model. Importantly, tFUS was found to be safe, causing no adverse effects on motor function or the brain's neuropathology. In conclusion, the validated proof-of-principle experimental evidence demonstrates the translational potential of novel focused ultrasound neuromodulation for next-generation pain treatment without adverse effects.

Continuous Catheter Techniques Versus Single-Injection Nerve Blocks: A Comprehensive Review of Postoperative Pain Management Strategies

Effective postoperative pain management is crucial for optimizing patient recovery and enhancing surgical outcomes. This review compares two prominent regional anesthesia techniques, continuous catheter techniques and single-injection nerve blocks, focusing on their efficacy, safety, and impact on patient outcomes. Single-injection nerve blocks involve administering a one-time anesthetic dose to a specific nerve or plexus, offering immediate but transient pain relief. In contrast, continuous catheter techniques utilize a catheter to deliver a continuous infusion of anesthetic, providing extended analgesia. The review synthesizes current evidence on the effectiveness of each method, highlighting that single-injection blocks are advantageous for their simplicity and rapid onset but may require supplementary pain management for longer procedures. Continuous catheter techniques, while offering prolonged pain relief, carry risks such as infection and catheter displacement. The comparative analysis of these techniques reveals that both have distinct roles in postoperative care, with choice depending on the surgical procedure and patient needs. Patient satisfaction, recovery times, and overall outcomes are critical factors in determining the optimal pain management strategy. Future research should focus on refining these techniques and exploring innovations to improve patient care and pain management outcomes. This review provides insights for clinicians to make informed decisions about postoperative pain management to enhance patient comfort and recovery.

Recent Advances in Implantable Neural Interfaces for Multimodal Electrical Neuromodulation

Electrical neuromodulation plays a pivotal role in enhancing patient outcomes among individuals suffering from neurological disorders. Implantable neural interfaces are vital components of the electrical neuromodulation system to ensure desirable performance; However, conventional devices are limited to a single function and are constructed with bulky and rigid materials, which often leads to mechanical incompatibility with soft tissue and an inability to adapt to the dynamic and complex 3D structures of biological systems. In addition, current implantable neural interfaces utilized in clinical settings primarily rely on wire-based techniques, which are associated with complications such as increased risk of infection, limited positioning options, and movement restrictions. Here, the state-of-art applications of electrical neuromodulation are presented. Material schemes and device structures that can be employed to develop robust and multifunctional neural interfaces, including flexibility, stretchability, biodegradability, self-healing, self-rolling, or morphing are discussed. Furthermore, multimodal wireless neuromodulation techniques, including optoelectronics, mechano-electrics, magnetoelectrics, inductive coupling, and electrochemically based self-powered devices are reviewed. In the end, future perspectives are given.

Electrical stimulation of the dorsal motor nucleus of the vagus in male mice can regulate inflammation without affecting the heart rate

BACKGROUND

The vagus nerve plays an important role in neuroimmune interactions and in the regulation of inflammation. A major source of efferent vagus nerve fibers that contribute to the regulation of inflammation is the brainstem dorsal motor nucleus of the vagus (DMN), as recently shown using optogenetics. In contrast to optogenetics, electrical neuromodulation has broad therapeutic implications. However, the anti-inflammatory effectiveness of electrical stimulation of the DMN (eDMNS) and the possible heart rate (HR) alterations associated with this approach have not been investigated. Here, we examined the effects of eDMNS on HR and cytokine levels in mice administered with lipopolysaccharide (LPS, endotoxin) and in mice subjected to cecal ligation and puncture (CLP) sepsis.

METHODS

Anesthetized male 8-10-week-old C57BL/6 mice on a stereotaxic frame were subjected to eDMNS using a concentric bipolar electrode inserted into the left or right DMN or sham stimulation. eDMNS (500, 250 or 50 μA at 30 Hz, for 1 min) was performed and HR recorded. In endotoxemia experiments, sham or eDMNS utilizing 250 μA or 50 μA was performed for 5 mins and was followed by LPS (0.5 mg/kg) i.p. administration. eDMNS was also applied in mice with cervical unilateral vagotomy or sham operation. In CLP experiments sham or left eDMNS was performed immediately post CLP. Cytokines and corticosterone were analyzed 90 mins after LPS administration or 24 h after CLP. CLP survival was monitored for 14 days.

RESULTS

Either left or right eDMNS at 500 μA and 250 μA decreased HR, compared with baseline pre-stimulation. This effect was not observed at 50 μA. Left side eDMNS at 50 μA, compared with sham stimulation, significantly decreased serum and splenic levels of the pro-inflammatory cytokine TNF and increased serum levels of the anti-inflammatory cytokine IL-10 during endotoxemia. The anti-inflammatory effect of eDMNS was abrogated in mice with unilateral vagotomy and was not associated with serum corticosterone alterations. Right side eDMNS in endotoxemic mice suppressed serum TNF and increased serum IL-10 levels but had no effects on splenic cytokines. In mice with CLP, left side eDMNS suppressed serum IL-6, as well as splenic IL-6 and increased splenic IL-10 and significantly improved the survival rate of CLP mice.

CONCLUSIONS

For the first time we show that a regimen of eDMNS which does not cause bradycardia alleviates LPS-induced inflammation. These eDMNS anti-inflammatory effects require an intact vagus nerve and are not associated with corticosteroid alterations. eDMNS also decreases inflammation and improves survival in a model of polymicrobial sepsis. These findings are of interest for further studies exploring bioelectronic anti-inflammatory approaches targeting the brainstem DMN.

Sacral Magnetic Neuromodulation with Intermittent Theta Burst Waveform Enhances Overactive Bladder: In Vivo Study

BACKGROUND

The current treatment options for overactive bladder (OAB) continue to pose challenges for refractory cases and may involve invasive procedures. To assess the potential benefit of non-invasive repetitive peripheral magnetic stimulation (rPMS) on sacral roots using intermittent theta burst stimulation (iTBS) as treatment option for OAB. The study involved a total of 33 rats, which were divided into three different experimental phases.

MATERIALS AND METHODS

To induce bladder overactivity rats were pretreated with a continuous transvesical infusion of 0.5% acetic acid (AA). During bladder infusion, the intravesical pressure was recorded using cystometrography (CMG) to investigate the effects of AA pretreatment and the therapeutic intervention of acute sacral rPMS using iTBS.

RESULTS

Pre-application of rPMS with iTBS at a 100% intensity significantly extended the mean first voiding time (Tv) in normal healthy rats to 132%. Acute rPMS iTBS at a 100% intensity resulted in a significant increase of the inter-contraction interval (ICI) to 121%. An AA model was established with continuous saline infusion after 0.5% AA treatment and resulted in significant reductions of Tv to 42% and ICI to 56% of the corresponding control values. Subsequently, rPMS iTBS at a 100% intensity on the sacral nerve effectively inhibited AA-induced bladder overactivity and significantly increased the ICI to 167%∼222%. No significant changes in maximum bladder pressure (Pmax) were found.

CONCLUSIONS

Sacral nerve rPMS with iTBS demonstrated the ability to suppress AA-induced bladder overactivity. This promising modality could be developed as an alternative approach to enhance bladder continence in OAB syndrome patients.

Non-Invasive Brain Sensing Technologies for Modulation of Neurological Disorders

The non-invasive brain sensing modulation technology field is experiencing rapid development, with new techniques constantly emerging. This study delves into the field of non-invasive brain neuromodulation, a safer and potentially effective approach for treating a spectrum of neurological and psychiatric disorders. Unlike traditional deep brain stimulation (DBS) surgery, non-invasive techniques employ ultrasound, electrical currents, and electromagnetic field stimulation to stimulate the brain from outside the skull, thereby eliminating surgery risks and enhancing patient comfort. This study explores the mechanisms of various modalities, including transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS), highlighting their potential to address chronic pain, anxiety, Parkinson's disease, and depression. We also probe into the concept of closed-loop neuromodulation, which personalizes stimulation based on real-time brain activity. While we acknowledge the limitations of current technologies, our study concludes by proposing future research avenues to advance this rapidly evolving field with its immense potential to revolutionize neurological and psychiatric care and lay the foundation for the continuing advancement of innovative non-invasive brain sensing technologies.

An Investigation of Parameter-Dependent Cell-Type Specific Effects of Transcranial Focused Ultrasound Stimulation Using an Awake Head-Fixed Rodent Model

Transcranial focused ultrasound (tFUS) is a promising neuromodulation technique able to target shallow and deep brain structures with high precision. Previous studies have demonstrated that tFUS stimulation responses are both cell-type specific and controllable through altering stimulation parameters. Specifically, tFUS can elicit time-locked neural activity in regular spiking units (RSUs) that is sensitive to increases in pulse repetition frequency (PRF), while time-locked responses are not seen in fast spiking units (FSUs). These findings suggest a unique capability of tFUS to alter circuit network dynamics with cell-type specificity; however, these results could be biased by the use of anesthesia, which significantly modulates neural activities. In this study, we develop an awake head-fixed rat model specifically designed for tFUS study, and address a key question if tFUS still has cell-type specificity under awake conditions. Using this novel animal model, we examined a series of PRFs and burst duty cycles (DCs) to determine their effects on neuronal subpopulations without anesthesia. We conclude that cell-type specific time-locked and delayed responses to tFUS as well as PRF and DC sensitivity are present in the awake animal model and that despite some differences in response, isoflurane anesthesia is not a major confound in studying the cell-type specificity of ultrasound neuromodulation. We further determine that, in an awake, head-fixed setting, the preferred PRF and DC for inducing time-locked excitation with our pulsed tFUS paradigm are 1500 Hz and 60%, respectively.

Infrared neuromodulation-a review

Infrared (IR) neuromodulation (INM) is an emerging light-based neuromodulation approach that can reversibly control neuronal and muscular activities through the transient and localized deposition of pulsed IR light without requiring any chemical or genetic pre-treatment of the target cells. Though the efficacy and short-term safety of INM have been widely demonstrated in both peripheral and central nervous systems, the investigations of the detailed cellular and biological processes and the underlying biophysical mechanisms are still ongoing. In this review, we discuss the current research progress in the INM field with a focus on the more recently discovered IR nerve inhibition. Major biophysical mechanisms associated with IR nerve stimulation are summarized. As the INM effects are primarily attributed to the spatiotemporal thermal transients induced by water and tissue absorption of pulsed IR light, temperature monitoring techniques and simulation models adopted in INM studies are discussed. Potential translational applications, current limitations, and challenges of the field are elucidated to provide guidance for future INM research and advancement.

A longitudinal electrophysiological and behavior dataset for PD rat in response to deep brain stimulation

Here we presented an electrophysiological dataset collected from layer V of the primary motor cortex (M1) and the corresponding behavior dataset from normal and hemi-parkinson rats over 5 consecutive weeks. The electrophysiological dataset was constituted by the raw wideband signal, neuronal spikes, and local field potential (LFP) signal. The open-field test was done and recorded to evaluate the behavior variation of rats among the entire experimental cycle. We conducted technical validation of this dataset through sorting the spike data to form action potential waveforms and analyzing the spectral power of LFP data, then based on these findings a closed-loop DBS protocol was developed by the oscillation activity response of M1 LFP signal. Additionally, this protocol was applied to the hemi-parkinson rat for five consecutive days while simultaneously recording the electrophysiological data. This dataset is currently the only publicly available dataset that includes longitudinal closed-loop DBS recordings, which can be utilized to investigate variations of neuronal activity within the M1 following long-term closed-loop DBS, and explore additional reliable biomarkers.

Driving innovation in addiction treatment: role of transcranial magnetic stimulation

Addictions comprises heterogenous psychiatric conditions caused by the complex interaction of genetic, neurobiological, psychological, and environmental factors with a chronic relapsing-remitting pattern. Despite the long-standing efforts of preclinical and clinical research studies, addiction field has seen relatively slow progress when it comes to the development of new therapeutic interventions, most of which failed to demonstrate a significant efficacy. This is likely due to the very complex interplay of many factors that contribute to both the development and expression of addictions. The imbalance between the salience and the reward brain network circuitry has been proposed as the neurobiological mechanisms explaining the pathognomonic symptoms of addictions.Non-invasive neuromodulation techniques have been proposed as a promising therapeutic intervention to restore these brain circuits dysfunctions. Here, we propose a multi-level strategy to innovate the diagnosis and the treatment of addictive disorders.

Efficacy and safety of trigeminal parasympathetic pathway stimulation for dry eye: A systematic review and meta-analysis

This study aimed to investigate the efficacy and safety of trigeminal parasympathetic pathway (TPP) stimulation in the treatment of dry eye. A comprehensive search for randomized clinical trials was performed in seven databases (MEDLINE, Embase, CENTRAL, etc.) up to 28 February 2023. After screening the suitable studies, the data were extracted and transformed as necessary. Data synthesis and analysis were performed using Review Manager 5.4, and the risk of bias and quality of evidence were evaluated with the recommended tools. Fourteen studies enrolling 1714 patients with two methods (electrical and chemical) of TPP stimulation were included. Overall findings indicate that TPP stimulation was effective in reducing subjective symptom score (standardized mean difference [SMD], -0.45; 95% confidence interval [CI], -0.63 to -0.28), corneal fluorescence staining (mean difference [MD], -0.78; 95% CI, -1.39 to -0.18), goblet cell area (MD, -32.10; 95% CI, -54.58 to -9.62) and perimeter (MD, -5.90; 95% CI, -10.27 to -1.53), and increasing Schirmer's test score (SMD, 0.98; 95% CI, 0.65 to 1.31) and tear film break-up time (SMD, 0.57; 95% CI, 0.19 to 0.95). Compared to inactive or low-activity stimulation controls, it has a higher incidence of adverse events. Therefore, TPP stimulation may be an effective treatment for dry eye, whether electrical or chemical. Adverse events are relatively mild and tolerable. Due to the high heterogeneity and low level of evidence, the current conclusions require to be further verified.

Critical review of the evidence for Vojta Therapy: a systematic review and meta-analysis

Introduction

It is essential to link the theoretical framework of any neurophysiotherapy approach with a detailed analysis of the central motor control mechanisms that influence motor behavior. Vojta therapy (VT) falls within interventions aiming to modify neuronal activity. Although it is often mistakenly perceived as exclusively pediatric, its utility spans various functional disorders by acting on central pattern modulation. This study aims to review the existing evidence on the effectiveness of VT across a wide range of conditions, both in the adult population and in pediatrics, and analyze common therapeutic mechanisms, focusing on motor control modulation.

Aim

The goals of this systematic review are to delineate the existing body of evidence concerning the efficacy of Vojta therapy (VT) in treating a broad range of conditions, as well as understand the common therapeutic mechanisms underlying VT with a specific focus on the neuromodulation of motor control parameters.

Methods

PubMed, Cochrane Library, SCOPUS, Web of Science, and Embase databases were searched for eligible studies. The methodological quality of the studies was assessed using the PEDro list and the Risk-Of-Bias Tool to assess the risk of bias in randomized trials. Methodological quality was evaluated using the Risk-Of-Bias Tool for randomized trials. Random-effects meta-analyses with 95% CI were used to quantify the change scores between the VT and control groups. The certainty of our findings (the closeness of the estimated effect to the true effect) was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE).

Results

Fifty-five studies were included in the qualitative analysis and 18 in the meta-analysis. Significant differences in cortical activity (p = 0.0001) and muscle activity (p = 0.001) were observed in adults undergoing VT compared to the control, as well as in balance in those living with multiple sclerosis (p < 0.03). Non-significant differences were found in the meta-analysis when evaluating gross motor function, oxygen saturation, respiratory rate, height, and head circumference in pediatrics.

Conclusion

Although current evidence supporting VT is limited in quality, there are indications suggesting its potential usefulness for the treatment of respiratory, neurological, and orthopedic pathology. This systematic review and meta-analysis show the robustness of the neurophysiological mechanisms of VT, and that it could be an effective tool for the treatment of balance in adult neurological pathology. Neuromodulation of motor control areas has been confirmed by research focusing on the neurophysiological mechanisms underlying the therapeutic efficacy of VT.Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=476848, CRD42023476848.

Evidence of compensatory neural hyperactivity in a subgroup of chemotherapy-treated breast cancer survivors and its association with brain aging

Chemotherapy-related cognitive impairment (CRCI) remains poorly understood in terms of the mechanisms of cognitive decline. Neural hyperactivity has been reported on average in cancer survivors, but it is unclear which patients demonstrate this neurophenotype, limiting precision medicine in this population. We evaluated a retrospective sample of 80 breast cancer survivors and 80 non-cancer controls, age 35-73, for which we had previously identified and validated three data-driven, biological subgroups (biotypes) of CRCI. We measured neural activity using the z-normalized percent amplitude of fluctuation from resting state functional magnetic resonance imaging (MRI). We tested established, quantitative criteria to determine if hyperactivity can accurately be considered compensatory. We also calculated brain age gap by applying a previously validated algorithm to anatomic MRI. We found that neural activity differed across the three CRCI biotypes and controls (F = 13.5, p < 0.001), with Biotype 2 demonstrating significant hyperactivity compared to the other groups (p < 0.004, corrected), primarily in prefrontal regions. Alternatively, Biotypes 1 and 3 demonstrated significant hypoactivity (p < 0.02, corrected). Hyperactivity in Biotype 2 met several of the criteria to be considered compensatory. However, we also found a positive relationship between neural activity and brain age gap in these patients (r = 0.45, p = 0.042). Our results indicated that neural hyperactivity is specific to a subgroup of breast cancer survivors and, while it seems to support preserved cognitive function, it could also increase the risk of accelerated brain aging. These findings could inform future neuromodulatory interventions with respect to the risks and benefits of up or downregulation of neural activity.

Neuromodulation techniques in poststroke motor impairment recovery: Efficacy, challenges, and future directions

Cerebrovascular accidents, also known as strokes, represent a major global public health challenge and contribute to substantial mortality, disability, and socioeconomic burden. Multidisciplinary approaches for poststroke therapies are crucial for recovering lost functions and adapting to new limitations. This review discusses the potential of neuromodulation techniques, repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation, spinal cord stimulation (SCS), vagus nerve stimulation (VNS), and deep brain stimulation (DBS), as innovative strategies for facilitating poststroke recovery. Neuromodulation is an emerging adjunct to conventional therapies that target neural plasticity to restore lost function and compensate for damaged brain areas. The techniques discussed in this review have different efficacies in enhancing neural plasticity, optimizing motor recovery, and mitigating poststroke impairments. Specifically, rTMS has shown significant promise in enhancing motor function, whereas SCS has shown potential in improving limb movement and reducing disability. Similarly, VNS, typically used to treat epilepsy, has shown promise in enhancing poststroke motor recovery, while DBS may be used to improve poststroke motor recovery and symptom mitigation. Further studies with standardized protocols are warranted to elucidate the efficacy of these methods and integrate them into mainstream clinical practice to optimize poststroke care.

Traumatic Brain Injury and Neuromodulation Techniques in Rehabilitation: A Scoping Review

BACKGROUND AND OBJECTIVES

Traumatic Brain Injury (TBI) is a condition in which an external force, usually a violent blow to the head, causes functional impairment in the brain. Neuromodulation techniques are thought to restore altered function in the brain, resulting in improved function and reduced symptoms. Brain stimulation can alter the firing of neurons, boost synaptic strength, alter neurotransmitters and excitotoxicity, and modify the connections in their neural networks. All these are potential effects on brain activity. Accordingly, this is a promising therapy for TBI. These techniques are flexible because they can target different brain areas and vary in frequency and amplitude. This review aims to investigate the recent literature about neuromodulation techniques used in the rehabilitation of TBI patients.

MATERIALS AND METHODS

The identification of studies was made possible by conducting online searches on PubMed, Web of Science, Cochrane, Embase, and Scopus databases. Studies published between 2013 and 2023 were selected. This review has been registered on OSF (JEP3S).

RESULTS

We have found that neuromodulation techniques can improve the rehabilitation process for TBI patients in several ways. Transcranial Magnetic Stimulation (TMS) can improve cognitive functions such as recall ability, neural substrates, and overall improved performance on neuropsychological tests. Repetitive TMS has the potential to increase neural connections in many TBI patients but not in all patients, such as those with chronic diffuse axonal damage.

CONCLUSIONS

This review has demonstrated that neuromodulation techniques are promising instruments in the rehabilitation field, including those affected by TBI. The efficacy of neuromodulation can have a significant impact on their lives and improve functional outcomes for TBI patients.

40-Hz optogenetic stimulation rescues functional synaptic plasticity after stroke

Evoked brain oscillations in the gamma range have been shown to assist in stroke recovery. However, the causal relationship between evoked oscillations and neuroprotection is not well understood. We have used optogenetic stimulation to investigate how evoked gamma oscillations modulate cortical dynamics in the acute phase after stroke. Our results reveal that stimulation at 40 Hz drives activity in interneurons at the stimulation frequency and phase-locked activity in principal neurons at a lower frequency, leading to increased cross-frequency coupling. In addition, 40-Hz stimulation after stroke enhances interregional communication. These effects are observed up to 24 h after stimulation. Our stimulation protocol also rescues functional synaptic plasticity 24 h after stroke and leads to an upregulation of plasticity genes and a downregulation of cell death genes. Together these results suggest that restoration of cortical dynamics may confer neuroprotection after stroke.

Acupuncture for brain diseases: Conception, application, and exploration

The brain is probably the most complex organ in the human body. It has been the hot spot and direction of brain science research all over the world to deeply study the pathogenesis of various kinds of brain diseases and find effective treatment methods. Acupuncture is a nonpharmacological therapy of traditional Chinese medicine originating from ancient clinical practice. The research on the treatment of brain diseases by acupuncture has been constantly enriched and updated with the promotion of interdisciplinary research. In order to account for the current achievements in the field of acupuncture for brain diseases, this article reviews it in terms of conception, application, and exploration. Based on the literature review, we found that in the past decades, acupuncture has received widespread attention worldwide and many literatures have reported the clinical efficacy and underlying mechanisms of acupuncture in the treatment of brain diseases. Presently, the conception, application, and exploration of acupuncture in the treatment of brain diseases have evolved from empirical medicine to evidence-based medicine and precision medicine, and are experiencing a deeper understanding of the information about acupuncture regulating the brain function based on interdisciplinary research.

Development and Validation of an IoT Neurostimulator for the Treatment of Neurogenic Bladder

Neurogenic bladder is a dysfunction in the lower urinary tract due to damage to the nervous system. One of the treatments that has shown important results is transcutaneous neuromodulation. The neuromodulation equipment available on the market does not allow remote activation or offer many resources for adjusting the parameters of the generated stimulus, as most devices operate with pre-established parameters in closed packages. For this reason, customizing therapy for each individual can be difficult. Therefore, the objective was to develop and validate a neuromodulation device capable of being remotely programmed and properly monitored. Materials and methods for validating devices were used according to the Brazilian Regulatory Standard (NBR), which deals with general requirements for the basic safety and essential performance of electromedical devices. After verifying the reliability of the device, which was capable of generating a biphasic and symmetrical wave, measured by an oscilloscope, considered safe by the technical requirements, it was tested in a real application. Users reported feeling a comfortable stimulus, similar to other previously used devices, and considered the device easy to use. In this way, it was possible to demonstrate the reliability and validity of the developed device.

A meta-analysis on the therapeutic efficacy of repetitive transcranial magnetic stimulation for cognitive functions in attention-deficit/hyperactivity disorders

BACKGROUND

Therapeutic efficacies of repetitive transcranial magnetic stimulation (rTMS) for improving cognitive functions in patients with deficit/hyperactivity disorder (ADHD) remained unclear. The aim of this meta-analysis was to investigate the therapeutic efficacy of rTMS focusing on different cognitive performances.

METHODS

Major databases were searched electronically from inception to February 2023 by using keywords mainly "rTMS" and "ADHD" to identify randomized controlled trials (RCTs) that investigated the therapeutic efficacy of rTMS for improving cognitive functions assessed by standardized tasks in patients with ADHD. The overall effect size (ES) was calculated as standardized mean difference (SMD) based on a random effects model.

RESULTS

Meta-analysis of five RCTs with 189 participants (mean age of 32.78 and 8.53 years in adult and child/adolescent populations, respectively) demonstrated that rTMS was more effective for improving sustained attention in patients with ADHD compared with the control groups (SMD = 0.54, p = 0.001).Our secondary analysis also showed that rTMS was more effective for improving processing speed than the control groups (SMD = 0.59, p = 0.002) but not for enhancing memory or executive function.

CONCLUSIONS

Our results supported the therapeutic efficacy of rTMS for improving sustained attention and processing speed. However, the limitation of available data warrants further studies to verify these findings.

Anatomical and Functional Connectivity of Critical Deep Brain Structures and Their Potential Clinical Application in Brain Stimulation

Subcortical structures, such as the hippocampus, amygdala, and nucleus accumbens (NAcc), play crucial roles in human cognitive, memory, and emotional processing, chronic pain pathophysiology, and are implicated in various psychiatric and neurological diseases. Interventions modulating the activities of these deep brain structures hold promise for improving clinical outcomes. Recently, non-invasive brain stimulation (NIBS) has been applied to modulate brain activity and has demonstrated its potential for treating psychiatric and neurological disorders. However, modulating the above deep brain structures using NIBS may be challenging due to the nature of these stimulations. This study attempts to identify brain surface regions as source targets for NIBS to reach these deep brain structures by integrating functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI). We used resting-state functional connectivity (rsFC) and probabilistic tractography (PTG) analysis to identify brain surface stimulation targets that are functionally and structurally connected to the hippocampus, amygdala, and NAcc in 119 healthy participants. Our results showed that the medial prefrontal cortex (mPFC) is functionally and anatomically connected to all three subcortical regions, while the precuneus is connected to the hippocampus and amygdala. The mPFC and precuneus, two key hubs of the default mode network (DMN), as well as other cortical areas distributed at the prefrontal cortex and the parietal, temporal, and occipital lobes, were identified as potential locations for NIBS to modulate the function of these deep structures. The findings may provide new insights into the NIBS target selections for treating psychiatric and neurological disorders and chronic pain.

Electrical stimulation of the dorsal motor nucleus of the vagus regulates inflammation without affecting the heart rate

Background

The vagus nerve plays an important role in neuroimmune interactions and in the regulation of inflammation. A major source of efferent vagus nerve fibers that contribute to the regulation of inflammation is the brainstem dorsal motor nucleus of the vagus (DMN) as recently shown using optogenetics. In contrast to optogenetics, electrical neuromodulation has broad therapeutic implications, but the anti-inflammatory efficacy of electrical DMN stimulation (eDMNS) was not previously investigated. Here, we examined the effects of eDMNS on heart rate (HR) and cytokine levels in murine endotoxemia as well as the cecal ligation and puncture (CLP) model of sepsis.

Methods

Anesthetized male 8-10-week-old C57BL/6 mice on a stereotaxic frame were subjected to eDMNS using a concentric bipolar electrode inserted into the left or right DMN or sham stimulation. eDMNS (50, 250 or 500 μA and 30 Hz, for 1 min) was performed and HR recorded. In endotoxemia experiments, sham or eDMNS utilizing 250 μA or 50 μA was performed for 5 mins and was followed by LPS (0.5 mg/kg) i.p. administration. eDMNS was also applied in mice with cervical unilateral vagotomy or sham operation. In CLP experiments sham or left eDMNS was performed immediately post CLP. Cytokines and corticosterone were analyzed 90 mins after LPS administration or 24h after CLP. CLP survival was monitored for 14 days.

Results

Either left or right eDMNS at 250 μA and 500 μA decreased HR, compared with pre- and post-stimulation. This effect was not observed at 50 μA. Left side eDMNS at 50 μA, compared with sham stimulation, significantly decreased serum and splenic levels of the pro-inflammatory cytokine TNF and increased serum levels of the anti-inflammatory cytokine IL-10 during endotoxemia. The anti-inflammatory effect of eDMNS was abrogated in mice with unilateral vagotomy and were not associated with serum corticosterone alterations. Right side eDMNS suppressed serum TNF levels but had no effects on serum IL-10 and on splenic cytokines. In mice with CLP, left side eDMNS suppressed serum TNF and IL-6, as well as splenic IL-6 and increased splenic IL-10 and significantly improved the survival rate of CLP mice.

Conclusions

For the first time we show that a regimen of eDMNS which does not cause bradycardia alleviates LPS-induced inflammation and these effects require an intact vagus nerve and are not associated with corticosteroid alterations. eDMNS also decreases inflammation and improves survival in a model of polymicrobial sepsis. These findings are of interest for further studies exploring bioelectronic anti-inflammatory approaches targeting the brainstem DMN.

Chronic Gq activation of ventral hippocampal neurons and astrocytes differentially affects memory and behavior

Network dysfunction is implicated in numerous diseases and psychiatric disorders, and the hippocampus serves as a common origin for these abnormalities. To test the hypothesis that chronic modulation of neurons and astrocytes induces impairments in cognition, we activated the hM3D(Gq) pathway in CaMKII+ neurons or GFAP+ astrocytes within the ventral hippocampus across 3, 6, and 9 months. CaMKII-hM3Dq activation impaired fear extinction at 3 months and acquisition at 9 months. Both CaMKII-hM3Dq manipulation and aging had differential effects on anxiety and social interaction. GFAP-hM3Dq activation impacted fear memory at 6 and 9 months. GFAP-hM3Dq activation impacted anxiety in the open field only at the earliest time point. CaMKII-hM3Dq activation modified the number of microglia, while GFAP-hM3Dq activation impacted microglial morphological characteristics, but neither affected these measures in astrocytes. Overall, our study elucidates how distinct cell types can modify behavior through network dysfunction, while adding a more direct role for glia in modulating behavior.

Focused Epicranial Brain Stimulation by Spatial Sculpting of Pulsed Electric Fields Using High Density Electrode Arrays

Transcranial electrical neuromodulation of the central nervous system is used as a non-invasive method to induce neural and behavioral responses, yet targeted non-invasive electrical stimulation of the brain with high spatial resolution remains elusive. This work demonstrates a focused, steerable, high-density epicranial current stimulation (HD-ECS) approach to evoke neural activity. Custom-designed high-density (HD) flexible surface electrode arrays are employed to apply high-resolution pulsed electric currents through skull to achieve localized stimulation of the intact mouse brain. The stimulation pattern is steered in real time without physical movement of the electrodes. Steerability and focality are validated at the behavioral, physiological, and cellular levels using motor evoked potentials (MEPs), intracortical recording, and c-fos immunostaining. Whisker movement is also demonstrated to further corroborate the selectivity and steerability. Safety characterization confirmed no significant tissue damage following repetitive stimulation. This method can be used to design novel therapeutics and implement next-generation brain interfaces.

A Predictive Visual Analytics System for Studying Neurodegenerative Disease Based on DTI Fiber Tracts

Diffusion tensor imaging (DTI) has been used to study the effects of neurodegenerative diseases on neural pathways, which may lead to more reliable and early diagnosis of these diseases as well as a better understanding of how they affect the brain. We introduce a predictive visual analytics system for studying patient groups based on their labeled DTI fiber tract data and corresponding statistics. The system's machine-learning-augmented interface guides the user through an organized and holistic analysis space, including the statistical feature space, the physical space, and the space of patients over different groups. We use a custom machine learning pipeline to help narrow down this large analysis space and then explore it pragmatically through a range of linked visualizations. We conduct several case studies using DTI and T1-weighted images from the research database of Parkinson's Progression Markers Initiative.

Multi-objective optimization method for coil current waveform of transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) has been proved to be effective in the treatment of many kinds of mental diseases. However, the clicking noise produced by the pulse current with large amplitude and short duration in the TMS coil may damage the hearing of patients. The heat produced by the high-frequency pulse current in the coil also reduces the efficiency of TMS equipment. A multi-objective waveform optimization method to improve heat and noise problems at the same time is presented. By analyzing the current waveforms of TMS, the relationship between the current and the vibration energy/Joule heating is established. Taking the Joule heating and the vibration energy as the optimization objectives, exceeding the same amount of neuronal membrane potential as the limiting condition, the Pareto fronts of different current models are obtained by applying the multi-objective particle swarm optimization algorithm (MOPSO). Therefore, the corresponding current waveforms are inversely deduced. A ringing suppression cTMS (RS-cTMS) proof-of-principle experimental platform is constructed. The feasibility of the proposed method is validated through experiments. The results show that the optimized current waveforms can greatly reduce the vibration and heating of the coil compared with the conventional full-sine, recified sine and half-sine waveforms, thus reducing the pulse noise and prolonging the using time of the equipment. The optimized diversified waveforms also provide a reference for the diversity of TMS.

Weak Ultrasound Contributes to Neuromodulatory Effects in the Rat Motor Cortex

Transcranial focused ultrasound (tFUS) is a novel neuromodulating technique. It has been demonstrated that the neuromodulatory effects can be induced by weak ultrasound exposure levels (spatial-peak temporal average intensity, I_SPTA < 10 mW/cm²) in vitro. However, fewer studies have examined the use of weak tFUS to potentially induce long-lasting neuromodulatory responses in vivo. The purpose of this study was to determine the lower-bound threshold of tFUS stimulation for inducing neuromodulation in the motor cortex of rats. A total of 94 Sprague-Dawley rats were used. The sonication region aimed at the motor cortex under weak tFUS exposure (I_SPTA of 0.338-12.15 mW/cm²). The neuromodulatory effects of tFUS on the motor cortex were evaluated by the changes in motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS). In addition to histology analysis, the in vitro cell culture was used to confirm the neuromodulatory mechanisms following tFUS stimulation. In the results, the dose-dependent inhibitory effects of tFUS were found, showing increased intensities of tFUS suppressed MEPs and lasted for 30 min. Weak tFUS significantly decreased the expression of excitatory neurons and increased the expression of inhibitory GABAergic neurons. The PIEZO-1 proteins of GABAergic neurons were found to involve in the inhibitory neuromodulation. In conclusion, we show the use of weak ultrasound to induce long-lasting neuromodulatory effects and explore the potential use of weak ultrasound for future clinical neuromodulatory applications.

Targeted neurorehabilitation strategies in post-stroke aphasia

BACKGROUND

Aphasia is a debilitating language impairment, affecting millions of people worldwide. About 40% of stroke survivors develop chronic aphasia, resulting in life-long disability.

OBJECTIVE

This review examines extrinsic and intrinsic neuromodulation techniques, aimed at enhancing the effects of speech and language therapies in stroke survivors with aphasia.

METHODS

We discuss the available evidence supporting the use of transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation, and functional MRI (fMRI) real-time neurofeedback in aphasia rehabilitation.

RESULTS

This review systematically evaluates studies focusing on efficacy and implementation of specialized methods for post-treatment outcome optimization and transfer to functional skills. It considers stimulation target determination and various targeting approaches. The translation of neuromodulation interventions to clinical practice is explored, emphasizing generalization and functional communication. The review also covers real-time fMRI neurofeedback, discussing current evidence for efficacy and essential implementation parameters. Finally, we address future directions for neuromodulation research in aphasia.

CONCLUSIONS

This comprehensive review aims to serve as a resource for a broad audience of researchers and clinicians interested in incorporating neuromodulation for advancing aphasia care.

Transcranial low-intensity ultrasound stimulation for treating central nervous system disorders: A promising therapeutic application

Transcranial ultrasound stimulation is a neurostimulation technique that has gradually attracted the attention of researchers, especially as a potential therapy for neurological disorders, because of its high spatial resolution, its good penetration depth, and its non-invasiveness. Ultrasound can be categorized as high-intensity and low-intensity based on the intensity of its acoustic wave. High-intensity ultrasound can be used for thermal ablation by taking advantage of its high-energy characteristics. Low-intensity ultrasound, which produces low energy, can be used as a means to regulate the nervous system. The present review describes the current status of research on low-intensity transcranial ultrasound stimulation (LITUS) in the treatment of neurological disorders, such as epilepsy, essential tremor, depression, Parkinson's disease (PD), and Alzheimer's disease (AD). This review summarizes preclinical and clinical studies using LITUS to treat the aforementioned neurological disorders and discusses their underlying mechanisms.

Automated pose estimation in primates

Understanding the behavior of primates is important for primatology, for psychology, and for biology more broadly. It is also important for biomedicine, where primates are an important model organism, and whose behavior is often an important variable of interest. Our ability to rigorously quantify behavior has, however, long been limited. On one hand, we can rigorously quantify low-information measures like preference, looking time, and reaction time; on the other, we can use more gestalt measures like behavioral categories tracked via ethogram, but at high cost and with high variability. Recent technological advances have led to a major revolution in behavioral measurement that offers affordable and scalable rigor. Specifically, digital video cameras and automated pose tracking software can provide measures of full-body position (i.e., pose) of primates over time (i.e., behavior) with high spatial and temporal resolution. Pose-tracking technology in turn can be used to infer behavioral states, such as eating, sleeping, and mating. We call this technological approach behavioral imaging. In this review, we situate the behavioral imaging revolution in the history of the study of behavior, argue for investment in and development of analytical and research techniques that can profit from the advent of the era of big behavior, and propose that primate centers and zoos will take on a more central role in relevant fields of research than they have in the past.