Electrical Stimulation Research Articles

Electroceuticals: Unlocking the promise of therapies.

Electroceuticals refers to the constantly growing disciplines of bioelectric and bioelectronic medication. These include a broad variety of devices that have been invented and are now being utilized in medical implants, wearable medical electronics, and bioelectronics. The primary aim of this study is to encompass several facets of electroceuticals, their applications, and recent advancements in the field of medical challenges. A complete literature study was conducted, which included a comprehensive review of globally recognized scientific research databases. The progressive refinement and diminution of technology, in conjunction with swift advancements in comprehending the role of electrical pathways in the human body, have rendered it progressively viable to manipulate these pathways for therapeutic purposes. Electrical stimulation impacts and modifies biological functioning and pathological processes in the body. In the contemporary era of medicine, health care practitioners from a variety of fields utilize electricity to cure disease or injury or to assess and diagnose using a variety of electrically driven medical tools.

Acupuncture for hypoxic ischemic encephalopathy in neonates.

Peripartum asphyxia affects three to five per 1000 live births, with moderate or severe hypoxic ischemic encephalopathy (HIE) occurring in 0.5 to 1 per 1000 live births, and is associated with high mortality and morbidity. Therapeutic hypothermia is an effective treatment, but alternative therapies such as acupuncture are also used. To determine the benefits and harms of acupuncture (e.g. needle acupuncture with or without electrical stimulation; laser acupuncture; non-penetrating types of manual or embedded acupressure) on mortality and morbidity in neonates with HIE, compared with 1) no treatment, 2) placebo or sham treatment, 3) any pharmacologic treatment, or 4) different types of acupuncture. We searched CENTRAL, PubMed, Embase, ClinicalTrials.gov, and the WHO ICTRP in March 2023. We conducted a search of the grey literature to identify reports of trials conducted by or referenced in research by CORDIS EU, National Institute for Health and Care Excellence (NICE), and NHSGGC Paediatrics for Health Professionals. We also checked the reference lists of relevant articles to identify additional studies. We included randomized controlled trials (RCTs) or quasi-RCTs and cluster-randomized trials. We included studies where participants were term infants (37 weeks or greater) and late preterm infants (34 + 0 to 36 + 6 weeks' gestation) 10 days of age or less, with evidence of peripartum asphyxia. We included studies on acupuncture (e.g. needle acupuncture with or without electrical stimulation; laser acupuncture; non-penetrating types of manual or embedded acupressure). We included studies where acupuncture was compared with: 1) no treatment; 2) placebo or sham treatment; 3) any pharmacologic treatment; or 4) different types of acupuncture. We used standard Cochrane methods. Our primary outcomes were all-cause mortality at the latest follow-up, major neurodevelopmental disability in children aged 18 to 24 months and aged 3 to 5 years, adverse events until hospital discharge, and length of hospital stay. We included four studies (enrolling 464 infants) that compared acupuncture with no treatment. The studies ranged in size from 60 to 200 infants. Three studies were conducted in China and one in Russia. None of the four studies reported on any of the prespecified outcomes of our review. We did not identify any ongoing studies. There is limited availability of studies addressing this specific population. The included studies did not assess mortality, long-term neurodevelopmental outcomes, or adverse effects of acupuncture. We are unable to draw any conclusions about the benefits and harms of acupuncture for HIE in neonates. In light of the current limitations, clinicians are urged to approach the use of acupuncture in neonates with HIE cautiously, as there is no evidence to support its routine application. The available trials assessed surrogate outcomes that have a relatively small impact on newborns, and failed to report important outcomes such as mortality and long-term neurodevelopmental outcomes. Other available trials were performed on older infants who had experienced neonatal HIE. Given the lack of available evidence, well-designed randomized controlled trials with relevant outcomes such as mortality and neurodevelopmental outcomes are essential to evaluate the efficacy and safety of acupuncture for HIE in neonates.

Neuromuscular Fatigue in Hamstring and Quadriceps Muscles Following Simulated Soccer Match-Play and Typical Training Sessions.

This study investigated the mechanisms of neuromuscular fatigue and recovery in quadriceps and hamstring muscles following soccer match-play and typical training sessions dedicated to the physical development of players. Fifteen male professional academy soccer players completed at different visits a 90-minute simulated soccer match-play (MATCH) and four training sessions modulating the metabolic nature (HIIT vs. SPRINT) and the mechanical load (number of changes of direction [COD]). Neuromuscular fatigue was evaluated via changes in pre to postexercise maximal voluntary contraction (MVC), potentiated twitch force (PTw, peripheral fatigue) and voluntary activation (VA, central fatigue) evoked by electrical stimulation in quadriceps and hamstring muscles. External load was assessed via GPS units. Following MATCH, ΔMVC was similar between quadriceps (-18.3 ± 11.6%) and hamstring (-23.2 ± 10.6%) muscles. However, hamstring muscles displayed greater ΔPTw (-27.2 ± 25.0% vs. -17.2 ± 10.9%), but lower ΔVA (-8.2 ± 14.0% vs. -18.1 ± 12.7%) than quadriceps muscles. Quadriceps and hamstring muscles fatigue recovered 24 h post-match. Increasing the mechanical load (number of COD) increased the magnitude of neuromuscular fatigue in quadriceps but not in hamstring muscles. Modulating the metabolic nature of the session (SPRINT vs. HIIT) did not influence neuromuscular fatigue in either muscle group. No correlation was found between ΔMVC and a fatigue index derived from GPS metrics for any muscle groups (r2 < 0.06, P > 0.38). The magnitude and etiology of neuromuscular fatigue were modulated by the muscle group investigated and the mechanical load of the exercise task. Moreover, the 'fatigue index' derived from GPS metrics is not a valid surrogate of neuromuscular fatigue on the field.

Striatal stimulation enhances cognitive control and evidence processing in rodents and humans.

Brain disorders, in particular mental disorders, might be effectively treated by direct electrical brain stimulation, but clinical progress requires understanding of therapeutic mechanisms. Animal models have not helped, because there are no direct animal models of mental illness. Here, we propose a potential path past this roadblock, by leveraging a common ingredient of most mental disorders: impaired cognitive control. We previously showed that deep brain stimulation (DBS) improves cognitive control in humans. We now reverse translate that result using a set-shifting task in rats. DBS-like stimulation of the midstriatum improved reaction times without affecting accuracy, mirroring our human findings. Impulsivity, motivation, locomotor, and learning effects were ruled out through companion tasks and model-based analyses. To identify the specific cognitive processes affected, we applied reinforcement learning drift-diffusion modeling. This approach revealed that DBS-like stimulation enhanced evidence accumulation rates and lowered decision thresholds, improving domain-general cognitive control. Reanalysis of prior human data showed that the same mechanism applies in humans. This reverse/forward translational model could have near-term implications for clinical DBS practice and future trial design.

Improving the Performance of Electrotactile Brain–Computer Interface Using Machine Learning Methods on Multi-Channel Features of Somatosensory Event-Related Potentials

Traditional tactile brain–computer interfaces (BCIs), particularly those based on steady-state somatosensory–evoked potentials, face challenges such as lower accuracy, reduced bit rates, and the need for spatially distant stimulation points. In contrast, using transient electrical stimuli offers a promising alternative for generating tactile BCI control signals: somatosensory event-related potentials (sERPs). This study aimed to optimize the performance of a novel electrotactile BCI by employing advanced feature extraction and machine learning techniques on sERP signals for the classification of users’ selective tactile attention. The experimental protocol involved ten healthy subjects performing a tactile attention task, with EEG signals recorded from five EEG channels over the sensory–motor cortex. We employed sequential forward selection (SFS) of features from temporal sERP waveforms of all EEG channels. We systematically tested classification performance using machine learning algorithms, including logistic regression, k-nearest neighbors, support vector machines, random forests, and artificial neural networks. We explored the effects of the number of stimuli required to obtain sERP features for classification and their influence on accuracy and information transfer rate. Our approach indicated significant improvements in classification accuracy compared to previous studies. We demonstrated that the number of stimuli for sERP generation can be reduced while increasing the information transfer rate without a statistically significant decrease in classification accuracy. In the case of the support vector machine classifier, we achieved a mean accuracy over 90% for 10 electrical stimuli, while for 6 stimuli, the accuracy decreased by less than 7%, and the information transfer rate increased by 60%. This research advances methods for tactile BCI control based on event-related potentials. This work is significant since tactile stimulation is an understudied modality for BCI control, and electrically induced sERPs are the least studied control signals in reactive BCIs. Exploring and optimizing the parameters of sERP elicitation, as well as feature extraction and classification methods, is crucial for addressing the accuracy versus speed trade-off in various assistive BCI applications where the tactile modality may have added value.

Enhancing Salty Taste Perception in Stroke Patients via Anodal Electrical Stimulation to the Chin

A lower salt intake is an effective management strategy for hypertension and ultimately stroke. However, this strategy compromises the taste of food. To overcome this, a taste manipulation strategey using electronic taste simulation (ETS) has been established, but this has only been studied in healthy individuals. Therefore, this study aimed to demonstrate and quantitatively evaluate the taste enhancement effect of ETS in patients admitted to a hospital due to stroke. Twenty patients (mean = 67.8 ± 13.6 years) underwent two psychophysical experiments to assess the effects of ETS on salt taste perception using salt-impregnated filter paper. The patients’ stroke types included twelve ischemic and eight hemorrhagic strokes. The median salt taste thresholds without ETS and with ETS were 0.7% and 0.6%, respectively (p = 0.083). The perceived concentration for the 0.8% concentration increased from 0.8% to 1.0% with the ETS (p = 0.041), and for the 1.0% concentration, from 1.0% to 1.2% (p &lt; 0.001). The findings suggest that ETS significantly enhances salty taste perception in patients who have experienced a stroke without altering salt concentration, potentially aiding in reducing daily salt intake. Further research is necessary to explore its broad applicability in dietary management and blood pressure control.

Osseoconductive CaTi4-zZrz(PO4)6 Ceramics: Solutions Towards Nonunion, Osteoporosis, and Osteoarthrosis Conditions?

Transition (Ti, Zr) metal-substituted calcium hexaorthophosphate CaTi4-zZrz(PO4)6 coatings with an NaSICon structure were deposited by atmospheric plasma spraying (APS) onto Ti6Al4Veli substrates using a statistical design of experiments (SDE) methodology. Several coating properties were determined, including chemical composition, porosity, surface roughness, tensile adhesion strength, shear strength, and solubility in protein-free simulated body fluid (pf-SBF) and TRIS-HCl buffer solution. The biological performance evaluation involved cell proliferation and vitality studies and osseointegration tests of coated Ti6Al4Veli rods intramedullary implanted in sheep femora. After a 6 months observation time, a satisfactory gap-bridging potential was apparent as shown by a continuous, well-adhering layer of newly formed cortical bone. These tests suggest that the coatings possess a suitable osseoconductive potential and present an enhanced expression of bone growth-supporting non-collagenous proteins and cytokines, a high cell proliferation, spreading and vitality, and substantial osseointegration by strong bone apposition. The moderate intrinsic ionic conductivity of CaTi4-zZrz(PO4)6 compounds can be augmented by doping with highly mobile Na+ or Li+ ions to levels that suggest their use in electric bone growth stimulation (EBGS) devices, able to treat nonunion (pseudoarthrosis) and osteoporosis, and that may also support spinal stabilisation by vertebral fusion.

The Diagnosis and Treatment of Neuropathic Pain.

The reported prevalence of neuropathic pain in the general population in Germany is from 6.9% to 10%. There are both medical and surgical treatment options. This review is based on pertinent publications retrieved by a selective search in PubMed, with consideration of clinical trials, meta-analyses, and guidelines. Neuropathic pain is diagnosed when pain of the appropriate character is accompanied by further features such as hypesthesia/anesthesia, allodynia, or hyperalgesia. It is generally treated initially with drugs (antidepressant drugs, anticonvulsant drugs, opioids, topical agents, and others); the number needed to treat (NNT) is between 7 and 8 for gabapentin and 3.6 for amitryptiline, as estimated in meta-analyses. For nerve compression and entrapment syndromes, surgical decompression is a treatment directed against the cause of the problem, which can therefore be curative. Microvascular decompression (MVD) is often used to treat supposed compression syndromes of cranial nerves, above all classic trigeminal neuralgia; according to a meta-analysis, MVD brings about a pain-free state in 92.9% [89.1; 96.8] of patients after 5 months to 5 years of follow-up. Ablative surgical procedures are used for symptom control in patients with refractory and/or cancer-related pain. Further symptom-directed treatment options for medically intractable neuropathic pain include neuromodulatory techniques, which involve minimally invasive electrical stimulation of neural structures, and the chronic intrathecal application of drugs such as opioids and ziconotide. The treatment of neuropathic pain can be either cause-directed or symptom-directed, depending on its origin. Multidisciplinary collaboration can facilitate both the diagnostic evaluation and the selection of the optional modality and timing of treatment.

The psychophysical assessments of tactile, temperature and electrical perception for implants with metal prosthetic surfaces.

The tactile function and thermal perception are two primary functions of oral structures. Implants without periodontal ligament and pulp might fail to sense the tactile and temperature change. This study aimed to investigate implants' tactile, thermal, and electrical perception by detailed psychophysical assessments. A total of forty-eight patients with single implant restoration were recruited. Mechanical (5 intensities), cold (4 temperatures), and electrical stimulation were respectively applied to implants and natural teeth, and the psychophysical results were recorded with a visual analog scale (VAS) and compared between implants and natural teeth. For tactile perception, at low and medium forces, implants were significantly poorer than natural teeth (P<0.01), but at the largest force, there were no significant differences (P >0.05). Regarding thermal perception, thermal changes on implants could be detected, although the signals were weaker when compared to natural teeth (P<0.01). Implants were less sensitive to electrical stimulation than natural teeth (P<0.01). Even though there is no periodontium and pulp, dental implants could perceive the mechanical, thermal, and electrical stimulation weakly.

The Effect of Cranial Sutures Should Be Considered in Transcranial Electrical Stimulation.

Computational modeling is used to optimize transcranial electrical stimulation (tES) approaches, and the precision of these models is dependent on their anatomical accuracy. We are unaware of any computational modeling of tES that has included cranial sutures. The aims of the study were to review the literature on the timing of closure of the coronal and squamous sutures, which are situated under electrode placements used in tES; to review the literature regarding differences in skull and suture conductivity and to determine a more accurate conductivity for sutures; and to identify magnetic resonance image (MRI) techniques that could be used to detect cranial sutures. A scoping review of medical literature was conducted. We conducted computational modeling of a cranial bone plug using COMSOL Multiphysics finite element software, utilizing methodology and results from a previous study. We assessed use of the "3D Slicer" software to identify sutures in routine T1-weighted MRI scans. Reports from forensic examinations and computed tomography (CT) scans showed suture closure does not correlate with age. Our computational modeling determined a cranial suture conductivity of 0.32 S/m, which is much higher than for skull (compact skull 0.004 S/m, standard trilayer 0.013 S/m). 3D slicer enabled rapid and precise identification of the anatomy and location of cranial sutures. Cranial sutures persist throughout the lifespan and have a far higher conductivity than skull bone. Cranial sutures can be localized quickly and precisely using a combination of MRI and readily available modeling software. Sutures should be included in tES computational modeling and electroencephalography source imaging to improve the accuracy of results.

The electrochemical ion membrane system (EIMs) enhanced light reactions of photosynthesis with intermittent electrical stimulation.

Despite the widespread application of electrochemical systems in bioproduction, their detailed effects on photosynthetic organisms remain to be explored. In this study, a three-chamber electrochemical ion membrane system (EIMs) was optimized for minimizing carbon resource interference in the cathode chamber, thereby elucidating the role of EIMs in the light reactions of photosynthesis. By applying intermittent electrical stimulation, the photosynthetic activity of microalgae was enhanced, manifesting as the promoted accumulation of intracellular ATP and NADPH, while allowing the collection of hydrogen and oxygen as by-products. These findings suggest that EIMs not only facilitate photosynthesis by enhancing both light and dark reactions but also provide new avenues for improving the efficiency of photosynthetic production and advancing sustainable biotechnological processes.

The Interplay Between Muscular Activity and Pattern Recognition of Electro-Stimulated Haptic Cues During Normal Walking: A Pilot Study

This pilot study explored how muscle activation influences the pattern recognition of tactile cues delivered using electrical stimulation (ES) during each 10% window interval of the normal walking gait cycle (GC). Three healthy adults participated in the experiment. After identifying the appropriate threshold, ES as the haptic cue was applied to the gastrocnemius lateralis (GL) and biceps brachii (BB) of participants walking on a treadmill. Findings revealed variable recognition patterns across participants, with the BB showing more variability during walking due to its minimal activity compared to the actively engaged GL. Dynamic time warping (DTW) was used to assess the similarity between muscle activation and electro-stimulated haptic perception. The DTW distance between electromyography (EMG) signals and muscle recognition patterns was significantly smaller for the GL (4.87 ± 0.21, mean ± SD) than the BB (8.65 ± 1.36, mean ± SD), showing a 78.6% relative difference, indicating that higher muscle activation was generally associated with more consistent haptic perception. However, individual differences and variations in recognition patterns were observed, suggesting personal variability influenced the perception outcomes. The study underscores the complexity of human neuromuscular responses to artificial sensory stimuli and suggests a potential link between muscle activity and haptic perception.

Wrist posture unpredictably affects perception of targeted transcutaneous electrical nerve stimulation with wrist-placed electrodes

ObjectiveTargeted transcutaneous electrical nerve stimulation (tTENS) is a non-invasive neural stimulation technique that involves activating sensory nerve fibers to elicit tactile sensations in a distal, or referred, location. Though tTENS is a promising approach for delivering haptic feedback in virtual reality or for use by those with somatosensory deficits, it was not known how the perception of tTENS might be influenced by changing wrist position during sensorimotor tasks.ApproachWe worked with 12 able-bodied individuals and delivered tTENS by placing electrodes on the wrist, thus targeting the ulnar, median, and radial nerves, and eliciting tactile sensations in the hand. We recorded perceptual data across three wrist postures: neutral, 45° extension, and 45° flexion. For each posture, the participants drew where they perceived the elicited percepts on a map of the hand. They verbally reported the quality of the percepts in their own words. We also varied the pulse amplitude and width of the stimulation to generate a strength-duration curve, from which we extracted the rheobase current and chronaxie time. Linear mixed models were run on the slope and intercept of the linear fit between pulse width and pulse amplitude to investigate effects of gender, posture, and electrode placement.Main resultsAs wrist posture changed, sensation quality was modulated for half of the participants, and percept location changed for 11/12 participants. The rheobase, chronaxie, and percept sizes were influenced by wrist posture, but the direction of these changes varied by participant and therefore the effect was not systematic. The statistical models indicated interactions between posture and electrode placement, as well as an effect of gender.SignificanceIf using tTENS with electrodes placed on the wrist to convey haptic feedback during sensorimotor tasks, in which wrist posture will likely change, it may be important to characterize perception on an individual basis.

Exogenous Beta-guanidinopropionic acid administration enhances electromyostimulation-induced mitochondrial biogenesis in rat skeletal muscle

Abstract Objectives Exercise training induces several skeletal muscle adaptations. Beta-guanidinopropionic acid (β-GPA) is a creatine analog that simulates the effect of exercise to induce mitochondrial biogenesis. However, the effects of β-GPA on resistance training adaptation, such as muscle hypertrophy and mitochondrial biogenesis, are unclear. Therefore, using a resistance exercise model in rats, the present study was designed to investigate the effects of β-GPA administration on resistance training adaptations. Methods This study was approved by the Ethics Committee for Animal Experiments at Ritsumeikan University (approval number: BKC2022-009). Male Sprague Dawley rats were randomly divided into placebo or β-GPA groups. β-GPA (1000 mg/kg) was orally administered once daily, starting seven days before the initiation of electromyostimulation as a model for resistance exercise, and continued throughout the training period. Electromyostimulation was applied to the right gastrocnemius muscle via electrical stimulation every other day for a total of 12 sessions Results Peroxisome proliferators-activated receptor-γ co-activator-1α, a regulator of mitochondrial biogenesis, was significantly increased by the combination of training and β-GPA compared to the training leg (p&lt;0.05). Protein expression of Total OXPHOS, a marker of mitochondrial content, was significantly increased by the combination of training and β-GPA compared to the training leg (p&lt;0.05). β-GPA intake reduced muscle mass (main effect of β-GPA, p&lt;0.05) and was associated with muscle protein breakdown-related Fbx32 and LC3-II protein expression levels but did not counteract the increase in muscle mass caused by resistance training. Conclusions Administration of exogenous β-GPA enhanced resistance training-induced mitochondrial biogenesis. Moreover, β-GPA still permitted resistance electromyostimulation-induced muscle mass gains, but that effect was attenuated as compared to placebo.

Neuromodulation techniques in traumatic brain injury: a narrative review of the current state.

Traumatic brain injury (TBI) is a leading cause of death and disability throughout the world. Despite significant advances in medical care, many TBI survivors continue to have cognitive, physical, and psychological deficits that have a significant impact on their quality of life. Neuromodulation techniques, which use electrical or magnetic stimulation to modulate brain activity, have shown promise in the treatment of TBI symptoms. The purpose of this narrative review is to provide an overview of the current state of neuromodulation techniques for TBI, such as transcranial magnetic stimulation, transcranial direct current stimulation, deep brain stimulation, and vagus nerve stimulation. This review summarizes the evidence for using these techniques, as well as their potential mechanisms of action and limitations. Additionally, the review discusses future research directions in this field, as well as the possibility of combining neuromodulation techniques with other interventions to improve outcomes for TBI patients.

Enhancing the outcomes of bariatric surgery with inhibitory control training, electrical brain stimulation and psychosocial aftercare: a pilot study protocol

BackgroundNotwithstanding the documented short- and long-term weight loss and remission of physical and mental diseases following bariatric surgery, a significant proportion of patients fail to respond (fully) to treatment in terms of physical and mental health improvement. Mounting evidence links food-specific impulsivity, prefrontal cortex (PFC) hypoactivity and disrupted hormone secretion in bariatric surgery candidates to poorer post-surgical health outcomes. Neuromodulatory treatments like transcranial direct current stimulation (tDCS) uniquely target these neurobehavioral impairments. We present a pilot study protocol offering tDCS combined with an inhibitory control training and a structured psychosocial intervention to patients after bariatric surgery.MethodsA total of N = 20 patients are randomized to 6 sessions of verum or sham tDCS over the PFC, combined with an individualized food-specific inhibitory control training and a structured psychosocial intervention within 18 months after bariatric surgery (t0). Beyond acceptability, feasibility and satisfaction of the intervention, effects of verum versus sham tDCS on food-specific impulsivity and on secondary outcomes quality of life, general impulsivity and psychopathology, food-related cravings, eating disorder psychopathology, weight trajectory and endocrine markers are assessed 4 weeks (t1) and 3 months after the intervention (t2).DiscussionResults will provide information on the potential of combining tDCS with an inhibitory control training and a structured psychosocial intervention to enhance physical and mental outcomes after bariatric surgery. The present study may guide the development of future research with regard to tDCS as a brain-based intervention and of future post-surgical clinical programs, paving the way for randomized-controlled trials in larger samples.Trial registrationThe trial was prospectively registered on July 8, 2024, under the registration number DRKS00034620 in the German Clinical Trials Register (https://drks.de/search/de/trial/DRKS00034620).

Digital‐Analog Integrated Optoelectronic Memristor Based on Carbon Dot for Ternary Opto‐Electronic Logic and Sen‐Memory Applications

AbstractOptoelectronic memristor with light as an additional stimulus is generating interest in various remarkable optical‐electrical‐coupled applications. Herein, an optoelectronic memristor with hybrid digital‐analog switching behavior is developed by incorporating carbon dots (CDs) into the polymethylmethacrylate and the polystyrene layers as charge trapping medium. The memristor exhibits tri‐stable digital switching behavior under electro‐optical programming and analog switching behavior under optical programming. For the digital switching, the SET and RESET voltage of the memristor can be modulated through UV light illumination. Taking advantage of the cooperation of electrical and light stimuli, new ternary optoelectronic logic algorithm implementations with all‐electric or all‐optical signals as inputs are proposed. For the analog switching, the device resistance can be gradually modulated through UV light illumination and output intensity‐ and duration‐dependent characteristics. These features endow the memristor with fused image sensing‐and‐memory (sen‐memory) capability without an auxiliary bias. In addition, the sen‐memory can perform image contrast enhancement operation as the preprocessing operation of the human retina, which can improve the subsequent image recognition rate in the processing tasks. The multifunctional memristor highlights the potential for ternary optoelectronic computing and artificial vision applications, and also, is expected to expand the application scopes of CDs.

Classification of speech arrests and speech impairments during awake craniotomy: a multi-databases analysis.

Awake craniotomy presents a unique opportunity to map and preserve critical brain functions, particularly speech, during tumor resection. The ability to accurately assess linguistic functions in real-time not only enhances surgical precision, but also contributes significantly to improving postoperative outcomes. However, today, its evaluation is subjective as it relies on a clinician's observations only. This paper explores the use of a deep learning based model for the objective assessment of speech arrest and speech impairments during awake craniotomy. We extracted 1883 3-second audio clips containing the patient's response following direct electrical stimulation from 23 awake craniotomies recorded from two operating rooms of the Tokyo Women's Medical University Hospital (Japan) and two awake craniotomies recorded from the University Hospital of Brest (France). A Wav2Vec2-based model has been trained and used to detect speech arrests and speech impairments. Experiments were performed with different datasets settings and preprocessing techniques and the performances of the model were evaluated using the F1-score. The F1-score was 84.12% when the model was trained and tested on Japanese data only. In a cross-language situation, the F1-score was 74.68% when the model was trained on Japanese data and tested on French data. The results are encouraging even in a cross-language situation but further evaluation is required. The integration of preprocessing techniques, in particular noise reduction, improved the results significantly.

Effects of Transcranial Electrical Stimulation on Physiological Responses to Acute Stress: A Systematic Review

AbstractPhysiological responses to acute stress generally proceed through two phases: first, a rapid and transient sympathetic and parasympathetic nervous system response, and second, a slow and relatively sustained hypothalamic-pituitary-adrenal (HPA) response. These responses are associated with changes in heart rate, heart rate variability, electrodermal responses, blood pressure, and salivary biomarkers such as alpha amylase and cortisol. Through the interactions of biochemical responses to stress and distributed brain regions including the amygdala, hippocampus, striatum, and prefrontal cortex, acute stress exposure can also adversely affect cognitive function. Transcranial electrical stimulation (tES), including transcranial direct, alternating, and random noise stimulation (tDCS, tACS, tRNS), has been examined for its potential ability to modulate physiological responses to stress and buffer negative impacts of stress on cognitive function. This systematic review surveyed research examining the effects of tES on physiological responses to acute stress in healthy neurotypical samples, examining cardiorespiratory (e.g., blood pressure, heart rate), peripheral (e.g., electrodermal), and biochemical (e.g., alpha amylase, salivary cortisol) outcomes. Sixteen reports were identified for inclusion. The articles showed low to high risk of bias, used a diverse set of acute stress induction techniques and tES methodologies, and examined a wide range of physiological outcomes. We found mixed evidence for the effectiveness of tES in reducing acute stress responses, and suggest that some tES methodologies may be more promising than others. Several directions for continuing research are proposed to help elucidate the mechanisms underlying tES effects on acute stress responses and clarify its potential for application to cognitive enhancement domains.

Stimulation-based compassion mapping to assess risk of insular resection for surgical epilepsy management: illustrative case.

The insula is a central node in network models of compassion and empathy. Because of this, resection of the insula for the treatment of drug-resistant epilepsy can change an individual's level of compassion. Here, the authors present the clinical case of a woman with drug-resistant epilepsy localized to the nondominant insula. Because of the widespread literature implicating insular function in empathy and compassion, including lesion studies, her primary concern was changes in her compassion level after insular resection. In this case, the authors performed a novel compassion mapping paradigm before resection, using 30-second video clips to elicit compassion. This showed no changes in compassion with electrical stimulation of sites spanning the anterior insula, providing some reassurance that resection would not affect her compassion. Consistent with this, pre- and postresection testing, along with informal subjective reports by the patient, demonstrated no change in compassion or subcomponents of compassion (sadness and empathy) after right insular resection. While resection of the nondominant insular cortex warrants caution, this case illustrates a compassion mapping paradigm that reassured the clinical team and the patient that her compassion would not be affected and formal postoperative testing that was consistent with this. https://thejns.org/doi/10.3171/CASE24339.