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Driver drowsiness is one of the main factors leading to road fatalities and hazards in the transportation industry. Electroencephalography (EEG) has been considered as one of the best physiological signals to detect drivers' drowsy states, since it directly measures neurophysiological activities in the brain. However, designing a calibration-free system for driver drowsiness detection with EEG is still a challenging task, as EEG suffers from serious mental and physical drifts across different subjects. In this paper, we propose a compact and interpretable Convolutional Neural Network (CNN) to discover shared EEG features across different subjects for driver drowsiness detection. We incorporate the Global Average Pooling (GAP) layer in the model structure, allowing the Class Activation Map (CAM) method to be used for localizing regions of the input signal that contribute most for classification. Results show that the proposed model can achieve an average accuracy of 73.22% on 11 subjects for 2-class cross-subject EEG signal classification, which is higher than conventional machine learning methods and other state-of-art deep learning methods. It is revealed by the visualization technique that the model has learned biologically explainable features, e.g., Alpha spindles and Theta burst, as evidence for the drowsy state. It is also interesting to see that the model uses artifacts that usually dominate the wakeful EEG, e.g., muscle artifacts and sensor drifts, to recognize the alert state. The proposed model illustrates a potential direction to use CNN models as a powerful tool to discover shared features related to different mental states across different subjects from EEG signals. National Research Foundation (NRF) Submitted/Accepted version This research is supported by the National Research Foundation, Singapore under its International Research Centres in Singapore Funding Initiative.

BACKGROUND. Older adults with late-life depression (LLD) often experience incomplete or lack of response to first-line pharmacotherapy. The treatment of LLD could be improved using objective biological measures to predict response. Transcranial magnetic stimulation (TMS) can be used to measure cortical excitability, inhibition, and plasticity, which have been implicated in LLD pathophysiology, and associated with brain stimulation treatment outcomes in younger adults with depression. TMS measures have not yet been investigated as predictors of treatment outcomes in LLD, or pharmacotherapy outcomes in adults of any age with depression. METHODS. We assessed whether pre-treatment single-pulse and paired-pulse TMS measures, combined with clinical and demographic measures, predict venlafaxine treatment response in 76 outpatients with LLD. We compared the predictive performance of machine learning models including or excluding TMS predictors. RESULTS. Two single-pulse TMS measures predicted venlafaxine response: cortical excitability (neuronal membrane excitability), and the variability of cortical excitability (dynamic fluctuations in excitability levels). In cross-validation, models using a combination of these TMS predictors, clinical markers of treatment resistance, and age, classified patients with 73±11% balanced accuracy (average correct classification rate of responders and non-responders; permutation testing, p

To study the features of clinical course and disorders of neuromuscular transmission in patients with myasthenia gravis depending on the structural changes in the thymus, we have analyzed the results of clinical and neurophysiological examination of 78 patients. Materials and methods. Depending on the structural changes in the thymus, all patients were divided into 3 groups. The first group — 29 patients with myasthenia gravis and no changes in the structure of the thymus. The second group — 30 patients, in whom myasthenia gravis was associated with thymic hyperplasia. The third group — 19 patients with myasthenia gravis against the background of thymoma. The severity of the disease was assessed using quantitative myasthenia gravis score (QMGS) and clinical classification of Myathenia Gravis Foundation of America (MGFA), 2001. Evaluation of neuromuscular transmission was conducted based on the analysis of decrement test results and amplitude of negative phase of M-response at low-frequency indirect supramaximal stimulation of m.abductor digiti minimi and m.orbicularis oculi. Results and conclusions. Changes in the structure of the thymus have a negative impact on the course of myasthenia gravis, as evidenced by indicators of QMGS and MGFA classification. The greatest disease severity (with the prevalence of lesions of bulbar muscles) was associated with the presence of thymoma in patients, and the lowest one was noted in patients with normal thymic structure. The predominance of females in the group of patients with myasthenia gravis against the background of thymic hyperplasia may indicate the influence of hormonal state both on the structure of the thymus gland with the development of hyperplasia, and on the course of myasthenia gravis, which requires further study. We have noted a direct correlation between structural changes in the thymus and reduced amplitude of the negative phase of M-response, indicating a negative effect of morphological disorders of the thymus on neuromuscular transmission of impulses. A significant reduction in the amplitude of the negative phase of M-response on the background of high performance of decrement test may be considered as a marker of a severe course of the disease.

Objectives: To detect seed-based functional connectivity (FC) between various cortical sub-regions and the thalamus in lifelong premature ejaculation (LPE) patients and explore whether specific thalamocortical networks are significantly altered in PE patients compared to healthy controls (HCs) Methods: Fifty non-medicated LPE patients and 40 age-matched HCs underwent a resting-state functional MRI. FC was adopted to identify specific thalamocortical connectivity between the thalamus and six cortical regions of interest (i.e. the motor cortex/supplementary motor, the prefrontal cortex, the temporal lobe, the posterior parietal cortex, the somatosensory cortex and the occipital lobe). In LPE patients, regression analysis was subsequently conducted to assess relationships of thalamocortical connectivity with the Premature Ejaculation Diagnostic Tool (PEDT) score and the Intravaginal Ejaculatory Latency Time (IELT). Results: LPE patients had significantly decreased FC between the motor cortex and bilateral ventral thalamus, between the prefrontal cortex and left dorsomedial thalamus, as well as between the temporal cortex and bilateral ventromedial thalamus. In LPE patients, PEDT score was significantly positively associated with the thalamus-posterior parietal cortex FC, and negatively associated with the thalamus-temporal cortex FC, while IELT was positively associated with the thalamus-temporal cortex and thalamus-motor cortex FC. Conclusion: These results enrich the imaging evidence for the understanding of the neurobiological mechanisms and/or consequences of LPE.

Emotion classification based on neurophysiology signals has being a challenging issue in the literature. Recent neuroscience findings suggest that brain network structure underlying the different emotions provide a window in understanding human affection. In this paper, we propose a novel method to capture the distinct minimum spanning tree (MST) topology underpinning the different emotions. Specifically, we propose a hierarchical aggregation-based graph neural network to investigate the MST structure in emotion recognition. Extensive experiments on the public available DEAP dataset demonstrate the superior performance of the model in emotion classification as compared to existing methods. In addition, the results show that the theta, lower beta and gamma frequency band network information are more sensitive to emotions, suggesting a multi-frequency interaction in emotion processing.

Graphical abstract, Highlights • The development of scientific research in CIBP was elaborated in a complete and clear perspective. • The possible mechanisms, including the new achievements in central sensitization, glial cell activation, acid environment, of CIBP were reviewed. • Several key molecules and treatments as well as the potential targets and promising therapies were also briefly reviewed. • The challenges we faced and the future directions are also summarized and elaborated., Background Cancer-induced Bone Pain (CIBP) is an important factor affecting their quality of life of cancer survivors. In addition, current clinical practice and scientific research suggest that neuropathic pain is a representative component of CIBP. However, given the variability of cancer conditions and the complexity of neuropathic pain, related mechanisms have been continuously supplemented but have not been perfected. Aim of Review Therefore, the current review highlights the latest progress in basic research on the field and proposes potential therapeutic targets, representative drugs and upcoming therapies. Key Scientific Concepts of Review Notably, factors such as central sensitization, neuroinflammation, glial cell activation and an acidic environment are considered to be related to neuropathic pain in CIBP. Nonetheless, further research is needed to ascertain the mechanism of CIBP in order to develop highly effective drugs. Moreover, more attention needs to be paid to the care of patients with advanced cancer.

Driving a car requires high cognitive demands, from sustained attention to perception and action planning. Recent research investigated the neural processes reflecting the planning of driving actions, aiming to better understand the factors leading to driving errors and to devise methodologies to anticipate and prevent such errors by monitoring the driver’s cognitive state and intention. While such anticipation was shown for discrete driving actions, such as emergency braking, there is no evidence for robust neural signatures of continuous action planning. This study aims to fill this gap by investigating continuous steering actions during a driving task in a car simulator with multimodal recordings of behavioural and electroencephalography (EEG) signals. System identification is used to assess whether robust neurophysiological signatures emerge before steering actions. Linear decoding models are then used to determine whether such cortical signals can predict continuous steering actions with progressively longer anticipation. Results point to significant EEG signatures of continuous action planning. Such neural signals show consistent dynamics across participants for anticipations up to 1 s, while individual-subject neural activity could reliably decode steering actions and predict future actions for anticipations up to 1.8 s. Finally, we use canonical correlation analysis to attempt disentangling brain and non-brain contributors to the EEG-based decoding. Our results suggest that low-frequency cortical dynamics are involved in the planning of steering actions and that EEG is sensitive to that neural activity. As a result, we propose a framework to investigate anticipatory neural activity in realistic continuous motor tasks.

Contemporary biomarker collection techniques in blood and cerebrospinal fluid have to date offered only modest clinical insights into neurologic diseases such as epilepsy and glioma. Conversely, the collection of human electroencephalography (EEG) data has long been the standard of care in these patients, enabling individualized insights for therapy and revealing fundamental principles of human neurophysiology. Increasing interest exists in simultaneously measuring neurochemical biomarkers and electrophysiological data to enhance our understanding of human disease mechanisms. This review compares microdialysis, microperfusion, and implanted EEG probe architectures and performance parameters. Invasive consequences of probe implantation are also investigated along with the functional impact of biofouling. Finally, previously developed microdialysis electrodes and microperfusion electrodes are reviewed in preclinical and clinical settings. Critically, current and precedent microdialysis and microperfusion probes lack the ability to collect neurochemical data that is spatially and temporally coincident with EEG data derived from depth electrodes. This ultimately limits diagnostic and therapeutic progress in epilepsy and glioma research. However, this gap also provides a unique opportunity to create a dual-sensing technology that will provide unprecedented insights into the pathogenic mechanisms of human neurologic disease.

Objective Ketamine is an anesthetic drug associated with dissociation. Decreased electroencephalogram alpha (8–13 Hz) and low-beta (13–20 Hz) oscillation power have been associated with ketamine-induced dissociation. We aimed to characterize surface electroencephalogram signatures that may serve as biomarkers for dissociation. Methods We analyzed data from a single-site, open-label, high-density surface electroencephalogram study of ketamine anesthesia (2 mg/kg, n = 15). We assessed dissociation longitudinally using the Clinician Administered Dissociation States Scale (CADSS) and administered midazolam to attenuate dissociation and enable causal inference. We analyzed electroencephalogram power and global coherence with multitaper spectral methods. Mixed effects models were used to assess whether power and global coherence signatures of ketamine could be developed into dissociation-specific biomarkers. Results Compared to baseline, ketamine unresponsiveness was associated with increased frontal power between 0.5 to 9.3 Hz, 12.2 to 16.6 Hz, and 24.4 to 50 Hz. As subjects transitioned into a responsive but dissociated state (mean CADSS ± SD, 22.1 ± 17), there was a decrease in power between 0.5 to 10.3 Hz and 11.7 to 50 Hz. Midazolam reduced dissociation scores (14.3 ± 11.6), decreased power between 4.4 to 11.7 Hz and increased power between 14.2 to 50 Hz. Our mixed-effects model demonstrated a quadratic relationship between time and CADSS scores. When models (frontal power, occipital power, global coherence) were reanalyzed with midazolam and electroencephalogram features as covariates, only midazolam was retained. Conclusions Ketamine is associated with structured electroencephalogram power and global coherence signatures that may enable principled anesthetic state but not dissociation monitoring. Significance A neurophysiological biomarker for dissociation may lead to a better understanding of neuropsychiatric disorders.

We evaluate existing spike sorters and present a new one that resolves many sorting challenges. The new sorter, called “full binary pursuit” or FBP, comprises multiple steps. First, it thresholds and clusters to identify the waveforms of all unique neurons in the recording. Second, it uses greedy binary pursuit to optimally assign all the spike events in the original voltages to separable neurons. Third, it resolves spike events that are described more accurately as the superposition of spikes from two other neurons. Fourth, it resolves situations where the recorded neurons drift in amplitude or across electrode contacts during a long recording session. Comparison with other sorters on ground-truth data sets reveals many of the failure modes of spike sorting. We examine overall spike sorter performance in ground-truth data sets and suggest postsorting analyses that can improve the veracity of neural analyses by minimizing the intrusion of failure modes into analysis and interpretation of neural data. Our analysis reveals the tradeoff between the number of channels a sorter can process, speed of sorting, and some of the failure modes of spike sorting. FBP works best on data from 32 channels or fewer. It trades speed and number of channels for avoidance of specific failure modes that would be challenges for some use cases. We conclude that all spike sorting algorithms studied have advantages and shortcomings, and the appropriate use of a spike sorter requires a detailed assessment of the data being sorted and the experimental goals for analyses. NEW & NOTEWORTHY Electrophysiological recordings from multiple neurons across multiple channels pose great difficulty for spike sorting of single neurons. We propose methods that improve the ability to determine the number of individual neurons present in a recording and resolve near-simultaneous spike events from single neurons. We use ground-truth data sets to demonstrate the pros and cons of several current sorting algorithms and suggest strategies for determining the accuracy of spike sorting when ground-truth data are not available.

1AbstractComputational models which predict the neurophysiological response from experimental stimuli have played an important role in human neuroimaging. One type of computational model, the population receptive field (pRF), has been used to describe cortical responses at the millimeter scale using functional magnetic resonance imaging (fMRI) and electrocorticography (ECoG). However, pRF models are not widely used for non-invasive electromagnetic field measurements (EEG/MEG), because individual sensors pool responses originating from several centimeter of cortex, containing neural populations with widely varying spatial tuning. Here, we introduce a forward-modeling approach in which pRFs estimated from fMRI data are used to predict MEG sensor responses. Subjects viewed contrast-reversing bar stimuli sweeping across the visual field in separate fMRI and MEG sessions. Individual subject’s pRFs were modeled on the cortical surface at the millimeter scale using the fMRI data. We then predicted cortical time series and projected these predictions to MEG sensors using a biophysical MEG forward model, accounting for the pooling across cortex. We compared the predicted MEG responses to observed visually evoked steady-state responses measured in the MEG session. We found that pRF parameters estimated by fMRI could explain a substantial fraction of the variance in steady-state MEG sensor responses (up to 60% in individual sensors). Control analyses in which we artificially perturbed either pRF size or pRF position reduced MEG prediction accuracy, indicating that MEG data are sensitive to pRF properties derived from fMRI. Our model provides a quantitative approach to link fMRI and MEG measurements, thereby enabling advances in our understanding of spatiotemporal dynamics in human visual field maps.

Background and Study Aims Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is a highly effective therapy for primary generalized and focal dystonias, but therapeutic success is compromised by a nonresponder rate of up to 20%. Variability in electrode placement and in tissue stimulated inside the GPi may explain in part different outcomes among patients. Refinement of the target within the pallidal area could be helpful for surgery planning and clinical outcomes. The objective of this study was to discuss current and potential methodological (somatotopy, neuroimaging, and neurophysiology) aspects that might assist neurosurgical targeting of the GPi, aiming to treat generalized or focal dystonia. Methods We selected published studies by searching electronic databases and scanning the reference lists for articles that examined the anatomical and electrophysiologic aspects of the GPi in patients with idiopathic/inherited dystonia who underwent functional neurosurgical procedures. Results The sensorimotor sector of the GPi was the best target to treat dystonic symptoms, and was localized at its lateral posteroventral portion. The effective volume of tissue activated (VTA) to treat dystonia had a mean volume of 153 mm3 in the posterior GPi area. Initial tractography studies evaluated the close relation between the electrode localization and pallidothalamic tract to control dystonic symptoms.Regarding the somatotopy, the more ventral, lateral, and posterior areas of the GPi are associated with orofacial and cervical representation. In contrast, the more dorsal, medial, and anterior areas are associated with the lower limbs; between those areas, there is the representation of the upper limb. Excessive pallidal synchronization has a peak at the theta band of 3 to 8 Hz, which might be responsible for generating dystonic symptoms. Conclusions Somatotopy assessment of posteroventral GPi contributes to target-specific GPi sectors related to segmental body symptoms. Tractography delineates GPi output pathways that might guide electrode implants, and electrophysiology might assist in pointing out areas of excessive theta synchronization. Finally, the identification of oscillatory electrophysiologic features that correlate with symptoms might enable closed-loop approaches in the future.

Objectives: Neonatal hyperbilirubinemia leads to neurological damages including encephalopathy and hearing loss. This study aimed to screen and evaluate the hearing loss in neonates after recovery from hyperbilirubinemia using the Brainstem evoked response audiometry (BERA) test. Materials and Methods: This cross-sectional comparative study was conducted in Physiology Department at Chitwan Medical College, Nepal. It included 20 age and sex-matched neonates recently recovered from hyperbilirubinemia and 20 normal healthy controls. The external acoustic canals of subjects were checked for any blockage or collapse before BERA testing. The BERA recordings were performed after the neonate’s natural sleep following a standard lab protocol explained by Taylor’s Evoked Potential in Clinical Testing. Results: The BERA wave latencies were delayed with a higher number of case group neonates I (IL-75%, IR-80%), III (IIIL-70%, III R-80%), and V (VL-80%, VR-85%) than those of controls. The percentage of neonates with delayed interwave latencies was comparable between groups. The neonate’s hearing sensitivity assessed using the grades of hearing impairment by WHO revealed slight (threshold of hearing left ear [THL]-25% and threshold of hearing right ear [THR]-30%) and moderate (THL-40% and THR-35%) grades among cases whereas no impairment (THL-60% and THR-55%) in controls. The hearing thresholds were more in cases. Conclusion: The auditory pathway is highly sensitive to elevated serum bilirubin. BERA detects even a minute degree of hearing damage seen after complete treatment of hyperbilirubinemia. Therefore, BERA is a helpful tool in the early screening of hearing impairment in neonates. This improves prognosis by early management so that the neurosensory systems develop to their full extent and one can enjoy a normal social life.

PURPOSE OF REVIEW: This review article analyzes current evidence on the neurophysiology of swallowing during development and offers expert opinion on clinical implications and future research directions. RECENT FINDINGS: In the past five years, basic and clinical research has offered advances in our understanding of pediatric swallowing neurophysiology. Animal models have elucidated the role of brainstem circuits and the peripheral and central nervous system in neonatal swallowing. Recent human studies have further showcased that fetal and infant swallowing require cerebral inputs in order to develop functionally. Finally, neurophysiological and neuroimaging studies are starting to better define these cerebral inputs, as well as neuroplastic adaptations that may be needed for optimal feeding development. SUMMARY: The neural development of swallowing is a complex and dynamic process. Continued research is needed to better understand influences on swallowing neural development, which can be essential for improving prevention, diagnosis, and interventions for pediatric dysphagia.

Amyotrophic lateral sclerosis is a devastating disease characterized primarily by motor system degeneration, with clinical evidence of cognitive and behavioural change in up to 50% of cases. Amyotrophic lateral sclerosis is both clinically and biologically heterogeneous. Subgrouping is currently undertaken using clinical parameters, such as site of symptom onset (bulbar or spinal), burden of disease (based on the modified El Escorial Research Criteria) and genomics in those with familial disease. However, with the exception of genomics, these subcategories do not take into account underlying disease pathobiology, and are not fully predictive of disease course or prognosis. Recently, we have shown that resting-state EEG can reliably and quantitatively capture abnormal patterns of motor and cognitive network disruption in amyotrophic lateral sclerosis. These network disruptions have been identified across multiple frequency bands, and using measures of neural activity (spectral power) and connectivity (comodulation of activity by amplitude envelope correlation and synchrony by imaginary coherence) on source-localized brain oscillations from high-density EEG. Using data-driven methods (similarity network fusion and spectral clustering), we have now undertaken a clustering analysis to identify disease subphenotypes and to determine whether different patterns of disruption are predictive of disease outcome. We show that amyotrophic lateral sclerosis patients (n = 95) can be subgrouped into four phenotypes with distinct neurophysiological profiles. These clusters are characterized by varying degrees of disruption in the somatomotor (α-band synchrony), frontotemporal (β-band neural activity and γl-band synchrony) and frontoparietal (γl-band comodulation) networks, which reliably correlate with distinct clinical profiles and different disease trajectories. Using an in-depth stability analysis, we show that these clusters are statistically reproducible and robust, remain stable after reassessment using a follow-up EEG session, and continue to predict the clinical trajectory and disease outcome. Our data demonstrate that novel phenotyping using neuroelectric signal analysis can distinguish disease subtypes based exclusively on different patterns of network disturbances. These patterns may reflect underlying disease neurobiology. The identification of amyotrophic lateral sclerosis subtypes based on profiles of differential impairment in neuronal networks has clear potential in future stratification for clinical trials. Advanced network profiling in amyotrophic lateral sclerosis can also underpin new therapeutic strategies that are based on principles of neurobiology and designed to modulate network disruption.

Актуальність. Розробка сучасних інтенсивних технологій реабілітації пацієнтів iз дитячим церебральним паралічем (ДЦП), спрямованих на покращення різних аспектів функціонування дитини, є актуальним завданням фахівців­практиків та дослідників. Одним iз таких підходів є система інтенсивної нейрофізіологічної реабілітації (СІНР), що поєднує різнопланові методи лікування, спрямовані на досягнення функціональних цілей та об’єднані в один інтенсивний курс. Метою дослідження була оцінка змін великих моторних функцій, спастичності м’язів та об’єму пасивних рухів у суглобах у пацієнтів із спастичними формами ДЦП після двотижневого курсу лікування за СІНР. Матеріали та методи. Одностороннє сліпе дослідження було проведене в групі з 57 дітей віком від 4 до 12 років зі спастичними формами ДЦП, які проходили курс лікування у спеціалізованій реабілітаційній клініці. Пацієнтів обстежували до та після двотижневого курсу лікування за СІНР, що включав численні втручання загальною тривалістю 4–5 годин на добу. Виконання пацієнтом завдань тесту щодо оцінки великих моторних функцій (GMFM­66) записувалося на відео та оцінювалося незалежно двома фахівцями. Час запису (до чи після лікування) був замаскований. Об’єм пасивних рухів в суглобах нижніх кінцівок оцінювали за допомогою гоніометра, м’язову спастичність — модифікованої шкали Ашворта. Результати. Після курсу лікування за СІНР відмічене статистично вірогідне підвищення результату тесту GMFM­66 з 58,8 до 60,2 бала, iз середньою різницею 1,4 ± 2,9 бала. Істотне покращення об’єму пасивних рухів було відзначене при виконаннi 5 з 7 рухiв, найбільш виражене при приведенні кульшового суглоба — в середньому на 8,0 ± 5,8 градуса та тильному згинанні стопи — на 8,0 ± 6,1 градуса. Зниження м’язового тонусу спостерігалось у всіх інших м’язових групах, що оцінювалися. Статистично вірогідне зниження спастичності відзначене в згиначах стегна, iз середнім зниженням на 0,25 пункту за шкалою Ашворта (95% довірчий інтервал (ДІ) = 0,06–0,44), та аддукторах стегна — на 0,30 пункту (95% ДІ = 0,08–0,51). Висновки. Після двотижневого курсу лікування за СІНР зареєстровані покращення великих мотор­них функцій, збільшення об’єму пасивних рухів і зниження спастичності м’язів нижніх кінцівок. Інтенсивна реабілітація за СІНР потребує проведення подальших досліджень, у тому числі рандомізованих контрольованих.

The stretching of a myopic eye is associated with several structural and functional changes in the retina and posterior segment of the eye. Recent research highlights the role of retinal signaling in ocular growth. Evidence from studies conducted on animal models and humans suggests that visual mechanisms regulating refractive development are primarily localized at the retina and that the visual signals from the retinal periphery are also critical for visually guided eye growth. Therefore, it is important to study the structural and functional changes in the retina in relation to refractive errors. This review will specifically focus on electroretinogram (ERG) changes in myopia and their implications in understanding the nature of retinal functioning in myopic eyes. Based on the available literature, we will discuss the fundamentals of retinal neurophysiology in the regulation of vision-dependent ocular growth, findings from various studies that investigated global and localized retinal functions in myopia using various types of ERGs.

Introduction. Dynamic monitoring and evaluation of the results of therapy of patients with malignant brain diseases is a complex and urgent problem in modern medicine. The aim of the study was to assess the reliability of the transcranial magnetic stimulation technique as a tool for neurophysiological monitoring in patients with malignant brain tumors. Material and methods. Two groups of patients were formed: adults with large focal solitary lesions of the central nervous system (glioma) (n=20), who underwent radiotherapy, and a control comparison group (n=16). All patients underwent diagnostic transcranial magnetic stimulation before and after treatment. Results. In the main group the application of transcranial magnetic stimulation in dynamics allowed to reveal reliable improvement of conduction along the central motor pathways (increase in amplitude of the evoked motor response). The obtained data of neurophysiological examination correlated with clinical improvement in the patient group. Discussion. Some parameters of the motor evoked response (MEP) changed reliably, as after the radiation treatment performed. Obtained changes (amplitude of MEP and, especially, its threshold) to the greatest extent reflect functional state of cortical motoneurons, as well as their anatomical preservation in case of organic changes. Before therapy in all cases there was a reliable tendency to a smaller amplitude and a higher threshold of cortical MEPs, which reflects a decrease in the functional activity of motor cortex neurons; a slower central motor conduction time also draws attention. These changes had a universal character and were registered in all patients. Conclusion. Diagnostic transcranial magnetic stimulation, taking into account age limitations inherent to it as a technique, is a valuable additional neurophysiological technique. It is safe, inexpensive and does not require expensive consumables, and is applicable to a wide range of diseases.

Although neuropathy remains one of the most problematic issues faced by leprosy patients, the evolving process of its findings continues a challenge particularly in pure neural leprosy (PNL). We evaluated neurological examination, nerve conduction studies and histhopathological data of patients with PNL and ulnar neuropathy. Patients with longer duration of symptoms had reduction in the motor conduction velocities and patients with fibrosis in the biopsy had axonal damage in the nerve conduction studies. This suggests that focal demyelination may be present in leprosy patients at the moment of the diagnosis and be related to the duration of the neuropathy.

Single intradermal injections of nerve growth factor (NGF) evoke prolonged but temporally distinct sensitization patterns to somatosensory stimuli. Focal administration of the non-histaminergic pruritogen cowhage but not histamine resulted in elevated itch at day 21 after NGF administration. Here, we injected bovine adrenal medulla peptide 8–22 (BAM8–22), β-alanine (β-ALA) and endothelin-1 (ET-1) into NGF-treated skin of 11 healthy volunteers and investigated the corresponding itch/pain and flare reactions. β-ALA was the weakest pruritogen, while BAM8–22 and ET-1 were equally potent as histamine. NGF did not sensitize itch or flare reactions induced by any compound, but injection and evoked pain were increased at day 21 and 49. The involvement of histamine H1 receptors in itch was explored in eight subjects after oral cetirizine. ET-1-induced itch and flare were significantly reduced. BAM8–22 and β-ALA itch were not affected, but flare responses after BAM8–22 reduced by 50%. The results indicate that a single NGF injection does not sensitize for experimentally induced itch but increases pain upon pruritogen injection. In healthy humans, pruritic and algetic processing appear differentially regulated by NGF. However, in patients suffering chronic itch, prolonged elevation of NGF-levels under inflammatory conditions may contribute to elevated itch.

Recent developments in performance and practicality of optically-pumped magnetometers (OPMs) have enabled new capabilities in non-invasive brain function mapping through magnetoencephalography. In particular, the lack of cryogenic operating conditions allows for more flexible placement of sensor heads closer to the brain, leading to improved spatial resolution and source localisation capabilities. Through recording visually evoked brain fields (VEFs), we demonstrate that the closer sensor proximity can be exploited to improve temporal resolution. We use OPMs, and superconducting quantum interference devices (SQUIDs) for reference, to measure brain responses to flash and pattern reversal stimuli. We find highly reproducible signals with consistency across multiple participants, stimulus paradigms and sensor modalities. The temporal resolution advantage of OPMs is manifest in a twofold improvement, compared to SQUIDs. The capability for improved spatio-temporal signal tracing is illustrated by simultaneous vector recordings of VEFs in the primary and associative visual cortex, where a time lag on the order of 10–20 ms is consistently found. This paves the way for further spatio-temporal studies of neurophysiological signal tracking in visual stimulus processing, and other brain responses, with potentially far-reaching consequences for time-critical mapping of functionality in healthy and pathological brains.

Exercise is beneficial for brain health, inducing neuroplasticity and vascular plasticity in the hippocampus, which is possibly mediated by brain-derived neurotrophic factor (BDNF) levels. Here we investigated the short-term effects of exercise, to determine if a 1-week intervention is sufficient to induce brain changes. Fifteen healthy young males completed five supervised exercise training sessions over seven days. This was preceded and followed by a multi-modal magnetic resonance imaging (MRI) scan (diffusion-weighted MRI, perfusion-weighted MRI, dual-calibrated functional MRI) acquired 1 week apart, and blood sampling for BDNF. A diffusion tractography analysis showed, after exercise, a significant reduction relative to baseline in restricted fraction—an axon-specific metric—in the corpus callosum, uncinate fasciculus, and parahippocampal cingulum. A voxel-based approach found an increase in fractional anisotropy and reduction in radial diffusivity symmetrically, in voxels predominantly localised in the corpus callosum. A selective increase in hippocampal blood flow was found following exercise, with no change in vascular reactivity. BDNF levels were not altered. Thus, we demonstrate that 1 week of exercise is sufficient to induce microstructural and vascular brain changes on a group level, independent of BDNF, providing new insight into the temporal dynamics of plasticity, necessary to exploit the therapeutic potential of exercise.

Sleep plays a critical role in homeostasis of the body and mind. Insomnia is a disease that causes disturbances in the initiation and maintenance of sleep. Insomnia is known to affect not only the sleep process itself but also an individual’s cognitive function and emotional regulation during the daytime. It increases the risk of various neuropsychiatric diseases such as depression, anxiety disorder, and dementia. Although it might appear that insomnia only affects the nervous system, it is also a systemic disease that affects several aspects of the body, such as the cardiovascular, endocrine, and immune systems; therefore, it increases the risk of various diseases such as hypertension, diabetes mellitus, and infection. Insomnia has a wide range of effects on our bodies because sleep is a complex and active process. However, a high proportion of patients with insomnia do not seek treatment, which results in high direct and indirect costs. This is attributed to the disregard of many of the negative effects of insomnia. Therefore, we expect that understanding insomnia as a systemic disease will provide an opportunity to understand the condition better and help prevent secondary impairment due to insomnia.

The human electroencephalogram (EEG) constitutes a nonstationary, nonlinear electrophysiological signal resulting from synchronous firing of neurons in thalamocortical structures of the brain. Due to the complexity of the brain's physiological structures and its rhythmic oscillations, analysis of EEG often utilises spectral analysis methods.Aim: to improve clinical monitoring of neurophysiological signals and to further explain basic principles of functional mechanisms in the brain during anaesthesia.Material and methods. In this paper we used Empirical Mode decomposition (EMD), a novel spectral analysis method especially suited for nonstationary and nonlinear signals. EMD and the related Hilbert-Huang Transform (HHT) decompose signal into constituent Intrinsic Mode Functions (IMFs). In this study we applied EMD to analyse burst-suppression (BS) in the human EEG during induction of general anaesthesia (GA) with propofol. BS is a state characterised by cyclic changes between significant depression of brain activity and hyper-active bursts with variable duration, amplitude, and waveform shape. BS arises after induction into deep general anaesthesia after an intravenous bolus of general anaesthetics. Here we studied the behaviour of BS using the burst-suppression ratio (BSR).Results. Comparing correlations between EEG and IMF BSRs, we determined BSR was driven mainly by alpha activity. BSRs for different spectral components (IMFs 1-4) showed differing rates of return to baseline after the end of BS in EEG, indicating BS might differentially impair neural generators of low-frequency EEG oscillations and thalamocortical functional connectivity.Conclusion. Studying BS using EMD represents a novel form of analysis with the potential to elucidate neurophysiological mechanisms of this state and its impact on post-operative patient prognosis.

Despite a huge effort of the scientific community, the functioning of Long-Term Memory (LTM) processes is still debated and far from being elucidated. Functional and neurophysiological data point to an involvement of Dorsolateral Prefrontal Cortex (DLPFC) in both encoding and retrieval phases. However, the recently proposed Explicit/Implicit Memory Encoding and Retrieval (EIMER) model proposes that LTM at the encoding phase consists of anatomically and chronologically different sub-phases. On this basis, we aimed to investigate the role of right DLPFC during a late-encoding phase by means of low-frequency rTMS. Thirty right-handed healthy subjects were divided into three experimental groups. Inhibitory rTMS was applied over right-DLPFC immediately after the encoding phase (Late-Encoding Group) or before recognition phase (Pre-Recognition Group), 24 h after, of an LTM task. Both groups also received sham stimulation during the non-target phase, while the third group (Sham Group) received only sham stimulation in both phases. The Late-Encoding Group collected a lower number of correct responses compared with Sham Group (p = 0.00), while Pre-Retrieval Group increased accuracy as compared to the Sham Group (p = 0.0). rTMS-inhibition of the right DLPFC seems able to interfere with LTM memory performances when delivered at a late stage of the encoding phase, with opposite effects at the pre-retrieval phase.

Type 2 diabetes (Т2DM) both directly and indirectly impacts the development of morphological and functional changes of the central nervous system.The study was to determine clinical and neurophysiological patterns of cognitive impairment (CI) in patients with chronic cerebrovascular diseases (CCD) and Т2DM.We examined 132 patients with CCD. First group included 58 patients without Т2DM aged 64.5 [58; 72], second group 74 patients with CCD and Т2DM 63 [57; 70]. Clinical, neurological, neuropsychological, neurophysiological (cognitive evoked potentials (EP) and neurovisualisation (brain MRI) examination was carried out to all patients.Somatic and neurological characteristics of the patients were similar in both groups with the exception of more distinct metabolic changes in Т2DM patients. Neurovisualisation study of the brain MRI in Т2DM patients revealed more distinct changes in the form of white matter hyperintensity and subarachnoidal spaces enlargement. Neuropsychological examination in patients revealed the reduction of intellectual flexibility, constructive praxis disruption, optical spatial dysfunction and deteoration of delayed word recall. Significant disorders in the way of overall cognitive impairment, lobar dysfunction and impaired verbal associative productivity, proved by statistically lower amplitude and higher latency of P300 EP peak were noted in Т2DM patients. Correlation links were detected: for P300 amplitude and direct and inverse number listing test (r=0.366 and r=0.520; p=0.006 and p0.001 respectively); P300 latency and HbA1c (r=0.32; р0.05) in group 2 and glucose levels in both groups (r=0.30; p0.05); inverse relationship of latency with control functions evaluation (r=-0.34; p=0.008).CCD especially with Т2DM manifests with neurocognitive imbalance, including control functions disruption and are accompanied by neurophysiological and neurovisualistion changes.Обоснование. Сахарный диабет (СД) оказывает влияние на развитие морфологических и функциональных изменений центральной нервной системы. Цель. Определение клинико-нейрофизиологического паттерна когнитивных нарушений у пациентов с хроническими цереброваскулярными заболеваниями (ХЦВЗ) и СД 2. Материалы и методы. Обследовали 132 пациента с ХЦВЗ, в 1-ю группу вошли 58 человек без СД 2 в возрасте 64,5 [58; 72] года, во 2-ю 74 с сочетанием ХЦВЗ и СД 2 (63 [57; 70] года). Всем пациентам проводилось общеклиническое, неврологическое, нейропсихологическое, нейрофизиологическое (когнитивные вызванные потенциалы) и нейровизуализационное обследование (магнитно-резонансная томография головного мозга). Результаты. Общесоматическая и неврологическая характеристика обследованных значимо не различалась в группах. При исследовании вещества головного мозга у пациентов с СД 2 чаще отмечались более выраженные изменения гиперинтенсивности белого вещества, наличие лакунарных инфарктов и расширение ликворных пространств. Нейропсихологическое тестирование выявило снижение интеллектуальной гибкости, нарушение конструктивного праксиса, оптико-пространственные нарушения и ухудшение отстроченного воспроизведения слов. Нарушения когнитивных функций при СД 2 подтверждены изменением амплитуды и латентности пика когнитивных вызванных потенциалов Р300. Обнаружены корреляционные взаимосвязи: для амплитуды Р300 с тестом перечисления цифр в прямом и обратном порядке (r=0,366 и r=0,520; р=0,006 и р0,001 соответственно); латентности пика Р300 и уровня гликированного гемоглобина (r=0,32; р0,05) во 2-й группе и глюкозой плазмы в обеих группах больных (r=0,30; p0,05); обратная взаимосвязь латентности с оценкой управляющих функций (r=-0,34; p=0,008). Заключение. ХЦВЗ, особенно в сочетании с СД 2, проявляются нейрокогнитивным дисбалансом, включая нарушение управляющих функций, и сопровождаются нейрофизиологическими и нейровизуализационными изменениями.

Conditioned pain modulation (CPM) can discriminate between healthy and chronic pain patients. However, its relationship with neurophysiological pain mechanisms is poorly understood. Brain oscillations measured by electroencephalography (EEG) might help gain insight into this complex relationship. Objective To investigate the relationship between CPM response and self-reported pain intensity in non-specific chronic low back pain (NSCLBP) and explore respective EEG signatures associated to these mechanisms. Design Cross-sectional analysis. Participants Thirty NSCLBP patients participated. Methods Self-reported low back pain, questionnaires, mood scales, CPM (static and dynamic quantitative sensory tests), and resting surface EEG data were collected and analyzed. Linear regression models were used for statistical analysis. Results CPM was not significantly correlated with self-reported pain intensity scores. Relative power of EEG in the beta and high beta bands as recorded from the frontal, central, and parietal cortical areas were significantly associated with CPM. EEG relative power at delta and theta bands as recorded from the central area were significantly correlated with self-reported pain intensity scores while controlling for self-reported depression. Conclusions Faster EEG frequencies recorded from pain perception areas may provide a signature of a potential cortical compensation caused by chronic pain states. Slower EEG frequencies may have a critical role in abnormal pain processing.

Chronic disorders of consciousness include several conditions that differ significantly in both clinical and neurophysiological features. As medical technology continues to develop, the differential diagnosis of disorders of consciousness extends beyond purely clinical work. Nevertheless, all types of consciousness disorders are united by varying degrees of dissociation between wakefulness, cognitive and motor activity. The external similarity and minimal differences in clinical symptoms in unresponsive patients may hide different morphofunctional variants of this condition. In particular, use of electroencephalography and functional magnetic re- sonance imaging techniques allows us to detect covert consciousness in some clinically unresponsive patients. Based on various estimates, this phenomenon occurs in 515% of all cases. A special instance of covert consciousness is cognitive motor dissociation (CMD), defined as activation of cortical motor centers, recorded using neurophysiological techniques, in response to a corresponding instruction to perform a movement without its visible performance. Some researchers believe that detection of CMD indicates a more favourable prognosis for the subsequent restoration of consciousness, rather than its absence. The aim of this review is to examine CMD and its potential significance for outcomes in patients with chronic disorders of consciousness.

During active object manipulation, the finger-object interactions give rise to complex fingertip skin deformations. These deformations are in turn encoded by the local tactile afferents and provide rich and behaviorally relevant information to the central nervous system. Most of the work studying the mechanical response of the finger to dynamic loading has been performed under a passive setup, thereby precisely controlling the kinematics or the dynamics of the loading. However, to identify aspects of the deformations that are relevant to online control during object manipulation, it is desirable to measure the skin response in an active setup. To that end, we developed a device that allows us to monitor finger forces, skin deformations, and kinematics during fine manipulation. We describe the device in detail and test it to precisely describe how the fingertip skin in contact with the object deforms during a simple vertical oscillation task. We show that the level of grip force directly influences the fingerpad skin strains and that the strain rates are substantial during active manipulation (norm up to 100%/s). The developed setup will enable us to causally relate sensory information, i.e. skin deformation, to online control, i.e. grip force adjustment, in future studies.

Background Numerous studies report changes in neuromuscular control in people with low back pain (LBP). However, the relationship between pain and altered neuromuscular control is challenging to unravel given the heterogeneity that exists in clinical populations. One approach commonly adopted to overcome this issue is the use of experimental pain models, but it is currently unclear if the effects of experimental pain are consistent between studies. Therefore, this planned study will systematically evaluate and summarise the effect of experimentally induced pain in the lumbar region on neuromuscular control at sites both locally and remote to the low back. Methods This protocol has been developed following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). MEDLINE, EMBASE, CINAHL, ZETOC, Web of Science, and grey literature will be searched up to August 31, 2021. Screening processes (title/abstract and full-text), data extraction, and risk of bias assessment will be conducted by two independent reviewers. Studies investigating the effects of exogenous pain models delivered to the low back region on neuromuscular control in healthy individuals will be included. Muscle activity and body kinematics will be the outcomes of interest. The comparisons of interest will be between baseline or control conditions and the experimental pain condition, as well as between the experimental pain and post-pain conditions. Randomised crossover and non-randomised studies of interventions will be included and their risk of bias will be evaluated with the Cochrane Risk-of-Bias tool or with the Risk Of Bias In Non-randomised Studies of Interventions tool, respectively. A random-effect meta-analysis will be conducted for quantitative synthesis when clinical and methodological consistency is ensured. Quality of evidence will be evaluated using the Grading of Recommendations, Assessment, Development and Evaluation guidelines. Discussion The current review will provide new insights to understand if and what neuromuscular adaptations are caused by pain experimentally induced in the lumbar region. Our findings will reveal which experimental pain model is able to better reproduce adaptations similar to those identified in people with low back pain, possibly contributing to improving our understanding of motor adaptation to low back pain in the long term. Systematic review registration PROSPERO CRD42020220130

Hearing is one of the five sensory organs that allows us to interact with society and our environment. However, one in eight Americans suffers from sensorineural hearing loss that is great enough to adversely impact their daily life. There is an urgent need to identify what part/degree of the auditory pathway (sensory or neural) is compromised so that appropriate treatment/intervention can be implemented. Single- or two-tone evoked potentials, the electrocochleography (eCochG), were measured along the auditory pathway, i.e., at the round window and remotely at the vertex, with simultaneous recordings of ear canal distortion product otoacoustic emissions. Sensory (cochlear) and neural components in the (remote-) eCochG responses showed distinct level- and frequency-dependent features allowing to be differentiated from each other. Specifically, the distortion products in the (remote-)eCochGs can precisely localize the sensory damage showing that they are effective to determine the sensory or neural damage along the auditory pathway.

The authors present a review of the current use of somatosensory evoked potentials (SSEPs) in neurological practice as a non-invasive neurophysiological technique. For this purpose we have reviewed articles published in English or Portuguese in the PubMed and LILACS databases. In this review, we address the role of SSEPs in neurological diseases that affect the central nervous system and the peripheral nervous system, especially in demyelinating diseases, for monitoring coma, trauma and the functioning of sensory pathways during surgical procedures. The latter, along with new areas of research, has become one of the most important applications of SSEPs. Resumo Os autores apresentam uma revisão do uso atual do potencial evocado somatossensitivo (PESS) na prática neurológica como uma técnica neurofisiológica não invasiva. Revisamos artigos publicados em Inglês ou Português nas bases de dados PubMed e LILACS. Nesta revisão abordamos o papel do PESS nas doenças neurológicas que atingem o sistema nervoso central e o sistema nervoso periférico, especialmente, nas doenças desmielinizantes, no monitoramento do coma, do trauma e da função das vias sensitivas durante os procedimentos cirúrgicos, que se tornou uma de suas aplicações mais importantes, assim como novas áreas de pesquisa.

I list a summary of the major clinical observations of SVIN in patients with total unilateral vestibular loss (TUVL) and show how basic results from neurophysiology can explain these clinical observations. The account integrates results from single neuron recordings of identified semicircular canal and otolith afferent neurons in guinea pigs in response to low frequency skull vibration with evidence of the eye movement response in cats to selective semicircular canal stimulation (both individual and combined) and a simple model of nystagmus generation to show how these results explain most of the major characteristics of SVIN.

Objective This proof-of-principle-study evaluated the extent to which spontaneous activity (SA) of the muscle can be detected via non-invasive magnetomyography (MMG) with optically pumped magnetometers (OPM). Methods Five patients, who together exhibited all forms of SA (fibrillations, positive sharp waves, fasciculations, myotonic discharges, complex-repetitive discharges) with conventional needle electromyography (EMG), were studied by OPM-MMG and simultaneous surface EMG (sEMG) while at rest, during light muscle activation, and when a muscle stretch reflex was elicited. Three healthy subjects were measured as controls. SA was considered apparent in the OPM-MMG if a signal could be visually detected that corresponded in shape and frequency to the SA in the respective needle EMG. Results SA in the context of fasciculations could be detected in 2 of 5 patients by simultaneous OPM-MMG/sEMG. Other forms of SA could not be detected at rest, during light muscle activation, or after provocation of a muscle stretch reflex. Conclusions This proof-of-principle study shows that fasciculations could be detected non-invasively via a new method (OPM). Significance We show that other forms of SA are not detectable with current OPM and propose necessary technical solutions to overcome this circumstance. Our results motivate to pursue OPM-MMG as a new clinical neurophysiological diagnostic.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a well-established interventional treatment for improving motor symptoms of patients suffering from Parkinson’s disease (PD). While STN is originally localized using imaging modalities, additional intraoperative guidance such as microelectrode recording (MER) is crucial to refine the final electrode trajectory. Analysis of MER by an experienced neurophysiologist maintains good clinical outcomes, although the procedure requires long duration and jeopardizes the safety of the surgery. Lately, local field potentials (LFP) investigation has inspired the emergence of adaptive DBS and revealed beneficial perception of PD mechanisms. Several studies confronting LFP analysis to detect the anatomical borders of STN, have focused on handcrafted feature engineering, which does not certainly capture delicate differences in LFP. This study gauges the ability of deep learning to exhibit valuable insight into the electrophysiological neural rhythms of STN using LFP. A recurrent convolutional neural network (CNN) strategy is presented, where local features are extracted from LFP signals via CNN, followed by recurrent layers to aggregate the best features for classification. The proposed model outperformed the state-of-the-art techniques, yielding highest average accuracy of 96.79%. This is the first study on the analysis of LFP signals to localize STN using deep recurrent CNN. The developed model has the potential to extract high level biomarkers regarding STN region, which would boost the neurosurgeon’s confidence in adjusting the trajectory intraoperatively for optimal lead implantation. LFP is a robust guidance tool and could be an alternative solution to the current scenario using MER.

Sleep disturbances are commonly observed in schizophrenia, including in chronic, early-course, and first-episode patients. This has generated considerable interest, both in clinical and research endeavors, in characterizing the relationship between disturbed sleep and schizophrenia. Sleep features can be objectively assessed with EEG recordings. Traditionally, EEG studies have focused on sleep architecture, which includes non-REM and REM sleep stages. More recently, numerous studies have investigated alterations in sleep-specific rhythms, including EEG oscillations, such as sleep spindles and slow waves, in individuals with schizophrenia compared with control subjects. In this article, the author reviews state-of-the-art evidence of disturbed sleep in schizophrenia, starting from the relationship between sleep disturbances and clinical symptoms. First, the author presents studies demonstrating abnormalities in sleep architecture and sleep-oscillatory rhythms in schizophrenia and related psychotic disorders, with an emphasis on recent work demonstrating sleep spindles and slow-wave deficits in early-course and first-episode schizophrenia. Next, the author shows how these sleep abnormalities relate to the cognitive impairments in patients diagnosed with schizophrenia and point to dysfunctions in underlying thalamocortical circuits, Ca+ channel activity, and GABA-glutamate neurotransmission. Finally, the author discusses some of the next steps needed to further establish the role of altered sleep in schizophrenia, including the need to investigate sleep abnormalities across the psychotic spectrum and to establish their relationship with circadian disturbances, which in turn will contribute to the development of novel sleep-informed treatment interventions.

The vagus nerve relays mood-altering signals originating in the gut lumen to the brain. In mice, an intact vagus is required to mediate the behavioural effects of both intraluminally applied selective serotonin reuptake inhibitors and a strain of Lactobacillus with antidepressant-like activity. Similarly, the prodepressant effect of lipopolysaccharide is vagus nerve dependent. Single vagal fibres are broadly tuned to respond by excitation to both anti- and prodepressant agents, but it remains unclear how neural responses encode behaviour-specific information. Here we demonstrate using ex vivo experiments that for single vagal fibres within the mesenteric neurovascular bundle supplying the mouse small intestine, a unique neural firing pattern code is common to both chemical and bacterial vagus-dependent antidepressant luminal stimuli. This code is qualitatively and statistically discernible from that evoked by lipopolysaccharide, a non-vagus-dependent antidepressant or control non-antidepressant Lactobacillus strain and are not affected by sex status. We found that all vagus dependent antidepressants evoked a decrease in mean spike interval, increase in spike burst duration, decrease in gap duration between bursts and increase in intra-burst spike intervals. Our results offer a novel neuronal electrical perspective as one explanation for mechanisms of action of gut-derived vagal dependent antidepressants. We expect that our ex vivo individual vagal fibre recording model will improve the design and operation of new, extant electroceutical vagal stimulation devices currently used to treat major depression. Furthermore, use of this vagal antidepressant code should provide a valuable screening tool for novel potential oral antidepressant candidates in preclinical animal models.

Repetitive transcranial magnetic stimulation (rTMS) of the brain is an effective clinical treatment for psychiatric disorders. Noninvasive neuroimaging during rTMS allows visualization of cortical brain activations and responses, and it is a potential tool for investigating the neurophysiological response occurring actively during stimulation. In this paper, we present a fast diffuse optical tomography (DOT) approach for three-dimensional brain mapping of hemodynamics during rTMS. Eight healthy subjects were enrolled in the study. These subjects received 10 Hz stimulation with 80%and 100%of resting motor threshold (rMT), respectively, for 4 seconds for each stimulation. Significant hemodynamic activation was observed in all cases with the strongest response when 100%rMT stimulation was applied. This work demonstrates that fast DOT has the potential to become a powerful tool for noninvasive three-dimensional imaging of the brain during rTMS.

Microelectrode recording (MER) or microelectrode signals recording of local field potentials by means of subthalamic-nuclei deep brain stimulation is highly successful for construing or deducing Parkinson disease (PD) signal analysis acquiescent to elucidation are fetching ever more germane. These signals are supposed to emulate STN neurons action-potential movement and, these potential frequency modulations are coupled to spiking-events. The method uses auto regression stochastic (random nature) model machine learning approach and, other standard techniques as of system identification field. A usual conventional local field potential implication involves computing spectral-densities, i.e., power (P S Ds) of these signals—waveforms, that confines power on different frequencies. But, P S D s is second-order statistics might not confine non trivial temporal-dependencies which subsist in unprocessed data. Hence, we suggest L F Ps technique which is valuable in support of relating or unfolding distinctive plus sole features of temporal-dependencies in L F P waveforms. This technique is derived as of auto-regression (A R) modeling originating as of the systems plus control theory in fastidious systems-identification. We have distinctively, built A R models of L F P movement activity plus inferred, and also verified statistically major differentiations in temporal-dependencies among damaged tissues of nuclei plus protective areas in Parkinson`s receiving innocuous microelectrodes via deep brain stimulator (D BS). Differentiations in spectral-densities of field-waveforms amid the two conglomerates were not statistically-significant. Keywords: Microelectrode recording (MER), Parkinson disease (PD).

Introduction Neurological complications of SARS-CoV-2 disease have received growing attention, but only few studies have described to date clinical and neurophysiological findings in COVID patients during their stay in intensive care units (ICUs). Here, we neurophysiologically assessed the presence of either critical illness neuropathy (CIP) or myopathy (CIM) in ICU patients. Materials and Methods Patients underwent a neurophysiological assessment, including bilateral examination of the median, ulnar, deep peroneal and tibial motor nerves and of the median, ulnar, radial and sural sensory nerves. Needle electromyography (EMG) was performed for both distal and proximal muscles of the lower and upper limbs. In order to differentiate CIP from CIM, Direct Muscle Stimulation (DMS) was applied either to the deltoid or tibialis anterior muscles. Peak to peak amplitudes and onset latencies of the responses evoked by DMS (DMSamp, DMSlat) or by motor nerve stimulation (MNSamp, MNSlat) were compared. The ratio MNSamp to DMSamp (NMR) and the MNSlat to DMSlat difference (NMD: MNSlat − DMSlat) were also evaluated. Results Nerve conduction studies showed a sensory-motor polyneuropathy with axonal neurogenic pattern, as confirmed by needle EMG. Both MNSamp and NMR were significantly reduced when compared to controls (p

Objective Quantitative Encephalography (qEEG) depicts synthetically the features of EEG signal and represents a promising tool in the assessment of neurophysiological changes brought about by Anti-Seizure Medications (ASMs). In this study we characterized qEEG alterations related to add-on therapy with Perampanel (PER). PER is the only ASM presenting a direct glutamatergic antagonism, hence the characterization of PER induced EEG changes could help to better understand its large spectrum of efficacy. Methods We analysed standard-19 channel-EEG from 25 People with Epilepsy (PwE) both before (T0) and after (T1) the introduction of PER as add-on treatment. Normal values were obtained in 30 healthy controls (HC) matched for sex and age. EEGs were analysed using Matlab™ and the EEGlab and Brainstorm toolkits. We extracted spectral power and connectivity (Phase locking Value) of EEG signal and then compared these features between T0 and T1 and across groups (PwE, HC), we also evaluated the correlations with clinical features. Results PwE showed increased theta power (p = 0.036) after the introduction of PER but no significant change of EEG connectivity. We also found that PwE have reduced beta power (p = 0.012) and increased connectivity in delta (p = 0.013) and theta (p = 0.007) range as compared to HC, but no significant change was observed between T0 and T1 in PwE. Finally, we found that PwE classified as drug responders to PER have greater alpha power both at T0 and at T1 (p = 0.024) suggesting that this parameter may predict response to treatment. Conclusions PER causes slight increase of theta activity and does not alter connectivity as assessed by standard EEG. Moreover, greater alpha power could be a good marker of response to PER therapy, and potentially ASM therapy in general. Significance Our results corroborate the hypothesis that pharmaco-EEG is a viable tool to study neurophysiological changes induced by ASM. Additionally, our work highlights the role of alpha power as a marker of ASM therapeutic response.

Prior neuroimaging and neurophysiological studies have found that the right posterior parietal cortex (PPC) plays an important role in mental rotation ability. Transcranial direct-current stimulation (tDCS) has been shown the potential to enhance cognitive ability by delivering a low current to the brain cortex of interest, via electrodes on the scalp. Here, we tested whether stimulating the PPC with tDCS can improve three-dimensional mental rotation performance and narrow gender difference. The classic three-dimensional Shepard-Metzler task was measured after three stimulation conditions (right PPC, left PPC, sham stimulation). The results indicated that stimulating the right PPC induced an improvement in accuracy and response time of mental rotation relative to sham stimulation. Stimulating the left PPC caused an enhancement in the accuracy but not in the response time. Gender difference during mental rotation was diminished after stimulation. These findings indicated that the PPC regions played a causal role in mental rotation ability. tDCS could be used as a promising non-invasive method to improve mental rotation skills in individuals with lower ability and to provide an effective therapeutic tool for neurological disorder rehabilitation.

BACKGROUND: Noninvasive transcranial electrical stimulation (tES) research has been plagued with inconsistent effects. Recent work has suggested neuroanatomical and neurophysiological variability may alter tES efficacy. However, direct evidence is limited. OBJECTIVE: We have previously replicated effects of transcranial alternating current stimulation (tACS) on improving multitasking ability in young adults. Here, we attempt to assess whether these stimulation parameters have comparable effects in older adults (aged 60–80 years), which is a population known to have greater variability in neuroanatomy and neurophysiology. It is hypothesized that this variability in neuroanatomy and neurophysiology will be predictive of tACS efficacy. METHODS: We conducted a pre-registered study where tACS was applied above the prefrontal cortex (between electrodes F3-F4) while participants were engaged in multitasking. Participants were randomized to receive either 6-Hz (theta) tACS for 26.67 minutes daily for three days (80 minutes total; Long Exposure Theta group), 6-Hz tACS for 5.33 minutes daily (16-minutes total; Short Exposure Theta group), or 1-Hz tACS for 26.67 minutes (80 minutes total; Control group). To account for neuroanatomy, magnetic resonance imaging data was used to form individualized models of the tACS-induced electric field (EF) within the brain. To account for neurophysiology, electroencephalography data was used to identify individual peak theta frequency. RESULTS: Results indicated that only in the Long Theta group, performance change was correlated with modeled EF and peak theta frequency. Together, modeled EF and peak theta frequency accounted for 54% – 65% of the variance in tACS-related performance improvements, which sustained for a month. CONCLUSION: These results demonstrate the importance of individual differences in neuroanatomy and neurophysiology in tACS research and help account for inconsistent effects across studies.

To understand the information encoded in a connection between the neurons, postsynaptic current (PSC) has been widely measured as a primary index of synaptic strength in the field of neurophysiology. Although several automatic detection methods for PSCs have been proposed to simplify a workflow in the analysis, repetitive steps such as quantification and management of PSC data should be still performed with much effort. Here, we present Minhee Analysis Package, an integrated standalone software package that is capable of detecting, sorting, and quantifying PSC data. First, we developed a stepwise exploratory algorithm to detect PSC and validated our detection algorithm using the simulated and experimental data. We also described all the features and examples of the package so that users can use and follow them properly. In conclusion, our software package is expected to improve the convenience and efficiency of neurophysiologists to analyze PSC data by simplifying the workflow from detection to quantification. Minhee Analysis Package is freely available to download from http://www.github.com/parkgilbong/Minhee_Analysis_Pack.

The neurophysiological mechanisms underlying the behavioural improvements usually associated with an external (EF) compared with an internal focus of attention (IF) remain poorly investigated. Surround inhibition in the primary cortex has been shown to be more pronounced with an EF, indicating a more spatial restriction of the motor command. However, the influence of different foci on the temporal aspect of the motor command, such as the modulation of fast versus slow(er) motor pathways, remains unknown and was therefore investigated in this study. Fourteen participants were asked to press on a pedal with the right foot to match its position with a target line displayed on a screen. The deviation of the pedal from the target line was used as a behavioural parameter and compared between both foci (EF vs IF). Additionally, conditioned H-reflexes were evoked during the motor task to assess the excitability of fast (direct) and slower (more indirect) motor pathways when adopting an EF or IF. With an EF compared to an IF, the motor performance was enhanced (P = .001; + 24%) and the activation of slow(er) motor pathways was reduced (P

Repetitive transcranial magnetic stimulation (rTMS) is effective for treatment resistant depression (TRD), but little is known about rTMS' effects on neurophysiological markers. We previously identified neurophysiological markers in depression (N45 and N100) of GABA receptor mediated inhibition. Here, we indexed TMS-electroencephalographic (TMS-EEG) effects of rTMS.TMS-EEG data was analyzed from a double blind 2:1 randomized active (10 Hz left/bilateral):sham rTMS TRD trial. Participants underwent TMS-EEG over left dorsolateral prefrontal cortex (DLPFC) before and after 6 weeks of rTMS. 30 had useable datasets. TMS-evoked potentials (TEP) and components (N45, N100, P60) were examined with global mean field analysis (GMFA) and locally in DLPFC regions of interest.The N45 amplitude differed between active and sham groups over time, N100 amplitude did not. N45 (t = 2.975, p = 0.007) and N100 amplitudes (t = 2.177, p = 0.042) decreased after active rTMS, demonstrating alterations in cortical inhibition. TEP amplitudes decreased after active rTMS in left (t = 4.887, p 0.001) and right DLPFC (t = 4.403, p 0.001) not sham rTMS, demonstrating alterations in cortical excitability.Our results provide important new knowledge regarding rTMS effects on TMS-EEG measures in TRD, suggesting rTMS reduces neurophysiological markers of inhibition and excitability.These findings uncover potentially important neurophysiological mechanisms of rTMS action.

Self-massage using foam rollers, sticks, or balls has become a popular technique to enhance joint range of motion (ROM). Although increases are reported to be larger in females than males, the mechanisms of this observation are unclear. The present study aimed to investigate the effect of roller massage (RM) on ROM, passive tissue stiffness, and neurophysiological markers as a function of sex. Males (n = 15, 22.8 ± 2.9 yrs.) and females (n = 14, 21.1 ± 0.7 yrs.) performed three 60-second bouts of calf RM. Outcomes assessed pre-, and post-intervention included passive dorsiflexion (DF) ROM, passive tissue stiffness, passive torque, DF angle at the first stretch sensation, shear elastic modulus, and spinal excitability. DF ROM (+35.9 %), passive torque at DF ROM (+46.4 %), DF angle at first stretch sensation (+32.9 %), and pain pressure threshold (+25.2 %) increased in both groups (p 0.05). No changes were observed for passive stiffness, shear elastic modulus, and spinal excitability (p > 0.05). Roller massage may increase ROM independently of sex, which, in the present study, could not be ascribed to alterations in passive stiffness or neurophysiological markers. Future studies may further elucidate the role of sensory alterations as possible factors driving RM-induced changes in flexibility.

Daily rhythms of behavior and neurophysiology are integral to the circadian clocks of all animals. Examples of circadian clock regulation in the human brain include daily rhythms in sleep-wake, cognitive function, olfactory sensitivity, and risk for ischemic stroke, all of which overlap with symptoms displayed by many COVID-19 patients. Motivated by the relatively unexplored, yet pervasive, overlap between circadian functions and COVID-19 neurological symptoms, this perspective piece uses daily variations in the sense of smell and the timing of sleep and wakefulness as illustrative examples. We propose that time-stamping clinical data and testing may expand and refine diagnosis and treatment of COVID-19.