Electroencephalographic Changes Research Articles

Electroencephalographic (EEG) Stages in Patients With Cerebral Edema Following Cardiac Arrest.

To describe electroencephalographic (EEG) changes in pediatric patients with cerebral edema after cardiac arrest. A retrospective study of patients admitted to the pediatric intensive care unit from July 2021 to January 2023. We included patients with cardiac arrest and changes in EEG background with clinical changes and/or neuroimaging consistent with cerebral edema. We excluded patients with electrographic seizures. We applied American Clinical Neurophysiology Society standardized critical care EEG terminology to classify EEG background, noting timing of the change in background classification. Clinical variables included age, sex, and neuroimaging findings and were described with descriptive statistics. Nine patients met inclusion criteria, with median age 24 months (interquartile range 21-49), and 89% were male. There were 5 common EEG stages: stage 1, burst suppression/burst attenuation; stage 2, continuous/discontinuous ± multifocal sporadic epileptiform discharges ± rhythmic or periodic patterns; stage 3, discontinuous/burst suppression/burst attenuation ± rhythmic or periodic patterns; stage 4, gradual voltage suppression; and stage 5, diffuse suppression. The ranges for each stage were as follows: stage 1, 2-10 hours; stage 2, 2.5-15.5 hours; stage 3, 0.5-6.24 hours; and stage 4, 0.5-11 hours. We could not calculate the duration of stage 5 given no uniform time to EEG discontinuation. One patient had a clinical change in stage 3. Remaining patients presented with fixed and dilated pupils with global anoxic injury. EEG stages of cerebral edema have not been described after pediatric cardiac arrest. These stages may be relevant to other patient populations. Early stages may be a therapeutic target for intracranial pressure-lowering medications and/or neuroprotective strategies to minimize sequalae of cerebral edema.

Treatment strategies for smartphone addiction: efficacy study of transcranial direct current stimulation and exergaming.

Smartphone addiction is on the rise globally. This study aimed to compare the rehabilitative effects of transcranial direct current stimulation (tDCS) and exergames on smartphone addiction among college students. Additionally, we discussed the central mechanisms through changes in electroencephalography (EEG) to provide clinical insights. Thirty-six participants were randomly assigned to three groups: control group, tDCS group (bilateral dorsolateral prefrontal cortex stimulation), and exergame group. The intervention lasted for 4 weeks with twice-weekly sessions. Outcome measures included the Smartphone Addiction Scale - Chinese Version (SAS-C), Iowa Gambling Task (IGT) net scores, and event-related potential (ERP) data collected during the IGT, focusing on P300 and feedback-related negativity (FRN) amplitudes. All groups showed significant reductions in SAS-C scores post-intervention. Behaviorally, post-intervention scores improved, indicating significant effects of different interventions on participants' strategy choices. P300 amplitudes increased significantly at outcome electrode sites for all groups, with the most notable increase in tDCS group FC2 and CP1. FRN amplitudes decreased significantly post-intervention in the control and tDCS groups, with significant differences between the two groups. All three interventions appeared to have alleviating effect on smartphone addiction. After 4 weeks, participants showed improved executive control and decision-making abilities. Specifically, significant effects were observed in the tDCS group, with increased P300 amplitudes in the frontal, parietal, and central regions, as well as FRN amplitudes in the central and frontal regions. This suggested that tDCS enhanced psychological resources and improved inhibition control capabilities.

Absolute beta power in exercisers and nonexercisers in preparation for the oddball task.

High levels of physical conditioning are associated with improvements in cognitive performance. In this sense, electroencephalographic (ECG) correlates are used to investigate the enhancing role of physical exercise on executive functions. Oscillations in the β frequency range are proposed to be evident during sensorimotor activity. To investigate the ECG changes influenced by aerobic and resistance exercises performed in an attention task by analyzing the differences in absolute β power in the prefrontal and frontal regions before, during, and after the oddball paradigm in practitioners and nonpractitioners of physical exercise. There were 15 physical activity practitioners (aged 27 ± 4.71) and 15 nonpractitioners (age 28 ± 1.50) recruited. A two-way analysis of variance (ANOVA) was implemented to observe the main effect and the interaction between groups and moments (rest 1, pre-stimulus, and rest 2). An interaction between group and moment factors was observed for Fp1 (p < 0.001); Fp2 (p = 0.001); F7 (p < 0.001); F8 (p < 0.001); F3 (p < 0.001); Fz (p < 0.001); and F4 (p < 0.001). Electrophysiological findings clarified exercisers' specificity and neural efficiency in each prefrontal and frontal subarea. Our findings lend support to the current understanding of the cognitive processes underlying physical exercise and provide new evidence on the relationship between exercise and cortical activity.

Switching to Low Neurotoxic Antiretrovirals to Improve Neurocognition Among People Living With HIV-1-Associated Neurocognitive Disorder: The MARAND-X Randomized Clinical Trial

Background: The pathogenesis of HIV-associated neurocognitive (NC) impairment is multifactorial, and antiretroviral (ARV) neurotoxicity may contribute. However, interventional pharmacological studies are limited. Methods: Single-blind, randomized (1:1), controlled trial to assess the change of NC performance (Global Deficit Score, GDS, and domain scores) in PLWH with NC impairment randomized to continue their standard of care treatment or to switch to a less neurotoxic ARV regimen: darunavir/cobicistat, maraviroc, emtricitabine (MARAND-X). Participants had plasma and cerebrospinal fluid HIV RNA&lt; 50 copies/mL, R5-tropic HIV, and were on ARV regimens that did not include efavirenz and darunavir. The change of resting-state electroencephalography was also evaluated. The outcomes were assessed at week 24 of the intervention through tests for longitudinal paired data and mixed-effect models. Results: Thirty-eight participants were enrolled and 28 completed the follow-up. Global Deficit Score improved over time but with no difference between arms in longitudinal adjusted models. Perceptual functions improved in the MARAND-X, while long-term memory improved only in participants within the MARAND-X for whom the central nervous system penetration-effectiveness (CNS penetration effectiveness) score increased by ≥3. No significant changes in resting-state electroencephalography were observed. Conclusions: In this small but well-controlled study, the use of less neurotoxic ARV showed no major beneficial effect over an unchanged regimen. The beneficial effects on the memory domain of increasing CNS penetration effectiveness score suggest that ARV neuropenetration may have a role in cognitive function.

Electroencephalographic changes in children with attention deficit hyperactivity disorder

BackgroundAttention deficit hyperactivity disorder (ADHD) is the most prevalent psychiatric disorder in children who experience delayed language development. This work aimed to study electroencephalographic (EEG) changes in children with ADHD and establish a strategy for prompt identification and suitable management in the future.MethodsThis descriptive cross-sectional study was conducted on 100 children aged between 5 and 12 years old, both sexes, diagnosed with ADHD according to DSM-V Criteria, diagnosed as ADHD children with the Arabic version of Conner’s Parent Rating Scale. Psychometric evaluation by intelligence quotient (IQ) using Stanford Binet Intelligence test. The Receptive Expressive Arabic Language Scale was used to assess language profile.ResultsThere was a significant negative correlation between the severity of ADHD and IQ scores. There was an insignificant negative correlation between ADHD and scaled receptive language score and scaled expressive language score. There was an insignificant positive correlation between ADHD and scaled expressive language score. There was a significant difference between EEG changes and combined subtype of ADHD and scaled score of receptive language (P < 0.05). There was an insignificant difference between (EEG changes and language development), the scaled score of expressive, total language, and the scaled score of language.ConclusionsEEG has clinical utility in the diagnosis of ADHD. The results of EEG analysis in children with ADHD have been quite important, and this novel methodology could offer supplementary factors to strengthen its diagnostic impact.

Age-Related Differences in Prestimulus EEG Affect ERPs and Behaviour in the Equiprobable Go/NoGo Task.

Detailed studies of the equiprobable auditory Go/NoGo task have allowed for the development of a sequential-processing model of the perceptual and cognitive processes involved. These processes are reflected in various components differentiating the Go and NoGo event-related potentials (ERPs). It has long been established that electroencephalography (EEG) changes through normal lifespan development. It is also known that ERPs and behaviour in the equiprobable auditory Go/NoGo task change from children to young adults, and again in older adults. Here, we provide a novel examination of links between in-task prestimulus EEG, poststimulus ERPs, and behaviour in three gender-matched groups: children (8-12 years), young adults (18-24 years), and older adults (59-74 years). We used a frequency Principal Component Analysis (f-PCA) to estimate prestimulus EEG components and a temporal Principal Component Analysis (t-PCA) to separately estimate poststimulus ERP Go and NoGo components in each age group to avoid misallocation of variance. The links between EEG components, ERP components, and behavioural measures differed markedly between the groups. The young adults performed best and accomplished this with the simplest EEG-ERP-behaviour brain dynamics pattern. The children performed worst, and this was reflected in the most complex brain dynamics pattern. The older adults showed some reduction in performance, reflected in an EEG-ERP-behaviour pattern with intermediate complexity between those of the children and young adults. These novel brain dynamics patterns hold promise for future developmental research.

Comparing the effects of resistance and aerobic exercise on mood-related symptoms and EEG activity in young healthy adults: A non-randomized pilot study

Background and aimsExercise offers several benefits in combating mood-related symptoms in humans. Participation in various types of physical activity improves brain and mental health. However, the different effects and mechanisms depending on the type of exercise on an individual's mood and brain remain unclear. This pilot trial aimed to reveal the feasibility of the effects of resistance and aerobic exercise on mood-related symptoms and explain the different patterns of brain waves. MethodsThis 15-week single-arm pre-test/post-test trial including 3 measurement periods was held in Seoul, Republic of Korea. Overall, 18 healthy participants aged 19–29 years were recruited. After 6 weeks of respective aerobic and resistance exercise, anxiety/depression-related questionnaire scores and electroencephalography (EEG) changes were measured (single blinded outcome assessment). Specifically, changes in frontal alpha asymmetry (FAA), absolute band power of beta waves, and theta waves were measured in the prefrontal and frontal regions, which play a critical role in regulating mood and cognition. ResultsResistance exercise resulted in a significant reduction in Beck Depression Inventory-II scores (p = 0.002, effect size = 0.76) while significant improvement was shown in Beck Anxiety Inventory scores (p = 0.01, effect size = 0.77) after aerobic exercise. In regarding EEG analysis, ten participants completed the assessment. After resistance exercise, there was a significant elevation in frontal beta waves (p = 0.01, effect size = 0.81). Aerobic exercise did not result in significant EEG changes. There were no adverse events related to study participation. ConclusionOur findings suggest that resistance and aerobic exercises may be feasible for the alleviation of mood-related symptoms and EEG activities. As our pilot trial has a small sample size and did not include a control group, future research that accurately reflects the effects of different types of exercises on mood symptoms and changes of EEG activities is required.

Neuronal Activity Topography Reveals Neuronal Change in Comatose Patients Treated by tDCS.

BACKGROUND: In our hospital, transcranial direct current stimulation (tDCS) is applied in combination with occupational therapy (OT) for patients with persistent consciousness disorders. There have been reports from some research groups on Left dorsolateral prefrontal area (F3) anodal stimulation as wells as Frontal pole (Fpz) anodal stimulation under different conditions. We chose either anodal stimulation site depending on the patient's condition. CASES: Nine patients underwent tDCS with Fpz or F3 anodal stimulation for 10 days, followed by a 2-day break, after which the stimulation sites were switched, and the patients were stimulated for another 10 days. Their Electroencephalography changes were evaluated by using visual images of neuronal activity topography (NAT). The asymmetry index (AI) was also calculated to compare lateral differences in neuronal changes in the frontal lobe. Seven out of nine cases started with Fpz anode, and two with F3 anode. In the former setting, six cases improved, two aggravated and one remained unchanged. In the latter, one case unchanged and one remained aggravated. After applying tDCS, NAT and AI of the improved cases showed a tendency to approximate the normal control group. Discussion: Among these cases, all but one showed improvement in CRS-R scores, especially in Fpz stimulation. Additionally, changes in the scores indicated that most cases showed improvements in responses to visual and auditory stimulation. Furthermore, the NAT system allows for the rapid and minimally invasive assessment of changes in neuronal activity. Consequently, it is suggested that this system may be valuable for evaluating the therapeutic effects of tDCS and identifying effective stimulation sites.

Spectral changes in electroencephalography linked to neuroactive medications: A computational pipeline for data mining and analysis

Background and objectivesThe increasing amount of open-access medical data provides new opportunities to gain clinically relevant information without recruiting new patients. We developed an open-source computational pipeline, that utilizes the publicly available electroencephalographic (EEG) data of the Temple University Hospital to identify EEG profiles associated with the usage of neuroactive medications. It facilitates access to the data and ensures consistency in data processing and analysis, thus reducing the risk of errors and creating comparable and reproducible results. Using this pipeline, we analyze the influence of common neuroactive medications on brain activity. MethodsThe pipeline is constructed using easily controlled modules. The user defines the medications of interest and comparison groups. The data is downloaded and preprocessed, spectral features are extracted, and statistical group comparison with visualization through a topographic EEG map is performed. The pipeline is adjustable to answer a variety of research questions. Here, the effects of carbamazepine and risperidone were statistically compared with control data and with other medications from the same classes (anticonvulsants and antipsychotics). ResultsThe comparison between carbamazepine and the control group showed an increase in absolute and relative power for delta and theta, and a decrease in relative power for alpha, beta, and gamma. Compared to antiseizure medications, carbamazepine showed an increase in alpha and theta for absolute powers, and for relative powers an increase in alpha and theta, and a decrease in gamma and delta. Risperidone compared with the control group showed a decrease in absolute and relative power for alpha and beta and an increase in theta for relative power. Compared to antipsychotic medications, risperidone showed a decrease in delta for absolute powers. These results show good agreement with state-of-the-art research. The database allows to create large groups for many different medications. Additionally, it provides a collection of records labeled as “normal” after expert assessment, which is convenient for the creation of control groups. ConclusionsThe pipeline allows fast testing of different hypotheses regarding links between medications and EEG spectrum through ecological usage of readily available data. It can be utilized to make informed decisions about the design of new clinical studies.

Application of Mozart's Sonata for Two Pianos in D Major in Children with Epilepsy and Effect of Acoustic Quality on Epileptic Discharges.

Mozart's Sonata for Two Pianos in D Major (K448) is a classic double piano work. This study investigated its effect on children with epilepsy (EP) and analyzed the changes in electroencephalography (EEG) among children on the basis of acoustic quality. The clinical data of 150 children with EP in the Affiliated Hospital (Group) of Putian University from March 2020 to March 2023 were retrospectively analyzed. They were divided into group A (n = 73, antiepileptic drug therapy) and group B (n = 77, antiepileptic drug therapy + Mozart K448) in accordance with the treatment methods. The seizure frequency, frequency of epileptic discharges (EDs), and Quality of Life in Childhood Epilepsy Questionnaire-16 in both groups were compared before and after treatment. The changes in EEG before, during, and after music appreciation were observed. The effects of the acoustic characteristics (rhythm, root mean square value, roughness, and spectral flux) of Mozart K448 on EDs in children were explored. After treatment, group A had a higher seizure frequency (P < 0.001), a higher frequency of EDs (P < 0.05), and significantly lower scores of cognition and emotion than group B (P < 0.001), without significant difference in the scores of social function and physical function (P > 0.05). The frequency of EDs before music appreciation was significantly higher than that during music appreciation (P < 0.01). Spearman correlation analysis showed that the rhythm, spectral flux, and roughness in Mozart K488 were related to the decrease in EDs among children with EP (P < 0.001). This study confirmed the application effect of Mozart K448 in children with EP. Mozart K448 can decrease the seizure frequency, reduce the ED occurrence, and improve the quality of life. The acoustic characteristics of K448 may be the reason for improving EP in children.

Electroencephalographic insights into the pathophysiological mechanisms of emergence delirium in children and corresponding clinical treatment strategies.

Emergence delirium is a common postoperative complication in patients undergoing general anesthesia, especially in children. In severe cases, it can cause unnecessary self-harm, affect postoperative recovery, lead to parental dissatisfaction, and increase medical costs. With the widespread use of inhalation anesthetic drugs (such as sevoflurane and desflurane), the incidence of emergence delirium in children is gradually increasing; however, its pathogenesis in children is complex and unclear. Several studies have shown that age, pain, and anesthetic drugs are strongly associated with the occurrence of emergence delirium. Alterations in central neurophysiology are essential intermediate processes in the development of emergence delirium. Compared to adults, the pediatric nervous system is not fully developed; therefore, the pediatric electroencephalogram may vary slightly by age. Moreover, pain and anesthetic drugs can cause changes in the excitability of the central nervous system, resulting in electroencephalographic changes. In this paper, we review the pathogenesis of and prevention strategies for emergence delirium in children from the perspective of brain electrophysiology-especially for commonly used pharmacological treatments-to provide the basis for understanding the development of emergence delirium as well as its prevention and treatment, and to suggest future research direction.

Alteration in neural oscillatory activity and phase‐amplitude coupling after sleep deprivation: Evidence for impairment and compensation effects

SummaryInsufficient sleep can significantly affect vigilance and increase slow‐wave electroencephalographic power as homeostatic sleep pressure accumulates. Phase‐amplitude coupling is involved in regulating the spatiotemporal integration of physiological processes. This study aimed to examine the functional associations of resting‐state electroencephalographic power and delta/theta‐gamma phase‐amplitude coupling from the prefrontal cortex (PFC) to posterior regions with vigilance performance after sleep deprivation. Forty‐six healthy adults underwent 24‐hr sleep deprivation with resting‐state electroencephalographic recordings, and vigilant attention was measured using the Psychomotor Vigilance Task. Power spectral and phase‐amplitude coupling analyses were conducted, and correlation analysis was utilized to reveal the relationship between electroencephalographic patterns and changes in vigilance resulting from sleep deprivation. Sleep deprivation significantly declined vigilance performance, accompanied by increased resting‐state electroencephalographic power in all bands and delta/theta‐gamma phase‐amplitude coupling. The increased theta activity in centro‐parieto‐occipital areas significantly correlated with decreased mean and slowest response speed. Conversely, the increased delta‐low gamma and theta‐high gamma phase‐amplitude couplings negatively correlated with the deceleration of the fastest Psychomotor Vigilance Task reaction times. These findings suggest that sleep deprivation affects vigilance by altering electroencephalographic spectral power and information communication across frequency bands in different brain regions. The distinct effects of increased theta power and delta/theta‐gamma phase‐amplitude coupling might reflect the impairment and compensation of sleep deprivation on vigilance performance, respectively.

Neuroprotective Effect of Brivaracetam and Perampanel Combination on Electrographic Seizures and Behavior Anomalies in Pentylenetetrazole-Kindled Mice.

Pentylenetetrazole (PTZ)-induced kindling is a broadly used experimental model to study the anticonvulsive potential of new and existing chemical moieties with the aim of discovering drugs hindering seizure progression and associated neurological comorbidities. In the present study, the impact of brivaracetam (BRV) (10 and 20 mg/kg) as monotherapy as well as in combination with 0.25 mg/kg of perampanel (PRP) was investigated on seizure progression with simultaneous electroencephalographic changes in PTZ kindling mouse model. Subsequently, mice were experimentally analyzed for anxiety, cognition, and depression after which their brains were biochemically evaluated for oxidative stress. The outcomes demonstrated that BRV alone delayed the kindling process, but BRV + PRP combination significantly (p < 0.0001) protected the mice from seizures of higher severity and demonstrated an antikindling effect. The PTZ-kindled mice exhibited anxiety, memory impairment, and depression in behavioral tests, which were remarkably less (p < 0.001) in animals treated with drug combination (in a dose-dependent manner) as these mice explored central, illuminated, and exposed zones of open-field test, light/dark box, and elevated plus maze. Moreover, memory impairment was demonstrated by kindled mice, which was significantly (p < 0.001) protected by BRV + PRP as animal's spontaneous alteration, object discrimination, and step-through latencies were increased in various tests employed for the assessment of cognitive abilities. The brains of PTZ-kindled mice had increased malondialdehyde and reduced antioxidant enzymes while treatment with BRV + PRP combination prevented kindling-induced elevation in oxidative markers. The outcomes of this study demonstrate that combining the PRP at low dose augmented the antiseizure properties of BRV as both drugs when administered simultaneously hindered the process of kindling by reducing PTZ-induced excessive electrical activity and oxidative stress in the brain.

The Association of Epileptic Seizures after Acute Ischemic Stroke with Cerebral Cortical Involvement and Electroencephalographic Changes.

Background and objectives: while acute ischemic stroke is the leading cause of epilepsy in the elderly population, data about its risk factors have been conflicting. Therefore, the aim of our study is to determine the association of early and late epileptic seizures after acute ischemic stroke with cerebral cortical involvement and electroencephalographic changes. Materials and methods: a prospective cohort study in the Hospital of the Lithuanian University of Health Sciences Kaunas Clinics Department of Neurology was conducted and enrolled 376 acute ischemic stroke patients. Data about the demographical, clinical, radiological, and encephalographic changes was gathered. Patients were followed for 1 year after stroke and assessed for late ES. Results: the incidence of ES was 4.5%, the incidence of early ES was 2.7% and the incidence of late ES was 2.4%. The occurrence of early ES increased the probability of developing late ES. There was no association between acute cerebral cortical damage and the occurrence of ES, including both early and late ES. However, interictal epileptiform discharges were associated with the occurrence of ES, including both early and late ES.

The Surgical Method of Craniectomy Differentially Affects Acute Seizures, Brain Deformation, and Behavior in a Traumatic Brain Injury Animal Model.

Traumatic brain injury (TBI) is the leading cause of morbidity and mortality worldwide. Multiple injury models have been developed to study this neurological disorder. One such model is the lateral fluid percussion injury (LFPI) rodent model. The LFPI model can be generated with different surgical procedures that could affect the injury and be reflected in neurobehavioral dysfunction and acute electroencephalograph (EEG) changes. A craniectomy was performed either with a trephine hand drill or with a trephine electric drill that was centered over the left hemisphere of adult, male Sprague Dawley rats. Sham craniectomy groups were assessed by hand-drilled (ShamHMRI) and electric-drilled (ShamEMRI) to evaluate by magnetic resonance imaging (MRI). Then, TBI was induced in separate groups, (TBIH) and (TBIE), using a fluid-percussion device. Sham-injured rats (ShamH/ShamE) underwent the same surgical procedures as the TBI rats. During the same surgery session, rats were implanted with screw and microwire electrodes positioned in the neocortex and hippocampus and the EEG activity was recorded 24 h for the first 7 days after TBI for assessing the acute EEG seizure and gamma event coupling. The electric drilling craniectomy induced greater tissue damage and sensorimotor deficits compared with the hand drill. Analysis of the EEG revealed acute seizures in at least one animal from each group after the procedure. Both TBI and Sham rats from the electric drill groups had a significant greater total number of seizures than the animals that were craniectomized manually (p < 0.05). Similarly, EEG functional connectivity was lower in ShamE compared with ShamH rats. These results suggest that electrical versus hand-drilling craniectomies produce cortical injury in addition to the LFPI which increases the likelihood for acute post-traumatic seizures. Differences in the surgical approach could be one reason for the variability in the injury that makes it difficult to replicate results between preclinical TBI studies.

The maintenance treatment with opium tincture and exercise normalize the electroencephalographic changes and reduce visual image-induced craving in opioid use disorder patients

The maintenance treatment with opium tincture and exercise normalize the electroencephalographic changes and reduce visual image-induced craving in opioid use disorder patients

Monitoring Changes in TMS-Evoked EEG and EMG Activity During 1 Hz rTMS of the Healthy Motor Cortex.

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique capable of inducing neuroplasticity as measured by changes in peripheral muscle electromyography (EMG) or electroencephalography (EEG) from pre-to-post stimulation. However, temporal courses of neuromodulation during ongoing rTMS are unclear. Monitoring cortical dynamics via TMS-evoked responses using EMG (motor-evoked potentials; MEPs) and EEG (transcranial-evoked potentials; TEPs) during rTMS might provide further essential insights into its mode of action - temporal course of potential modulations. The objective of this study was to first evaluate the validity of online rTMS-EEG and rTMS-EMG analyses, and second to scrutinize the temporal changes of TEPs and MEPs during rTMS. As rTMS is subject to high inter-individual effect variability, we aimed for single-subject analyses of EEG changes during rTMS. Ten healthy human participants were stimulated with 1,000 pulses of 1 Hz rTMS over the motor cortex, while EEG and EMG were recorded continuously. Validity of MEPs and TEPs measured during rTMS was assessed in sensor and source space. Electrophysiological changes during rTMS were evaluated with model fitting approaches on a group- and single-subject level. TEPs and MEPs appearance during rTMS was consistent with past findings of single pulse experiments. Heterogeneous temporal progressions, fluctuations or saturation effects of brain activity were observed during rTMS depending on the TEP component. Overall, global brain activity increased over the course of stimulation. Single-subject analysis revealed inter-individual temporal courses of global brain activity. The present findings are in favor of dose-response considerations and attempts in personalization of rTMS protocols.

Clinical and diagnostic features of repeated mild traumatic brain injuries

Repeated mild traumatic brain injury (TBI) leads to new changes and exacerbates the existing ones caused by the primary trauma. The pathogenetic mechanisms of repeated TBI are the result of traumatic effects and their cumulation. They cause various morphological and functional changes in the brain. Objective — to improve the diagnosis of pathological changes in patients with repeated mild traumatic brain injury. Materials and methods. The study involved 199 patients with a history of repeated mild TBI. Men predominated among them — 158 (79.40 %). There were 80 (40.20 %) patients of youthful age (17—24 years), 78 (39.20 %) of young age (25—44 years), and 41 (20.60 %) of middle-aged (45—60 years). The number of repeated TBIs per patient ranged from two to five. All patients were examined in the remote period of TBI. The control group consisted of 30 people aged 18 to 50 years (mean age — (33.11 ± 3.09) years) who had no history of TBI. Cognitive impairment (CI) was assessed by neuropsychological examination using the Mini-Mental State Examination (MMSE), the Frontal Area Battery (FAB), and the clock drawing test. Methods of neuropsychological analysis, neuroimaging and neurophysiological methods were used. The data of clinical and neurological examinations and studies of cognitive functions were analyzed, structural changes of the brain and cerebrospinal tract were established on the basis of neuroimaging studies of the brain, and the peculiarities of cerebral hemodynamics in patients with mild repeated TBI were determined. The characteristics of neurophysiological changes in patients are given based on the study of the features of electroencephalographic changes and the study of cognitive evoked potentials of the brain. The immune status was evaluated in patients who had repeated mild TBI. Results. Repeated TBI in our study was observed in the form of mild concussions and brain contusions. Their number in one patient ranged from 1 to 5. Clinical manifestations of repeated mild TBI had peculiarities: cephalalgic, cerebral and cerebrospinal hypertensive syndrome, cognitive impairment, diffuse neurological symptoms, and pyramidal insufficiency prevailed in the clinical picture. Only in the main group were cases of a combination of three to eight neurological syndromes detected. A decrease in cognitive function was found in patients with repeated mild TBI compared to the control group according to neuropsychological testing. The analysis of cognitive evoked potentials revealed an increase in the latent period of the cognitive complex P300 in patients with repeated TBI compared with the control group, indicating a decrease in cognitive function. More frequent CP was detected in the main group. The use of modern neuroimaging methods revealed that patients with repeated TBI had increased width of the lateral ventricles on both sides, ventricle III, and the cavity of the septum compared with the control group, as well as a higher frequency of expansion of the septum and convexity of the subarachnoid spaces. Patients with repeated mild TBI are characterised by an increase in blood flow velocity in the extracranial parts of the carotid basin and a decrease in velocity in the vessels of the vertebrobasilar basin with a change in vascular resistance, in the segments of the intracranial part of the carotid basin — a decrease in blood flow velocity without a change in vascular resistance. Disorders of venous cerebral circulation (increased velocity in the internal jugular vein and Rosenthal veins) were recorded in the majority of the main group. According to the data of the CEG, in patients with repeated TBI against the background of diffuse changes in brain bioelectrical activity, focal changes in the left hemisphere of the brain are more common. Dominant arrhythmia was recorded in 97.78 % of patients in the main group. The amplitude of arrhythmia in patients with repeated TBI is lower compared to the control group, and the frequency of arrhythmic oscillations is higher. Conclusions. The use of clinical and diagnostic control allows to prevent the development of damage and obtain objective information about the state of the brain and its structures.

Electrical Activity Changes and Neurovascular Unit Markers in the Brains of Patients after Cardiac Surgery: Effects of Multi-Task Cognitive Training.

There is growing interest in finding methods to enhance cognitive function and comprehend the neurophysiological mechanisms that underlie these improvements. It is assumed that non-pharmacological interventions have better results in cognitive recovery. The aim of this study was to assess the effect of multi-task cognitive training (MTT) on electroencephalographic (EEG) changes and markers of the neurovascular unit in patients undergoing coronary artery bypass grafting (CABG). This prospective cohort study involved 62 CABG patients aged 45-75 years, 30 of whom underwent a 5-7-day MTT course. The groups of patients were comparable with respect to baseline clinical and anamnestic characteristics. An EEG study was performed before surgery and 11-12 days after CABG. Markers of the neurovascular unit (S100β, NSE, and BDNF) were examined at three time points: before surgery, within the first 24 h after surgery, and 11-12 days after CABG. Patients without training demonstrated higher relative theta power changes compared to the MTT patients. The course of MTT was associated with low plasma S100β concentration but high BDNF levels at the end of the training course. The theta activity changes and the markers of the neurovascular unit (S100β, BDNF) indicated that the severity of brain damage in cardiac surgery patients after a short course of MTT was slightly reduced. Electrical brain activity indicators and vascular markers can be informative for monitoring the process of cognitive rehabilitation in cardiac surgery patients.

Cortical Changes of Dual Cognitive-Task Balance Training in Patients With Chronic Ankle Instability: A Randomized Trial.

Researchers have shown that patients with chronic ankle instability (CAI) have deficits in memory and attention allocation. This functional deficit affects lower extremity performance. Motor-cognitive dual-task training may improve lower limb dysfunction caused by central nervous system injury. Further study is needed to determine whether dual-task training is more favorable than single-task training for improving neuromuscular control in patients with CAI. To compare the effects of balance-cognition dual-task training and balance single-task training on lower limb function and electroencephalography changes during static postural control in patients with CAI. Randomized clinical trial (Chinese Clinical Trial Registry: ChiCTR2300073875). Rehabilitation training room. A total of 24 patients with CAI (age = 22.33 ± 2.43 years, height = 175.62 ± 7.7 cm, mass = 70.63 ± 14.59 kg) were block randomized into 2 groups. Protocols were performed 3 times per week for 6 weeks. The single-task group underwent 1-legged static balance training with eyes open and closed and hopping balance training. The dual-task group underwent balance and cognitive training (backward-counting task). Cortical activity, proprioception, muscle onset time (difference between the muscle activation time and touchdown time), and dynamic balance were assessed before and after the interventions. We performed multivariate analyses of variance to identify main effects and interactions across groups and time. A post hoc Bonferroni test was performed for pairwise comparisons when interactions were present. All participants successfully completed the 6-week interventions. Proprioception, peroneus longus (PL) muscle onset time, and dynamic postural control improved after the interventions in both groups (P < .05). Dual-task training was superior to single-task training in improving joint position sense in plantar flexion, shortening PL muscle onset time, and altering cortical activity (P < .05). A 6-week program of balance training or balance combined with cognitive training could improve the functional deficits associated with CAI. The dual-task training could also improve joint position sense in plantar flexion, PL muscle onset time, and cortical activity.