Effects of Transcutaneous Auricular Vagus Nerve Stimulation on Cortical Excitability in Healthy Adults.

OBJECTIVE: Vagus nerve stimulation (VNS) has recently been reported to exert additional benefits for functional recovery in patients with brain injury. However, the mechanisms underlying these effects have not yet been elucidated. This study examined the effects of transcutaneous auricular VNS (taVNS) on cortical excitability in healthy adults. MATERIALS AND METHODS: We recorded subthreshold and suprathreshold single- and paired-pulse motor-evoked potentials (MEPs) in the right-hand muscles of 16 healthy adults by stimulating the left primary motor cortex. Interstimulus intervals were set at 2 milliseconds and 3 milliseconds for intracortical inhibition (ICI), and 10 milliseconds and 15 milliseconds for intracortical facilitation (ICF). taVNS was applied to the cymba conchae of both ears for 30 minutes. The intensity of taVNS was set to a maximum tolerable level of 1.95 mA. MEPs were measured before stimulation, 20 minutes after the beginning of the stimulation, and 10 minutes after the cessation of stimulation. RESULTS: The participants' age was 33.25 ± 7.08 years, and nine of 16 were male. No statistically significant changes were observed in the mean values of the single-pulse MEPs before, during, or after stimulation. Although the ICF showed an increasing trend after stimulation, the changes in ICI and ICF were not significant, primarily because of the substantial interindividual variability. CONCLUSIONS: The effect of taVNS on cortical excitability varied in healthy adults. An increase in ICF was observed after taVNS, although the difference was not statistically significant. Our findings contribute to the understanding of the mechanisms by which taVNS is effective in patients with brain disorders.

Inter-rater and Intra-rater Reliability of the Videofluoroscopic Dysphagia Scale with the Standardized Protocol.

This study aimed to develop a standardized protocol for the assessment of videofluoroscopic dysphagia scale (VDS) and to demonstrate the inter-rater and intra-rater reliability of the VDS by applying the new standard protocol. A standardized protocol for the VDS was developed by dysphagia experts, including the original developer. To identify the reliability of the VDS using the protocol, 60 patients who underwent videofluoroscopic swallowing study (VFSS) for various etiologies were recruited retrospectively from three tertiary medical centers. Ten randomly selected cases were duplicated to evaluate the intra-rater reliability. Six physicians evaluated the VFSS data sets. Intraclass correlation coefficients were calculated for inter-rater and intra-rater reliability of the VDS score, and Gwet's kappa values for each VDS item were calculated. The inter-rater and intra-rater reliability of the total VDS score was 0.966 and 0.896, respectively. Notably, the evaluators' experience did not appear to have a significant impact on the reliability (physiatrists: 0.933/0.869, residents: 0.922/0.922). The reliability was consistent across different centers and dysphagia etiologies. The inter-rater and intra-rater reliability of the oral and pharyngeal sub-scores were 0.953/0.861 and 0.958/0.907, respectively. The inter-rater agreement of individual items ranged from 0.456 to 0.929, and nine items demonstrated good to very good level of agreement. Assessment of dysphagia using the VDS with the standard protocol showed excellent inter-rater and intra-rater reliabilities regardless of the evaluator's experience, VFSS equipment, and dysphagia etiologies. The VDS can be a useful assessment scale in the quantitative analysis of dysphagia based on VFSS findings.

Multiplexed Quantitative Proteomics Reveals Proteomic Alterations in Two Rodent Traumatic Brain Injury Models.

In many cases of traumatic brain injury (TBI), conspicuous abnormalities, such as scalp wounds and intracranial hemorrhages, abate over time. However, many unnoticeable symptoms, including cognitive, emotional, and behavioral dysfunction, often last from several weeks to years after trauma, even for mild injuries. Moreover, the cause of such persistence of symptoms has not been examined extensively. Recent studies have implicated the dysregulation of the molecular system in the injured brain, necessitating an in-depth analysis of the proteome and signaling pathways that mediate the consequences of TBI. Thus, in this study, the brain proteomes of two TBI models were examined by quantitative proteomics during the recovery period to determine the molecular mechanisms of TBI. Our results show that the proteomes in both TBI models undergo distinct changes. A bioinformatics analysis demonstrated robust activation and inhibition of signaling pathways and core proteins that mediate biological processes after brain injury. These findings can help determine the molecular mechanisms that underlie the persistent effects of TBI and identify novel targets for drug interventions.

Changes of neural coupling between cognitive and motor networks associated with dual-task performance in Parkinson's disease.

BACKGOUND: Although cognitive control is essential for efficient gait, the associations between cognitive and motor networks regarding gait in individuals with Parkinson's disease (PD) remain to be determined. Herein, we enrolled 28 PD and 28 controls to compare internetwork coupling among cognitive and motor networks and examine its relationship with single- and dual-task gait performance in PD. METHODS: The dorsal attention network (DAN), left and right frontoparietal control networks (FPNs), sensorimotor network, and lateral motor network were identified using resting-state functional magnetic resonance imaging data. The time taken to complete a 10-m walk test during cognitive or physical dual-tasks in PD was calculated representing gait performance. RESULTS: We observed that the internetwork couplings between the DAN and motor networks and between the motor networks decreased whereas those between the left FPN and DAN and motor networks increased in PD compared to controls using a permutation test. There was no significant correlation between the internetwork couplings and single- and dual-task gait performance in PD. Nevertheless, improved cognitive dual-task performance showed a positive correlation with the DAN and left FPN coupling and a negative correlation with the DAN and lateral motor network coupling in a good performance group. The opposite relationship was observed in the poor cognitive dual-task performance group. CONCLUSION: Our findings suggest a neural mechanism of cognitive control on gait to compensate for reduced goal-directed attention in PD who maintain cognitive dual-task performance.

Proteomic discovery of prognostic protein biomarkers for persisting problems after mild traumatic brain injury.

Some individuals with mild traumatic brain injury (mTBI), also known as concussion, have neuropsychiatric and physical problems that last longer than a few months. Symptoms following mTBI are not only impacted by the kind and severity of the injury but also by the post-injury experience and the individual's responses to it, making the persistence of mTBI particularly difficult to predict. We aimed to identify prognostic blood-based protein biomarkers predicting 6-month outcomes, in light of the clinical course after the injury, in a longitudinal mTBI cohort (N = 42). Among 420 target proteins quantified by multiple-reaction monitoring-mass spectrometry assays of blood samples, 31, 43, and 15 proteins were significantly associated with the poor recovery of neuropsychological symptoms at < 72 h, 1 week, and 1 month after the injury, respectively. Sequential associations among clinical assessments (depressive symptoms and cognitive function) affecting the 6-month outcomes were evaluated. Then, candidate biomarker proteins indirectly affecting the outcome via neuropsychological symptoms were identified. Using the identified proteins, prognostic models that can predict the 6-month outcome of mTBI were developed. These protein biomarkers established in the context of the clinical course of mTBI may have potential for clinical application.

A Systematic Review of the Learning Dynamics of Proprioception Training: Specificity, Acquisition, Retention, and Transfer.

OBJECTIVE: We aimed to identify key aspects of the learning dynamics of proprioception training including: 1) specificity to the training type, 2) acquisition of proprioceptive skills, 3) retention of learning effects, and 4) transfer to different proprioceptive skills. METHODS: We performed a systematic literature search using the database (MEDLINE, EMBASE, Cochrane Library, and PEDro). The inclusion criteria required adult participants who underwent any training program that could enhance proprioceptive function, and at least 1 quantitative assessment of proprioception before and after the intervention. We analyzed within-group changes to quantify the effectiveness of an intervention. RESULTS: In total, 106 studies with 343 participant-outcome groups were included. Proprioception-specific training resulted in large effect sizes with a mean improvement of 23.4 to 42.6%, nonspecific training resulted in medium effect sizes with 12.3 to 22% improvement, and no training resulted in small effect sizes with 5.0 to 8.9% improvement. Single-session training exhibited significant proprioceptive improvement immediately (10 studies). For training interventions with a midway evaluation (4 studies), trained groups improved by approximately 70% of their final value at the midway point. Proprioceptive improvements were largely maintained at a delayed follow-up of at least 1 week (12 studies). Finally, improvements in 1 assessment were significantly correlated with improvements in another assessment (10 studies). CONCLUSIONS: Proprioceptive learning appears to exhibit several features similar to motor learning, including specificity to the training type, 2 time constant learning curves, good retention, and improvements that are correlated between different assessments, suggesting a possible, common mechanism for the transfer of training.

Kinematic mechanism of the rehabilitative effect of 4-channel NMES: post-hoc analysis of a prospective randomized controlled study.

The sequential 4-channel neuromuscular electrical stimulation (NMES), based on the normal contractile sequences of swallowing-related muscles, is a new rehabilitative treatment. The objective of this study was to explore the mechanism of the rehabilitative effect of the 4-channel NMES using kinematic analysis of videofluoroscopic swallowing study (VFSS) data. For this post-hoc analysis, we included a subset of participants from the prospective randomized controlled study on the clinical effectiveness of the sequential 4-channel NMES compared with that of the conventional 2-channel NMES. Seventeen subjects (11 and six in the 4- and 2-channel NMES groups, respectively) were eligible for the kinematic analysis of VFSS data. The hyoid bone movement was analyzed by evaluating the distance and time parameters with four peak points (A, B, C, D). The 4-channel NMES group showed significant improvement in vertical distances (A-C), horizontal distance (A-B, A-C), time interval (A-B-C) and total time, compared with their pretreatment data. The 2-channel NMES group showed significant improvements in time interval (A-B); however, the Euclidean distance (A-D) and mean velocity of the Euclidean distance (A-C) were significantly decreased. When the two groups were directly compared, the 4-channel group showed significantly greater improvement in horizontal distance (A-B), Euclidean distance (A-D), time interval (A-B-C), and mean velocity the Euclidean distance (A-D). The results in this study suggest that the sequential 4-channel NMES might lead to the physiologic circular movement of the hyoid bone during swallowing, and therefore be an effective treatment for dysphagia.Trial registration: Clinicaltrials.gov, registration number: NCT03670498.

Clinical Practice Guidelines for Oropharyngeal Dysphagia.

OBJECTIVE: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one's physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. METHODS: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. RESULTS: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. CONCLUSION: This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

Fully immersive virtual reality exergames with dual-task components for patients with Parkinson's disease: a feasibility study.

BACKGROUND: Dual-task training in Parkinson's disease (PD) improves spatiotemporal gait parameters, cognition, and quality of life. Virtual reality (VR) has been used as a therapeutic tool for patients to participate in activities in a safe environment, engage in multisensory experiences, and improve motivation and interest in rehabilitation. This study aimed to investigate the feasibility of fully immersive VR exergames with dual-task components in patients with PD. METHODS: We developed VR exergames (go/no-go punch game, go/no-go stepping game, and number punch game) to improve habitual behavior control using motor-cognitive dual-task performance in patients with PD. The participants underwent 10 sessions 2-3 times a week, consisting of 30 min per session. The Unified Parkinson's Disease Rating Scale, Timed Up and Go test (TUG) under single- and dual-task (cognitive and physical) conditions, Berg balance scale (BBS), Stroop test, trail-making test, and digit span were evaluated before and after intervention. The Simulator Sickness Questionnaire (SSQ) was used to assess VR cybersickness. Usability was assessed using a self-reported questionnaire. RESULTS: Twelve patients were enrolled and completed the entire training session. The mean age of participants was 73.83 ± 6.09 years; mean disease duration was 128.83 ± 76.96 months. The Hoehn and Yahr stages were 2.5 in seven patients and 3 in five patients. A significant improvement was observed in BBS and Stroop color-word test (p = 0.047 and p = 0.003, respectively). TUG time and dual-task interferences showed positive changes, but these changes were not statistically significant. The median SSQ total score was 28.05 (IQR: 29.92), 13.09 (IQR: 11.22), and 35.53 (IQR: 52.36) before, after the first session, and after the final session, respectively; the differences were not significant. Overall satisfaction with the intervention was 6.0 (IQR: 1.25) on a 7-point Likert-type scale. CONCLUSIONS: Fully immersive VR exergames combined with physical and cognitive tasks may be used for rehabilitation of patients with PD without causing serious adverse effects. Furthermore, the exergames using dual-task components improved executive function and balance. Further development of VR training content may be needed to improve motor and dual-task performances. Trial registration NCT04787549 ( https://clinicaltrials.gov/ct2/show/NCT04787549 ).

Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging for Language Mapping in Brain Tumor Surgery: Validation With Direct Cortical Stimulation and Cortico-Cortical Evoked Potential.

OBJECTIVE: Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging-derived tractography (DTI-t) contribute to the localization of language areas, but their accuracy remains controversial. This study aimed to investigate the diagnostic performance of preoperative fMRI and DTI-t obtained with a simultaneous multi-slice technique using intraoperative direct cortical stimulation (DCS) or corticocortical evoked potential (CCEP) as reference standards. MATERIALS AND METHODS: This prospective study included 26 patients (23-74 years; male:female, 13:13) with tumors in the vicinity of Broca's area who underwent preoperative fMRI and DTI-t. A site-by-site comparison between preoperative (fMRI and DTI-t) and intraoperative language mapping (DCS or CCEP) was performed for 226 cortical sites to calculate the sensitivity and specificity of fMRI and DTI-t for mapping Broca's areas. For sites with positive signals on fMRI or DTI-t, the true-positive rate (TPR) was calculated based on the concordance and discordance between fMRI and DTI-t. RESULTS: Among 226 cortical sites, DCS was performed in 100 sites and CCEP was performed in 166 sites. The specificities of fMRI and DTI-t ranged from 72.4% (63/87) to 96.8% (122/126), respectively. The sensitivities of fMRI (except for verb generation) and DTI-t were 69.2% (9/13) to 92.3% (12/13) with DCS as the reference standard, and 40.0% (16/40) or lower with CCEP as the reference standard. For sites with preoperative fMRI or DTI-t positivity (n = 82), the TPR was high when fMRI and DTI-t were concordant (81.2% and 100% using DCS and CCEP, respectively, as the reference standards) and low when fMRI and DTI-t were discordant (≤ 24.2%). CONCLUSION: fMRI and DTI-t are sensitive and specific for mapping Broca's area compared with DCS and specific but insensitive compared with CCEP. A site with a positive signal on both fMRI and DTI-t represents a high probability of being an essential language area.

Clinical and Swallowing Characteristics Related With Respiratory Infection in Parkinsonism Patients.

OBJECTIVE: To investigate the clinical and swallowing characteristics related to respiratory infection in patients with parkinsonism. METHODS: One hundred and forty-two patients with parkinsonism who underwent videofluoroscopic swallowing studies (VFSS) were enrolled in this study. The initial clinical and VFSS characteristics were compared between patients with and without a history of respiratory infection in the past year. A multivariate logistic regression model was applied to identify clinical and swallowing characteristics related to respiratory infections. RESULTS: Patients with respiratory infections were older (74.75±10.20 years vs. 70.70±8.83 years, p=0.037), had a higher Hoehn and Yahr (H&Y) stage (stage IV-V, 67.9% vs. 49.1%; p=0.047), and were more likely to have a diagnosis of idiopathic Parkinson's disease (IPD) (67.9% vs. 41.2%, p=0.011) than those without respiratory infections. Among VFSS findings, bolus formation, premature bolus loss, oral transit time, pyriform sinus residues, pharyngeal wall coatings, and penetration/aspiration were significantly worse in patients with respiratory infections (p<0.05). Regarding clinical characteristics, higher H&Y stage (odds ratio [OR], 3.174; 95% confidence interval [CI], 1.226-8.216; p=0.017) and diagnosis of IPD (OR, 0.280, 95% CI, 0.111-0.706; p=0.007) were significantly related to respiratory infections in the multivariate analysis. Among VFSS findings, pyriform sinus residue (OR, 14.615; 95% CI, 2.257-94.623; p=0.005) and premature bolus loss (OR, 5.151; 95% CI, 1.047-25.338; p=0.044) were also significantly associated with respiratory infection. CONCLUSION: This study suggests that disease severity, diagnosis, pyriform sinus residue, and premature bolus loss observed in VFSS are associated with respiratory infection in patients with parkinsonism.

Deciphering Functional Connectivity Differences Between Motor Imagery and Execution of Target-Oriented Grasping.

This study aimed to delineate overlapping and distinctive functional connectivity in visual motor imagery, kinesthetic motor imagery, and motor execution of target-oriented grasping action of the right hand. Functional magnetic resonance imaging data were obtained from 18 right-handed healthy individuals during each condition. Seed-based connectivity and multi-voxel pattern analyses were employed after selecting seed regions with the left primary motor cortex and supplementary motor area. There was equivalent seed-based connectivity during the three conditions in the bilateral frontoparietal and temporal areas. When the seed region was the left primary motor cortex, increased connectivity was observed in the left cuneus and superior frontal area during visual and kinesthetic motor imageries, respectively, compared with that during motor execution. Multi-voxel pattern analyses revealed that each condition was differentiated by spatially distributed connectivity patterns of the left primary motor cortex within the right cerebellum VI, cerebellum crus II, and left lingual area. When the seed region was the left supplementary motor area, the connectivity patterns within the right putamen, thalamus, cerebellar areas IV-V, and left superior parietal lobule were significantly classified above chance level across the three conditions. The present findings improve our understanding of the spatial representation of functional connectivity and its specific patterns among motor imagery and motor execution. The strength and fine-grained connectivity patterns of the brain areas can discriminate between motor imagery and motor execution.

Exploratory Investigation of the Effects of Tactile Stimulation Using Air Pressure at the Auricular Vagus Nerve on Heart Rate Variability.

OBJECTIVE: To explore the effects of tactile stimulation using air pressure at the auricular branch of the vagus nerve on autonomic activity in healthy individuals. METHODS: Three types of tactile stimulation were used in this study: continuous low-amplitude, continuous high-amplitude, and pulsed airflow. The tactile stimulations were provided to the cymba concha to investigate autonomic activity in 22 healthy participants. The mean heart rate (HR) and parameters of HR variability, including the standard deviation of R-R intervals (SDNN) and root mean square of successive R-R interval differences (RMSSD) were compared at baseline, stimulation, and recovery periods. RESULTS: Two-way repeated measures ANOVA indicated a significant main effect of time on HR (p=0.001), SDNN (p=0.003), and RMSSD (p<0.001). These parameters showed significant differences between baseline and stimulation periods and baseline and recovery periods in the post-hoc analyses. There were no significant differences in the changes induced by stimulation type and the interaction between time and stimulation type for all parameters. One-way repeated measures ANOVA showed that HR, SDNN, and RMSSD did not differ significantly among the three time periods during sham stimulation. CONCLUSION: Parasympathetic activity can be enhanced by auricular tactile stimulation using air pressure, targeting the cymba concha. Further studies are warranted to investigate the optimal stimulation parameters for potential clinical significance.

Tuning Surface Acidity of Mixed Conducting Electrodes: Recovery of Si-Induced Degradation of Oxygen Exchange Rate and Area Specific Resistance.

Metal oxides are an important class of functional materials, and for many applications, ranging from solid oxide fuel/electrolysis cells, oxygen permeation membranes, and oxygen storage materials to gas sensors (semiconducting and electrolytic) and catalysts, the interaction between the surface and oxygen in the gas phase is central. Ubiquitous Si-impurities are known to impede this interaction, commonly attributed to the formation of glassy blocking layers on the surface. Here, the surface oxygen exchange coefficient (kchem ) is examined for Pr0.1 Ce0.9 O2-δ (PCO), a model mixed ionic electronic conductor, via electrical conductivity relaxation measurements, and the area-specific resistance (ASR) by electrochemical impedance spectroscopy. It is demonstrated that even low silica levels, introduced by infiltration, depress kchem by a factor 4000, while the ASR increases 40-fold and we attribute this to its acidity relative to that of PCO. The ability to fully regenerate the poisoned surface by the subsequent addition of basic Ca- or Li-species is further shown. This ability to not only recover Si-poisoned surfaces by tuning the relative surface acidity of an oxide surface, but subsequently outperform the pre-poisoned response, promises to extend the operating life of materials and devices for which the catalytic oxygen/solid interface reaction is central.

Efficacy and Safety of Botulinum Toxin Type A (NABOTA) for Post-stroke Upper Extremity Spasticity: A Multicenter Phase IV Trial.

OBJECTIVE: To evaluate the efficacy and safety of Daewoong botulinum toxin type A (NABOTA) after its launch in South Korea. METHODS: This prospective, multicenter, open-label phase IV clinical trial included 222 patients with stroke. All patients visited the clinic at baseline and at weeks 4, 8, and 12 after injection of upto 360 units of NABOTA into the wrist, elbow, and finger flexor muscles at the first visit. The primary outcome was the change in Modified Ashworth Scale (MAS) score for the wrist flexor muscles between baseline and week 4. The secondary outcomes were the changes in MAS, Disability Assessment Scale (DAS), and Caregiver Burden Scale (CBS) scores between baseline and each visit, and the Global Assessment Scale (GAS) score at week 12. RESULTS: There was a statistically significant decrease in the MAS score for the wrist flexors between baseline and week 4 (-0.97±0.66, p<0.001). Compared with baseline, the MAS, DAS and CBS scores improved significantly during the study period. The GAS was rated as very good or good by 86.8% of physicians and by 60.0% of patients (or caregivers). The incidence of adverse events was 14.4%, which is smaller than that in a previous trial. CONCLUSION: NABOTA showed considerable efficacy and safety in the management of upper limb spasticity in stroke patients.

Exploring user perspectives on a robotic arm with brain-machine interface: A qualitative focus group study.

Brain-machine Interface (BMI) is a system that translates neuronal data into an output variable to control external devices such as a robotic arm. A robotic arm can be used as an assistive living device for individuals with tetraplegia. To reflect users' needs in the development process of the BMI robotic arm, our team followed an interactive approach to system development, human-centered design, and Human Activity Assistive Technology model. This study aims to explore the perspectives of people with tetraplegia about activities they want to participate in, their opinions, and the usability of the BMI robotic arm. Eight people with tetraplegia participated in a focus group interview in a semistructured interview format. A general inductive analysis method was used to analyze the qualitative data. The 3 overarching themes that emerged from this analysis were: 1) activities, 2) acceptance, and 3) usability. Activities that the users wanted to do using the robotic arm were categorized into the following 5 activity domains: activities of daily living (ADL), instrumental ADL, health management, education, and leisure. Participants provided their opinions on the needs and acceptance of the BMI technology. Participants answered usability and expected standards of the BMI robotic arm within 7 categories such as accuracy, setup, cost, etc. Participants with tetraplegia have a strong interest in the robotic arm and BMI technology to restore their mobility and independence. Creating BMI features appropriate to users' needs, such as safety and high accuracy, will be the key to acceptance. These findings from the perspectives of potential users should be taken into account when developing the BMI robotic arm.

Evaluation of Motion Segment Size as a New Sensor-based Functional Outcome Measure in Stroke Rehabilitation.

OBJECTIVE: To evaluate a novel parameter, motion segment size (MSS), in stroke patients with upper limb impairment and validate its clinical applicability by correlating results with a standard clinical task-based functional evaluation tool. METHODS: In this cross-sectional study, patients with hemiplegia and healthy controls equipped with multiple inertial measurement unit (IMU) sensors performed Action Research Arm Test (ARAT) and activities of daily living (ADL) tasks. Acceleration of the wrist and Euler angles of each upper limb segment were measured. The average and maximum MSS, accumulated motion, total performance time, and average motion speed (AMS) were extracted for analysis. RESULTS: Data from nine patients and 10 controls showed that the average MSS of forearm supination/pronation and elbow flexion/extension during full ARAT tasks showed a significant difference between patients and controls and a significant correlation with ARAT scores. CONCLUSIONS: We suggest that MSS may provide clinically relevant information regarding upper limb functional status in stroke patients.

An exploratory study on functional connectivity after mild traumatic brain injury: Preserved global but altered local organization.

INTRODUCTION: This study aimed to investigate alterations in whole-brain functional connectivity after a concussion using graph-theory analysis from global and local perspectives and explore the association between changes in the functional network properties and cognitive performance. METHODS: Individuals with mild traumatic brain injury (mTBI, n = 29) within a month after injury, and age- and sex-matched healthy controls (n = 29) were included. Graph-theory measures on functional connectivity assessed using resting state functional magnetic resonance imaging data were acquired from each participant. These included betweenness centrality, strength, clustering coefficient, local efficiency, and global efficiency. Multi-domain cognitive functions were correlated with the graph-theory measures. RESULTS: In comparison to the controls, the mTBI group showed preserved network characteristics at a global level. However, in the local network, we observed decreased betweenness centrality, clustering coefficient, and local efficiency in several brain areas, including the fronto-parietal attention network. Network strength at the local level showed mixed-results in different areas. The betweenness centrality of the right parahippocampus showed a significant positive correlation with the cognitive scores of the verbal learning test only in the mTBI group. CONCLUSION: The intrinsic functional connectivity after mTBI is preserved globally, but is suboptimally organized locally in several areas. This possibly reflects the neurophysiological sequelae of a concussion. The present results may imply that the network property could be used as a potential indicator for clinical outcomes after mTBI.

Preservation of language function by mapping the arcuate fasciculus using intraoperative corticocortical evoked potential under general anesthesia in glioma surgery.

OBJECTIVE: Intraoperative language mapping under general anesthesia is imperative for brain tumor surgery because awake surgery is not always feasible. Monitoring corticocortical evoked potential (CCEP) is known to be a useful method for tracking neuronal connectivity and localizing functional areas. The authors evaluated the clinical benefit of intraoperative CCEP monitoring for language function preservation in patients undergoing glioma surgery. METHODS: Between January 2019 and June 2021, the authors performed a total of 29 consecutive glioma surgeries using CCEP monitoring under general anesthesia because of a risk of speech impairment; these were analyzed. Language area mapping was implemented by the anterior language area to posterior language area CCEP method for arcuate fasciculus mapping, and tumor resection was performed while avoiding the localized language areas. Language function before and after surgery was evaluated by the Controlled Oral Word Association Test (COWAT). RESULTS: Intraoperative CCEP was successfully monitored in 25 patients (86.2%), and a valid signal was undetectable in the other 4 patients. Language function evaluation was possible before and after surgery in a total of 20 patients. Overall, the preservation rate of language function was 65.0%, and the deterioration rate was 35.0% after tumor resection with CCEP monitoring. Among those 8 patients with preoperative COWAT scores ≥ 18, 5 patients (62.5%) successfully preserved their language function, with COWAT scores > 18 after tumor resection. Among the 12 patients with preoperative deteriorated language function (COWAT score < 18), 8 patients (66.7%) showed improvement or preserved language function after surgery. CONCLUSIONS: Intraoperative CCEP monitoring of the arcuate fasciculus is an acceptable technology for the preservation of language function under general anesthesia in glioma surgery in patients in whom awake surgery is not feasible.

Fracture risk and impact of osteoporosis in patients with Parkinson's disease: a nationwide database study.

INTRODUCTION: Patients with Parkinson's disease (PD) showed an increased risk of fractures in previous studies and a high prevalence of osteoporosis is reportedly a potential contributor. We conducted a nationwide database study on the risk of fractures and the impact of osteoporosis on patients with PD compared to controls. MATERIALS AND METHODS: Using a nationwide database in South Korea, we identified incident patients with PD in 2004-2006 and selected four age- and sex-matched controls. We checked the occurrence rates of overall and hip fractures and plotted Kaplan-Meier curves and a Cox proportional hazards model to determine risk. We also conducted stratified analyses according to the presence or absence of osteoporosis. RESULTS: We identified 9126 patients with PD and 35,601 controls. Patients with PD had a greater probability of fractures throughout the study period in Kaplan-Meier curves, and an increased risk of overall (aHR 1.35, 95% CI 1.297-1.405) and hip (aHR 1.814, 95% CI 1.66-1.983) fractures in a Cox proportional hazards model. In the stratified analysis, the increased risk of overall fracture (aHR 1.333, 95% CI 1.273-1.396 and aHR 1.412, 95% CI 1.301-1.532, respectively) and hip fracture (aHR 1.773, 95% CI 1.604-1.96 and aHR 2.008, 95% CI 1.657-2.434, respectively) due to PD was similar between patients with and without osteoporosis. DISCUSSION: Patients with PD, with or without osteoporosis, are more likely to experience fractures, especially hip fractures. There seems to be no interaction between PD and osteoporosis in regard to the occurrence of fractures, and therefore no effect modification by osteoporosis.