Interrelating differences in structural and functional connectivity in the older adult's brain.

In the normal aging process, the functional connectome restructures and shows a shift from more segregated to more integrated brain networks, which manifests itself in highly different cognitive performances in older adults. Underpinnings of this reorganization are not fully understood, but may be related to age-related differences in structural connectivity, the underlying scaffold for information exchange between regions. The structure-function relationship might be a promising factor to understand the neurobiological sources of interindividual cognitive variability, but remain unclear in older adults. Here, we used diffusion weighted and resting-state functional magnetic resonance imaging as well as cognitive performance data of 573 older subjects from the 1000BRAINS cohort (55-85 years, 287 males) and performed a partial least square regression on 400 regional functional and structural connectivity (FC and SC, respectively) estimates comprising seven resting-state networks. Our aim was to identify FC and SC patterns that are, together with cognitive performance, characteristic of the older adults aging process. Results revealed three different aging profiles prevalent in older adults. FC was found to behave differently depending on the severity of age-related SC deteriorations. A functionally highly interconnected system is associated with a structural connectome that shows only minor age-related decreases. Because this connectivity profile was associated with the most severe age-related cognitive decline, a more interconnected FC system in older adults points to a process of dedifferentiation. Thus, functional network integration appears to increase primarily when SC begins to decline, but this does not appear to mitigate the decline in cognitive performance.

Implementation of Bronchoscopic Lung Volume Reduction Using One-Way Endobronchial Valves: A Retrospective Single-Centre Cohort Study.

BACKGROUND: Bronchoscopic lung volume reduction (BLVR) using 1-way endobronchial valves (EBV) has become a guideline treatment in patients with advanced emphysema. Evidence from this minimally invasive treatment derives mainly from well-designed controlled trials conducted in high-volume specialized intervention centres. Little is known about real-life outcome data in hospitals setting up this novel treatment and which favourable conditions are required for a continuous successful program. OBJECTIVES: In this study, we aim to evaluate the eligibility rate for BLVR and whether the implementation of BLVR in our academic hospital is feasible and yields clinically significant outcomes. METHOD: A retrospective evaluation of patients treated with EBV between January 2016 and August 2019 was conducted. COPD assessment test (CAT), forced expiratory volume in 1 s (FEV1), residual volume (RV), and 6-min walking test (6MWT) were measured at baseline and 3 months after intervention. Paired sample t tests were performed to compare means before and after intervention. RESULTS: Of 350 subjects screened, 283 (81%) were not suitable for intervention mostly due to lack of a target lobe. The remaining 67 subjects (19%) underwent bronchoscopic assessment, and if suitable, valves were placed in the same session. In total, 55 subjects (16%) were treated with EBV of which 10 did not have complete follow-up: 6 subjects had their valves removed because of severe pneumothorax (n = 2) or lack of benefit (n = 4) and the remaining 4 had missing follow-up data. Finally, 45 patients had complete follow-up at 3 months and showed an average change ± SD in CAT -4 ± 6 points, FEV1 +190 ± 140 mL, RV -770 ± 790 mL, and +37 ± 65 m on the 6MWT (all p < 0.001). After 1-year follow-up, 34 (76%) subjects had their EBV in situ. CONCLUSION: Implementing BLVR with EBV is feasible and effective. Only 16% of screened patients were eligible, indicating that this intervention is only applicable in a small subset of highly selected subjects with advanced emphysema, and therefore a high volume of COPD patients is essential for a sustainable BLVR program.

Cerebrospinal Fluid Drainage in Thoracic and Thoracoabdominal Endovascular Aortic Repair: A Survey of Current Clinical Practice in European Medical Centers.

OBJECTIVES: The aim of this survey was to evaluate the daily clinical practice in European hospitals regarding the modalities to prevent spinal cord ischemia, with an emphasis on cerebrospinal fluid drainage (CSFD), in patients undergoing thoracic and thoracoabdominal endovascular repair. DESIGN: A 21-item online survey on current practice of spinal cord protection with an emphasis on CSFD. SETTING: Online service using Castor EDC software. PARTICIPANTS: Members of the European Association of Cardiothoracic Anaesthesiology and Intensive Care and European Society of Vascular Surgeons. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred eighty invitations were sent and 104 were used for analysis. A majority of respondents used a written protocol for spinal cord protection during endovascular thoracic and thoracoabdominal repair (81/104 = 78%). The most common protective measures used were CSFD (79/81 = 98%), controlled hypertension (59/81 = 73%), drugs (11/81 = 14%), and hypothermia (6/81 = 7%). The two most common indications for placement of a spinal catheter were the length of the stent (83/104 = 80%) and location of aneurysm (71/104 = 68%). Preventive placement of the spinal drain (96/104) is the most common approach. In the subgroup of high-volume centers, 86% (12/14) of the respondents used a written protocol and all protocols include CSFD. Ninety-two percent (11/12) had included controlled arterial hypertension in the protocol compared with 70% (48/69) of the non-high-volume centers respondents. CONCLUSIONS: The majority of European centers use a written protocol that includes CSFD. This survey showed the similarities and differences in the management of CSFD in patients undergoing endovascular thoracic and thoracoabdominal repair.

Challenges in the Cardiothoracic and Vascular Anesthesia Fellowship Program Since the Coronavirus Disease 2019 (COVID-19) Pandemic: An Electronic Survey on Potential Solutions.

OBJECTIVE: The authors explored the current practice of fellowship training in cardiothoracic and vascular anesthesia and surveyed the acceptability of potential solutions to mitigate the interrupted fellowship training during the severe acute respiratory syndrome coronavirus disease 2019 (COVID-19) pandemic. DESIGN: A prospective electronic questionnaire-based survey. SETTING: The survey was initiated by the Education Committee of the European Association of Cardiothoracic Anesthesiology and Intensive Care (EACTAIC). PARTICIPANTS: The study comprised EACTAIC fellows, EACTAIC, and non-EACTAIC subscribers to the EACTAIC newsletter and EACTAIC followers on different social media platforms. INTERVENTIONS: After obtaining the consent of participants, the authors assessed the perioperative management of COVID-19 patients, infrastructural aspects of the workplace, local routines for preoperative testing, the perceived availability of personal protective equipment (PPE), and the impact of COVID-19 on fellowship training. In addition, participants rated suggested solutions by the investigators to cope with the interruption of fellowship training, using a traffic light signal scale. MEASUREMENTS AND MAIN RESULTS: The authors collected 193 responses from 54 countries. Of the respondents, 82.4% reported cancelling or postponing elective cases during the first wave, 89.7% had provided care for COVID-19 patients, 75.1% reported staff in their center being reassigned to work in the intensive care unit (ICU), and 45% perceived a shortage of PPE at their centers. Most respondents reported the termination of local educational activities (79.6%) and fellowship assessments (51.5%) because of the pandemic (although 84% of them reported having time to participate in online teaching), and 83% reported a definitive psychological impact. More than 90% of the respondents chose green and/or yellow traffic lights to rate the importance of the suggested solutions to cope with the interrupted fellowship training during the pandemic. CONCLUSIONS: The COVID-19 pandemic led to the cancellation of elective cases, the deployment of anesthesiologists to ICUs, the involvement of anesthesiologists in perioperative care for COVID-19 patients, and the interruption of educational activities and trainees' assessments. There is some consensus on the suggested solutions for mitigation of the interruption in fellowship training.

European Association of Cardiothoracic Anesthesiology and Intensive Care Pediatric Cardiac Anesthesia Fellowship Curriculum: First Edition.

Pediatric cardiac anesthesia is a subspecialty of cardiac and pediatric anesthesiology dedicated to the perioperative care of patients with congenital heart disease. Members of the Congenital and Education Subcommittees of the European Association of Cardiothoracic Anaesthesiology and Intensive Care (EACTAIC) agreed on the necessity to develop an EACTAIC pediatric cardiac anesthesia fellowship curriculum. This manuscript represents a consensus on the composition and the design of the EACTAIC Pediatric Cardiac Anesthesia Fellowship program. This curriculum provides a basis for the training of future pediatric cardiac anesthesiologists by clearly defining the theoretical and practical requirements for fellows and host centers.

Inter-subject and inter-parcellation variability of resting-state whole-brain dynamical modeling.

Modern approaches to investigate complex brain dynamics suggest to represent the brain as a functional network of brain regions defined by a brain atlas, while edges represent the structural or functional connectivity among them. This approach is also utilized for mathematical modeling of the resting-state brain dynamics, where the applied brain parcellation plays an essential role in deriving the model network and governing the modeling results. There is however no consensus and empirical evidence on how a given brain atlas affects the model outcome, and the choice of parcellation is still rather arbitrary. Accordingly, we explore the impact of brain parcellation on inter-subject and inter-parcellation variability of model fitting to empirical data. Our objective is to provide a comprehensive empirical evidence of potential influences of parcellation choice on resting-state whole-brain dynamical modeling. We show that brain atlases strongly influence the quality of model validation and propose several variables calculated from empirical data to account for the observed variability. A few classes of such data variables can be distinguished depending on their inter-subject and inter-parcellation explanatory power.

European Association of Cardiothoracic and Vascular Anesthesiology and Intensive Care Fellowship Program: The Graduates' Experience.

OBJECTIVES: In 2009, the European Association of Cardiothoracic Anesthesiology and Intensive Care (EACTAIC) established a fellowship program to train highly qualified specialists in the field of cardiac anesthesia. For the further development of the program, a survey among graduates was distributed to get information about the individual motivation and career perspectives of fellows. DESIGN: Online survey among graduates of the EACTAIC cardiothoracic and vascular anesthesia (CTVA) fellowship program. SETTING: Twenty-four-item online survey after personal invitation from the EACTAIC office PARTICIPANTS: Forty-nine graduates. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The survey had a response rate of 77%. On average, graduates joined the EACTAIC fellowship program four years after completing their residency program. Participants felt well-prepared by the program regarding their clinical and nonclinical skills. The majority participated in research activities during the fellowship and continued to work in the field of CTVA. Ninety-two percent of the respondents found a job opportunity within a reasonable time after completing the training. CONCLUSIONS: Among the respondents, the survey showed a high satisfactory rate with the received training and good job opportunities after completing the fellowship. Further research should investigate the question of beneficial effects on research activities after completing the fellowship.

Interruption of the European Association of Cardiothoracic Anaesthesiology (EACTA) Fellowship Program During the Coronavirus Disease 2019 Pandemic: Consequences and Solutions.

This article discusses the impact of the COVID-19 pandemic on the EACTA fellowship program. The authors present three points that in their view are important and give cause for concern because they could make it difficult or impossible to achieve the original goals of the fellowship program. Corresponding points are discussed and possible solutions are presented. An implementation in the fellowship curriculum is planned.

Perspectives on the Fellowship Training in Cardiac, Thoracic, and Vascular Anesthesia and Critical Care in Europe From Program Directors and Educational Leads Around Europe.

This article reviews fellowship training in adult cardiac, thoracic, and vascular anesthesia and critical care from the perspective of European program initiators and educational leaders in these subspecialties together with current training fellows. Currently, the European Association of Cardiothoracic Anaesthesiology (EACTA) network has 20 certified fellowship positions each year in 10 hosting centers within 7 European countries, with 2 positions outside Europe (São Paulo, Brazil). Since 2009, 42 fellows have completed the fellowship training. The aim of this article is to provide an overview of the rationale, requirements, and contributions of the fellows, in the context of the developmental progression of the EACTA fellowship in adult cardiac, thoracic, and vascular anesthesia and critical care from inception to present. A summary of the program structure, accreditation of host centers, requirements to join the program, teaching and assessment tools, certification, and training requirements in transesophageal electrocardiography is outlined. In addition, a description of the current state of EACTA fellowships across Europe, and a perspective for future steps and challenges to the educational program, is provided.

European Association of Cardiothoracic Anesthesiology (EACTA) Cardiothoracic and Vascular Anesthesia Fellowship Curriculum: First Edition.

This special article summarizes the design and certification process of the European Association of Cardiothoracic Anesthesiology (EACTA) Cardiothoracic and Vascular Anesthesia (CTVA) Fellowship Program. The CTVA fellowship training includes a two-year curriculum at an EACTA-accredited educational facility. Before fellows are accepted into the program, they must meet a number of requirements, including evidence of a valid license to practice medicine, a specialist degree examination in anesthesiology, and appropriate language skills as required in the host centers. The CVTA Fellowship Program has 2 sequential and complementary levels of training-both with a modular structure that allows for individual planning and also takes into account the differing national healthcare needs and requirements of the 36 countries represented in EACTA. The basic training period focuses on the anesthetic management of patients undergoing cardiac, thoracic, and vascular surgery and related procedures. The advanced training period is intended to deepen and to extend the clinical and nontechnical skills that fellows have acquired during the basic training. The goal of the EACTA fellowship is to produce highly trained and competent perioperative physicians who are able to care for patients undergoing cardiac, thoracic, and vascular anesthesia.

Fiber length profiling: A novel approach to structural brain organization.

There has been a recent increased interest in the structural connectivity of the cortex. However, an important feature of connectivity remains relatively unexplored; tract length. In this article, we develop an approach to characterize fiber length distributions across the human cerebral cortex. We used data from 76 participants of the Adult WU-Minn Human Connectome Project using probabilistic tractography. We found that connections of different lengths are not evenly distributed across the cortex. They form patterns where certain areas have a high density of fibers of a specific length while other areas have very low density. To assess the relevance of these new maps in relation to established characteristics, we compared them to structural indices such as cortical myelin content and cortical thickness. Additionally, we assessed their relation to resting state network organization. We noted that areas with very short fibers have relatively more myelin and lower cortical thickness while the pattern is inverted for longer fibers. Furthermore, the cortical fiber length distributions produce specific correlation patterns with functional resting state networks. Specifically, we find evidence that as resting state networks increase in complexity, their length profiles change. The functionally more complex networks correlate with maps of varying lengths while primary networks have more restricted correlations. We posit that these maps are a novel way of differentiating between 'local modules' that have restricted connections to 'neighboring' areas and 'functional integrators' that have more far reaching connectivity.

Neostigmine-based reversal of intermediate acting neuromuscular blocking agents to prevent postoperative residual paralysis: A systematic review.

BACKGROUND: Neostigmine is widely used to antagonise residual paralysis. Over the last decades, the benchmark of acceptable neuromuscular recovery has increased progressively to a train-of-four (TOF) ratio of at least 0.9. Raising this benchmark may impact on the efficacy of neostigmine. OBJECTIVE(S): The systematic review evaluates the efficacy of neostigmine to antagonise neuromuscular block to attain a TOF ratio of at least 0.9. DESIGN: We performed a systematic search of the literature from January 1992 to December 2015. DATA SOURCES OR SETTING: PubMed, EMBASE and the Cochrane Controlled Clinical Trials database were searched for randomised controlled human studies. Search was performed without language restrictions, using the following free text terms: 'neostigmine', 'sugammadex', 'edrophonium' or 'pyridostigmine' AND 'neuromuscular block', 'reversal' or 'reverse'. ELIGIBILITY CRITERIA: Studies were accepted for inclusion if they used quantitative neuromuscular monitoring and neostigmine as the reversal agent. Selected trials were checked by two of the authors for data integrity. Trials relevant for inclusion had to report the number of patients included, the type of anaesthetic maintenance, the type of neuromuscular blocking agent used, the reversal agent and dose used, the depth of neuromuscular block when neostigmine was administered and the reversal time (time from injection of neostigmine until a TOF ratio ≥0.9 was attained). RESULTS: 19 trials were eligible for quantitative analysis. In patients with deep residual block [T1 (first twitch height) <10%] 70 µg kg neostigmine was used (five trials, 118 patients), and the mean reversal time was 17.1 min (95% confidence interval (CI) [12.4 to 21.8]). In patients with moderate residual block (T1 10% to <25%) the mean neostigmine dose was 56 µg kg (seven trials, 342 patients), and the mean reversal time was 11.3 min (95% CI [9.2 to 13.4]). In patients with a shallow residual block (T1 ≥ 25%) the mean neostigmine dose was 40 µg kg (13 trials, 535 patients), and the mean reversal time was 8.0 min (95% CI [6.8 to 9.2]). CONCLUSION: Based on the findings of this systematic review, we recommend that the administration of neostigmine be delayed until an advanced degree of prereversal recovery has occurred (i.e. a T1 >25% of baseline), or that a recovery time longer than 15 min be accepted.

Emotion regulation and trait anxiety are predicted by the microstructure of fibers between amygdala and prefrontal cortex.

Diffusion tensor imaging revealed that trait anxiety predicts the microstructural properties of a prespecified fiber tract between the amygdala and the perigenual anterior cingulate cortex. Besides this particular pathway, it is likely that other pathways are also affected. We investigated white matter differences in persons featuring an anxious or a nonanxious personality, taking into account all potential pathway connections between amygdala and anxiety-related regions of the prefrontal cortex (PFC). Diffusion-weighted images, measures of trait anxiety and of reappraisal use (an effective emotion-regulation style), were collected in 48 females. With probabilistic tractography, pathways between the amygdala and the dorsolateral PFC, dorsomedial PFC, ventromedial PFC, and orbitofrontal cortex (OFC) were delineated. The resulting network showed a direct ventral connection between amygdala and PFC and a second limbic connection following the fornix and the anterior limb of the internal capsule. Reappraisal use predicted the microstructure of pathways to all calculated PFC regions in the left hemisphere, indicating stronger pathways for persons with high reappraisal use. Trait anxiety predicted the microstructure in pathways to the ventromedial PFC and OFC, indexing weaker connections in trait-anxious persons. These effects appeared in the right hemisphere, supporting lateralization and top-down inhibition theories of emotion processing. Whereas a specific microstructure is associated with an anxious personality, a different structure subserves emotion regulation. Both are part of a broad fiber tract network between amygdala and PFC.

Predicting early signs of dyslexia at a preliterate age by combining behavioral assessment with structural MRI.

BACKGROUND: Recent studies suggest that neurobiological anomalies are already detectable in pre-school children with a family history of developmental dyslexia (DD). However, there is a lack of longitudinal studies showing a direct link between those differences at a preliterate age and the subsequent literacy difficulties seen in school. It is also not clear whether the prediction of DD in pre-school children can be significantly improved when considering neurobiological predictors, compared to models based on behavioral literacy precursors only. METHODS: We recruited 53 pre-reading children either with (N=25) or without a family risk of DD (N=28). Quantitative T1 MNI data and literacy precursor abilities were assessed at kindergarten age. A subsample of 35 children was tested for literacy skills either one or two years later, that is, either in first or second grade. RESULTS: The group comparison of quantitative T1 measures revealed significantly higher T1 intensities in the left anterior arcuate fascicle (AF), suggesting reduced myelin concentration in preliterate children at risk of DD. A logistic regression showed that DD can be predicted significantly better (p=.024) when neuroanatomical differences between groups are used as predictors (80%) compared to a model based on behavioral predictors only (63%). The Wald statistic confirmed that the T1 intensity of the left AF is a statistically significant predictor of DD (p<.05). CONCLUSIONS: Our longitudinal results provide evidence for the hypothesis that neuroanatomical anomalies in children with a family risk of DD are related to subsequent problems in acquiring literacy. Particularly, solid white matter organization in the left anterior arcuate fascicle seems to play a pivotal role.

Beyond fractional anisotropy: extraction of bundle-specific structural metrics from crossing fiber models.

Diffusion MRI (dMRI) measurements are used for inferring the microstructural properties of white matter and to reconstruct fiber pathways. Very often voxels contain complex fiber configurations comprising multiple bundles, rendering the simple diffusion tensor model unsuitable. Multi-compartment models deliver a convenient parameterization of the underlying complex fiber architecture, but pose challenges for fitting and model selection. Spherical deconvolution, in contrast, very economically produces a fiber orientation density function (fODF) without any explicit model assumptions. Since, however, the fODF is represented by spherical harmonics, a direct interpretation of the model parameters is impossible. Based on the fact that the fODF can often be interpreted as superposition of multiple peaks, each associated to one relatively coherent fiber population (bundle), we offer a solution that seeks to combine the advantages of both approaches: first the fiber configuration is modeled as fODF represented by spherical harmonics and then each of the peaks is parameterized separately in order to characterize the underlying bundle. In this work, the fODF peaks are approximated by Bingham distributions, capturing first and second-order statistics of the fiber orientations, from which we derive metrics for the parametric quantification of fiber bundles. We propose meaningful relationships between these measures and the underlying microstructural properties. We focus on metrics derived directly from properties of the Bingham distribution, such as peak length, peak direction, peak spread, integral over the peak, as well as a metric derived from the comparison of the largest peaks, which probes the complexity of the underlying microstructure. We compare these metrics to the conventionally used fractional anisotropy (FA) and show how they may help to increase the specificity of the characterization of microstructural properties. While metrics relying on the first moments of the Bingham distributions provide relatively robust results, second-order metrics representing the peak spread are only meaningful, if the SNR is very high and no fiber crossings are present in the voxel.

Plausibility Tracking: a method to evaluate anatomical connectivity and microstructural properties along fiber pathways.

Diffusion MRI is a non-invasive method that potentially gives insight into the brain's white matter structure regarding the pathway of connections and properties of the axons. Here, we propose a novel global tractography method named Plausibility Tracking that provides the most plausible pathway, modeled as a smooth spline curve, between two locations in the brain. Compared to other tractography methods, plausibility tracking combines the more complete connectivity pattern of probabilistic tractography with smooth tracks that are globally optimized using the fiber orientation density function and hence is relatively robust against local noise and error propagation. It has been tested on phantom and biological data and compared to other methods of tractography. Plausibility tracking provides reliable local directions all along the fiber pathways which makes it especially interesting for tract-based analysis in combination with direction dependent indices of diffusion MRI. In order to demonstrate this potential of plausibility tracking, we propose a framework for the assessment and comparison of diffusion derived tissue properties. This framework comprises atlas-guided parameterization of tract representation and advanced bundle-specific indices describing fiber density, fiber spread and white matter complexity. We explore the new method using real data and show that it allows for a more specific interpretation of the white matter's microstructure compared to rotationally invariant indices derived from the diffusion tensor.

Management of neuromuscular blockade in ambulatory patients.

PURPOSE OF REVIEW: The use of neuromuscular blocking agents in ambulatory surgery has been described as a double-edged sword. Muscle relaxants may improve the outcome following endotracheal intubation and could be helpful for the surgeon to some extent. However, these agents might increase the risk of postoperative complications because of residual paralysis. This review should summarize recent developments in neuromuscular blockade, neuromuscular monitoring, and reversal with a special reference to day case surgery. RECENT FINDINGS: The use of neuromuscular blocking agents begs a risk of postoperative muscle weakness and has been associated with adverse respiratory events. From the surgical side, there could be an increased request for a more intense neuromuscular block during laparoscopic surgery. Therefore, the use of quantitative neuromuscular monitoring and selective reversal binding agents may gain more importance in the future. For the reversal of a shallow neuromuscular block, cholinesterase inhibitors are still appropriate. SUMMARY: The management of neuromuscular blocks in day case surgery requests a comprehensive approach that should include an adequate dosing of the muscle relaxant, quantitative objective monitoring, and a sufficient and appropriate reversal.