Computational network analysis provides new methods to analyze the brain's structural organization based on diffusion imaging tractography data. Networks are characterized by global and local metrics that have recently given promising insights into diagnosis and the further understanding of psychiatric and neurologic disorders. Most of these metrics are based on the idea that information in a network flows along the shortest paths. In contrast to this notion, communicability is a broader measure of connectivity which assumes that information could flow along all possible paths between two nodes. In our work, the features of network metrics related to communicability were explored for the first time in the healthy structural brain network. In addition, the sensitivity of such metrics was analysed using simulated lesions to specific nodes and network connections. Results showed advantages of communicability over conventional metrics in detecting densely connected nodes as well as subsets of nodes vulnerable to lesions. In addition, communicability centrality was shown to be widely affected by the lesions and the changes were negatively correlated with the distance from lesion site. In summary, our analysis suggests that communicability metrics that may provide an insight into the integrative properties of the structural brain network and that these metrics may be useful for the analysis of brain networks in the presence of lesions. Nevertheless, the interpretation of communicability is not straightforward; hence these metrics should be used as a supplement to the more standard connectivity network metrics.

Computational network analysis provides new methods to analyze the human connectome. Brain structural networks can be characterized by global and local metrics that recently gave promising insights for diagnosis and further understanding of neurological, psychiatric, and neurodegenerative disorders. In order to ensure the validity of results in clinical settings, the precision and repeatability of the networks and the associated metrics must be evaluated. In the present study, 19 healthy subjects underwent two consecutive measurements enabling us to test reproducibility of the brain network and its global and local metrics. As it is known that the network topology depends on the network density, the effects of setting a common density threshold for all networks were also assessed. Results showed good to excellent repeatability for global metrics, while for local metrics it was more variable and some metrics were found to have locally poor repeatability. Moreover, between-subjects differences were slightly inflated when the density was not fixed. At the global level, these findings confirm previous results on the validity of global network metrics as clinical biomarkers. However, the new results in our work indicate that the remaining variability at the local level as well as the effect of methodological characteristics on the network topology should be considered in the analysis of brain structural networks and especially in network comparisons.

BackgroundIdentifying essential competencies in end-of-life care, as well as general practitioners’ (GPs) confidence in these competencies, is essential to guide training and quality improvement efforts in this domain.AimTo determine which competencies in end-of-life care are considered important by GPs, to assess GPs’ confidence in these competencies in a European context and their reasons to refer terminally ill patients to a specialist.Design and SettingCross-sectional postal survey involving a stratified random sample of 2000 GPs in Switzerland in 2014.MethodSurvey development was informed by a previous qualitative exploration of relevant end-of-life GP competencies. Main outcome measures were GPs’ assessment of the importance of and confidence in 18 attributes of end-of-life care competencies, and reasons for transferring care of terminally-ill patients to a specialist. GP characteristics associated with main outcome measures were tested using multivariate regression models.ResultsThe response rate was 31%. Ninety-nine percent of GPs considered the recognition and treatment of pain as important, 86% felt confident about it. Few GPs felt confident in cultural (16%), spiritual (38%) and legal end-of-life competencies such as responding to patients seeking assisted suicide (35%) although more than half of the respondents regarded these competencies as important. Most frequent reasons to refer terminally ill patients to a specialist were lack of time (30%), better training of specialists (23%) and end-of-life care being incompatible with other duties (19%). In multiple regression analyses, confidence in end-of-life care was positively associated with GPs’ age, practice size, home visits and palliative training.ConclusionsGPs considered non-somatic competencies (such as spiritual, cultural, ethical and legal aspects) nearly as important as pain and symptom control. Yet, few GPs felt confident in these non-somatic competencies. These findings should inform training and quality improvement efforts in this domain, in particular for younger, less experienced GPs.

Structural and functional connectivity are intrinsic properties of the human brain and represent the amount of cognitive capacities of individual subjects. These connections are modulated due to development, learning, and disease. Momentary adaptations in functional connectivity alter the structural connections, which in turn affect the functional connectivity. Thus, structural and functional connectivity interact on a broad timescale. In this study, we aimed to explore distinct measures of connectivity assessed by functional magnetic resonance imaging and diffusion tensor imaging and their association to the dominant electroencephalogram oscillatory property at rest: the individual alpha frequency (IAF). We found that in 21 healthy young subjects, small intraindividual temporal IAF fluctuations were correlated to increased blood oxygenation level-dependent signal in brain areas associated to working memory functions and to the modulation of attention. These areas colocalized with functionally connected networks supporting the respective functions. Furthermore, subjects with higher IAF show increased fractional anisotropy values in fascicles connecting the above-mentioned areas and networks. Hence, due to a multimodal approach a consistent functionally and structurally connected network related to IAF was observed.

BackgroundPoor medication-adherence is common in chronic lung patients, resulting in reduced health-outcomes and increased healthcare-costs. This study aimed to investigate the impact of an acoustic reminder and support calls on adherence to inhaled therapy in asthma and COPD patients and to determine their effect on exacerbations.MethodsThis single-blinded randomized controlled trial investigated asthma and COPD patients during 6 months in an ambulatory setting. The intervention consisted of daily alarm clock and support phone calls, whenever use of rescue medication doubled or inhaled medication was not taken as prescribed. Primary outcome was time to next exacerbation. Frequency of exacerbations, adherence to inhaled medication and quality of life scores were secondary outcomes. Cox and Poisson regression were used to determine intervention effect on time to exacerbation and frequency of exacerbations, respectively.ResultsSeventy-five participants were assigned to the intervention group and 74 to usual follow-up care. During a median follow-up of 6.2 months, 22 and 28% in the intervention and control groups respectively, experienced at least one exacerbation. Intervention had no effect on time to first exacerbation (HR 0.65, 95% CI 0.21 to 2.07, P = .24), but showed a trend toward a 39% decreased frequency of exacerbations (RR = 0.61, 95% CI 0.35 to 1.03, P = .070) for the adjusted models, respectively. The intervention group had significantly more days with 80–100% taking adherence regarding puff inhalers (82 ± 14% vs. 60 ± 30%, P < .001) and dry powder capsules (90 ± .10% vs. 80 ± 21%, P = .01). Timing adherence in participants using puff inhalers was higher in the intervention group (69 ± 25% vs. 51 ± 33%, P < .001). No significant differences in QoL were found between the two groups.ConclusionParticipants assigned to the intervention group had significantly better taking and timing adherence of inhaled medication resulting in a trend towards a decreased frequency of exacerbations. However, no effect on time to next exacerbation was observed.Trial registrationClinicalTrials.gov: NCT02386722, Registered 14 February 2014.

Background Dementia is often underdiagnosed in general practice, which may be based on general practitioners’ (GPs’) knowledge and emotional factors as well as external problems. This study aimed to describe GPs’ attitudes toward early diagnosis of dementia. Methods Cross-sectional postal survey in Switzerland in 2017. Members of the Swiss Association of General Practitioners ( N = 4460) were asked to participate in the survey. The questionnaire assessed attitudes, enablers and barriers to early dementia diagnosis and post-diagnostic intervention strategies. Exploratory factor analysis and linear regression were used. Results The survey response rate was 21%. 85% of GPs agreed with enablers of early dementia recognition (e.g. “Plan for the future, organize support and care”, “Minimize the strain and insecurity of patients and their informal family caregivers”). On the other hand, 15% of respondents perceived barriers towards early dementia recognition (e.g. “Time constraints in carrying out the necessary procedures to diagnose dementia”). GPs who were more likely to agree with barriers would less often counsel family members (β = − 0.05, 95% CI = − 0.09 - -0.02) or test fitness to drive (β = − 0.05, 95% CI = − 0.09 - -0.02), and more often choose a watchful waiting strategy (β = 0.05, 95% CI = 0.02–0.09). Conclusions The attitude of the majority of GPs is not characterized by diagnostic and therapeutic nihilism. However, negative attitudes were associated with sub-optimal management after the diagnosis. Thus, health systems are required to critically examine the use of available resources allowing GPs to look after patients and their relatives in a holistic way. Electronic supplementary material The online version of this article (10.1186/s12875-019-0956-1) contains supplementary material, which is available to authorized users.

BackgroundWhite matter (WM) fibers connect different brain regions and are critical for proper brain function. However, little is known about the cerebral blood flow in WM and its relation to WM microstructure. Recent improvements in measuring cerebral blood flow (CBF) by means of arterial spin labeling (ASL) suggest that the signal in white matter may be detected. Its implications for physiology needs to be extensively explored. For this purpose, CBF and its relation to anisotropic diffusion was analyzed across subjects on a voxel-wise basis with tract-based spatial statistics (TBSS) and also across white matter tracts within subjects.MethodsDiffusion tensor imaging and ASL were acquired in 43 healthy subjects (mean age = 26.3 years).ResultsCBF in WM was observed to correlate positively with fractional anisotropy across subjects in parts of the splenium of corpus callosum, the right posterior thalamic radiation (including the optic radiation), the forceps major, the right inferior fronto-occipital fasciculus, the right inferior longitudinal fasciculus and the right superior longitudinal fasciculus. Furthermore, radial diffusivity correlated negatively with CBF across subjects in similar regions. Moreover, CBF and FA correlated positively across white matter tracts within subjects.ConclusionThe currently observed findings on a macroscopic level might reflect the metabolic demand of white matter on a microscopic level involving myelination processes or axonal function. However, the exact underlying physiological mechanism of this relationship needs further evaluation.

Background and Aim Functional dyspepsia (FD) is a common disorder of gut–brain interaction with incompletely understood pathophysiology. Consequently, heterogeneous expert opinions on diagnostic tests and assessment of treatment efficacies exist. So far, no consensus about the most relevant diagnostic and outcome tool has been reached. In this study, we aimed to analyze the significance of a combined lactulose hydrogen breath test (LHBT) and liquid meal, yet representing a standardized test in irritable bowel syndrome (IBS), in FD. Methods We analyzed data of 146 FD, 204 IBS patients, and 50 healthy volunteers (HV). All patients underwent LHBT with a meal‐drink consisting of 30‐g Lactulose and 400‐mL Ensure®. Effect of abdominal symptom generation in FD/IBS compared with HV was assessed on a patient‐reported Likert‐scale. Results There was a significant difference between FD/IBS patients and HV in LHBT‐induced abdominal pain (odds ratio [OR] 246.9, 95% confidence interval [CI] 26.6–2290.7; OR 161.2, 95% CI 16.9–1534.8), abdominal bloating (OR 384.8, 95% CI 92.9–2135.4; OR 524.1, 95% CI 114.7–3432.3), borborygmi (OR 9.9, 95% CI 2.2–46.9; OR 17.7, 95% CI 4.7–67.4), nausea only in FD (OR 174.4, 95% CI 15.5–5375.5), and diarrhea in IBS only (OR 25.8, 95% CI 2.0–7012.6). Hydrogen production was not significantly different in FD/IBS and HV. Conclusions In this study, we demonstrated significant differences in postprandial symptom generation in FD and IBS compared with HV after LHBT. This does not only allow us to discriminate FD/IBS from HV but may also represent a diagnostic and monitoring tool for FD/IBS in the future, including monitoring of treatment effects.