Intracortical brain-heart interplay: An EEG model source study of sympathovagal changes.

The interplay between cerebral and cardiovascular activity, known as the functional brain-heart interplay (BHI), and its temporal dynamics, have been linked to a plethora of physiological and pathological processes. Various computational models of the brain-heart axis have been proposed to estimate BHI non-invasively by taking advantage of the time resolution offered by electroencephalograph (EEG) signals. However, investigations into the specific intracortical sources responsible for this interplay have been limited, which significantly hampers existing BHI studies. This study proposes an analytical modeling framework for estimating the BHI at the source-brain level. This analysis relies on the low-resolution electromagnetic tomography sources localization from scalp electrophysiological recordings. BHI is then quantified as the functional correlation between the intracortical sources and cardiovascular dynamics. Using this approach, we aimed to evaluate the reliability of BHI estimates derived from source-localized EEG signals as compared with prior findings from neuroimaging methods. The proposed approach is validated using an experimental dataset gathered from 32 healthy individuals who underwent standard sympathovagal elicitation using a cold pressor test. Additional resting state data from 34 healthy individuals has been analysed to assess robustness and reproducibility of the methodology. Experimental results not only confirmed previous findings on activation of brain structures affecting cardiac dynamics (e.g., insula, amygdala, hippocampus, and anterior and mid-cingulate cortices) but also provided insights into the anatomical bases of brain-heart axis. In particular, we show that the bidirectional activity of electrophysiological pathways of functional brain-heart communication increases during cold pressure with respect to resting state, mainly targeting neural oscillations in the δ $$ \delta $$ , ß $$ \beta $$ , and γ $$ \gamma $$ bands. The proposed approach offers new perspectives for the investigation of functional BHI that could also shed light on various pathophysiological conditions.

A framework for quantifying the coupling between brain connectivity and heartbeat dynamics: Insights into the disrupted network physiology in Parkinson's disease.

Parkinson's disease (PD) often shows disrupted brain connectivity and autonomic dysfunctions, progressing alongside with motor and cognitive decline. Recently, PD has been linked to a reduced sensitivity to cardiac inputs, that is, cardiac interoception. Altogether, those signs suggest that PD causes an altered brain-heart connection whose mechanisms remain unclear. Our study aimed to explore the large-scale network disruptions and the neurophysiology of disrupted interoceptive mechanisms in PD. We focused on examining the alterations in brain-heart coupling in PD and their potential connection to motor symptoms. We developed a proof-of-concept method to quantify relationships between the co-fluctuations of brain connectivity and cardiac sympathetic and parasympathetic activities. We quantified the brain-heart couplings from electroencephalogram and electrocardiogram recordings from PD patients on and off dopaminergic medication, as well as in healthy individuals at rest. Our results show that the couplings of fluctuating alpha and gamma connectivity with cardiac sympathetic dynamics are reduced in PD patients, as compared to healthy individuals. Furthermore, we show that PD patients under dopamine medication recover part of the brain-heart coupling, in proportion with the reduced motor symptoms. Our proposal offers a promising approach to unveil the physiopathology of PD and promoting the development of new evaluation methods for the early stages of the disease.

Longitudinal measurement invariance of the Patient Health Questionnaire-9 across racial/ethnic groups: Results from the traumatic brain injury model system study.

PURPOSE/OBJECTIVE: The aim of this article is to evaluate the measurement invariance (MI) of the Patient Health Questionnaire-9 (PHQ-9) in a sample of individuals during the first 2 years after traumatic brain injury (TBI). MI was examined among racial/ethnic groups and over time to determine the utility of the PHQ-9 across these dimensions. RESEARCH METHOD/DESIGN: In total, N = 3,227 (20% of the total sample) at 1 year and N = 3,153 (19% of the total sample) at 2 years were included for cross-sectional analyses. For the longitudinal analyses, participants with the PHQ-9 at both time points (N = 2,234; 14% of the total study sample) were included. RESULTS: Results were that the PHQ-9 is fully invariant and maintains its unidimensional factorial structure across racial/ethnic groups during the first 2 years after TBI, suggesting the scale measures the same construct equally well for participants from each group. CONCLUSION/IMPLICATIONS: Based on these results, clinicians should feel confident using the PHQ-9 with diverse TBI patient populations, and researchers can reliably and validly employ it in TBI studies across racial/ethnic groups in the United States. Given the high rates of depression among individuals after TBI and its negative impact on their lives, this instrument will continue to be a key tool to measure the prognosis and success of rehabilitation programs. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Cognitive and brain connectivity trajectories in critically ill COVID-19 patients.

BACKGROUND: Multiple Organ failure (MOF) is one of the main causes of admission to the Intensive Care Unit (ICU) of patients infected with COVID-19 and can cause short- and long-term neurological deficits. OBJECTIVE: To compare the cognitive functioning and functional brain connectivity at 6-12 months after discharge in two groups of individuals with MOF, one due to COVID-19 and the other due to another cause (MOF-group), with a group of Healthy Controls (HC). METHODS: Thirty-six participants, 12 from each group, underwent a neuropsychological and neuroimaging assessment at both time-points. Functional connectivity of the resting state networks was compared between COVID-19 and HC while controlling for the effect of MOF. The association between functional connectivity and neuropsychological performance was also investigated. RESULTS: Compared to the HC, COVID-19 group demonstrated hypoconnectivity between the Default Mode Network and Salience Network. This pattern was associated with worse performance on tests of attention and information processing speed, at both time-points. CONCLUSION: The study of the association between cognitive function and brain functional connectivity in COVID-19 allows the understanding of the short- and long-term neurological alterations of this disease and promotes the development of intervention programs to improve the quality of life for this understudied population.

Bayesian at heart: Towards autonomic outflow estimation via generative state-space modelling of heart rate dynamics.

Recent research is revealing how cognitive processes are supported by a complex interplay between the brain and the rest of the body, which can be investigated by the analysis of physiological features such as breathing rhythms, heart rate, and skin conductance. Heart rate dynamics are of particular interest as they provide a way to track the sympathetic and parasympathetic outflow from the autonomic nervous system, which is known to play a key role in modulating attention, memory, decision-making, and emotional processing. However, extracting useful information from heartbeats about the autonomic outflow is still challenging due to the noisy estimates that result from standard signal-processing methods. To advance this state of affairs, we propose a novel approach in how to conceptualise and model heart rate: instead of being a mere summary of the observed inter-beat intervals, we introduce a modelling framework that views heart rate as a hidden stochastic process that drives the observed heartbeats. Moreover, by leveraging the rich literature of state-space modelling and Bayesian inference, our proposed framework delivers a description of heart rate dynamics that is not a point estimate but a posterior distribution of a generative model. We illustrate the capabilities of our method by showing that it recapitulates linear properties of conventional heart rate estimators, while exhibiting a better discriminative power for metrics of dynamical complexity compared across different physiological states.

Aberrant brain-heart coupling is associated with the severity of post cardiac arrest brain injury.

OBJECTIVE: To investigate autonomic nervous system activity measured by brain-heart interactions in comatose patients after cardiac arrest in relation to the severity and prognosis of hypoxic-ischemic brain injury. METHODS: Strength and complexity of bidirectional interactions between EEG frequency bands (delta, theta, and alpha) and ECG heart rate variability frequency bands (low frequency, LF and high frequency, HF) were computed using a synthetic data generation model. Primary outcome was the severity of brain injury, assessed by (i) standardized qualitative EEG classification, (ii) somatosensory evoked potentials (N20), and (iii) neuron-specific enolase levels. Secondary outcome was the 3-month neurological status, assessed by the Cerebral Performance Category score [good (1-2) vs. poor outcome (3-4-5)]. RESULTS: Between January 2007 and July 2021, 181 patients were admitted to ICU for a resuscitated cardiac arrest. Poor neurological outcome was observed in 134 patients (74%). Qualitative EEG patterns suggesting high severity were associated with decreased LF/HF. Severity of EEG changes were proportional to higher absolute values of brain-to-heart coupling strength (p < 0.02 for all brain-to-heart frequencies) and lower values of alpha-to-HF complexity (p = 0.049). Brain-to-heart coupling strength was significantly higher in patients with bilateral absent N20 and correlated with neuron-specific enolase levels at Day 3. This aberrant brain-to-heart coupling (increased strength and decreased complexity) was also associated with 3-month poor neurological outcome. INTERPRETATION: Our results suggest that autonomic dysfunctions may well represent hypoxic-ischemic brain injury post cardiac arrest pathophysiology. These results open avenues for integrative monitoring of autonomic functioning in critical care patients.

Magnetic resonance elastography captures a transient benefit of exercise intervention on forebrain stiffness in a rat model of fetal alcohol spectrum disorders.

BACKGROUND: Fetal alcohol spectrum disorders (FASD), a group of prevalent conditions resulting from prenatal alcohol exposure, affect the maturation of cerebral white matter as first identified with neuroimaging. However, traditional methods are unable to track subtle microstructural alterations to white matter. This preliminary study uses a highly sensitive and clinically translatable magnetic resonance elastography (MRE) protocol to assess brain tissue microstructure through its mechanical properties following an exercise intervention in a rat model of FASD. METHODS: Female rat pups were either alcohol-exposed (AE) via intragastric intubation of alcohol in milk substitute (5.25 g/kg/day) or sham-intubated (SI) on postnatal days (PD) four through nine to model alcohol exposure during the brain growth spurt. On PD 30, half of AE and SI rats were randomly assigned to either a wheel-running or standard cage for 12 days. Magnetic resonance elastography was used to measure whole brain and callosal mechanical properties at the end of the intervention (around PD 42) and at 1 month post-intervention, and findings were validated with histological quantification of oligoglia. RESULTS: Alcohol exposure reduced forebrain stiffness (p = 0.02) in standard-housed rats. The adolescent exercise intervention mitigated this effect, confirming that increased aerobic activity supports proper neurodevelopmental trajectories. Forebrain damping ratio was lowest in standard-housed AE rats (p < 0.01), but this effect was not mitigated by intervention exposure. At 1 month post-intervention, all rats exhibited comparable forebrain stiffness and damping ratio (p > 0.05). Callosal stiffness and damping ratio increased with age. With cessation of exercise, there was a negative rebound effect on the quantity of callosal oligodendrocytes, irrespective of treatment group, which diverged from our MRE results. CONCLUSIONS: This is the first application of MRE to measure the brain's mechanical properties in a rodent model of FASD. MRE successfully captured alcohol-related changes in forebrain stiffness and damping ratio. Additionally, MRE identified an exercise-related increase to forebrain stiffness in AE rats.

The Effects of Differential Learning on the Standing Broad Jump.

In this investigation, we examined the influence of two approaches of motor skill learning (differential learning and repetition-based) for an explosive motor skill. Twenty-seven individuals completed four training sessions of a standing broad jump task, presented with either differential training or a repetition-based approach. We collected pre-and post-training assessments that included maximal jump distances used to index performance and the recording of ground reaction forces to determine potential biomechanical changes (normalized vertical ground reaction force - GRFvert, rate of force development - RFD, and horizontal take-off velocity - Vhor). Results showed that differential training exhibited greater jump distances than repetition-based training (p < .001) but no training effect was found for jump distances between pre- and post-assessments for either training approach (p = .15). However, a significant increase occurred for Vhor with greater velocities achieved following training (p = .03). Overall, differential training failed to show the expected performance enhancements for a discrete, explosive motor task; this may be related to limited exposure and task specific demands of the movement. Further research is needed to better understand the task factors influencing skill acquisition from differential training.

IGF2 prevents dopaminergic neuronal loss and decreases intracellular alpha-synuclein accumulation in Parkinson's disease models.

Parkinson's disease (PD) is the second most common late-onset neurodegenerative disease and the predominant cause of movement problems. PD is characterized by motor control impairment by extensive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). This selective dopaminergic neuronal loss is in part triggered by intracellular protein inclusions called Lewy bodies, which are composed mainly of misfolded alpha-synuclein (α-syn) protein. We previously reported insulin-like growth factor 2 (IGF2) as a key protein downregulated in PD patients. Here we demonstrated that IGF2 treatment or IGF2 overexpression reduced the α-syn aggregates and their toxicity by IGF2 receptor (IGF2R) activation in cellular PD models. Also, we observed IGF2 and its interaction with IGF2R enhance the α-syn secretion. To determine the possible IGF2 neuroprotective effect in vivo we used a gene therapy approach in an idiopathic PD model based on α-syn preformed fibrils intracerebral injection. IGF2 gene therapy revealed a significantly preventing of motor impairment in idiopathic PD model. Moreover, IGF2 expression prevents dopaminergic neuronal loss in the SN together with a decrease in α-syn accumulation (phospho-α-syn levels) in the striatum and SN brain region. Furthermore, the IGF2 neuroprotective effect was associated with the prevention of synaptic spines loss in dopaminergic neurons in vivo. The possible mechanism of IGF2 in cell survival effect could be associated with the decrease of the intracellular accumulation of α-syn and the improvement of dopaminergic synaptic function. Our results identify to IGF2 as a relevant factor for the prevention of α-syn toxicity in both in vitro and preclinical PD models.

Normative Data Estimation in Neuropsychological Tests: A Systematic Review.

OBJECTIVE: To quantify the evolution, impact, and importance of normative data (ND) calculation by identifying trends in the research literature and what approaches need improvement. METHODS: A PRISMA-guideline systematic review was performed on literature from 2000 to 2022 in PubMed, Pub-Psych, and Web of Science. Inclusion criteria included scientific articles about ND in neuropsychological tests with clear data analysis, published in any country, and written in English or Spanish. Cross-sectional and longitudinal studies were included. Bibliometric analysis was used to examine the growth, productivity, journal dispersion, and impact of the topic. VOSViewer compared keyword co-occurrence networks between 1952-1999 and 2000-2022. RESULTS: Four hundred twelve articles met inclusion and exclusion criteria. The most studied predictors were age, education, and sex. There were a greater number of studies/projects focusing on adults than children. The Verbal Fluency Test (12.7%) was the most studied test, and the most frequently used variable selection strategy was linear regression (49.5%). Regression-based approaches were widely used, whereas the traditional approach was still used. ND were presented mostly in percentiles (44.2%). Bibliometrics showed exponential growth in publications. Three journals (2.41%) were in the Core Zone. VOSViewer results showed small nodes, long distances, and four ND-related topics from 1952 to 1999, and there were larger nodes with short connections from 2000 to 2022, indicating topic spread. CONCLUSIONS: Future studies should be conducted on children's ND, and alternative statistical methods should be used over the widely used regression approaches to address limitations and support growth of the field.

Conscious processing of global and local auditory irregularities causes differentiated heartbeat-evoked responses.

Recent research suggests that brain-heart interactions are associated with perceptual and self-consciousness. In this line, the neural responses to visceral inputs have been hypothesized to play a leading role in shaping our subjective experience. This study aims to investigate whether the contextual processing of auditory irregularities modulates both direct neuronal responses to the auditory stimuli (ERPs) and the neural responses to heartbeats, as measured with heartbeat-evoked responses (HERs). HERs were computed in patients with disorders of consciousness, diagnosed with a minimally conscious state or unresponsive wakefulness syndrome. We tested whether HERs reflect conscious auditory perception, which can potentially provide additional information for the consciousness diagnosis. EEG recordings were taken during the local-global paradigm, which evaluates the capacity of a patient to detect the appearance of auditory irregularities at local (short-term) and global (long-term) levels. The results show that local and global effects produce distinct ERPs and HERs, which can help distinguish between the minimally conscious state and unresponsive wakefulness syndrome patients. Furthermore, we found that ERP and HER responses were not correlated suggesting that independent neuronal mechanisms are behind them. These findings suggest that HER modulations in response to auditory irregularities, especially local irregularities, may be used as a novel neural marker of consciousness and may aid in the bedside diagnosis of disorders of consciousness with a more cost-effective option than neuroimaging methods.

The autophagy protein Def8 is altered in Alzheimer's disease and Aß42-expressing Drosophila brains.

Alzheimer's disease (AD) is the most common neurodegenerative disorder, characterized by protein accumulation in the brain as a main neuropathological hallmark. Among them, Aß42 peptides tend to aggregate and create oligomers and plaques. Macroautophagy, a form of autophagy characterized by a double-membrane vesicle, plays a crucial role in maintaining neuronal homeostasis by degrading protein aggregates and dysfunctional organelles as a quality control process. Recently, DEF8, a relatively uncharacterized protein, has been proposed as a participant in vesicular traffic and autophagy pathways. We have reported increased DEF8 levels in lymphocytes from mild cognitive impairment (MCI) and early-stage AD patients and a neuronal profile in a murine transgenic AD model. Here, we analyzed DEF8 localization and levels in the postmortem frontal cortex of AD patients, finding increased levels compared to healthy controls. To evaluate the potential function of DEF8 in the nervous system, we performed an in silico assessment of its expression and network profiles, followed by an in vivo evaluation of a neuronal Def8 deficient model using a Drosophila melanogaster model of AD based on Aß42 expression. Our findings show that DEF8 is an essential protein for maintaining cellular homeostasis in the nervous system, and it is upregulated under stress conditions generated by Aß42 aggregation. This study suggests DEF8 as a novel actor in the physiopathology of AD, and its exploration may lead to new treatment avenues.

Monitoring lasting changes to brain tissue integrity through mechanical properties following adolescent exercise intervention in a rat model of Fetal Alcohol Spectrum Disorders.

Background: Fetal Alcohol Spectrum Disorders (FASD) encompass a group of highly prevalent conditions resulting from prenatal alcohol exposure. Alcohol exposure during the third trimester of pregnancy overlapping with the brain growth spurt is detrimental to white matter growth and myelination, particularly in the corpus callosum, ultimately affecting tissue integrity in adolescence. Traditional neuroimaging techniques have been essential for assessing neurodevelopment in affected youth; however, these methods are limited in their capacity to track subtle microstructural alterations to white matter, thus restricting their effectiveness in monitoring therapeutic intervention. In this preliminary study we use a highly sensitive and clinically translatable Magnetic Resonance Elastography (MRE) protocol for assessing brain tissue microstructure through its mechanical properties following an exercise intervention in a rat model of FASD. Methods: Rat pups were divided into two groups: alcohol-exposed (AE) pups which received alcohol in milk substitute (5.25 g/kg/day) via intragastric intubation on postnatal days (PD) four through nine during the rat brain growth spurt (Dobbing and Sands, 1979), or sham-intubated (SI) controls. In adolescence, on PD 30, half AE and SI rats were randomly assigned to either a modified home cage with free access to a running wheel or to a new home cage for 12 days (Gursky and Klintsova, 2017). Previous studies conducted in the lab have shown that 12 days of voluntary exercise intervention in adolescence immediately ameliorated callosal myelination in AE rats (Milbocker et al., 2022, 2023). MRE was used to measure longitudinal changes to mechanical properties of the whole brain and the corpus callosum at intervention termination and one-month post-intervention. Histological quantification of precursor and myelinating oligoglia in corpus callosum was performed one-month post-intervention. Results: Prior to intervention, AE rats had lower forebrain stiffness in adolescence compared to SI controls ( p = 0.02). Exercise intervention immediately mitigated this effect in AE rats, resulting in higher forebrain stiffness post-intervention in adolescence. Similarly, we discovered that forebrain damping ratio was lowest in AE rats in adolescence ( p < 0.01), irrespective of intervention exposure. One-month post-intervention in adulthood, AE and SI rats exhibited comparable forebrain stiffness and damping ratio (p > 0.05). Taken together, these MRE data suggest that adolescent exercise intervention supports neurodevelopmental "catch-up" in AE rats. Analysis of the stiffness and damping ratio of the body of corpus callosum revealed that these measures increased with age. Finally, histological quantification of myelinating oligodendrocytes one-month post-intervention revealed a negative rebound effect of exercise cessation on the total estimate of these cells in the body of corpus callosum, irrespective of treatment group which was not convergent with noninvasive MRE measures. Conclusions: This is the first application of MRE to measure changes in brain mechanical properties in a rodent model of FASD. MRE successfully captured alcohol-related changes to forebrain stiffness and damping ratio in adolescence. These preliminary findings expand upon results from previous studies which used traditional diffusion neuroimaging to identify structural changes to the adolescent brain in rodent models of FASD (Milbocker et al., 2022; Newville et al., 2017). Additionally, in vivo MRE identified an exercise-related alteration to forebrain stiffness that occurred in adolescence, immediately post-intervention.

Nonlinear neural patterns are revealed in high frequency functional near infrared spectroscopy analysis.

Functional Near Infrared Spectroscopy (fNIRS) is a useful tool for measuring hemoglobin concentration. Linear theory of the hemodynamic response function supports low frequency analysis (<0.2 Hz). However, we hypothesized that nonlinearities, arising from the complex neurovascular interactions sustaining vasomotor tone, may be revealed in higher frequency components of fNIRS signals. To test this hypothesis, we simulated nonlinear hemodynamic models to explore how blood flow autoregulation changes may alter evoked neurovascular signals in high frequencies. Next, we analyzed experimental fNIRS data to compare neural representations between fast (0.2-0.6 Hz) and slow (<0.2 Hz) waves, demonstrating that only nonlinear representations quantified by sample entropy are distinct between these frequency bands. Finally, we performed group-level distance correlation analysis to show that the cortical distribution of activity is independent only in the nonlinear analysis of fast and slow waves. Our study highlights the importance of analyzing nonlinear higher frequency effects seen in fNIRS for a comprehensive analysis of cortical neurovascular activity. Furthermore, it motivates further exploration of the nonlinear dynamics driving regional blood flow and hemoglobin concentrations.

Analysis of the psychometric properties of the Buss-Perry Aggression Questionnaire (AQ) in Colombian adolescents / Análisis de las propiedades psicométricas del cuestionario de agresividad (AQ) de Buss y Perry en adolescentes colombianos

The psychometric properties of the Buss and Perry AQ questionnaire of aggression, one of the most used questionnaires worldwide to measure aggressive behavior, were examined in a sample of adolescents (n=779 participants) from the cities of Barranquilla (n= 410) and Pereira (n= 369), in Colombia. In total, 752 participants (Mean age of 15.3 years, SD = 1.9; 57,4%. women and 42,6 men) completed the Buss and Perry AQ questionnaire. Subsequently, the univariate and multivariate normality of the items was evaluated, and a confirmatory factor analysis (CFA) was performed on the data set. Likewise, the fit of two models was evaluated, a multidimensional a priori model, and a model with a second-order factor (aggressive behavior), which could explain the variance of the items. Finally, the reliability indices of the questionnaire were identified. The results showed acceptable goodness-of-fit indices (X2/df = 2.29, CFI = .977, IFI = .977, GFI = .984, AGFI = .979, RNI = .984, NFI = .972, RMSEA of .047 [90% CI = .016 - .036] and SRMR = .059) for the second-order one-factor model, as well as acceptable reliability indices (α= .55 - .88). In conclusion, these results show that the scale can be applicable to Colombian preadolescents and adolescents, but warn of the limitations of its use for the non-aggression subscale. Nevertheless, the application of the scale in its original version is suggested to determine its psychometric behavior. (AU)

Las propiedades psicométricas del cuestionario de agresión Buss y Perry AQ, uno de los cuestionarios más utilizados mundialmente para medir la conducta agresiva, fue examinado en una muestra de adolescentes (n=779 participantes) de las ciudades de Barranquilla (n= 410) y Pereira (n= 369), en Colombia. En total, 752 participantes (edad media de 15,3 años, DE = 1,9; 57,4%. mujeres y 42,6 hombres) completaron el cuestionario AQ de Buss y Perry. Posteriormente, se evaluó la normalidad univariante y multivariante de los ítems, y se realizó un análisis factorial confirmatorio (AFC) sobre el conjunto de datos. Asimismo, se evaluó el ajuste de dos modelos, un modelo multidimensional a priori, y un modelo con un factor de segundo orden (conducta agresiva), que podría explicar la varianza de los ítems. Por último, se identificaron los índices de fiabilidad del cuestionario. Los resultados mostraron índices de bondad de ajuste aceptables (X2/df = 2,29, CFI = .977, IFI = .977, GFI = .984, AGFI = .979, RNI = .984, NFI = .972, RMSEA de .047 [90% CI = .016 - .036] y SRMR = .059) para el modelo de un factor de segundo orden, así como índices de fiabilidad aceptables (α= .55 - .88). En conclusión, estos resultados muestran que la escala puede ser aplicable a preadolescentes y adolescentes colombianos, pero advierten de las limitaciones de su uso para la subescala de no agresión. No obstante, se sugiere la aplicación de la escala en su versión original para determinar su comportamiento psicométrico. (AU)

Reduced Heartbeat-Evoked Responses in a Near-Death Case Report.

BACKGROUND AND PURPOSE: Whether brain-heart communication continues under ventricular fibrillation (VF) remains to be determined. There is weak evidence of physiological changes in cortical activity under VF. Moreover, brain-heart communication has not previously been studied in this condition. We aimed to measure parallel changes in heart-rate variability (HRV), cortical activity, and brain-heart interactions in a patient who experienced VF. METHODS: The EEG and EKG signals for the case report were acquired for approximately 20 h. We selected different 1-min-long segments based on the changes in the EKG waveform. We present the changes in heartbeat-evoked responses (HERs), HRV, and EEG power for each selected segment. RESULTS: The overall physiological activity appeared to deteriorate as VF proceeded. Brain-heart interactions measured using HERs disappeared, with a few aberrant amplitudes appearing occasionally. The parallel changes in EEG and HRV were not pronounced, suggesting the absence of bidirectional neural control. CONCLUSIONS: Our measurements of brain-heart interactions suggested that the evolving VF impairs communication between the central and autonomic nervous systems. These results may support that reduced brain-heart interactions reflect loss of consciousness and deterioration in the overall health state.

Psychometric properties of the Alexian Brother Urge to Self-Injure (ABUSI) Spanish version for adolescents.

Objective: This study aimed to evaluate the psychometric properties of the Alexian Brother Urge to Self-Injure (ABUSI) in its Spanish version for Colombian adolescents. This instrument was created to measure cognitive and emotional aspects of the urge to self-injure by assessing the frequency, the urge, thoughts associated with time and place, the capacity for resistance, and thoughts associated with the urge to self-injure. Method: A total of 752 preadolescents and adolescents between 10 and 18 years of age, with a mean of 15.3 years (SD = 1.97), participated. The instruments used were The Alexian Brother Urge to Self-Injure ABUSI, ERS Suicide Risk Scale, Plutchik Suicide Risk Scale, and the Zimet The MSPSS Perceived Social Support Scale. Confirmatory factor analysis, inter-test correlations, to estimate cut-off point discriminant validity Receiver Operating Characteristics (ROC) and to determine convergent validity, a Pearson's coincidence analysis was performed between the ABUSI total score and the ERS Suicide Risk Scale, the Plutchik's Suicide Risk Scale and Zimet's Perceived Social Support Scale assessments. Results: The presence of a unidimensional model of the instrument is confirmed with adequate fit, reliability, and concurrent validity indices. The high score classification was determined from six (6) points for the total of the scale. These results show that ABUSI is a valid and reliable tool for the clinical assessment of self-injurious behavior in adolescents and preadolescents.

Multidimensional assessment of heartbeat-evoked responses in disorders of consciousness.

Because consciousness does not necessarily translate into overt behaviour, detecting residual consciousness in noncommunicating patients remains a challenge. Bedside diagnostic methods based on EEG are promising and cost-effective alternatives to detect residual consciousness. Recent evidence showed that the cortical activations triggered by each heartbeat, namely, heartbeat-evoked responses (HERs), can detect through machine learning the presence of minimal consciousness and distinguish between overt and covert minimal consciousness. In this study, we explore different markers to characterize HERs to investigate whether different dimensions of the neural responses to heartbeats provide complementary information that is not typically found under standard event-related potential analyses. We evaluated HERs and EEG average non-locked to heartbeats in six types of participants: healthy state, locked-in syndrome, minimally conscious state, vegetative state/unresponsive wakefulness syndrome, comatose and brain-dead patients. We computed a series of markers from HERs that can generally separate the unconscious from the conscious. Our findings indicate that HER variance and HER frontal segregation tend to be higher in the presence of consciousness. These indices, when combined with heart rate variability, have the potential to enhance the differentiation between different levels of awareness. We propose that a multidimensional evaluation of brain-heart interactions could be included in a battery of tests to characterize disorders of consciousness. Our results may motivate further exploration of markers in brain-heart communication for the detection of consciousness at the bedside. The development of diagnostic methods based on brain-heart interactions may be translated into more feasible methods for clinical practice.

Phonological and semantic verbal fluency test: Scoring criteria and normative data for clustering and switching strategies for Colombian children and adolescents.

BACKGROUND: Verbal fluency tests (VFT) are highly sensitive to cognitive deficits. Usually, the score on VFT is based on the number of correct words produced, yet it alone gives little information regarding underlying test performance. The implementation of different strategies (cluster and switching) to perform efficiently during the tasks provide more valuable information. However, normative data for clustering and switching strategies are scarce. Moreover, scoring criteria adapted to Colombian Spanish are missing. AIMS: (1) To describe the Colombian adaptation of the scoring system guidelines for clustering and switching strategies in VFT; (2) to determine its reliability; and (3) to provide normative data for Colombian children and adolescents aged 6-17 years. METHODS & PROCEDURES: A total of 691 children and adolescents from Colombia completed phonological (/f/, /a/, /s/, /m/, /r/ and /p/) and semantic (animals and fruits) VFT, and five scores were calculated: total score (TS), number of clusters (NC), cluster size (CS), mean cluster size (MCS) and number of switches (NS). The intraclass correlation coefficient was used for interrater reliability. Hierarchical multiple regressions were conducted to investigate which strategies were associated with VFT TS. Multiple regressions were conducted for each strategy, including as predictors age, age2 , sex, mean parents' education (MPE), MPE2 and type of school, to generate normative data. OUTCOMES & RESULTS: Reliability indexes were excellent. Age was associated with VFT TS, but weakly compared with strategies. For both VFT TS, NS was the strongest variable, followed by CS and NC. Regarding norms, age was the strongest predictor for all measures, while age2 was relevant for NC (/f/ phoneme) and NS (/m/ phoneme). Participants with higher MPE obtained more NC, and NS, and larger CS in several phonemes and categories. Children and adolescents from private school generated more NC, NS and larger CS in /s/ phoneme. CONCLUSIONS & IMPLICATIONS: This study provides new scoring guidelines and normative data for clustering and switching strategies for Colombian children and adolescents between 6 and 17 years old. Clinical neuropsychologists should include these measures as part of their everyday practice. WHAT THIS PAPER ADDS: What is already known on the subject VFT are widely used within the paediatric population due to its sensitivity to brain injury. Its score is based on the number of correct words produced; however, TS alone gives little information regarding underlying test performance. Several normative data for VFT TS in the paediatric population exist, but normative data for clustering and switching strategies are scarce. What this paper adds to existing knowledge The present study is the first to describe the Colombian adaptation of the scoring guidelines for clustering and switching strategies, and provided normative data for these strategies for children and adolescents between 6 and 17 years old. What are the potential or actual clinical implications of this work? Knowing VFT's performance, including strategy development and use in healthy children and adolescents, may be useful for clinical settings. We encourage clinicians to include not only TS, but also a careful analysis of strategies that may be more informative of the underlying cognitive processes failure than TS.

Assessing the Reliability and Validity of the Spanish Version of the Actual Scope of Nursing Practice Scale.

Nursing workforce shortage is one of the main challenges for healthcare organizations and it is important to determine if nurses are fulfilling their full scope of practice. There is a questionnaire that measures the activities carried out by nurses, but there is no version available for the Spanish context. The purpose of this study was to develop a cross-cultural adaptation of the "Actual Scope of Nursing Practice" questionnaire by D'Amour et al., and to assess the psychometric characteristics of the Spanish version. An exploratory sequential research design was used. The cross-cultural adaptation was performed using translation, back-translation, review, and pre-testing. Psychometric properties were assessed to determine its construct validity and internal consistency. Among the 501 eligible nurses from the three main hospitals in the region, the first 310 nurses to respond to an online questionnaire were included in our study. The response rate was 61.9%. They were invited via email and completed the survey using the SurveyMonkey platform. The Spanish version of the questionnaire was obtained. A final scale with twenty items and two factors was confirmed with an adequate fit, with the item scores demonstrating that all items were optimally related to their respective latent construct. The alpha coefficients for the Spanish ASCOP scale were robust and revealed good internal consistency. This study showed that the Spanish version of the scale, "Scope of Nursing Practice", has a good degree of validity and reliability. This questionnaire can support nurse managers in realising nursing activities within their organisations and in promoting desirable work outcomes among nurses.