What does cognitive screening reveal about early cognitive performance following endovascular clot retrieval and intravenous thrombolysis in acute ischaemic stroke?

Background Little is known regarding cognitive outcomes following treatment with endovascular clot retrieval (ECR) and intravenous tissue plasminogen activator (t-PA). We aimed to determine if there were any differences on a measure of cognitive screening between patients treated with ECR, t-PA, and those who were managed conservatively. Methods The medical records of ischaemic stroke patients admitted to Monash Medical Centre between January 2019 and December 2019 were retrospectively reviewed. Information extracted from medical records included age, sex, National Institutes of Health Stroke Scale at presentation, location of occlusion, treatment type, medical history, and cognitive screening performance measured by the Montreal Cognitive Assessment (MoCA). Results Eighty-two patients met the inclusion criteria (mean age = 66.5 ± 13.9; 49 male, 33 female). Patients treated with ECR performed significantly better on the MoCA (n = 36, 24.1 ± 4.3) compared to those who were managed conservatively (n = 26, 20.7 ± 5.5). Performance for patients treated with t-PA (n = 20, 23.9 ± 3.5) fell between the ECR and conservative management groups, but they did not significantly differ from either. Conclusion Our retrospective chart review found that ischaemic stroke patients treated with ECR appear to perform better on cognitive screening compared to patients who are managed conservatively. We also found that patients treated with ECR and t-PA appear to have similar cognitive screening performances in the acute stages following ischaemic stroke, although this finding is likely to have been impacted by group differences in stroke characteristics and may reflect the possibility that the ECR group performed better than expected based on their stroke severity.

Prospective associations of technostress at work, burnout symptoms, hair cortisol, and chronic low-grade inflammation.

BACKGROUND: Working conditions in the age of digitalization harbor risks for chronic stress and burnout. However, real-world investigations into biological effects of technostress, that is stress in the context of digital technology use, are sparse. This study prospectively assessed associations between technostress, general work stress, burnout symptoms, hair cortisol, and chronic low-grade inflammation. METHODS: Hospital employees (N = 238, 182 females, Mage = 28.5 years) participated in a prospective cohort study with two follow-ups six months apart (T2, T3). Participants answered standardized questionnaires on general job strain (job demand-control ratio), technostressors (work interruptions, multitasking, information overload), burnout symptoms (exhaustion, mental distance), and relevant confounders. Moreover, they provided capillary blood samples for C-reactive protein (CRP) and hair strands for hair cortisol concentration (HCC) analysis. Structural equation modelling was performed. RESULTS: The factorial structure of survey measures was confirmed. Burnout symptoms (MT2 = 2.17, MT3 = 2.33) and HCC (MT2 = 4.79, MT3 = 9.56; pg/mg) increased over time, CRP did not (MT2 = 1.15, MT3 = 1.21; mg/L). Adjusted path models showed that technostress was negatively associated with HCC (ß = -0.16, p =.003), but not with burnout and CRP. General work stress in contrast, was not significantly associated with burnout, HCC or CRP. Furthermore, there were reciprocal effects of CRP on HCC (ß = 0.28, p =.001) and of HCC on CRP (ß = -0.10, p ≤.001). Associations were robust in additional analyses including further confounders. CONCLUSION: This is the first study on prospective effects of technostress on employees' endocrine and inflammatory systems. Results suggest differential effects of technostress on the hypothalamic-pituitary-adrenocortical axis activity. Given its key role for long-term health, the findings have important implications for occupational health and safety in digitalized work environments.

Active or passive? Investigating different types of cognitive fatigue.

Research in cognitive fatigue has identified the negative impact that cognitive exertion can have on subsequent task performance. An underexamined question is whether there are different types of fatigue, particularly: active fatigue, similar to cognitive fatigue, and passive fatigue, similar to boredom. This online study examined whether active and passive fatigue can be elicited and differentiated using computerized cognitive tasks. We compared subjective and behavioural outcomes to look for distinctions between fatigue types in response to different cognitive tasks. A sample of 122 participants (53% male; age 30.04 ± 3.50 years) rated their subjective state before and after one of three 8-min cognitive task conditions (TloadDback, Mackworth Clock, Documentary/Control). Next, participants also completed a second cognitive task (Flanker task). The task expected to be actively fatiguing (TloadDback) was rated the most difficult, effortful, and mentally and temporally demanding. The task expected to be passively fatiguing (Mackworth Clock) had the greatest increases in subjective fatigue, boredom, and sleepiness, and the greatest decrease in "want-to" motivation. There were no differences between conditions for Flanker performance. We showed that different fatigue types could be elicited using different computerized cognitive tasks. The passively fatiguing task had the most negative influence on subjective fatigue and motivation, suggesting a nonengaging or "boringly fatiguing" task induces a more detrimental type of fatigue. A key next step is to examine longer cognitive tasks to determine whether effects from different fatigue types become more prominent with time-on-task. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Universal Digital Programs for Promoting Mental and Relational Health for Parents of Young Children: A Systematic Review and Meta-Analysis.

Digital parenting programs aim to increase program access, improve psychosocial outcomes for parents and children, and support triage to targeted interventions where required. This meta-analysis assessed the efficacy of online parenting programs in improving parenting skills and capabilities, and by consequence, the mental health and well-being of parents and children, and the quality of the parent-child relationship. Studies were included if they were: (1) online, (2) self-delivered, (3) designed for universal general population prevention, (4) evaluated experimental or quasi-experimental designs, and (5) assessed parent and child emotional and/or relational health, from pregnancy to 5 years of age. A systematic search of electronic databases and grey literature identified 22 studies that met inclusion criteria, including 24 independent samples, with 5671 unique parents. Meta-analyses were conducted using random effects models and Cohen's d effects. Small-to-moderate improvements in parent depression, anxiety, self-efficacy, and social support were observed. No effects on parent stress, satisfaction, or parent-child relationship quality were observed. Meta-regression and sub-group analysis were conducted to identify sensitivity or moderation effects. Collectively, findings suggest any benefits of online parenting programs mostly occur at the time of the intervention, for parent mental health and well-being outcomes, and that enduring effects are unlikely. However, given the cost effectiveness and accessibility of online programs, further research into ways of sustaining effects on parenting outcomes is warranted. Furthermore, given the centrality of the parent-child bond to child development across the lifecourse, additional investment in new digitally facilitated approaches focusing on this bond are likewise warranted.PROSPERO registration CRD42021275647.

Association between dietary factors, symptoms, and psychological factors in adults with dyspepsia: A cross-sectional study.

BACKGROUND: Evidence-based dietary management approaches for symptoms of dyspepsia are lacking. This study aimed to compare dietary factors, symptoms, quality of life (QOL) and salivary cortisol in dyspepsia participants and healthy controls. METHODS: A cross-sectional survey was completed by adults with dyspepsia (n = 121) meeting Rome IV criteria and healthy controls (n = 52). Outcome measures included self-reported questionnaires about dietary habits, triggers, restrictions, dietary management approaches, nutritional intake, psychological variables, QOL, gastrointestinal symptoms, and optional cortisol awakening response (CAR) via saliva samples. Data were analyzed using Chi-square or Mann-Whitney U. Cortisol awakening response data was analyzed using moderated regression controlling for age, gender and distress. KEY RESULTS: Fermentable carbohydrates (FODMAPs) (55%) were the most reported trigger in adults with dyspepsia. The dyspepsia group (88%) followed special diets more than controls (47%; p < 0.001), with a low FODMAP diet being most common (69%). The dyspepsia group consumed less fiber (p = 0.014), calcium (p = 0.015), and total FODMAPs (p < 0.001) than controls. There was a greater prevalence of comorbid anxiety (41%) and depression (31%) in dyspepsia compared to controls (15% and 12%, respectively, p < 0.001 and p = 0.006). The dyspepsia group had poorer QOL and greater gastrointestinal symptom severity than controls (p < 0.001). There was a negative association between anxiety and CAR (p = 0.001) in dyspepsia but not in controls. CONCLUSIONS & INFERENCES: Adults with dyspepsia follow special diets more than controls and perceive FODMAPs as a key dietary trigger. These findings highlight the importance of monitoring nutritional adequacy and QOL, and emphasize mechanisms of depleted stress response in dyspepsia, warranting further exploration.

The brain-derived neurotrophic factor Val66met polymorphism is associated with better attention and working memory performance and resilience to mild chronic stress.

The val66met polymorphism of the brain-derived neurotrophic factor (BDNF) gene has been identified as a potential moderator for the relationship between chronic stress and executive functioning. However, whether the presence of the met allele increases cognitive vulnerability or resilience to stress has yet to be determined. Given the established effects of autonomic activity and psychological arousal on executive functioning, in the present study, 56 healthy university students completed self-report measures of chronic stress, positive arousal (vigour) and negative arousal (anxiety) and measured heart-rate variability to quantify autonomic activity. Participants then completed a cognitive test battery that measured attention, decision-making, visual learning and working memory. Regression analyses demonstrated that Val/met participants performed better on attention and working memory tasks than Val/val participants, but no differences were seen in decision-making and visual learning. Further, Val/met participants were protected from stress-related differences in attention seen in Val/val participants. Val66met was not associated with physiological or psychological arousal. This study demonstrates that val66met plays an important but selective role in cognitive performance.

Activities to promote empathy for patients among pharmacy learners: A scoping review.

BACKGROUND: Provider empathy has been shown to be directly linked to improved patient outcomes. The objective of this scoping review of the literature was to identify and describe learning activities that promote empathy for patients among pharmacy learners. METHODS: This scoping review was conducted using the following inclusion criteria: publication in English, activities conducted in any academic pharmacy training program (professional degree program, experiential, residency, or fellowship), description of the learning activity(ies) provided, and focus on the experience of empathy/caring/compassion for patients, either human or animal. Articles were excluded if they focused only on skills such as empathic responding or if they did not describe the learning experience. All study designs other than reviews were included. RESULTS: The scoping review revealed 89 full-text articles that met the inclusion criteria. Included studies demonstrated a wide variety of approaches to the design of learning experiences as well as methods of measurement of empathy. Various types of learning modalities have been used to develop empathy in pharmacy learners, with reflection being the most common. A large proportion of studies that assessed empathy development used quasi-experimental or qualitative designs and did not report tests of statistical significance, which would make it difficult to compare the effectiveness of the different learning activities. IMPLICATIONS: A variety of approaches have been used among pharmacy learners to develop empathy for patients. Due to the high level of variability in approaches, more rigorous studies are needed to assess the effectiveness of these learning activities.

Quality of life and psychological health after mild traumatic brain injury in older people: Three- and six-month follow up.

OBJECTIVES: Examine quality of life (QoL) and psychological health after mild traumatic brain injury (mTBI) in older people (65+ years) at 3- and 6-month follow-up and explore which injury factors predicted QoL. METHODS: mTBI patients were compared to trauma comparison (TC) and community comparison (CC) groups. QoL and psychological health were measured at both timepoints. After accounting for 3-month psychological health, injury severity, neuroimaging, and 3-month neuropsychological performance were assessed as predictors of 6-month QoL. RESULTS: Overall 3-month QoL was lower for mTBI (Cohen's d = 0.938) and TC (Cohen's d = 0.485) groups compared to CCs, but by 6 months only mTBI patients continued to report poorer overall QoL (Cohen's d = 0.577) and physical QoL (Cohen's d = 0.656). Despite group differences, QoL for most (~92%) was within normative limits. 3-month psychological health predicted QoL 6-months postinjury (ß = -.377, 95% CI -.614, -.140) but other proposed risk factors (GCS <15, neuroimaging, 3-month neuropsychological performance) did not uniquely predict QoL. CONCLUSIONS: Older adults following mTBI reported lower QoL up to 6-months postinjury compared to non-injured peers, indicating that mTBI patients were particularly susceptible to ongoing differences in QoL 6-months postinjury.

A Systematic Review and Revised Meta-analysis of the Effort-Reward Imbalance Model of Workplace Stress and Hypothalamic-Pituitary-Adrenal Axis Measures of Stress.

OBJECTIVE: Despite considerable research in the past 20 years into associations between the effort-reward imbalance (ERI) model and various health outcomes, the mechanisms responsible for the association remain unclear. Our meta-analysis assessed the associations of ERI and overcommitment (OC) in the workplace with measures from the hypothalamic-pituitary-adrenal (HPA) axis. METHODS: Electronic databases were searched with the phrase "effort * reward * imbalance," which yielded 319 studies leading to 56 full-text studies being screened. Thirty-two studies within 14 articles met the inclusion criteria and were meta-analyzed using mixed- and random-effects models. RESULTS: Greater ERI was associated with increased HPA axis activity (r = 0.05, p = .02, k = 14, n = 2461). The cortisol waking concentrations (r = 0.11, p = .02, k = 6, n = 493) were the only subgroup associated with ERI. Meta-regression revealed that studies that contained more men had stronger ERI to HPA marker associations. When all HPA markers were considered collectively, OC was not associated with greater HPA axis activity (r = 0.01, p = .70, k = 10, n = 1684), with only cortisol (pm) associated with OC (r = -0.24, p = .02, k = 2, n = 95). CONCLUSIONS: ERI and OC were associated with HPA responsivity. Although the cortisol waking concentrations and not the CAR were associated with ERI, this may be due to heterogeneity in the experience of stress between studies. Future studies should consider the concurrent assessment of burnout to better assist the interpretation of ERI with HPA responsivity.

Mild Traumatic Brain Injury and Functional Outcome in Older Adults: Pain Interference But Not Cognition Mediates the Relationship Between Traumatic Injury and Functional Difficulties.

OBJECTIVE: To examine functional status of older people 3 months after mild traumatic brain injury (mTBI) and identify whether pain interference or cognition mediates any relationship found between injury status and functional outcomes. SETTING: Patients admitted to a Melbourne-based emergency department. PARTICIPANTS: Older adults 65 years and older: 40 with mTBI, 66 with orthopedic injury without mTBI (TC), and 47 healthy controls (CC) without injury. DESIGN: Observational cohort study. MAIN MEASURES: Functional outcome was measured using the World Health Organization Disability Assessment Schedule (WHODAS 2.0) and single- and dual-task conditions of the Timed-Up-and-Go task. Pain interference and cognitive performance at 3 months post-injury were examined as mediators of the relationship between injury status (injured vs noninjured) and functional outcome. RESULTS: Patients with mTBI and/or orthopedic injury reported greater difficulties in overall functioning, including community participation, compared with noninjured older people (CC group). Both trauma groups walked slower than the CC group on the mobility task, but all groups were similar on the dual-task condition. Pain interference mediated the relationship between injury status and overall functioning [ b = 0.284; 95% CI = 0.057, 0.536), community participation ( b = 0.259; 95% CI = 0.051, 0.485), and mobility ( b = 0.116; 95% CI = 0.019, 0.247). However, cognition did not mediate the relationship between injury status and functional outcomes. CONCLUSIONS: Three months after mild traumatic injury (with and without mTBI), patients 65 years and older had greater functional difficulties compared with noninjured peers. Pain interference, but not cognition, partially explained the impact of traumatic injury on functional outcomes. This highlights the importance of reducing pain interference for older patients after injury (including mTBI) to support better functional recovery.

Cognitive performance in older people after mild traumatic brain injury: Trauma effects and other risk factors.

OBJECTIVE: Cognitive symptoms are common in the initial weeks after mTBI, but recovery is generally expected within three months. However, there is limited information about recovery specifically in older age cohorts. Therefore, this study investigated cognitive outcome three months after mTBI in older adults (≥ 65 years) compared to trauma and community age-matched controls and explored risk factors for outcome after traumatic injury. METHODS: Older mTBI patients (n = 40) and older adults with mild traumatic injury but without head injury (n = 66) were compared to a noninjured community control group (n = 47). Cognitive assessment included neuropsychological and computerized tests. Group differences were compared on individual tasks and overall cognitive performances using composite scores. Regression analyses identified predictors of outcome for trauma patients and moderator analyses explored possible interactions of mTBI severity with age and cognition. RESULTS: As well as lower performances in processing speed and memory, both trauma groups had significantly lower performance on composite neuropsychological (d = .557 and .670) and computerized tasks (d = .783 and .824) compared to noninjured controls. Age, education, and history of depression were direct predictors of cognitive performance after mild traumatic injury (with or without head injury). Further moderation analysis demonstrated that mTBI severity (Glasgow Coma Scale < 15) moderated the impact of older age on computerized assessment (ß = -.138). CONCLUSIONS: Three months after mild trauma (regardless of head injury), older people demonstrate lower cognition compared to noninjured peers. However, severity of mTBI (Glasgow Coma Scale < 15) can interact with older age to predict poorer cognitive outcomes.

Observed Strategies on Naturalistic Associative Memory Tasks in Healthy Older Adults and Amnestic Mild Cognitive Impairment.

BACKGROUND: Understanding the strategies people with amnestic mild cognitive impairment (aMCI) spontaneously use can inform targeted memory training. METHOD: Strategy use was observed for 99 people with aMCI and 100 healthy older adults (HOA) on two memory tasks. RESULTS: No differences were found between aMCI and HOA in the amount or types of strategies used, but strategy use varied with task. Association was more effective for one task, whereas on the other task, use of written notes or multiple strategies were detrimental to performance and related to poorer performance than active (spaced) retrieval, for aMCI. CONCLUSION: Our findings suggest the importance of identifying ineffective habits, in addition to instruction in more beneficial approaches.

Clinical and Blood Biomarker Trajectories after Concussion: New Insights from a Longitudinal Pilot Study of Professional Flat-Track Jockeys.

There is a recognized need for objective tools for detecting and tracking clinical and neuropathological recovery after sports-related concussion (SRC). Although computerized neurocognitive testing has been shown to be sensitive to cognitive deficits after SRC, and some blood biomarkers have shown promise as indicators of axonal and glial damage, the potential utility of these measures in isolation and combination for assisting SRC diagnosis and tracking recovery is not well understood. To provide new insights, we conducted a prospective study of 64 male and female professional flat-track jockeys (49 non-SRC, 15 SRC), with each jockey undergoing symptom evaluation, cognitive testing using the CogSport battery, and serum biomarker quantification of glial fibrillary acidic protein (GFAP), tau, and neurofilament light (NfL) using a Simoa HD-X Analyzer. Measures were performed at baseline (i.e., pre-injury), and 2 and 7 days and 1 and 12 months after SRC. Symptoms were most pronounced at 2 days and had largely resolved by either 7 days or 1 month. CogSport testing at 2 days revealed cognitive impairments relative to both non-concussed peers and their own pre-injury baselines, with SRC classification utility found at 2 days, and to a slightly lesser extent, at 7 days. Relatively prolonged changes in serum NfL were observed, with elevated levels and classification utility persisting beyond the resolution of SRC symptoms and cognitive deficits. Finally, SRC classification performance throughout the 1st month after SRC was optimized through the combination of cognitive testing and serum biomarkers. Considered together, these findings provide further evidence for a role of computerized cognitive testing and fluid biomarkers of neuropathology as objective measures to assist in the identification of SRC and the monitoring of clinical and neuropathological recovery.

Gender and Workplace Stress Affect the Association Between Concussion History and Depression Symptoms in Professional Jockeys.

OBJECTIVE: Professional jockeys experience high rates of concussion, workplace stress, and poor mental health. The present cross-sectional study, for the first time, concurrently assessed the potential interplay between concussion history and workplace stress with current depression symptoms. METHOD: Seventy-two professional flat-track jockeys (male = 49, female = 23) were grouped based on self-reported concussion history (CG; n = 56) and those who did not report a concussion history (NCG; total n = 16). Analyses featured both between (CG vs NCG) and within group (CG only) assessment on self-reported measures of workplace stress and depression symptoms (affect, daily functioning). RESULTS: Jockeys in the CG had more symptoms of negative affect than the NCG. This association, however, was nonsignificant after covarying for age, gender, and workplace stress. Higher workplace stress (p = .005) and gender (p = .001) were associated with poorer daily functioning after controlling for concussion history (CG vs. NCG) and age. Gender moderated the association between concussion group and poorer daily functioning (ß = -18.739, t (71) = -2.924, p = .005), with the difference between CG and NCG significant for females, but not males (ß = 33.648, t (71) = 3.420, p = .001). CONCLUSIONS: The findings provide preliminary evidence that previously concussed females may be more likely to report poorer daily functioning than males with a history of concussion, and that workplace stress may reduce the association between a history of concussion and depression symptoms. Prospective studies are required to validate and extend these findings.

Within subject rise in serum TNFα to IL-10 ratio is associated with poorer attention, decision-making and working memory in jockeys.

Jockeys work in high-risk environments that rely heavily on attention- and decision-making to perform well and safely. Workplace stress literature has often overlooked the impact of stress on cognition, and designs that include physiological measures are rare. This study assessed the prospective concurrent relationships between workplace stress, depression symptoms and low-grade inflammation with cognitive performance among professional jockeys. Professional jockeys (N = 35, Mage = 32.29) provided information on workplace stress and depression symptoms, with serum levels of inflammatory cytokines (IL-6, IL-10, TNFα) and cytokine balance (IL-6: IL-10, TNFα: IL-10) quantified with SIMOA, and cognitive performance with CogSport computer-based testing battery. These measures were repeated after a twelve-month interval. Increased workplace stress between testing intervals was associated to an increased cytokine imbalance (ß = 0.447, p = .015) after controlling for age and gender. Increases in cytokine imbalance occurred in unison with decreases in attention (ß = 0.516, p = .002), decision-making (ß = 0.452, p = .009) and working memory (ß = 0.492, p = .004). These preliminary findings suggest the underlying mechanisms linking workplace stress and reduced cognitive performance may be influenced by measures of low-grade inflammation and specifically a cytokine imbalance. Our findings suggest a measure of cytokine balance may explain the heterogenous findings in previous studies that have focussed solely on the association of workplace stress with pro-inflammatory cytokines. Future work is needed however, to provide a broader evidence-base for our claims to better inform designs to intervene in the higher workplace stress-poorer cognition relationship.

Mentorship in Undergraduate Biomedical Education: Identifying Student Opinions and Expectations.

Objective: To evaluate undergraduate biomedical education student opinions and expectations on mentorship. Methods: A survey was administered to students enrolled in the undergraduate biology, neuroscience and nursing programs at a large public research-intensive university. The survey queried demographics, previous mentorship experiences, ideal qualities of mentors, benefits/value of mentorship and future plans for seeking mentorship. Survey responses were evaluated using either t-test comparisons or one-way ANOVA. Results: The majority of the respondents were female and were interested in pursuing professional schools (nursing and medicine). Survey results indicate high student interest in receiving mentoring, but few were active participants in a mentoring relationship. Respondents indicated either lack of knowledge or discomfort in identifying a mentor. While faculty mentors versus peer mentors were preferred, respondents indicated that mentoring by either faculty or peers would be of value. Survey results indicate that desired benefits of mentoring included guidance in future education and career decisions, networking and career advice. Conclusion: The major conclusions are that despite high student interest in being mentored, their participation in mentoring is very low. These finding are supportive of the development of structured mentoring programs to facilitate and enhance mentoring of undergraduate STEM students and aid in their academic career progression.

Sympathovagal Balance Is a Strong Predictor of Post High-Volume Endurance Exercise Cardiac Arrhythmia.

Regular physical activity is important for cardiovascular health. However, high-volume endurance exercise has been associated with increased number of electrocardiogram (ECG) abnormalities, including disturbances in cardiac rhythm (arrhythmias) and abnormalities in ECG pattern. The aim of this study was to assess if heart rate variability (HRV) is associated with ECG abnormalities. Fifteen participants with previous cycling experience completed a 21-day high-volume endurance exercise cycle over 3,515 km. Participants wore a 5-lead Holter monitor for 24 h pre- and post-exercise, which was used to quantify ECG abnormalities and export sinus R-to-R intervals (NN) used to calculate HRV characteristics. As noise is prevalent in 24-h HRV recordings, both 24-h and heart rate collected during stable periods of time (i.e., deep sleep) were examined. Participants experienced significantly more arrhythmias post high-volume endurance exercise (median = 35) compared to pre (median = 12; p = 0.041). All 24-h and deep sleep HRV outcomes were not different pre-to-post high-volume endurance exercise (p > 0.05). Strong and significant associations with arrhythmia number post-exercise were found for total arrhythmia (total arrhythmia number pre-exercise, ρ = 0.79; age, ρ = 0.73), supraventricular arrhythmia (supraventricular arrhythmia number pre-exercise: ρ = 0.74; age: ρ = 0.66), and ventricular arrhythmia (age: ρ = 0.54). As a result, age and arrhythmia number pre-exercise were controlled for in hierarchical regression, which revealed that only deep sleep derived low frequency to high frequency (LF/HF) ratio post high-volume endurance exercise predicted post total arrhythmia number (B = 0.63, R 2Δ = 34%, p = 0.013) and supraventricular arrhythmia number (B = 0.77, R 2Δ = 69%, p < 0.001). In this study of recreationally active people, only deep sleep derived LF/HF ratio was associated with more total and supraventricular arrhythmias after high-volume endurance exercise. This finding suggests that measurement of sympathovagal balance during deep sleep might be useful to monitor arrhythmia risk after prolonged high-volume endurance exercise performance.

Behavioral phenotyping of a rat model of the BDNF Val66Met polymorphism reveals selective impairment of fear memory.

The common brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is associated with reduced activity-dependent BDNF release and increased risk for anxiety disorders and PTSD. Here we behaviorally phenotyped a novel Val66Met rat model with an equivalent valine to methionine substitution in the rat Bdnf gene (Val68Met). In a three-day fear conditioning protocol of fear learning and extinction, adult rats with the Met/Met genotype demonstrated impaired fear memory compared to Val/Met rats and Val/Val controls, with no genotype differences in fear learning or extinction. This deficit in fear memory occurred irrespective of the sex of the animals and was not seen in adolescence (4 weeks of age). There were no changes in open-field locomotor activity or anxiety measured in the elevated plus maze (EPM) nor in other types of memory measured using the novel-object recognition test or Y-maze. BDNF exon VI expression in the dorsal hippocampus was higher and BDNF protein level in the ventral hippocampus was lower in female Val/Met rats than female Val/Val rats, with no other genotype differences, including in total BDNF, BDNF long, or BDNF IV mRNA. These data suggest a specific role for the BDNF Met/Met genotype in fear memory in rats. Further studies are required to investigate gene-environment interactions in this novel animal model.

Development and clinical application of a deep learning model to identify acute infarct on magnetic resonance imaging.

Stroke is a leading cause of death and disability. The ability to quickly identify the presence of acute infarct and quantify the volume on magnetic resonance imaging (MRI) has important treatment implications. We developed a machine learning model that used the apparent diffusion coefficient and diffusion weighted imaging series. It was trained on 6,657 MRI studies from Massachusetts General Hospital (MGH; Boston, USA). All studies were labelled positive or negative for infarct (classification annotation) with 377 having the region of interest outlined (segmentation annotation). The different annotation types facilitated training on more studies while not requiring the extensive time to manually segment every study. We initially validated the model on studies sequestered from the training set. We then tested the model on studies from three clinical scenarios: consecutive stroke team activations for 6-months at MGH, consecutive stroke team activations for 6-months at a hospital that did not provide training data (Brigham and Women's Hospital [BWH]; Boston, USA), and an international site (Diagnósticos da América SA [DASA]; Brazil). The model results were compared to radiologist ground truth interpretations. The model performed better when trained on classification and segmentation annotations (area under the receiver operating curve [AUROC] 0.995 [95% CI 0.992-0.998] and median Dice coefficient for segmentation overlap of 0.797 [IQR 0.642-0.861]) compared to segmentation annotations alone (AUROC 0.982 [95% CI 0.972-0.990] and Dice coefficient 0.776 [IQR 0.584-0.857]). The model accurately identified infarcts for MGH stroke team activations (AUROC 0.964 [95% CI 0.943-0.982], 381 studies), BWH stroke team activations (AUROC 0.981 [95% CI 0.966-0.993], 247 studies), and at DASA (AUROC 0.998 [95% CI 0.993-1.000], 171 studies). The model accurately segmented infarcts with Pearson correlation comparing model output and ground truth volumes between 0.968 and 0.986 for the three scenarios. Acute infarct can be accurately detected and segmented on MRI in real-world clinical scenarios using a machine learning model.