Enhanced brainstem and cortical encoding of sound during synchronized movement.

Movement to a steady beat has been widely studied as a model of alignment of motor outputs on sensory inputs. However, how the encoding of sensory inputs is shaped during synchronized movements along the sensory pathway remains unknown. To investigate this, we simultaneously recorded brainstem and cortical electro-encephalographic activity while participants listened to periodic amplitude-modulated tones. Participants listened either without moving or while tapping in sync on every second beat. Cortical responses were identified at the envelope modulation rate (beat frequency), whereas brainstem responses were identified at the partials frequencies of the chord and at their modulation by the beat frequency (sidebands). During sensorimotor synchronization, cortical responses at beat frequency were larger than during passive listening. Importantly, brainstem responses were also enhanced, with a selective amplification of the sidebands, in particular at the lower-pitched tone of the chord, and no significant correlation with electromyographic measures at tapping frequency. These findings provide first evidence for an online gain in the cortical and subcortical encoding of sounds during synchronized movement, selective to behavior-relevant sound features. Moreover, the frequency-tagging method to isolate concurrent brainstem and cortical activities even during actual movements appears promising to reveal coordinated processes along the human auditory pathway.

Paying for Parenthood: Understanding Parental Leave Policies in Infectious Disease Fellowship.

Background: Many physician trainees plan pregnancy during residency and fellowship. A study of internal medicine program directors (PDs) demonstrated frequent misinterpretation of American Board of Internal Medicine (ABIM) leave policies applied to parental leave. The primary aim was to investigate how infectious disease (ID) PDs interpret current ABIM leave policies. Methods: We surveyed 155 ID PDs in an online anonymous questionnaire about knowledge of ABIM leave policies and application toward trainee leaves. Results: Of 155 PDs, 56 (36%) responded to the survey. Nearly 70% incorrectly identified leave limits permitted. A majority mistakenly chose to extend training when a competent fellow was within the allowed duration of leave. PDs reported that the majority of ID trainee maternity/birth parent leaves (60%) were ≤7 weeks and only 7% were ≥12 weeks; 50% of paternity/nonbirth parent leaves were ≤3 weeks. Conclusions: Surveyed ID fellowship PDs often misinterpret ABIM leave policies and apply policies incorrectly when given sample scenarios..

Functional connectivity development in the prenatal and neonatal stages measured by functional magnetic resonance imaging: A systematic review.

The prenatal and neonatal periods are two of the most important developmental stages of the human brain. It is therefore crucial to understand normal brain development and how early connections are established during these periods, in order to advance the state of knowledge on altered brain development and eventually identify early brain markers of neurodevelopmental disorders and diseases. In this systematic review (Prospero ID: CRD42024511365), we compiled resting state functional magnetic resonance imaging (fMRI) studies in healthy fetuses and neonates, in order to outline the main characteristics of typical development of the functional brain connectivity during the prenatal and neonatal periods. A systematic search of five databases identified a total of 12 573 articles. Of those, 28 articles met pre-established selection criteria based determined by the authors after surveying and compiling the major limitations reported within the literature. Inclusion criteria were: (1) resting state studies; (2) presentation of original results; (3) use of fMRI with minimum one Tesla; (4) a population ranging from 20 weeks of GA to term birth (around 37-42 weeks of PMA); (5) singleton pregnancy with normal development (absence of any complications known to alter brain development). Exclusion criteria were: (1) preterm studies; (2) post-mortem studies; (3) clinical or pathological studies; (4) twin studies; (5) papers with a sole focus on methodology (i.e. focused on tool and analysis development); (6) volumetric studies; (7) activation map studies; (8) cortical analysis studies; (9) conference papers. A risk of bias assessment was also done to evaluate each article's methodological rigor. 1877 participants were included across all the reviewed articles. Results consistently revealed a developmental gradient of increasing functional brain connectivity from posterior to anterior regions and from proximal-to-distal regions. A decrease in local small-world organization shortly after birth was also observed; small-world characteristics were present in fetuses and newborns, but appeared weaker in the latter group. Also, the posterior-to-anterior gradient could be associated with earlier development of the sensorimotor networks in the posterior regions while more complex higher-order networks (e.g. attention-related) mature later in the anterior regions. The main limitations of this systematic review stem from the inherent limitations of functional imaging in fetuses, mainly: unevenly distributed populations and limited sample sizes; fetal movements in the womb and other imaging obstacles; and a large voxel resolution when imaging a small brain. Another limitation specific to this review is the relatively small number of included articles compared to very a large search result, which may have led to relevant articles having been overlooked.

Language brain responses and neurodevelopmental outcome in preschoolers with congenital heart disease: A fNIRS study.

Neurodevelopmental disabilities affect up to 50% of survivors of congenital heart disease (CHD). Language difficulties are frequently identified during preschool period and can lead to academic, social, behavioral, and emotional difficulties. Structural brain alterations are associated with poorer neurodevelopmental outcomes in patients with CHD during infancy, childhood, and adolescence. However, evidence is lacking about the functional brain activity in children with CHD and its relationship with neurodevelopment. This study therefore aimed to characterize brain responses during a passive story-listening task in 3-year-old children with CHD, and to investigate the relationship between functional brain patterns of language processing and neurodevelopmental outcomes. To do so, we assessed hemodynamic concentration changes, using functional near-infrared spectroscopy (fNIRS), and neurodevelopmental outcomes, using the Wechsler Preschool and Primary Scale of Intelligence - 4th Edition (WPPSI-IV), in children with CHD (n = 19) and healthy controls (n = 23). Compared to their healthy peers, children with CHD had significantly lower scores on the Verbal comprehension index (VCI), the Vocabulary acquisition index (VAI), the General ability index (GAI), and the Information and the Picture Naming subtests of the WPPSI-IV. During the passive story-listening task, healthy controls showed significant hemodynamic brain responses in the temporal and the temporal posterior regions, with stronger activation in the temporal posterior than in the temporal regions. In contrast, children with CHD showed reduced activation in the temporal posterior regions compared to controls, with no difference of activation between regions. Reduced brain responses in the temporal posterior regions were also correlated with lower neurodevelopmental outcomes in both groups. This is the first study that reveals reduced brain functional responses in preschoolers with CHD during a receptive language task. It also suggests that the temporal posterior activation could be a potential brain marker of cognitive development. These findings provide support for the feasibility of identifying brain correlates of neurodevelopmental vulnerabilities in children with CHD.

Functional brain connectivity after corrective cardiac surgery for critical congenital heart disease: a preliminary near-infrared spectroscopy (NIRS) report.

Patients with congenital heart disease (CHD) requiring cardiac surgery in infancy are at high risk for neurodevelopmental impairments. Neonatal imaging studies have reported disruptions of brain functional organization before surgery. Yet, the extent to which functional network alterations are present after cardiac repair remains unexplored. This preliminary study aimed at investigating cortical functional connectivity in 4-month-old infants with repaired CHD, using resting-state functional near-infrared spectroscopy (fNIRS). After fNIRS signal frequency decomposition, we compared values of magnitude-squared coherence as a measure of connectivity strength, between 21 infants with corrected CHD and 31 healthy controls. We identified a subset of connections with differences between groups at an uncorrected statistical level of p < .05 while controlling for sex and maternal socioeconomic status, with most of these connections showing reduced connectivity in infants with CHD. Although none of these differences reach statistical significance after FDR correction, likely due to the small sample size, moderate to large effect sizes were found for group-differences. If replicated, these results would therefore suggest preliminary evidence that alterations of brain functional connectivity are present in the months after cardiac surgery. Additional studies involving larger sample size are needed to replicate our data, and comparisons between pre- and postoperative findings would allow to further delineate alterations of functional brain connectivity in this population.

Perspectives of primary care clinicians in Massachusetts on use of telemedicine with adults aged 65 and older during the COVID-19 pandemic.

To learn how to improve telemedicine for adults >65, we asked primary care clinicians ("PCPs") affiliated with one large Boston-area health system their views on using telemedicine (which included phone-only or video visits) with adults >65 during the COVID-19 pandemic. In open-ended questions, we asked PCPs to describe any challenges or useful experiences with telemedicine and suggestions for improving telemedicine as part of a larger web-based survey conducted between September 2020 and February 2021. Overall, 163/383 (42%) PCPs responded to the survey. Of these, 114 (70%) completed at least one open-ended question, 85% were non-Hispanic white, 59% were female, 75% were community-based, and 75% were in practice >20 years. We identified three major themes in participants' comments including the need to optimize telemedicine; integrate telemedicine within primary care; and that PCPs had disparate attitudes towards telemedicine for older adults. To optimize telemedicine, PCPs recommended more effective digital platforms, increased utilization of home medical equipment (e.g., blood pressure cuffs), and better coordination with caregivers. For integration, PCPs recommended targeting telemedicine for certain types of visits (e.g., chronic disease management), enabling video access, and reducing administrative burdens on PCPs. As for PCP attitudes, some felt telemedicine enhanced the doctor-patient relationship, improved the patient experience, and improved show rates. Others felt that telemedicine visits were incomplete without a physical exam, were less rewarding, and could be frustrating. Overall, PCPs saw a role for telemedicine in older adults' care but felt that more support is needed for these visits than currently offered.

Older adults' perspectives on primary care telemedicine during the COVID-19 pandemic.

BACKGROUND: Prior to the COVID-19 pandemic there were many barriers to telemedicine primary care for adults ≥65 years including insurance coverage restrictions and having lower digital access and literacy. With the pandemic, insurance coverage broadened and many older adults utilized telemedicine creating an opportunity to learn from their experiences to inform future policy. METHODS: Between April 2020 and June 2021, we conducted a cross-sectional multimethod study of English-speaking, cognitively-intact, adults ≥65, who had a phone-only and/or video telemedicine visit with their primary care physician within one large Massachusetts health system (10 different practices) since March 2020. The study questionnaire asked participants their overall satisfaction with telemedicine (7-point scale) and to compare telemedicine with in-person care. We used linear regression to examine the association between participants' demographics, Charlson comorbidity score, and survey completion date with their satisfaction score. The questionnaire also included open-ended questions on perceptions of telemedicine; which were analyzed using qualitative methods. RESULTS: Of 278 eligible patients reached, 208 completed the questionnaire; mean age was 74.4 years (±4.4), 61.5% were female, 91.4% were non-Hispanic White, 64.4% had ≥1 comorbidity, and 47.2% had a phone-only visit. Regardless of their age, participants reported being satisfied with telemedicine; median score was 6.0 on the 7-point scale (25th percentile = 5.0 and 75th percentile = 7.0). Non-Whites satisfaction scores were on average 1 point lower than those of non-Hispanic Whites (p = 0.02). Those with comorbidity reported scores that on average were 0.5 points lower than those without comorbidity (p = 0.07). Overall, 39.5% felt their telemedicine visit was worse than in-person care; 4.9% thought it was better. Participants appreciated telemedicine's convenience but described frustrating technical challenges. While participants preferred in-person care, most wanted telemedicine to remain available. CONCLUSIONS: Adults ≥65 reported being satisfied with primary care telemedicine during the pandemic's first 14 months and wanted telemedicine to remain available.

Parallel factor analysis for multidimensional decomposition of functional near-infrared spectroscopy data.

Significance: Current techniques for data analysis in functional near-infrared spectroscopy (fNIRS), such as artifact correction, do not allow to integrate the information originating from both wavelengths, considering only temporal and spatial dimensions of the signal's structure. Parallel factor analysis (PARAFAC) has previously been validated as a multidimensional decomposition technique in other neuroimaging fields. Aim: We aimed to introduce and validate the use of PARAFAC for the analysis of fNIRS data, which is inherently multidimensional (time, space, and wavelength). Approach: We used data acquired in 17 healthy adults during a verbal fluency task to compare the efficacy of PARAFAC for motion artifact correction to traditional two-dimensional decomposition techniques, i.e., target principal (tPCA) and independent component analysis (ICA). Correction performance was further evaluated under controlled conditions with simulated artifacts and hemodynamic response functions. Results: PARAFAC achieved significantly higher improvement in data quality as compared to tPCA and ICA. Correction in several simulated signals further validated its use and promoted it as a robust method independent of the artifact's characteristics. Conclusions: This study describes the first implementation of PARAFAC in fNIRS and provides validation for its use to correct artifacts. PARAFAC is a promising data-driven alternative for multidimensional data analyses in fNIRS and this study paves the way for further applications.

LIONirs: flexible Matlab toolbox for fNIRS data analysis.

BACKGROUND: Functional near-infrared spectroscopy (fNIRS) is a suitable tool for recording brain function in pediatric or challenging populations. As with other neuroimaging techniques, the scientific community is engaged in an evolving debate regarding the most adequate methods for performing fNIRS data analyses. NEW METHOD: We introduce LIONirs, a neuroinformatics toolbox for fNIRS data analysis, designed to follow two main goals: (1) flexibility, to explore several methods in parallel and verify results using 3D visualization; (2) simplicity, to apply a defined processing pipeline to a large dataset of subjects by using the MATLAB Batch System and available on GitHub. RESULTS: Within the graphical user interfaces (DisplayGUI), the user can reject noisy intervals and correct artifacts, while visualizing the topographical projection of the data onto the 3D head representation. Data decomposition methods are available for the identification of relevant signatures, such as brain responses or artifacts. Multimodal data recorded simultaneously to fNIRS, such as physiology, electroencephalography or audio-video, can be visualized using the DisplayGUI. The toolbox includes several functions that allow one to read, preprocess, and analyze fNIRS data, including task-based and functional connectivity measures. COMPARISON WITH EXISTING METHODS: Several good neuroinformatics tools for fNIRS data analysis are currently available. None of them emphasize multimodal visualization of the data throughout the preprocessing steps and multidimensional decomposition, which are essential for understanding challenging data. Furthermore, LIONirs provides compatibility and complementarity with other existing tools by supporting common data format. CONCLUSIONS: LIONirs offers a flexible platform for basic and advanced fNIRS data analysis, shown through real experimental examples.

Neurotoxin-mediated potent activation of the axon degeneration regulator SARM1.

Axon loss underlies symptom onset and progression in many neurodegenerative disorders. Axon degeneration in injury and disease is promoted by activation of the NAD-consuming enzyme SARM1. Here, we report a novel activator of SARM1, a metabolite of the pesticide and neurotoxin vacor. Removal of SARM1 completely rescues mouse neurons from vacor-induced neuron and axon death in vitro and in vivo. We present the crystal structure of the Drosophila SARM1 regulatory domain complexed with this activator, the vacor metabolite VMN, which as the most potent activator yet known is likely to support drug development for human SARM1 and NMNAT2 disorders. This study indicates the mechanism of neurotoxicity and pesticide action by vacor, raises important questions about other pyridines in wider use today, provides important new tools for drug discovery, and demonstrates that removing SARM1 can robustly block programmed axon death induced by toxicity as well as genetic mutation.

Cerebral flow velocities during daily activities depend on blood pressure in patients with chronic ischemic infarctions.

BACKGROUND AND PURPOSE: Target blood pressure (BP) values for optimal cerebral perfusion after an ischemic stroke are still debated. We sought to examine the relationship between BP and cerebral blood flow velocities (BFVs) during daily activities. METHODS: We studied 43 patients with chronic large vessel ischemic infarctions in the middle cerebral artery territory (aged 64.2+/-8.94 years; at 6.1+/-4.9 years after stroke) and 67 age-matched control subjects. BFVs in middle cerebral arteries were measured during supine baseline, sitting, standing, and tilt. A regression analysis and a dynamic phase analysis were used to quantify the BP-BFV relationship. RESULTS: The mean arterial pressure was similar between the groups (89+/-15 mm Hg). Baseline BFVs were lower by approximately 30% in the patients with stroke compared with the control subjects (P=0.0001). BFV declined further with postural changes and remained lower in the stroke group during sitting (P=0.003), standing (P=0.003), and tilt (P=0.002) as compared with the control group. Average BFVs on the stroke side were positively correlated with BP during baseline (R=0.54, P=0.0022, the slope 0.46 cm/s/mm Hg) and tilt (R=0.52, P=0.0028, the slope 0.40 cm/s/mm Hg). Regression analysis suggested that BFV may increase approximately 30% to 50% at mean BP >100 mm Hg. Orthostatic hypotension during the first minute of tilt or standing was independently associated with lower BFV on the stroke side (P=0.0008). Baseline BP-BFV phase shift derived from the phase analysis was smaller on the stroke side (P=0.0006). CONCLUSIONS: We found that BFVs are lower in patients with stroke and daily activities such as standing could induce hypoperfusion. BFVs increase with mean arterial pressure >100 mm Hg. Dependency of BFV on arterial pressure may have implications for BP management after stroke. Further prospective investigations are needed to determine the impact of these findings on functional recovery and strategies to improve perfusion pressure during daily activities after ischemic stroke.

Impacts of an Interdisciplinary Developmental Follow-Up Program on Neurodevelopment in Congenital Heart Disease: The CINC Study.

Objectives: This study investigates the impact of an early systematic interdisciplinary developmental follow-up and individualized intervention program on the neurodevelopment of children with complex congenital heart disease (CHD) who required cardiac surgery. Study Design: We prospectively enrolled 80 children with CHD: 41 were already followed at our neurocardiac developmental follow-up clinic from the age of 4 months, while 39 were born before the establishment of the program and therefore received standard health care. We conducted cognitive, motor, and behavioral assessments at 3 years of age. We used one-way multivariate analyses of variance to compare the neurodevelopmental outcome of both groups. Results: Between-group analyses revealed a distinct neurodevelopmental profile with clinically significant effect size (P < 0.001, partial η2 = 0.366). Children followed at our clinic demonstrated better receptive language performances (P = 0.048) and tended to show higher scores on visuo-constructive tasks (P = 0.080). Children who received standard health care exhibited greater performances in working memory tasks (P = 0.032). We found no group differences on global intellectual functioning, gross and fine motor skills, and behaviors. Referral rates for specific remedial services were higher in patients followed at our neurocardiac clinic compared to the historical cohort (P < 0.005). Conclusions: Overall, the impact of the developmental follow-up and individualized intervention program on neurodevelopmental outcomes remains subtle. Nevertheless, results, although limited by several factors, point toward an advantage for the children who took part in the program regarding receptive language skills over children who received standard health care. We hypothesize that group differences may be greater with growing age. Further research involving larger cohorts is needed to clearly assess the effectiveness of neurocardiac developmental follow-up programs at school age.

Assessing visual modulation along the human subcortical auditory pathway.

Experience of the world is inherently multisensory. It has been suggested that audiovisual modulation occurs as early as subcortical auditory stages. However, this was based on the frequency-following response, a measure recently found to be significantly generated from cortical sources. It therefore remains unclear whether subcortical auditory processing can indeed be modulated by visual information. We aimed to trace visual modulation along the auditory pathway by comparing auditory brainstem response (ABR) and middle-latency response (MLR) between unimodal auditory and multimodal audiovisual conditions. EEG activity was recorded while participants attended auditory clicks and visual flashes, either synchronous or asynchronous. No differences between auditory and audiovisual responses were observed at ABR or MLR levels. It suggested that ascending auditory processing does not seem to be modulated by visual cues at subcortical levels, at least for rudimentary stimuli. Multimodal modulation in the auditory brainstem observed in previous studies might therefore originate from cortical sources and top-down processes. More studies are needed to further disentangle subcortical and cortical influences on audiovisual modulation along the auditory pathway.

Extracellular Vesicles: Satellites of Information Transfer in Cancer and Stem Cell Biology.

The generation and shedding of extracellular vesicles (EVs), including exosomes and microvesicles (MVs), by cells has emerged as a form of intercellular communication with important roles in several physiological processes and diseases such as cancer. These membrane-enclosed packets can transfer specific proteins, RNA transcripts, microRNAs, and even DNA to target cells, thereby altering their function. Despite the exponential growth of the EV field, a great deal remains unclear about the mechanisms that regulate exosome and MV biogenesis, as well as about how to isolate different classes of EVs and how to best take advantage of them for clinical applications.

Microvesicles provide a mechanism for intercellular communication by embryonic stem cells during embryo implantation.

Communication between the inner cell mass (ICM) and the trophoblast layer of the blastocyst is known to occur, but its functional consequences on early developmental events is unclear. Here we demonstrate that embryonic stem (ES) cells derived from the ICM generate and shed microvesicles (MVs), a major class of extracellular vesicles (EVs), which influence trophoblast behaviour during the implantation process. The MV cargo proteins laminin and fibronectin interact with integrins along the surfaces of the trophoblasts, triggering the activation of two signalling kinases, JNK and FAK, and stimulating trophoblast migration. We further show that injecting MVs isolated from ES cells into blastocysts results in an increase in their implantation efficiency. Thus, these findings highlight a unique mechanism by which ES cells communicate with trophoblasts within the blastocyst to increase their ability to migrate into the uterus, thereby promoting one of the earliest and most important steps during pregnancy.

Assessment of barriers to improve diabetes management in older adults: a randomized controlled study.

OBJECTIVE: To evaluate whether assessment of barriers to self-care and strategies to cope with these barriers in older adults with diabetes is superior to usual care with attention control. The American Diabetes Association guidelines recommend the assessment of age-specific barriers. However, the effect of such strategy on outcomes is unknown. RESEARCH DESIGN AND METHODS: We randomized 100 subjects aged ≥69 years with poorly controlled diabetes (A1C >8%) in two groups. A geriatric diabetes team assessed barriers and developed strategies to help patients cope with barriers for an intervention group. The control group received equal amounts of attention time. The active intervention was performed for the first 6 months, followed by a "no-contact" period. Outcome measures included A1C, Tinetti test, 6-min walk test (6MWT), self-care frequency, and diabetes-related distress. RESULTS: We assessed 100 patients (age 75 ± 5 years, duration 21 ± 13 years, 68% type 2 diabetes, 89% on insulin) over 12 months. After the active period, A1C decreased by -0.45% in the intervention group vs. -0.31% in the control group. At 12 months, A1C decreased further in the intervention group by -0.21% vs. 0% in control group (linear mixed-model, P < 0.03). The intervention group showed additional benefits in scores on measures of self-care (Self-Care Inventory-R), gait and balance (Tinetti), and endurance (6MWT) compared with the control group. Diabetes-related distress improved in both groups. CONCLUSIONS: Only attention between clinic visits lowers diabetes-related distress in older adults. However, communication with an educator cognizant of patients' barriers improves glycemic control and self-care frequency, maintains functionality, and lowers distress in this population.

Frequent hypoglycemia among elderly patients with poor glycemic control.

BACKGROUND: Episodes of hypoglycemia are particularly dangerous in the older population. To reduce the risk of hypoglycemia, relaxation of the standard hemoglobin A(1c) (HbA(1c)) goals has been proposed for frail elderly patients. However, the risk of hypoglycemia in this population with higher HbA(1c) levels is unknown. METHODS: Patients 69 years or older with HbA(1C) values of 8% or greater were evaluated with blinded continuous glucose monitoring for 3 days. RESULTS: Forty adults (mean [SD] age, 75 [5] years; HbA(1C) value, 9.3% [1.3%]; diabetes duration, 22 [14] years; 28 patients [70%] with type 2 diabetes mellitus; and 37 [93%] using insulin) were evaluated. Twenty-six patients (65%) experienced 1 or more episodes of hypoglycemia (glucose level <70 mg/dL). Among these, 12 (46%) experienced a glucose level below 50 mg/dL and 19 (73%), a level below 60 mg/dL. The average number of episodes was 4; average duration, 46 minutes. Eighteen patients (69%) had at least 1 nocturnal episode (10 pm to 6 am). Of the total of 102 hypoglycemic episodes, 95 (93%) were unrecognized by finger-stick glucose measurements performed 4 times a day or by symptoms. CONCLUSIONS: Hypoglycemic episodes are common in older adults with poor glycemic control. Raising HbA(1C) goals may not be adequate to prevent hypoglycemia in this population.