Genetic mapping across autoimmune diseases reveals shared associations and mechanisms.

Autoimmune and inflammatory diseases are polygenic disorders of the immune system. Many genomic loci harbor risk alleles for several diseases, but the limited resolution of genetic mapping prevents determining whether the same allele is responsible, indicating a shared underlying mechanism. Here, using a collection of 129,058 cases and controls across 6 diseases, we show that ~40% of overlapping associations are due to the same allele. We improve fine-mapping resolution for shared alleles twofold by combining cases and controls across diseases, allowing us to identify more expression quantitative trait loci driven by the shared alleles. The patterns indicate widespread sharing of pathogenic mechanisms but not a single global autoimmune mechanism. Our approach can be applied to any set of traits and is particularly valuable as sample collections become depleted.

Prevalence and correlates of anxiety and depressive symptoms after Spontaneous Coronary Artery Dissection (SCAD): a cross-sectional study.

AIMS: Spontaneous coronary artery dissection (SCAD) is recognised as a particularly stressful cause of heart attack. However few studies have documented the prevalence of post-SCAD anxiety and depressive symptoms, or identified patients most at risk. This study documents the prevalence and correlates of post-SCAD anxiety and depressive symptoms. METHOD AND RESULTS: 310 (95% women) SCAD survivors were recruited by the Victor Chang Cardiac Research Institute from a database of 433 SCAD survivors. Participants completed an online questionnaire to gather demographic, medical and psychosocial information, including the Generalised Anxiety Disorder-7 (GAD-7) and the Patient Health Questionnaire-9 (PHQ-9). Bivariate and multivariate analyses were undertaken to identify the significant demographic, psychosocial and medical correlates of post-SCAD anxiety and depressive symptoms. Time between SCAD and questionnaire completion varied from 2 months to 18 years (mean = 5.5 years; SD = 3.5 years). Rates of anxiety and depressive symptoms were 20.7% (GAD-7 ≥ 10) and 20.9% (PHQ-9 ≥ 10) respectively, and did not vary by time since event. In bivariate analyses, correlates (p < .05) of anxiety and depressive symptoms were absence of a close confidante, financial strain, mental health diagnosis pre-SCAD, comorbid obesity, not being in paid employment (anxiety only), younger age (depression only), and not knowing another SCAD survivor (depression only). Variables retained in multivariate models were absence of a close confidante, financial strain, not being in paid employment, mental health diagnosis pre-SCAD (depression only), and younger age (depression only). CONCLUSION: This study demonstrated that over one in four SCAD survivors experience either anxiety or depressive symptoms after SCAD, and identified those who may need additional support in their psychological recovery.

Perioperative Health Interventions in Children With Chronic Neuromuscular Conditions Undergoing Major Musculoskeletal Surgery: A Scoping Review.

BACKGROUND AND OBJECTIVES: Children with chronic neuromuscular conditions (CCNMC) have many coexisting conditions and often require musculoskeletal surgery for progressive neuromuscular scoliosis or hip dysplasia. Adequate perioperative optimization may decrease adverse perioperative outcomes. The purpose of this scoping review was to allow us to assess associations of perioperative health interventions (POHI) with perioperative outcomes in CCNMC. METHODS: Eligible articles included those published from January 1, 2000 through March 1, 2022 in which the authors evaluated the impact of POHI on perioperative outcomes in CCNMC undergoing major musculoskeletal surgery. Multiple databases, including PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature, Web of Science, the Cochrane Library, Google Scholar, and ClinicalTrials.gov, were searched by using controlled vocabulary terms and relevant natural language keywords. Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines were used to perform the review. A risk of bias assessment for included studies was performed by using the Risk of Bias in Non-randomized Studies of Interventions tool. RESULTS: A total of 7013 unique articles were initially identified, of which 6286 (89.6%) were excluded after abstract review. The remaining 727 articles' full texts were then reviewed for eligibility, resulting in the exclusion of 709 (97.5%) articles. Ultimately, 18 articles were retained for final analysis. The authors of these studies reported various impacts of POHI on perioperative outcomes, including postoperative complications, hospital length of stay, and hospitalization costs. Because of the heterogeneity of interventions and outcome measures, meta-analyses with pooled data were not feasible. CONCLUSIONS: The findings reveal various impacts of POHI in CCNMC undergoing major musculoskeletal surgery. Multicenter prospective studies are needed to better address the overall impact of specific interventions on perioperative outcomes in CCNMC.

Cost-Effectiveness of Cardiovascular Magnetic Resonance for Rejection Surveillance After Cardiac Transplantation in the Australian Health Care System.

BACKGROUND: Heart transplantation is an effective treatment for end-stage congestive heart failure, however, achieving the right balance of immunosuppression to maintain graft function while minimising adverse effects is challenging. Serial endomyocardial biopsies (EMBs) are currently the standard for rejection surveillance, despite being invasive. Replacing EMB-based surveillance with cardiac magnetic resonance (CMR)-based surveillance for acute cardiac allograft rejection has shown feasibility. This study aimed to assess the cost-effectiveness of CMR-based surveillance in the first year after heart transplantation. METHOD: A prospective clinical trial was conducted with 40 orthotopic heart transplant (OHT) recipients. Participants were randomly allocated into two surveillance groups: EMB-based, and CMR-based. The trial included economic evaluations, comparing the frequency and cost of surveillance modalities in relation to quality-adjusted life years (QALYs) within the first year post-transplantation. Sensitivity analysis encompassed modelled data from observed EMB and CMR arms, integrating two hypothetical models of expedited CMR-based surveillance. RESULTS: In the CMR cohort, 238 CMR scans and 15 EMBs were conducted, versus (vs) 235 EMBs in the EMB group. CMR surveillance yielded comparable rejection rates (CMR 74 vs EMB 94 events, p=0.10) and did not increase hospitalisation risk (CMR 32 vs EMB 46 events, p=0.031). It significantly reduced the necessity for invasive EMBs by 94%, lowered costs by an average of AUD$32,878.61, and enhanced cumulative QALY by 0.588 compared with EMB. Sensitivity analysis showed that increased surveillance with expedited CMR Models 1 and 2 were more cost-effective than EMB (all p<0.01), with CMR Model 1 achieving the greatest cost savings (AUD$34,091.12±AUD$23,271.86 less) and utility increase (+0.62±1.49 QALYs, p=0.011), signifying an optimal cost-utility ratio. Model 2 showed comparable utility to the base CMR model (p=0.900) while offering the benefit of heightened surveillance frequency during periods of elevated rejection risk. CONCLUSIONS: CMR-based rejection surveillance in orthotopic heart transplant recipients provides a cost-effective alternative to EMB-based surveillance. Furthermore, it reduces the need for invasive procedures, without increased risk of rejection or hospitalisation for patients, and can be incorporated economically for expedited surveillance. These findings have important implications for improving patient care and optimising resource allocation in post-transplant management.

Computational modeling of dorsal root ganglion stimulation using an Injectrode.

Objective.Minimally invasive neuromodulation therapies like the Injectrode, which is composed of a tightly wound polymer-coated Platinum/Iridium microcoil, offer a low-risk approach for administering electrical stimulation to the dorsal root ganglion (DRG). This flexible electrode is aimed to conform to the DRG. The stimulation occurs through a transcutaneous electrical stimulation (TES) patch, which subsequently transmits the stimulation to the Injectrode via a subcutaneous metal collector. However, it is important to note that the effectiveness of stimulation through TES relies on the specific geometrical configurations of the Injectrode-collector-patch system. Hence, there is a need to investigate which design parameters influence the activation of targeted neural structures.Approach.We employed a hybrid computational modeling approach to analyze the impact of Injectrode system design parameters on charge delivery and neural response to stimulation. We constructed multiple finite element method models of DRG stimulation, followed by the implementation of multi-compartment models of DRG neurons. By calculating potential distribution during monopolar stimulation, we simulated neural responses using various parameters based on prior acute experiments. Additionally, we developed a canonical monopolar stimulation and full-scale model of bipolar bilateral L5 DRG stimulation, allowing us to investigate how design parameters like Injectrode size and orientation influenced neural activation thresholds.Main results.Our findings were in accordance with acute experimental measurements and indicate that the minimally invasive Injectrode system predominantly engages large-diameter afferents (Aß-fibers). These activation thresholds were contingent upon the surface area of the Injectrode. As the charge density decreased due to increasing surface area, there was a corresponding expansion in the stimulation amplitude range before triggering any pain-related mechanoreceptor (Aδ-fibers) activity.Significance.The Injectrode demonstrates potential as a viable technology for minimally invasive stimulation of the DRG. Our findings indicate that utilizing a larger surface area Injectrode enhances the therapeutic margin, effectively distinguishing the desired Aßactivation from the undesired Aδ-fiber activation.

Autism and neurodevelopmental disability risks in children with tracheostomies and ventilators.

BACKGROUND/OBJECTIVE: Infants who survive prematurity and other critical illnesses and require continued invasive mechanical ventilation (IMV) postdischarge (at home) are at high risk of developmental delays and disabilities. Studies of extremely preterm cohorts (<28-week gestation) demonstrate rates of 25% for intellectual disability (ID) and 7% for autism spectrum disorder (ASD). Rates of ASD and ID in children with IMV are unknown. This study aimed to determine neurodevelopmental disability risk in a cohort of children with postdischarge IMV. DESIGN/METHODS: A consecutive series of children with IMV were assessed 1 month, 6 months, and 1 year after discharge. Cognitive, social, and communicative domains were assessed by a Developmental and Behavioral Pediatrician using (1) clinical adaptive test/clinical linguistic and auditory milestone scale (CAT/CLAMS) of the capute scales; (2) pediatric evaluation of disability inventory computer adaptive test (PEDI-CAT); and (3) modified checklist for autism in toddlers, revised (MCHAT-R). Red flag signs and symptoms of ASD using DSM-V criteria were noted. Longitudinal testing was reviewed. Expert consensus impressions of evolving ASD and/or ID were determined. RESULTS: Eighteen children were followed for 1 year; at 1 year, the median age (range) was 23 (17-42) months. Children were 44% male, 33% non-Hispanic White, 39% non-Hispanic Black, and 28% Hispanic. Fifteen (83%) children were prematurity survivors. Median (range) developmental quotients (DQs): full-scale DQ 59 (11-86), CAT DQ 66.5 (8-96), and CLAMS DQ 49.5 (13-100). Twelve (67%) children were highly suspicious for ASD and/or evolving ID. CONCLUSIONS/SIGNIFICANCE: This cohort of children with at-home IMV demonstrates a higher risk of ASD and ID than prior premature cohorts. Larger investigations with longer follow-up are needed.

Outcomes for Pediatric Oncology and Hematopoietic Stem Cell Transplantation Patients Who Undergo Tracheostomy Placement: A Pediatric Health information System Database Cohort Study, 2009-2020.

OBJECTIVES: To describe the epidemiology, surgical complications, and long-term outcomes after tracheostomy in pediatric oncology and/or hematopoietic stem cell transplantation (HSCT) patients in U.S. Children's Hospitals. DESIGN: Retrospective cohort from the Pediatric Health information System (PHIS) database, 2009-2020. SETTING: The PHIS dataset incorporates data from 48 pediatric hospitals in the Children's Hospital Association. PATIENTS: Patients 0-21 years old with an oncologic diagnosis and/or underwent HSCT, received a tracheostomy, and were discharged from hospital between January 1, 2009, and December 31, 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There were 1061 patients included in the dataset, and 217 (20.5%) had undergone HSCT. The annual prevalence in tracheostomy usage did not change over the study period. The majority of patients (62.2%) underwent tracheostomy early (< 30 d) in the admission and those who underwent the procedure later (> 90 d) had a significant increase in mortality (52.6% vs. 17.6%; p < 0.001) and mechanical ventilation (MV) at discharge (51.9% vs. 24.5%; p < 0.001) compared with the early tracheostomy patients. Complications reported included tracheostomy site bleeding (< 1%) and infection (24%). The overall rate of MV at discharge was 32.6% and significantly associated with chronic lung (adjusted odds ratio [OR], 1.54; 95% CI, 1.03-2.32) and acute lung disease (OR, 2.18; 95% CI, 1.19-3.98). The overall rate of mortality was 19.6% within the cohort and significantly associated with HSCT (OR, 5.45; 95% CI, 3.88-7.70), diagnosis of sepsis (OR, 2.09; 95% CI, 1.28-3.41), and requirement for renal replacement therapy (OR, 2.76; 95% CI, 1.58-4,83). CONCLUSIONS: This study demonstrated a static prevalence of tracheostomy placement in the cohort population relative to the increasing trends in other reported groups. Regardless of underlying diagnosis, the study patients incurred substantial morbidity and mortality. However, tracheostomy specific complication rates were comparable with that of the general pediatric population and were not associated with increased odds of mortality within this population.

Multiformity of extracellular microelectrode recordings from Aδ neurons in the dorsal root ganglia: a computational modeling study.

Microelectrodes serve as a fundamental tool in electrophysiology research throughout the nervous system, providing a means of exploring neural function with a high resolution of neural firing information. We constructed a hybrid computational model using the finite element method and multicompartment cable models to explore factors that contribute to extracellular voltage waveforms that are produced by sensory pseudounipolar neurons, specifically smaller A-type neurons, and that are recorded by microelectrodes in dorsal root ganglia. The finite element method model included a dorsal root ganglion, surrounding tissues, and a planar microelectrode array. We built a multicompartment neuron model with multiple trajectories of the glomerular initial segment found in many A-type sensory neurons. Our model replicated both the somatic intracellular voltage profile of Aδ low-threshold mechanoreceptor neurons and the unique extracellular voltage waveform shapes that are observed in experimental settings. Results from this model indicated that tortuous glomerular initial segment geometries can introduce distinct multiphasic properties into a neuron's recorded waveform. Our model also demonstrated how recording location relative to specific microanatomical components of these neurons, and recording distance from these components, can contribute to additional changes in the multiphasic characteristics and peak-to-peak voltage amplitude of the waveform. This knowledge may provide context for research employing microelectrode recordings of pseudounipolar neurons in sensory ganglia, including functional mapping and closed-loop neuromodulation. Furthermore, our simulations gave insight into the neurophysiology of pseudounipolar neurons by demonstrating how the glomerular initial segment aids in increasing the resistance of the stem axon and mitigating rebounding somatic action potentials.NEW & NOTEWORTHY We built a computational model of sensory neurons in the dorsal root ganglia to investigate factors that influence the extracellular waveforms recorded by microelectrodes. Our model demonstrates how the unique structure of these neurons can lead to diverse and often multiphasic waveform profiles depending on the location of the recording contact relative to microanatomical neural components. Our model also provides insight into the neurophysiological function of axon glomeruli that are often present in these neurons.

Psychosocial and lifestyle impacts of spontaneous coronary artery dissection: A quantitative study.

INTRODUCTION: Recent studies suggest that acute myocardial infarction due to spontaneous coronary artery dissection (SCAD) carries significant psychosocial burden. This survey-based quantitative study builds on our earlier qualitative investigation of the psychosocial impacts of SCAD in Australian SCAD survivors. The study aimed to document the prevalence and predictors of a broad range of psychosocial and lifestyle impacts of SCAD. METHOD: Australian SCAD survivors currently enrolled in the Victor Chang Cardiac Research Institute genetics study were invited to participate in an online survey to assess the psychosocial impacts of SCAD. Participants completed a questionnaire, developed using findings from our earlier qualitative research, which assessed 48 psychosocial and five lifestyle impacts of SCAD. Participants also provided demographic and medical data and completed validated measures of anxiety and depression. RESULTS: Of 433 SCAD survivors invited to participate, 310 (72%) completed the questionnaire. The most common psychosocial impacts were 'shock about having a heart attack' (experienced by 87% respondents), 'worry about having another SCAD' (81%), 'concern about triggering another SCAD' (77%), 'uncertainty about exercise and physical activity' (73%) and 'confusion about safe levels of activity and exertion' (73.0%) and 'being overly aware of bodily sensations' (73%). In terms of lifestyle impacts, the SCAD had impacted on work capacity for almost two thirds of participants, while one in ten had sought financial assistance. The key predictors of psychosocial impacts were being under 50, current financial strain, and trade-level education. The key predictors of lifestyle impacts were being over 50, SCAD recurrence, trade-level education, and current financial strain. All psychosocial impacts and some lifestyle impacts were associated with increased risk of anxiety and/or depression. CONCLUSION AND IMPLICATIONS: This quantitative study extends our previous qualitative investigation by documenting the prevalence of each of 48 psychosocial and five lifestyle impacts identified in our earlier focus group research, and by providing risk factors for greater SCAD impacts. The findings suggest the need for supports to address initial experiences of shock, as well as fears and uncertainties regarding the future, including SCAD recurrence and exercise resumption. Support could be targeted to those with identified risk factors. Strategies to enable SCAD survivors to remain in or return to the paid workforce are also indicated.

Peritumoral administration of immunomodulatory antibodies as a triple combination suppresses skin tumor growth without systemic toxicity.

BACKGROUND: Skin cancers, particularly keratinocyte cancers, are the most commonly diagnosed tumors. Although surgery is often effective in early-stage disease, skin tumors are not always easily accessible, can reoccur and have the ability to metastasize. More recently, immunotherapies, including intravenously administered checkpoint inhibitors, have been shown to control some skin cancers, but with off-target toxicities when used in combination. Our study investigated whether peritumoral administration of an antibody combination targeting PD-1, 4-1BB (CD137) and VISTA might control skin tumors and lead to circulating antitumor immunity without off-target toxicity. METHODS: The efficacy of combination immunotherapy administered peritumorally or intravenously was tested using transplantable tumor models injected into mouse ears (primary tumors) or subcutaneously in flank skin (secondary tumors). Changes to the tumor microenvironment were tracked using flow cytometry while tumor-specific, CD8 T cells were identified through enzyme-linked immunospot (ELISPOT) assays. Off-target toxicity of the combination immunotherapy was assessed via serum alanine aminotransferase ELISA and histological analysis of liver sections. RESULTS: The data showed that local administration of antibody therapy eliminated syngeneic murine tumors transplanted in the ear skin at a lower dose than required intravenously, and without measured hepatic toxicity. Tumor elimination was dependent on CD8 T cells and was associated with an increased percentage of CD8 T cells expressing granzyme B, KLRG1 and Eomes, and a decreased population of CD4 T cells including CD4+FoxP3+ cells in the treated tumor microenvironment. Importantly, untreated, distal tumors regressed following antibody treatment of a primary tumor, and immune memory prevented growth of subcutaneous flank tumors administered 50 days after regression of a primary tumor. CONCLUSIONS: Together, these data suggest that peritumoral immunotherapy for skin tumors offers advantages over conventional intravenous delivery, allowing antibody dose sparing, improved safety and inducing long-term systemic memory. Future clinical trials of immunotherapy for primary skin cancer should focus on peritumoral delivery of combinations of immune checkpoint antibodies.

Polygenic Risk in Families With Spontaneous Coronary Artery Dissection.

Importance: Spontaneous coronary artery dissection (SCAD) is a poorly understood cause of acute coronary syndrome that predominantly affects women. Evidence to date suggests a complex genetic architecture, while a family history is reported for a minority of cases. Objective: To determine the contribution of rare and common genetic variants to SCAD risk in familial cases, the latter via the comparison of a polygenic risk score (PRS) with those with sporadic SCAD and healthy controls. Design, Setting, and Participants: This genetic association study analyzed families with SCAD, individuals with sporadic SCAD, and healthy controls. Genotyping was undertaken for all participants. Participants were recruited between 2017 and 2021. A PRS for SCAD was calculated for all participants. The presence of rare variants in genes associated with connective tissue disorders (CTD) was also assessed. Individuals with SCAD were recruited via social media or from a single medical center. A previously published control database of older healthy individuals was used. Data were analyzed from January 2022 to October 2023. Exposures: PRS for SCAD comprised of 7 single-nucleotide variants. Main Outcomes and Measures: Disease status (familial SCAD, sporadic SCAD, or healthy control) associated with PRS. Results: A total of 13 families with SCAD (27 affected and 12 unaffected individuals), 173 individuals with sporadic SCAD, and 1127 healthy controls were included. A total of 188 individuals with SCAD (94.0%) were female, including 25 of 27 with familial SCAD and 163 of 173 with sporadic SCAD; of 12 unaffected individuals from families with SCAD, 6 (50%) were female; and of 1127 healthy controls, 672 (59.6%) were female. Compared with healthy controls, the odds of being an affected family member or having sporadic SCAD was significantly associated with a SCAD PRS (where the odds ratio [OR] represents an increase in odds per 1-SD increase in PRS) (affected family member: OR, 2.14; 95% CI, 1.78-2.50; adjusted P = 1.96 × 10-4; sporadic SCAD: OR, 1.63; 95% CI, 1.37-1.89; adjusted P = 5.69 × 10-4). This association was not seen for unaffected family members (OR, 1.03; 95% CI, 0.46-1.61; adjusted P = .91) compared with controls. Further, those with familial SCAD were overrepresented in the top quintile of the control PRS distribution (OR, 3.70; 95% CI, 2.93-4.47; adjusted P = .001); those with sporadic SCAD showed a similar pattern (OR, 2.51; 95% CI, 1.98-3.04; adjusted P = .001). Affected individuals within a family did not share any rare deleterious variants in CTD-associated genes. Conclusions and Relevance: Extreme aggregation of common genetic risk appears to play a significant role in familial clustering of SCAD as well as in sporadic case predisposition, although further study is required.

Small-molecule inhibition of glycogen synthase 1 for the treatment of Pompe disease and other glycogen storage disorders.

Glycogen synthase 1 (GYS1), the rate-limiting enzyme in muscle glycogen synthesis, plays a central role in energy homeostasis and has been proposed as a therapeutic target in multiple glycogen storage diseases. Despite decades of investigation, there are no known potent, selective small-molecule inhibitors of this enzyme. Here, we report the preclinical characterization of MZ-101, a small molecule that potently inhibits GYS1 in vitro and in vivo without inhibiting GYS2, a related isoform essential for synthesizing liver glycogen. Chronic treatment with MZ-101 depleted muscle glycogen and was well tolerated in mice. Pompe disease, a glycogen storage disease caused by mutations in acid α glucosidase (GAA), results in pathological accumulation of glycogen and consequent autophagolysosomal abnormalities, metabolic dysregulation, and muscle atrophy. Enzyme replacement therapy (ERT) with recombinant GAA is the only approved treatment for Pompe disease, but it requires frequent infusions, and efficacy is limited by suboptimal skeletal muscle distribution. In a mouse model of Pompe disease, chronic oral administration of MZ-101 alone reduced glycogen buildup in skeletal muscle with comparable efficacy to ERT. In addition, treatment with MZ-101 in combination with ERT had an additive effect and could normalize muscle glycogen concentrations. Biochemical, metabolomic, and transcriptomic analyses of muscle tissue demonstrated that lowering of glycogen concentrations with MZ-101, alone or in combination with ERT, corrected the cellular pathology in this mouse model. These data suggest that substrate reduction therapy with GYS1 inhibition may be a promising therapeutic approach for Pompe disease and other glycogen storage diseases.

The myotubular and centronuclear myopathy patient registry: a multifunctional tool for translational research.

The Myotubular and Centronuclear Myopathy Registry is an international research database containing key longitudinal data on a diverse and growing cohort of individuals affected by this group of rare and ultra-rare neuromuscular conditions. It can inform and support all areas of translational research including epidemiological and natural history studies, clinical trial feasibility planning, recruitment for clinical trials or other research studies, stand-alone clinical studies, standards of care development, and provision of real-world evidence data. For ten years, it has also served as a valuable communications tool and provided a link between the scientific and patient communities. With the anticipated advent of disease-modifying therapies for these conditions, the registry is a key resource for the generation of post-authorisation data for regulatory decision-making, real world evidence, and patient-reported outcome measures. In this paper we present some key data from the current 444 registered individuals with the following genotype split: MTM1 n=270, DNM2 n=42, BIN1 n=4, TTN n=4, RYR1 n=12, other n=4, unknown n=108. The data presented are consistent with the current literature and the common understanding of a strong genotype/phenotype correlations in CNM, most notably the data supports the current knowledge that XLMTM is typically the most severe form of CNM. Additionally, we outline the ways in which the registry supports research, and, more generally, the importance of continuous investment and development to maintain the relevance of registries for all stakeholders. Further information on the registry and contact details are available on the registry website at www.mtmcnmregistry.org.

Extracellular glutamate and GABA transients at the transition from interictal spiking to seizures.

Focal epilepsy is associated with intermittent brief population discharges (interictal spikes), which resemble sentinel spikes that often occur at the onset of seizures. Why interictal spikes self-terminate whilst seizures persist and propagate is incompletely understood. We used fluorescent glutamate and GABA sensors in an awake rodent model of neocortical seizures to resolve the spatiotemporal evolution of both neurotransmitters in the extracellular space. Interictal spikes were accompanied by brief glutamate transients which were maximal at the initiation site and rapidly propagated centrifugally. GABA transients lasted longer than glutamate transients and were maximal ∼1.5 mm from the focus where they propagated centripetally. Prior to seizure initiation GABA transients were attenuated, whilst glutamate transients increased, consistent with a progressive failure of local inhibitory restraint. As seizures increased in frequency, there was a gradual increase in the spatial extent of spike-associated glutamate transients associated with interictal spikes. Neurotransmitter imaging thus reveals a progressive collapse of an annulus of feed-forward GABA release, allowing seizures to escape from local inhibitory restraint.

Preseason Measures of Cervical Spine Function, Vestibulo-Ocular Reflex, Dynamic Balance, and Divided Attention in Youth Ice Hockey Players.

OBJECTIVES: Report typical scores and examine preseason cervical spine, vestibulo-ocular reflex, dynamic balance, and divided attention measures in competitive youth ice hockey players aged 10 to 18 years with and without a previous concussion history. DESIGN: Cross-sectional secondary analysis. METHODS: The exposure of interest was self-reported history of concussion. The main outcomes were cervical spine measures (Cervical Flexor Endurance [CFE; seconds], Cervical Flexion-Rotation Test [normal/abnormal], Anterolateral Cervical Spine Strength [kilograms], Head Perturbation Test (/8), and Joint Position Error [JPE; centimeters]), vestibulo-ocular reflex (Dynamic Visual Acuity [logMAR], Head Thrust Test [Positive/Negative]), dynamic balance (Functional Gait Assessment [/30]) and divided attention (Walking While Talking Test [seconds]). Multivariable linear or logistic regression, adjusted for age-group, sex, level of play, and clustered by team, were used to assess potential differences by concussion history. RESULTS: We included data from 2311 participants in this study (87.2% male, 12.8% female, 39.0% reported a previous concussion). No differences by concussion history were found across any of the measures (P values range: 0.17-0.99). Measures of cervical spine function and divided attention differed by age group (eg, Median Left Anterolateral Cervical Spine Strength [kilograms] for males: U13 = 7.46, U15 = 9.10, U18 = 9.67). CONCLUSION: Clinical outcomes scores in youth ice hockey players did not differ by concussion history. Performance on cervical spine strength, CFE, and JPE test outcomes may improve with age, highlighting the importance of developmental considerations when interpreting test scores. J Orthop Sports Phys Ther 2024;54(3):1-11. Epub 30 November 2023. doi:10.2519/jospt.2023.11958.

Trends in vaping and smoking behavior before and during the COVID-19 pandemic in Canada: Beneficial and potentially detrimental changes.

INTRODUCTION: E-cigarette and cigarette use may have changed during the COVID-19 pandemic, however, there is no consensus in existing literature, and current Canadian studies have not used representative samples. Thus, there is a need for robust national estimates. OBJECTIVE AND METHODS: The primary objective was to describe the 30-day period prevalence of smoking and vaping before and during the COVID-19 pandemic in Canada. This study analyzed three years of the cross-sectional Canadian Tobacco and Nicotine Survey: 2019 (pre-pandemic), 2020 (9 months into the pandemic) and 2021 (21 months into pandemic). RESULTS: Thirty-day period prevalence of vaping over the 2019, 2020, and 2021 study periods were 4.8 (95%CI: 4.2-5.3), 4.6% (95%CI: 4.1-5.2), and 5.2% (95%CI: 4.7-5.7), respectively. The 30-day period prevalence of smoking over the 2019, 2020, and 2021 study periods were 11.9% (95%CI: 10.9-12.7), 10.3% (95%CI: 9.4-11.2), and 10.3% (95%CI: 9.4-11.1), respectively. Notably, estimates of smoking for females decreased considerably from 2019 (11.0%; 95%CI: 9.9--12.2%) to 2020 (8.6%; 95%CI: 7.5-9.7). Estimates of vaping in those aged 20-24 increased substantially from 2020 (13.0%; 95%CI: 10.9-15.1) to 2021 (17.2%; 95%CI: 15.4-18.9). CONCLUSIONS: Changes to smoking and vaping were restricted to subsets within the population. In those aged 20-24, there was a modest increase in vaping from 2020 to 2021. In females, there was a decrease in smoking from 2019 to 2020, which persisted in 2021.

Anti-seizure gene therapy for focal cortical dysplasia.

Focal cortical dysplasias are a common subtype of malformation of cortical development, which frequently presents with a spectrum of cognitive and behavioural abnormalities as well as pharmacoresistant epilepsy. Focal cortical dysplasia type II is typically caused by somatic mutations resulting in mammalian target of rapamycin (mTOR) hyperactivity, and is the commonest pathology found in children undergoing epilepsy surgery. However, surgical resection does not always result in seizure freedom, and is often precluded by proximity to eloquent brain regions. Gene therapy is a promising potential alternative treatment and may be appropriate in cases that represent an unacceptable surgical risk. Here, we evaluated a gene therapy based on overexpression of the Kv1.1 potassium channel in a mouse model of frontal lobe focal cortical dysplasia. An engineered potassium channel (EKC) transgene was placed under control of a human promoter that biases expression towards principal neurons (CAMK2A) and packaged in an adeno-associated viral vector (AAV9). We used an established focal cortical dysplasia model generated by in utero electroporation of frontal lobe neural progenitors with a constitutively active human Ras homolog enriched in brain (RHEB) plasmid, an activator of mTOR complex 1. We characterized the model by quantifying electrocorticographic and behavioural abnormalities, both in mice developing spontaneous generalized seizures and in mice only exhibiting interictal discharges. Injection of AAV9-CAMK2A-EKC in the dysplastic region resulted in a robust decrease (∼64%) in the frequency of seizures. Despite the robust anti-epileptic effect of the treatment, there was neither an improvement nor a worsening of performance in behavioural tests sensitive to frontal lobe function. AAV9-CAMK2A-EKC had no effect on interictal discharges or behaviour in mice without generalized seizures. AAV9-CAMK2A-EKC gene therapy is a promising therapy with translational potential to treat the epileptic phenotype of mTOR-related malformations of cortical development. Cognitive and behavioural co-morbidities may, however, resist an intervention aimed at reducing circuit excitability.