Faculty Bibliography

The landscape of Down syndrome-associated Alzheimer's disease (DSAD) research reflects decades of scientific endeavor and collaborative effort, charting a remarkable journey from initial observations to the elucidation of complex genetic and molecular mechanisms. This perspective article chronicles key milestones and breakthroughs, paying homage to the pioneering scientists and advancements that have shaped the field. A thorough review of historical and contemporary literature offers a comprehensive narrative, highlighting the evolution of knowledge surrounding DSAD, from early recognition to the characterization of clinical presentation and natural history. The unique challenges and ethical considerations associated with DSAD populations are also examined, underscoring the importance of tailoring research and clinical approaches. By reflecting on the field's trajectory, this work celebrates past achievements while emphasizing the critical need for sustained research efforts. As part of a special issue, this article provides a foundation for appreciating the challenges and opportunities that lie ahead in advancing DSAD understanding and care. HIGHLIGHTS: This article provides a comprehensive overview of Down syndrome-associated Alzheimer's disease (DSAD) history, from early descriptions to its recognition as a genetic form of AD. It reflects on historical challenges faced by individuals with intellectual disabilities in achieving inclusion in scientific research. This historical perspective highlights the critical contributions of individuals with DS in advancing understanding of AD natural history. It explores pivotal milestones and efforts that have driven progress in DSAD research. Finally, it provides context to understand challenges and opportunities in DSAD research and its future directions.

INTRODUCTION/BACKGROUND:Primary tauopathies, including corticobasal degeneration (CBD), Pick's disease (PiD), and progressive supranuclear palsy (PSP), have aggregated tau pathology in the brain. Many other proteins are likely altered in disease; however, these have not been well characterized. METHODS:We performed sarkosyl fractionation of post mortem human brain tissue to enrich soluble and insoluble proteins from CBD, PiD, and PSP cases (n = 5/group). We assessed differences in the soluble fraction, insoluble fraction, and protein solubility changes between diseases, followed by enrichment and correlation analysis. RESULTS:CBD and PiD showed the greatest proteomic similarity in both the soluble and insoluble fractions, while PSP was the most divergent in comparison to other diseases. We observed critical changes in the solubility of lysosomal regulators, postsynaptic proteins, the extracellular matrix (ECM), and mitochondrial proteins. DISCUSSION/CONCLUSIONS:We have contrasted the solubility patterns of proteins across three tauopathies for the first time. Protein solubility differences reveal divergence in disease processes. HIGHLIGHTS/CONCLUSIONS:Tau isoforms are differentially soluble in primary tauopathies PSP proteomics profile was the most divergent of the tauopathies examined SORT1 is highly insoluble in CBD and aggregates to different extents in tauopathies There are shifts in solubility for key signalling pathways; ROCK1 and JAK2 Unique lysosomal proteins are more insoluble in distinct tauopathies.

Individuals with Down Syndrome (DS) represent one of the most susceptible populations for developing severe COVID-19, and a unique human genetic condition for investigating molecular mechanisms underlying susceptibility of neurologically vulnerable individuals to SARS-CoV-2 infection. Human Chromosome-21 (HSA21) triplication in DS causes global transcriptional deregulation, affecting multiple genes that may directly (e.g., TMPRSS2) or indirectly influence the SARS-CoV-2 entry into central nervous system (CNS) cells. The anti-viral immune response may also be altered in cells with trisomy-21 (T21) due to triplication of genes encoding for several interferon receptor subunits and interferon-stimulated genes (ISGs). Here, we demonstrate that human cells derived from fetal cortical specimens and maintained in primary cultures are susceptible to infection with a molecular clone of vesicular stomatitis virus engineered to express the Spike protein of SARS-CoV-2 (VSV-eGFP-SARS-CoV-2) and to authentic SARS-CoV-2. The level of SARS-CoV-2 infectivity in cultures originated from different cortical specimens varied, seemingly depending on ploidy and chromosomal sex of the cells. We confirmed the presence of ACE2 and TMPRSS2 in cultures and found that XY T21 group had the highest TMPRSS2 mRNA levels, which was associated with increased infectivity in XY-compared to XX T21 cultures. The XX T21 cultures exhibited elevated expression of several ISGs (MX1, STAT1, and STAT2) which was associated with lower infectivity. The comparisons of postmortem aged brain specimens revealed reduced ACE2, TMPRSS2, but elevated STAT2 protein levels in individuals with DS and Alzheimer's disease (DS-AD) compared to control and Alzheimer's disease (AD) group. Collectively, these results suggest multifactorial regulation of SARS-CoV-2 infectivity in cortical cells that involves ploidy, chromosomal sex, and the expression of genes implicated in regulation of virus entry and anti-viral response as contributing factors.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Dural arteriovenous fistula (dAVF) surgery is a microsurgical procedure that requires confirmation of obliteration using formal cerebral angiography, but the lack of intraoperative angiogram or need for postoperative angiogram in some settings necessitates a search for alternative, less invasive methods to verify surgical success. This study evaluates the use of indocyanine green videoangiography FLOW 800 hemodynamic intraoperatively during cranial and spinal dAVF obliteration to confirm obliteration and predict surgical success. METHODS:A retrospective analysis was conducted using indocyanine green videoangiography FLOW 800 to intraoperatively measure 4 hemodynamic parameters-Delay Time, Speed, Time to Peak, and Rise Time-across venous drainage regions of interest pre/post-dAVF obliteration. Univariate and multivariate statistical analyses to evaluate and visualize presurgical vs postsurgical state hemodynamic changes included nonparametric statistical tests, logistic regression, and Bayesian analysis. RESULTS:A total of 14 venous drainage regions of interest from 8 patients who had successful spinal or cranial dAVF obliteration confirmed with intraoperative digital subtraction angiography were extracted. Significant hemodynamic changes were observed after dAVF obliteration, with median Speed decreasing from 13.5 to 5.5 s-1 (P = .029) and Delay Time increasing from 2.07 to 7.86 s (P = .020). Bayesian logistic regression identified Delay Time as the strongest predictor of postsurgical state, with a 50% increase associated with 2.16 times higher odds of achieving obliteration (odds ratio = 4.59, 95% highest density interval: 1.07-19.95). Speed exhibited a trend toward a negative association with postsurgical state (odds ratio = 0.62, 95% highest density interval: 0.26-1.42). Receiver operating characteristic-area under the curve analysis using logistic regression demonstrated a score of 0.760, highlighting Delay Time and Speed as key features distinguishing preobliteration and postobliteration states. CONCLUSION/CONCLUSIONS:Our findings demonstrate that intraoperative FLOW 800 analysis reliably quantifies and visualizes immediate hemodynamic changes consistent with dAVF obliteration. Speed and Delay Time emerged as key indicators of surgical success, highlighting the potential of FLOW 800 as a noninvasive adjunct to traditional imaging techniques for confirming dAVF obliteration intraoperatively.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Disturbances in brain catecholamine activity may be associated with symptoms after exposure to repetitive head impacts (RHIs) or related chronic traumatic encephalopathy (CTE). In this article, we studied CSF catecholamines in former professional and college American football players and examined the relationship with football proxies of RHI exposure, CTE probability, cognitive performance, neuropsychiatric symptoms, and parkinsonism. METHODS:In this observational cross-sectional study, we examined male former American football players, professional ("PRO") or college ("COL") level, and asymptomatic unexposed male ("UE") individuals from the DIAGNOSE CTE Research Project. Catecholamines-norepinephrine (NE) and its metabolite, 3,4-dihydroxyphenylglycol (DHPG), and dopamine (DA) and its precursor, 3,4-dihydroxyphenylalanine (l-DOPA), and metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC)-were measured in CSF with high-performance liquid chromatography and compared across groups with analysis of covariance. Multivariable linear regression models tested the relationship between CSF catecholamines and proxies of RHI exposure (e.g., total years of playing American football), factor scores for cognition, and neurobehavioral dysregulation (explosivity, emotional dyscontrol, impulsivity, affective lability), as well as depressive/anxiety symptoms, measured with the Beck Depression/Anxiety Inventories. CTE probability and parkinsonism were assessed using the National Institute of Neurological Disorders and Stroke consensus diagnostic criteria for traumatic encephalopathy syndrome (TES), and biomarkers were compared among different diagnostic groups. RESULTS:The cohort consisted of 120 former American football players (85 PRO players, 35 COL players) and 35 UE participants (age 45-75). Former players had significantly lower levels of NE (mean difference = -0.114, 95% CI -0.190 to -0.038), l-DOPA (-0.121, 95% CI -0.109 to -0.027), and DOPAC (-0.116, 95% CI -0.177 to -0.054) than UE participants. For NE and DOPAC, these overall group differences were primarily due to differences between the PRO and UE cohorts. No significant differences were found across TES-CTE probability subgroups or TES-parkinsonism diagnostic groups. Within the COL cohort, tested as post hoc analyses, higher CSF NE and l-DOPA were associated with higher neurobehavioral dysregulation factor scores, BAI total score, and worse executive functioning and processing speed. CSF DHPG and DOPAC were associated with impulsivity only in this subgroup. DISCUSSION/CONCLUSIONS:We observed reduced CSF catecholamine concentrations in former elite American football players, although the relationship with degree of RHI exposure and the clinical impact needs further study.

We introduce an intracranial EEG (iEEG) dataset collected as part of an adversarial collaboration between proponents of two theories of consciousness: Global Neuronal Workspace Theory and Integrated Information Theory. The data were recorded from 38 patients undergoing intracranial monitoring of epileptic seizures across three research centers using the same experimental protocol. Participants were presented with suprathreshold visual stimuli belonging to four different categories (faces, objects, letters, false fonts) in three orientations (front, left, right view), and for three durations (0.5, 1.0, 1.5 s). Participants engaged in a non-speeded Go/No-Go target detection task to identify infrequent targets with some stimuli becoming task-relevant and others task-irrelevant. Participants also engaged in a motor localizer task. The data were checked for its quality and converted to Brain Imaging Data Structure (BIDS). The de-identified dataset contains demographics, clinical information, electrode reconstruction, behavioral performance, and eye-tracking data. We also provide code to preprocess and analyze the data. This dataset holds promise for reuse in consciousness science and vision neuroscience to answer questions related to stimulus processing, target detection, and task-relevance, among many others.

BACKGROUND:To address financial barriers that limit access to genomic profiling and precision medicine, philanthropy supported clinical genomic testing was offered worldwide at no cost to patients with select rare cancers via the Make-an-IMPACT program. Herein, we report our findings in pediatric patients with solid or central nervous system (CNS) tumors. METHODS:Tumor DNA or CSF-derived circulating tumor DNA (CSF ctDNA) was analyzed using the MSK-IMPACT assay, supplemented by targeted RNA panel sequencing in select cases. Results were returned to the patients/families and treating oncologists. RESULTS:63 patients from 11 countries had successful MSK-IMPACT testing. The results provided clinically relevant new diagnostic or prognostic information in 41% and 38% of solid and CNS tumor patients, respectively. Potentially therapeutically actionable alterations were identified in 44% of pediatric solid tumor and 21% of pediatric CSF ctDNA samples, respectively. Four patients subsequently received molecularly guided therapy, resulting in partial responses in two and prolonged stable disease in one. Serial tumor and CSF sampling identified resistance mutations in two patients, informing additional molecular targeted therapy recommendations. CONCLUSIONS:The Make-an-IMPACT program provided global access to state-of-the-art tumor and CSF genomic profiling across a diverse cohort of pediatric cancer patients, providing clinically relevant and actionable diagnostic, prognostic and therapeutic information reported in real time to patients and local physicians.

Optic disc swelling, frequently associated with vitamin A toxicity, is infrequently linked to vitamin A deficiency. This report describes a 6-year-old male with autism spectrum disorder (ASD) and avoidant restrictive food intake disorder who presented with xerophthalmia, optic disc swelling, vision changes, and deficiencies in vitamins A, B₁, and iron. The patient's behavioral dysregulation posed important challenges for the evaluation, diagnosis, and treatment of his hypovitaminoses. This case underscores the importance of considering multiple nutritional deficiencies as the etiology of optic disc swelling in pediatric populations with autism spectrum disorder and avoidant restrictive food intake disorder, diagnoses that have increased in frequency. Early recognition and intervention can prevent further complications such as visual loss and improve outcomes.

OBJECTIVE:New-onset refractory status epilepticus (NORSE) occurs in people without pre-existing epilepsy or a rapidly identified structural, toxic, metabolic, or other cause. NORSE is a rare disorder with high morbidity and mortality rates and limited evidence for effective therapies. We aimed to assess whether the gut microbiome of NORSE and status epilepticus (SE) differs from that of chronic epilepsy, whether NORSE differs from SE at different disease time points, and to examine the correlations between specific gut microbiota and cytokines in NORSE and SE. METHODS:This longitudinal cohort study observed patients with NORSE (n = 15), SE (n = 17), and chronic epilepsy who were not in SE (n = 12). NORSE patients were recruited through the NORSE Consortium. Patients with NORSE and SE underwent longitudinal serial biospecimen collection. Fecal samples were subjected to whole-community shotgun metagenomics to characterize microbiome features. Cohorts were evaluated for prokaryotic, eukaryotic, and functional diversity. Correlations between blood inflammatory cytokine levels and microbiome features and covariate analysis with critical illness and clinical treatments were examined for NORSE and SE patients during and after SE resolution. RESULTS:During SE, NORSE and SE patients had significantly different prokaryotic, eukaryotic, and functional microbiome levels compared to chronic epilepsy patients without SE. Limited microbiome differences were observed within and between NORSE and SE, although these groups displayed differing correlation patterns between microbial species and cytokines. Patients who later died or were tube-fed harbored significantly different microbiomes than those who survived or were orally fed. SIGNIFICANCE/CONCLUSIONS:NORSE and SE patients present with a more variable and dramatically different fecal microbiome than chronic epilepsy patients, which may indicate gut dysbiosis that may be reciprocally linked to inflammatory responses. Although NORSE and SE patients had similar microbiome structures, fungal and bacterial correlates with inflammatory cytokines differed between NORSE and SE, with confounding factors influencing microbiome structure. Our data suggest a microbiome-specific response to NORSE and SE, with implications for future treatment strategies.