Faculty Bibliography

Language comprehension involves the prediction of upcoming linguistic units across multiple timescales. However, how this prediction process is hierarchically implemented in the human brain remains unclear. Combining natural language processing (NLP) and functional magnetic resonance imaging (fMRI) in a narrative comprehension task, we first applied the group-based general linear model (gGLM) to identify the neural underpinnings associated with anticipating upcoming words and sentences. Our results revealed a cortical hierarchy supporting linguistic prediction, extending from the superior temporal cortices to the default mode network (DMN). Next, we investigated how the word and sentence levels interact by testing two rival hypotheses: the continuous updating hypothesis posits that higher-level regions are updated continuously as inputs unfold over time, while the sparse updating hypothesis states that higher-level regions are updated only at the boundaries of their preferred timescales. Using computational modeling and autocorrelation analysis, we found that the sparse model outperformed the continuous model, with updating occurred at the sentence boundaries. Together, our results extend evidence for linguistic prediction to longer timescales and elucidate the neurocomputational mechanisms of hierarchical information updating in the human brain.

Polyaminopathies are a recently described family of rare genetic neurodevelopmental disorders. Polyaminopathies disrupt the biosynthesis of the primary polyamines: putrescine, spermidine, and spermine. Snyder-Robinson syndrome results from hemizygous loss-of-function variants in the spermine synthase (SMS) gene, resulting in decreased or complete loss of spermine synthase enzyme activity. Bachmann-Bupp syndrome results from heterozygous gain-of-function variants in the ornithine decarboxylase 1 (ODC1) gene, resulting in increased ornithine decarboxylase enzyme activity. Faundes-Banka syndrome results from heterozygous loss-of-function variants in the eukaryotic translation initiation factor 5A (EIF5A) gene, impairing eIF5A protein function. DHPS (deoxyhypusine synthase) deficiency is an autosomal recessive disease and results from bi-allelic hypomorphic variants in the deoxyhypusine synthase (DHPS) gene, which results in reduced deoxyhypusine synthase enzyme activity. Finally, DOHH (deoxyhypusine hydroxylase) disorder is an autosomal recessive disorder caused by bi-allelic loss-of-function variants in the deoxyhypusine hydroxylase (DOHH) gene, which causes decreased deoxyhypusine hydroxylase enzyme activity. Snyder-Robinson syndrome was first described in 1969, while the other four syndromes have only been identified in the past 7 years. A comprehensive phenotypic and genotypic description of these five syndromes is needed. We review the clinical and genetic features of these five polyaminopathies to create an inclusive clinical resource. A systematic keyword search strategy was used to identify all published cases in PubMed, Web of Science, and Scopus databases. The five known syndromes associated with the polyamine pathway share many similar clinical phenotypes, and yet patients with each syndrome present with distinctive syndromic features. This review will serve as a valuable resource for clinicians diagnosing and caring for patients with these rare polyaminopathies.

IMPORTANCE/UNASSIGNED:Neuroscientific, epidemiological, and electronic health record studies implicate herpes simplex virus (HSV) as potentially etiological for Alzheimer disease (AD). OBJECTIVE/UNASSIGNED:To compare the efficacy and adverse effects of valacyclovir vs placebo in participants with early symptomatic AD and HSV seropositivity (HSV-1 or HSV-2). DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:This randomized clinical trial included adults with a clinical diagnosis of probable AD or a clinical diagnosis of mild cognitive impairment with positive biomarkers for AD, a positive serum antibody test (IgG or IgM) for HSV-1 or HSV-2, and a Mini-Mental State Examination score of 18 to 28. The trial was conducted at 3 US outpatient clinics specializing in memory disorders. Recruitment occurred from January 2018 to May 2022; the last follow-up occurred in September 2024. INTERVENTION/UNASSIGNED:Either 4 g/d of valacyclovir (n = 60) or matching placebo (n = 60). MAIN OUTCOMES AND MEASURES/UNASSIGNED:The primary outcome was least-squares mean (LSM) change at 78 weeks in the 11-item Alzheimer's Disease Assessment Scale Cognitive (ADAS-Cognitive) Subscale score (range, 0-70; higher scores indicate greater impairment). The secondary outcomes were LSM change in the Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) Scale score; LSM change in the 18F-florbetapir amyloid positron emission tomography (PET) standardized uptake value ratio (SUVR; higher scores indicate higher amyloid levels) for 6 brain regions (medial orbitofrontal, anterior cingulate, parietal lobe, posterior cingulate, temporal lobe, and precuneus); and LSM change in 18F-MK-6240 tau PET medial temporal SUVR (higher scores indicate higher tau levels) for 4 brain regions (amygdala, hippocampus, entorhinal, and parahippocampus). The frequency of adverse events was the safety outcome. RESULTS/UNASSIGNED:Of the 120 participants (mean age, 71.4 [SD, 8.6] years; 55% were female), 93 (77.5%) completed the trial. At 78 weeks, the LSM change in the 11-item ADAS-Cognitive Subscale score was 10.86 (95% CI, 8.80 to 12.91) in the valacyclovir group vs 6.92 (95% CI, 4.88 to 8.97) in the placebo group, indicating greater cognitive worsening with valacyclovir than placebo (between-group difference, 3.93 [95% CI, 1.03 to 6.83]; P = .01). The LSM change in the ADCS-ADL Scale score at 78 weeks was -13.78 (95% CI, -17.00 to -10.56) in the valacyclovir group vs -10.16 (95% CI, -13.37 to -6.96) in the placebo group (between-group difference, -3.62 [95% CI, -8.16 to 0.93]). At 78 weeks, the LSM change in the 18F-florbetapir amyloid PET SUVR was 0.03 (95% CI, -0.04 to 0.10) in the valacyclovir group vs 0.01 (95% CI, -0.06 to 0.08) in the placebo group (between-group difference, 0.02 [95% CI, -0.08 to 0.12]). The LSM change in the 18F-MK-6240 tau PET medial temporal SUVR at 78 weeks was 0.07 (95% CI, -0.06 to 0.19) in the valacyclovir group vs -0.04 (95% CI, -0.15 to 0.07) in the placebo group (between-group difference, 0.11 [95% CI, -0.06 to 0.28]). The most common adverse events were elevated serum creatinine level (5 participants [8.3%] in the valacyclovir group vs 2 participants [3.3%] in the placebo group) and COVID-19 infection (3 [5%] vs 2 [3.3%], respectively). CONCLUSIONS AND RELEVANCE/UNASSIGNED:Valacyclovir was not efficacious with cognitive worsening for the primary outcome and it is not recommended to treat individuals with early symptomatic AD and HSV seropositivity. TRIAL REGISTRATION/UNASSIGNED:ClinicalTrials.gov Identifier: NCT03282916.

While the physical manifestations of NF2-related schwannomatosis (NF2-SWN) have been well documented, there are a limited number of qualitative studies on health-related quality of life in NF2-SWN. The present study sought to explore the cumulative impact of symptoms, treatments, and healthcare on the quality of life of individuals with NF2-SWN. We interviewed 16 adolescent and adult patients with NF2-SWN enrolled in the INTUITT-NF2 clinical trial and 10 clinicians with NF2-SWN expertise from the United States, United Kingdom, and Australia. Analysis of patient and clinician interviews yielded five overall themes: (1) impacts on daily living, (2) impacts on life roles, (3) impacts on relationships and social integration, (4) impacts on psychological and emotional wellbeing, and (5) burden of treatment and healthcare. Multiple symptom areas contributed to impairments in quality of life across each theme. These findings reveal that quality of life in NF2-SWN is shaped not only by individual symptoms, but by their complex, cumulative impact-highlighting the urgent need for disease-specific tools and holistic care approaches that reflect the lived realities of patients across the lifespan.

OBJECTIVE:Distinctive differences in multiple sclerosis (MS) disease severity, progression, and mortality have been observed among different races. Social determinants of health (SDH) can contribute to such racial disparities. This study aims to: 1) compare Non-Hispanic White (NHW) and Black (Bl) persons with MS in terms of MS and SDH; 2) explore the impact of SDH-adjustment in the association between race and Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25-FW), 9-Hole Peg Test (9-HPT), Symbol Digit Modalities Test (SDMT). METHODS:120 patients, self-identified as Bl (n = 60) or NHW (n = 60) persons, were included in this cross-sectional analysis from a prospectively enrolled cohort. We used parametric and non-parametric tests; logistic models were performed to select the most relevant SDH. Univariable linear regression models were used to explore differences in EDSS, T25-FW, 9-HPT, SDMT and models were adjusted for relevant SDH using propensity scores (PS). RESULTS:Significant racial disparities in adverse SDH were identified in Black persons with MS (BpwMS). BpwMS patients had a higher EDSS (β=0.66, p = 0.022), log-transformed T25-FW (β=0.16, p = 0.001), 9-HPT (β=2.89, p = 0.001) and lower SDMT (β=-5.97, p = 0.003); after PS-adjustment, associations were no longer significant except for T25-FW (β=0.13, p = 0.030) and the magnitude of all coefficients was reduced (EDSS: -27 %, T25-FW: -19 %, 9-HPT: -36 %, SDMT: -45 %). INTERPRETATION/CONCLUSIONS:More efforts are necessary to adequately address the SDH that distinguish Bl from NHW persons with MS; additional unknown or unmeasured variables, including biologic differences as well as other SDH, should be explored to elucidate the mechanisms behind worse MS outcomes in BpwMS.

OBJECTIVE:Sudden unexpected death in epilepsy (SUDEP) often follows generalized tonic-clonic seizures during sleep, likely resulting from impaired brainstem cardiorespiratory function. We used ictal electrocardiogram (ECG)-based cross-frequency phase-amplitude coupling (PAC) to detect cardiorespiratory disruptions, comparing SUDEP to non-SUDEP cohorts. Leveraging respiratory modulation of ECG signals can provide a robust indirect proxy of respiratory monitoring despite high-amplitude noise. METHODS:We analyzed ictal ECG and electroencephalographic recordings in 21 SUDEP cases and 21 non-SUDEP epilepsy controls. Ictal ECG segments from 76 seizures (38 SUDEP, 38 non-SUDEP) were processed using continuous wavelet transformation to compute PAC between respiratory (.1-.55 Hz, 6-33 breaths per minute) and cardiac (.7-3.7 Hz, 42-222 beats per minute) frequencies. Relative PAC coupling strength was evaluated for respiratory frequencies > .25 Hz (15 breaths per minute) and cardiac frequencies > 1.7 Hz (102 beats per minute). Furthermore, a 3 × 3 grid of PAC ranges was derived for each 20-s window, yielding 18 features (mean and SD) as inputs to a logistic regression model. RESULTS:Elevated ictal PAC at higher respiratory (>.25 Hz, p < .0001) and cardiac (>1.7 Hz, p < .0142) frequencies in SUDEP patients suggests ictal respiration modulates ictal tachycardia, leading to cardiorespiratory dysfunction, probably brainstem-mediated. The logistic model accurately distinguished 38 seizures in SUDEP cases from 38 seizures in non-SUDEP cases (receiver operating characteristic area under the curve = 91%). Seizures in SUDEP patients had higher propensity scores (p < .001) both per seizure and per patient. All six test seizures (three SUDEP, three non-SUDEP) were correctly classified using the optimal threshold. SIGNIFICANCE/CONCLUSIONS:Ictal ECG-based PAC analysis is a potential noninvasive biomarker for SUDEP risk, capturing cardiorespiratory dysregulation during seizures. Its integration into wearable ECG devices could enable real-time risk assessment, informing clinical interventions such as rescue medications, antiseizure medication adjustments, or surgical evaluations.

BACKGROUND:Familial dysautonomia (FD) is a hereditary neurodevelopmental disorder caused by aberrant splicing of the ELP1 gene, leading to a tissue-specific reduction in ELP1 protein expression. Preclinical models indicate that increasing ELP1 levels can mitigate disease manifestations. A blood-based ELP-1 protein assay may provide a reliable way to monitor gene target engagement. DESIGN AND METHODS/METHODS:Using a newly developed radioimmunoassay, we quantified ELP1 protein levels in peripheral blood samples collected from 59 homozygous FD patients carrying the IVS20 + 6T>C mutation and 66 heterozygous carriers. To assess the reproducibility of the measurement, replicate samples were collected in 43 participants. Longitudinal variability was evaluated in 22 participants who underwent repeat sampling 1 year later. RESULTS: = 0.827, p < 0.001). An ELP1 threshold of 492 pg/mL yielded a sensitivity of 80.2% (CI of 70.6 to 87.2%) and a specificity of 98.2% (95% CI of 90%-99%) with a positive likelihood ratio of 46.5, indicating that individuals with FD were over 46 times more likely to have ELP1 levels below this threshold compared to non-affected carriers. CONCLUSION/CONCLUSIONS:Blood ELP1 levels are robust and reproducible, with concentrations below 492 pg/mL strongly indicative of disease. Moreover, given their longitudinal stability, ELP1 can serve as a marker of target engagement to evaluate the efficacy of gene-targeted therapies aimed at correcting ELP1 gene splicing and protein production.

PURPOSE/OBJECTIVE:Examine sex-specific differences in Intracranial Aneurysms (IA) rupture at presentation and to retrospectively benchmark sex-stratified versus pooled classification models for their ability to discriminate rupture status, using a cross-sectional cohort. METHODS:We retrospectively analyzed 203 patients (46 males, 157 females) with 303 IAs from a single-center, IRB-approved registry. Of these, 76 IAs were ruptured and 227 unruptured at presentation. Clinical data and lesion characteristics were summarized into patient-level variables and used to develop sex-specific logistic regression models. Adjusted Odds ratios (ORs) were produced for clinical covariates. Cross-application assessed generalizability across sexes. RESULTS:Among females, 58.7% of ruptures were < 5 mm, with a median ruptured size of 4.2 mm at Anterior Communicating Artery (ACOM). Rupture likelihood in females peaked between ages 40 and 59 (aORs = 2.8 and 1.7), coinciding with perimenopause. In males, ACOM was the most frequent rupture site; although males had higher mean hemoglobin levels (14.1 vs. 12.5 g/dL, p < 0.0001), hemoglobin contributed less to rupture compared to sex-specific models incorporating age, location, and metabolic factors (hemoglobin concentration, blood glucose). Metabolic factors contributed significantly to the female-specific model, achieving strong discrimination (AUC-ROC: 0.80), while the male-specific model underperformed (AUC-ROC: 0.50), due to limited rupture events (n = 19). Cross-application of features between sexes drastically reduced performance, providing the first computational evidence that male and female rupture mechanisms represent distinct biological feature spaces requiring separate modeling architectures CONCLUSION: Women in this cohort more often presented with rupture IAs at smaller sizes and at midlife ages than men. These sex-specific patterns, though strictly cross-sectional and associative rather than predictive, highlight potential biological and clinical contributors to rupture presentation and may partly explain misclassification by pooled risk models. Future longitudinal, multicenter studies with balanced cohorts are required to validate these findings and to develop robust rupture-risk prediction tools that incorporate sex as a biological variable.

DNA methylation is a crucial epigenetic mechanism that regulates gene expression. Precise editing of DNA methylation has emerged as a promising tool for dissecting its biological function. However, challenges in delivery have limited most applications of DNA methylation editing to in vitro systems. Here, we develop two transgenic mouse lines harboring an inducible dCas9-DNMT3A or dCas9-TET1 editor to enable tissue-specific DNA methylation editing in vivo. We demonstrate that targeted methylation of the Psck9 promoter in the liver of dCas9-DNMT3A mice results in decreased Pcsk9 expression and a subsequent reduction in serum low-density lipoprotein cholesterol level. Targeted demethylation of the Mecp2 promoter in dCas9-TET1 mice reactivates Mecp2 expression from the inactive X chromosome and rescues neuronal nuclear size in Mecp2^+/- mice. Genome-wide sequencing analyses reveal minimal transcriptional off-targets, demonstrating the specificity of the system. These results demonstrate the feasibility and versatility of methylation editing, to functionally interrogate DNA methylation in vivo.