Faculty Bibliography

A transient ischemic attack is an acute neurologic event caused by focal ischemia affecting the brain, eye, or spinal cord, resolving quickly without infarction on magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI). It is a tissue-based diagnosis, highlighting the need for prompt recognition and risk stratification. Evaluation in the emergency department includes detailed history, risk assessment, neurologic examination, and initial noncontrast computed tomography (CT) to rule out other conditions, with MRI DWI as the gold standard for confirming no infarction. Vascular imaging, echocardiography, electrocardiogram (ECG), and laboratories help identify underlying causes. Central retinal artery occlusion (CRAO) requires urgent diagnosis and ophthalmology consultation to prevent permanent vision loss.

We report a case of an 83-year-old female patient who presented with binocular diplopia associated with left periorbital pain. She was diagnosed with a left pupil-involving third nerve palsy initially believed to be either microvascular or aneurysmal. However, negative vascular neuroimaging and further serologic workup suggested the possibility of neurosyphilis. Her clinical course was significant for persistent periorbital pain and a new seventh nerve palsy, despite syphilis treatment, prompting repeat neuroimaging and lumbar puncture. This case highlights the importance of the clinical history, imaging, CSF studies, and repeated workup in distinguishing between infectious and noninfectious causes of cranial neuropathies.

It is well recognized that many pandemic viruses are associated with neurologic complications, most recently with COVID-19. After the outbreak of the COVID-19 pandemic, neurologic surveillance platforms were implemented to characterize the complications of COVID-19. Surveillance platforms are invaluable in providing timely data, informing clinical practice, and directing future research. Lessons learned from recent neurologic surveillance networks include the importance of global and cross-specialty collaboration. It is critical for future surveillance systems to consider these aspects, as it will also serve to improve representation of low and middle-income countries (LMICs) and communities. Trainees played a critical role in the success of neurologic surveillance networks; as frontline health care workers, they were able to provide timely data collection, and their fresh insights are important for future pandemic surveillance system development. In this article, we review the methods of recent neurologic surveillance networks and discuss their strengths and limitations. We explore the outlook for pandemic surveillance platforms and the crucial role global collaboration plays in ensuring that LMICs are represented. We review the role of trainees in pandemic surveillance networks and discuss how it is vital to encourage their continued involvement to ensure that, as future health care leaders, they are prepared to manage future pandemics effectively.

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.

OBJECTIVE:Encephalitis is brain parenchyma inflammation, frequently resulting in seizures which worsens outcomes. Early anti-seizure medication could improve outcomes but requires identifying patients at greatest risk of acute seizures. The SEIZURE (SEIZUre Risk in Encephalitis) score was developed in UK cohorts to stratify patients by acute seizure risk. A 'basic score' used Glasgow Coma Scale (GCS), fever and age; the 'advanced score' added aetiology. This study aimed to evaluate the score internationally to determine its global applicability. DESIGN/METHODS:Patients were retrospectively analysed regionally, and by country, in this international evaluation study. Univariate analysis was conducted between patients who did and did not have inpatient seizures, followed by multivariable logistic regression, hierarchical clustering and analysis of the area under the receiver operating curves (AUROC) with 95% CIs. PARTICIPANTS AND SETTING/METHODS:2032 patients across 13 countries were identified, among whom 1324 were included in SEIZURE score calculations and 970 were included in regression modelling. The involved countries comprised 19 organisations spanning all WHO regions. OUTCOME MEASURES/METHODS:The primary outcome was measuring inpatient seizure rates. RESULTS:Autoantibody-associated encephalitis, low GCS and presenting with a seizure were frequently associated with inpatient seizures; fever showed no association. Globally, the score had limited discriminatory ability (basic AUROC 0.58 (95% CI 0.55 to 0.62), advanced AUROC 0.63 (95% CI 0.60 to 0.66)). The scoring system performed acceptably in western Europe, excluding Spain, with the best performance in Portugal (basic AUROC 0.82 (95% CI 0.69 to 0.94), advanced AUROC 0.83 (95% CI 0.72 to 0.95)). CONCLUSIONS:The SEIZURE score performed best in several countries in Western Europe but performed poorly elsewhere, partly due to differing and unknown aetiologies. In most regions, the score did not reach a threshold to be clinically useful. The Western European results could aid in designing clinical trials assessing primary anti-seizure prophylaxis in encephalitis following further prospective trials. Beyond Western Europe, there is a need for tailored, localised scoring systems and future large-scale prospective studies with optimised aetiological testing to accurately identify high-risk patients.

In eukaryotes, each ribosomal subunit includes a ribosomal protein (RP) that is encoded as a fusion protein with ubiquitin (Ub). In yeast, each Ub-RP fusion requires processing by deubiquitylating enzymes (DUBs) to generate ribosome assembly-competent RPs and contribute to the cellular Ub pool. However, how Ub-RP fusions are processed by DUBs in human cells remains unclear. Here, we discovered that Ub-RPs are substrates of the Ub-fusion degradation (UFD) pathway in human cells via lysine 29 and 48 (K29/K48)-specific ubiquitylation and proteasomal degradation. We identified a pool of DUBs that catalytically process Ub-RPs, as well as DUBs that physically occlude Ub-RP interaction with UFD pathway Ub E3 ligases to prevent their degradation in a non-catalytic manner. Our results suggest that DUBs both process and stabilize Ub-RPs, whereas the UFD pathway regulates levels of Ub-RPs that cannot be fully processed by DUBs to fine-tune protein homeostasis.