Faculty Bibliography

BACKGROUND:Carotid webs are increasingly recognized as a cause of ischemic stroke, but less is known about morphologically similar lesions in other arteries. We present the first study characterizing the clinical and radiographic features of extra-carotid arterial webs through a single-center case series and systematic review. METHODS:Patients with possible extra-carotid webs were identified from 2017 to 2025 using a natural language processing search of radiology reports at our institution. Candidate cases underwent imaging review with multiplanar and 3-dimensional reconstructions to distinguish webs from fenestrations, vessel tortuosity, dissection, or atherosclerotic plaque. In parallel, we performed a Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review (Web of Science and PubMed, inception to September 2025) to identify published cases of extra-carotid web. Data on demographics, vascular location, imaging modality, clinical presentation, treatment, and outcomes were extracted and synthesized descriptively. RESULTS:Four extra-carotid webs were identified at our institution (3 basilar and 1 subclavian). None were associated with stroke, and all patients remained stable on conservative management during 9 months to 4 years of follow-up. Across 16 published studies, 22 additional extra-carotid webs were identified, yielding 26 patients in aggregate (mean age, 52.7 years; 61.5% male). The vertebral artery was the most common site (53.8%), followed by the basilar (30.8%) and subclavian (15.4%) arteries. Ten patients with vertebral or basilar web presented with posterior circulation ischemic stroke, with recurrent events in 4 patients. Most patients were managed with antiplatelet therapy or observation, while 3 vertebral webs with recurrent stroke were successfully treated with stenting. CONCLUSIONS:Extra-carotid webs share morphological and clinical features with carotid webs and may represent a unified disease spectrum of cervical artery webs. Vertebral and basilar webs, though rare, may be an underrecognized source of posterior circulation stroke. Recognition of these lesions may broaden the differential for cryptogenic stroke though the lack of histopathologic visualization remains a critical limitation of our study.

INTRODUCTION/BACKGROUND:Measuring plasma biomarkers effectively assesses early-stage Alzheimer's disease. METHODS:Subjects were categorized as cognitively unimpaired (CU) (n = 66), CU with subjective cognitive decline (SCD) (n = 100), and mild cognitive impairment (MCI) (n = 25). Plasma biomarkers measured were amyloid beta (Aβ) 40, Aβ42, neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), tau phosphorylated at threonine 181 (pTau181), neuroinflammatory biomarkers, and blood-brain barrier biomarkers. Amyloid and tau positron emission tomography (PET) imaging was performed in 186 and 144 subjects, respectively. RESULTS:Comparing those having MCI, both CU and SCD participants had significantly lower amyloid PET standardized uptake value ratio (SUVR) (p < 0.001; p = 0.005). Higher amyloid PET SUVR was significantly associated with higher pTau181 (p = 0.001) and a higher pTau181/Aβ42 ratio (p < 0.001). Higher tau PET SUVR was associated with lower plasma Aβ42 (p = 0.020), older age (p = 0.005), higher GFAP (p = 0.020), and lower interleukin-8 levels (p < 0.001). DISCUSSION/CONCLUSIONS:Our study supports plasma biomarker monitoring of at-risk patients at various stages of pre-dementia.

Seizure frequency has been the primary endpoint in epilepsy trials, with enrollment usually requiring ≥4 seizures per month. This threshold is more and more misaligned with clinical reality, as the availability of more treatment options has reduced baseline seizure burden, with a risk of excluding a proportion of patients from trials. Although cognitive and developmental outcomes are gaining prominence, seizure control remains essential due to its impact on morbidity and mortality. We have tools to study all types of seizure frequency: Time-to-event designs, including time-to-pre-randomization seizure count or time to the Nth seizure, offer a validated alternative by enabling inclusion across a wider range of seizure frequencies while maintaining methodological rigor. Future trial designs should study cognitive outcomes, while studies focusing on anti-seizure efficacy remain critical.

BACKGROUND:Carotid webs are increasingly recognized as a significant cause of cryptogenic stroke in young adults, yet they remain frequently underdiagnosed due to their subtle radiographic appearance and atypical presentations. The natural history of untreated carotid webs includes high rates of recurrent ipsilateral ischemic events despite optimal medical therapy. OBSERVATIONS/METHODS:The authors present the case of a 44-year-old man with four recurrent right hemispheric ischemic events over 5 years. Despite multiple angiographic studies, an underlying carotid web was initially misinterpreted. Digital subtraction angiography ultimately revealed a subtle posterolateral carotid web. Prior to endarterectomy, intraoperative ultrasound uniquely visualized a large thrombus adherent to the web, a critical finding not appreciated on preoperative angiography. Successful en bloc removal of the web and thrombus was performed with histopathological confirmation. The patient remained stroke free at the 1-year follow-up. LESSONS/CONCLUSIONS:Atypical carotid webs may lack classic radiographic features and can be misclassified on noninvasive imaging. Intraoperative ultrasound provides real-time assessment of thrombus burden not visible on preoperative angiography, allowing for improved surgical planning. This case demonstrates that web-associated thrombi are dynamic and may not be apparent even on high-resolution angiography performed shortly before surgery. Surgical intervention with intraoperative ultrasound guidance offers definitive treatment and excellent long-term outcomes. https://thejns.org/doi/10.3171/CASE2610.

INTRODUCTION/BACKGROUND:Progression Independent of Relapse Activity (PIRA) is a critical measure of disability progression in multiple sclerosis (MS) independent of relapses but lacks a standardized definition. Current reliance on the Expanded Disability Status Scale (EDSS) limits sensitivity to non-motor domains, necessitating a stratified framework to enhance detection and guide management. OBJECTIVES/OBJECTIVE:To develop a novel seven-level stratified PIRA definition and assess its validity, enhanced sensitivity, clinical relevance, and feasibility through expert consensus, and propose a simplified framework based on feedback. METHODS:A two-stage study: (1) A four-expert panel developed a seven-level PIRA framework (PIRA 1: EDSS-based; PIRA 2: EDSS-plus measures; PIRA 3: stress tests; PIRA 4: patient-reported outcomes [PROs]; PIRA 5: conventional MRI; PIRA 6: advanced MRI; PIRA 7: biomarkers) via literature synthesis. (2) A survey of 90 MS experts (26 responded, 28.9%) from nine countries evaluated each level's validity, sensitivity (vs. EDSS), relevance, and feasibility (1-5 scale), with open-ended comments on barriers and suggestions. High agreement was defined as a score ≥ 4. Qualitative feedback on barriers and improvement suggestions was thematically analyzed. RESULTS:Strong support (24/26; 92.3%) endorsed a stratified PIRA definition. Respondents included primarily clinician-researchers (22/26; 84.6%), with 11/26 (42.3%) reporting more than 20 years of MS experience. High agreement for validity ranged from 15/26 (57.7%) for PIRA 1-23/26 (88.5%) for PIRA 6. Agreement regarding enhanced sensitivity was highest for PIRA 2 (25/26; 96.2%), followed by PIRA 6 (22/26; 84.6%) and PIRA 5 (19/26; 73.1%). Clinical relevance was rated highly for PIRA 1, PIRA 2, and PIRA 6 (each 25/26; 96.2%). Feasibility was highest for PIRA 1 (24/26; 92.3%) and declined for higher levels, particularly PIRA 7. Barriers included inter-rater variability (PIRA 1, 30.8%), subjectivity (PIRA 4, 23.1%), and cost/expertise (PIRA 6-7, 26.9% each). Suggestions included digital tools (PIRA 2-3), AI for MRI (PIRA 5-6), biomarker validation (PIRA 7), and combining PIRA 5-6. PIRA 1-2 were preferred for clinical practice, PIRA 5-7 for research. A three-tier framework was proposed: Probable PIRA (clinical), Definite PIRA (clinical + MRI), and Definite PIRA Plus (clinical + MRI + biomarkers). CONCLUSIONS:The proposed seven-level PIRA framework demonstrates strong expert support for its conceptual validity and clinical relevance but highlights feasibility challenges for advanced assessments. A simplified three-tier model may provide a practical structure for standardized evaluation of relapse-independent progression in MS. Further empirical validation in diverse clinical cohorts is required.

Human pluripotent stem cells (hPSCs) are a valuable tool for disease modeling. Further stem cells can be reprogrammed from adult somatic cells, called induced pluripotent stem cells (iPSC). iPSC technology allows for the evaluation of specific study participants and populations and ventures into personalized medicine. Blood is routinely taken and cryopreserved for research purposes. These samples are processed either as buffy coats, a blood sample containing white blood cells and platelets, or as peripheral blood mononuclear cells (PBMCs), which represent a more purified population of white blood cells without eosinophils, basophils, platelets, or red blood cells. Both are a readily available and relatively non-invasive source for reprogrammable somatic cells. Several reports detail reprogramming from PBMCs, whereas only one describes this process from frozen buffy coats. Recent experience revealed PBMC reprogramming protocols available in the literature and from manufacturers to be unsuccessful when applied to frozen buffy coat samples, necessitating the adaptations and troubleshooting strategies described here. For many researchers, who employ iPSC technologies, it is imperative to have thorough protocols with a high success rate, especially in cases, where patient samples may contain only few cells, are obtained in wide time intervals, are from limited participant pool, or are otherwise highly valuable. Here, checkpoints and troubleshooting strategies are identified to increase the chance of reprogramming human frozen buffy coats or purified PBMCs. Ultimately, this protocol will allow researchers to identify predictors of reprogramming success and strategize alternative approaches to improve the chances of successful iPSC derivation.

IMPORTANCE/UNASSIGNED:Seizure-induced brain injury is central to the treatment urgency of new-onset refractory status epilepticus (NORSE). Identifying biomarkers that reflect ongoing neuronal damage could inform therapeutic timing and improve outcomes. OBJECTIVE/UNASSIGNED:To quantify acute brain injury in patients with cryptogenic NORSE (cNORSE), etiology-defined status epilepticus (eSE), and chronic epilepsy. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:This was an international cross-sectional study conducted between 2013 and 2025. Patients were enrolled at 36 hospitals in the US, 2 in Canada, and 1 in Italy, France, and Belgium. Patients with cNORSE and eSE for which biological samples were obtained during ongoing seizure activity were enrolled in the study. Comparison groups without status epilepticus comprised individuals with chronic epilepsy and healthy participants. None were excluded. EXPOSURES/UNASSIGNED:Neurofilament light chain (NfL) and S100-beta (S100B) protein concentrations in serum and cerebrospinal fluid (CSF). MAIN OUTCOMES AND MEASURES/UNASSIGNED:Degree of neuronal and glial damage, indexed by NfL and S100B levels, and their association with short-term functional outcomes. RESULTS/UNASSIGNED:A total of 78 patients with cNORSE (mean [95% CI] age, 37 [30-41] years; 44 female [56%]) and 2 independent cohorts of 211 patients (mean [95% CI] age, 69 [66-71] years; 128 female [61%]) and 73 patients (mean [95% CI] age, 56 [45-65] years; 39 male [53%]) with eSE were included. NfL concentrations were markedly elevated in cNORSE-approximately 10-fold higher in CSF and 4-fold higher in serum-compared with the eSE cohorts (CSF: median [IQR], 6408 [1503-22 963] pg/mL compared with 694 [219-2389] pg/mL; serum: median [IQR], 231 [99-855] pg/mL compared with 55 [20-135] pg/mL; P <.001). Serum NfL levels were nearly 20-fold higher in cNORSE than in the cohort with epilepsy and in healthy controls (median [IQR], 11 [7-19 ] and 7 [5-14 ] pg/mL, respectively). Serum and CSF NfL levels were strongly correlated (Spearman ρ = 0.75; P < .001) and rose sharply between week 1 (median [IQR], 101 [51-137] pg/mL), week 2 (median [IQR], 197 [117-324] pg/mL), and week 3 (median [IQR], 598 [163-1000] pg/mL) after onset (P < .001). In contrast, S100B concentrations did not differ between groups and showed no consistent temporal pattern. NfL discriminated cNORSE from eSE (area under the receiver operating characteristic curve [AUROC], 0.79; 95% CI, 0.68-0.90) and from cohorts without status epilepticus (AUROC, 0.99; 95% CI, 0.78-1.00). Higher serum NfL was independently associated with poor functional outcome at discharge (Glasgow Outcome Scale extended score, 1-4; odds ratio, 1.01; 95% CI, 1.00-1.03; P = .03). CONCLUSIONS AND RELEVANCE/UNASSIGNED:Results of this cross-sectional study suggest that acute neuroaxonal injury, as reflected by elevated NfL levels, was substantially greater in cNORSE than in the cohorts with eSE and in controls without status epilepticus. The rapid early rise in NfL highlights a narrow therapeutic window, emphasizing the need for prompt, effective, and potentially neuroprotective interventions in cNORSE.

Caspase 5 (CASP5) is a member of the inflammatory caspase family of cysteine proteases that is involved in inflammation and cell death^1-3. CASP5 shares the highest homology with inflammatory CASP4, but whereas CASP4 is essential for noncanonical inflammasome activation, CASP5 is dispensable^4-6, and its function remains unknown. Here we show that CASP5 is restricted to the human intestinal epithelium and manifests as three isoforms-CASP5A, CASP5B and CASP5C-among which CASP5C uniquely promotes Wnt signalling, which is essential for epithelial development and regeneration⁷. We identified dishevelled, which bridges Wnt receptors to the β-catenin destruction complex⁸, as a prominent CASP5 binding partner in colonic epithelial cells. Dishevelled interacts with the CASP5 catalytic domain through its DEP (dishevelled, EGL-10 and pleckstrin) domain. Lacking the inhibitory caspase activation and recruitment domain (CARD) of CASP5A and CASP5B, CASP5C cleaves the central scaffold protein APC at Asp556 in the Armadillo repeat domain, destabilizing the β-catenin destruction complex and thereby enhancing Wnt signalling. CASP5C expression peaks in transit-amplifying cells, the Wnt-reliant progeny of intestinal stem cells⁷, whereas CASP5A and CASP5B predominate in mature enterocytes. Endogenous and ectopic CASP5C drive growth of colonic and small intestinal organoids, which is known to require proliferation of transit-amplifying cells⁹. Furthermore, CASP5C is selectively induced upon intestinal epithelial injury, and its expression is increased in inflammatory bowel disease. Thus, CASP5C is an enzymatic amplifier of Wnt signalling that cleaves APC to sustain proliferation of transit-amplifying cells amid a declining Wnt gradient, safeguarding epithelial renewal. These findings broaden the roles of inflammatory caspases beyond innate immunity, uncovering their contribution to tissue homeostasis.

Alzheimer's disease (AD) remains a major global health challenge, with prevalence projected to increase dramatically in the coming decades and no effective treatments available. Current therapies offer only symptomatic relief, reinforcing the need for disease-modifying strategies targeting underlying pathogenic mechanisms. Advances in understanding amyloid-β (Aβ) and tau pathology have propelled the development of targeted interventions, particularly monoclonal antibodies (mAbs) and small-molecule therapeutics. Recent anti-Aβ antibodies, such as aducanumab, lecanemab, and donanemab, have demonstrated significant biological activity and reductions in amyloid burden, leading to regulatory approvals that represent important proof-of-concept milestones. However, these therapies face ongoing controversies related to modest clinical efficacy, accessibility, cost, and safety concerns. In parallel, small-molecule development has expanded beyond failed secretase inhibitors toward more refined mechanisms, including tau aggregation inhibition, kinase modulation, mitochondrial stabilization, and anti-inflammatory pathways. These compounds offer advantages in oral administration, blood-brain barrier penetration, and multi-target engagement. Together, mAbs and small molecules represent complementary therapeutic strategies addressing different aspects of AD pathophysiology. Their integration with emerging biomarkers, genetic profiling, and early diagnostic frameworks is driving a transition toward personalized and stage-specific treatment approaches. This review synthesizes current mechanistic insights, clinical evidence, and translational challenges of both modalities, highlighting how their convergence may shape the next-generation of AD therapeutics.