Quiñones‐Hinojosa, Alfredo

BACKGROUND AND OBJECTIVES: Stroke has the largest proportion of the global burden of neurological disorders with projected mortality rates to increase more rapidly in low- and middle-income countries than in high-income countries, and people of African descent are at greater risk. To better understand the burden, risk factors, and care pathways, this study aimed to review the risk factors, clinical presentation, and outcomes of patients presenting with stroke or stroke-like symptoms in a tertiary hospital in Sierra Leone. METHODS: A retrospective chart review was conducted of all patients presenting with neurological or neurosurgical conditions from January 2019 through December 2023 and those with stroke or stroke-like symptoms were included in this study. RESULTS: One thousand two hundred ninety-seven patients were diagnosed with stroke. Of these, a small majority were male (712, 54.9%), and the mean age was 57.8 years. About a third (38.1%) of the stroke patients were aged 60 years and above, and 562 (43.3%) were between 41 and 60 years. A majority of stroke patients (68.6%) had a prior diagnosis of hypertension, while significantly fewer had a documented diagnosis of diabetes (8.8%) and 4.6% of patients had a known prior stroke. Only half (50.8%) with ordered computed tomography scan were able to complete the ordered imaging. From these imaging findings, 123 patients (9.6%) were diagnosed with hemorrhagic stroke, while the remainder were diagnosed with ischemic stroke or transient ischemic attack vs hypertensive urgency. 32.9% experienced in-hospital mortality, while only 6.5% followed up. CONCLUSION: This study documents the significant stroke burden in Sierra Leone, much of which is unaddressed due to lack of specialty resources including inadequate community engagement to raise awareness of risk factors and preventative measures. Poor health-seeking behavior and access to medical services also contribute to this burden. These data are imperative to identify systems gaps and help support ongoing capacity building efforts.

Abstract Glioma stem cells (GSCs) are considered a major driver of glioblastoma (GBM) progression and are highly resistant to standard cytotoxic treatments. BMP4 has been shown to promote GSC differentiation, enhance radiosensitivity, slow tumor growth, and extend survival in animal models. Despite this promise, BMP4 has yet to achieve clinical impact, owing largely to heterogeneous and nonlinear responses across preclinical experimental systems. To elucidate how BMP4 could function as an effective targeted differentiation therapy in GBM, we develop a mathematical model that describes the growth of a GBM tumor via a hierarchy of GSCs, progenitor and terminally differentiated cells. We parameterize our model using new radiotherapy and proliferation assay data (with and without BMP4 exposure) from twelve patient-derived GSC lines. This integration of model and data allows us, for the first time, to quantitatively capture patient-specific heterogeneity in BMP4 sensitivity. We perform global sensitivity analysis on the model, identifying proliferation rate and GSC self-renewal sensitivity as key determinants of BMP4 efficacy. These parameters act as model-derived biomarkers that distinguish BMP4-responsive tumors from non-responsive ones. In an in silico analysis across a broad cohort of virtual patients, we find that continuous BMP4 delivery from surgical resection through radiotherapy consistently outperforms a single-dose strategy. Virtual clinical trials further show that, without stratification using these model-derived biomarkers, BMP4 yields little observable therapeutic benefit. In contrast, selecting patients with more proliferative, BMP4-responsive GSCs markedly increases the likelihood of observing a significant treatment effect. Citation Format: Nicholas Harbour, Lee Curtin, Loizos Michaelides, Matthew E. Hubbard, Pamela Jackson, Vinitha Rani, Rajappa Kenchappa, Virginea Farias, Anna Carrano, Markus Owen, Alfredo Quinones-Hinojosa, Kristin Swanson. Virtual clinical trials of BMP4 differentiation therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6831.

Purpose: Subcortical functional brain mapping is a valuable technique, especially involving lesions within or near white matter tracts. Motor and language deficits caused by intraoperative damage to these subcortical fibers are associated with worse outcomes. However, there are variable approaches to performing subcortical functional brain mapping. This systematic review was performed to better understand indications and optimal stimulation parameters. Methods: A systematic review was performed by PRISMA guidelines, using PubMed, Scopus, and Medline databases. Search dates ranged from inception to November 30th, 2024. Studies included adults who underwent subcortical electrical stimulation for functional brain mapping. Results: A total of 55 articles (249 patients, mean age 44.8 years, 114 female) were included. The most common pathology was brain tumor (96.3%), primarily gliomas and metastases, and 24.4% of all cases had a history of epilepsy. The most frequently mapped white matter tracts were the arcuate fasciculus, corticospinal/pyramidal tract, and inferior fronto-occipital fasciculus, involving motor, language, and cognitive functions. Bipolar stimulation (50–60 Hz, 0.5–1 millisecond, 1–10 mA) was preferred over monopolar stimulation. Among 147 patients with outcome data, 89.1% did not suffer permanent adverse outcomes including neurologic deficits, although long-term outcomes were inconsistently reported. Conclusions: The methodologic variability of subcortical functional brain mapping and lack of long-term follow-up reported limits determination of optimal parameter selection for electrical stimulation although common trends are reported. Functional brain mapping approaches may be guided by the tract and network involved. Further studies are needed to develop a standardized approach and more definitive guideline to its performance.

Abstract High-grade gliomas (HGGs) are aggressive tumors with poor outcomes and limited treatment options. Here, we combined genomic and transcriptomic tumor profiling with drug testing in a patient-derived 3-dimensional culture model to identify individualized treatments and predictive biomarkers. Activity of single agents targeting frequently dysregulated glioma pathways was relatively poor ex vivo and generally reflected historical patient data. However, compounds targeting PI3K, epigenetic, and survival/senescence signaling were effective in some cases. Drug sensitivity correlated with transcriptional rather than genomic features and suggested heterogeneity as a resistance mechanism. Bromodomain and extraterminal domain inhibition was particularly effective in tumors enriched in the mesenchymal transcriptional subtype, promoted proneural transition, and was overcome by upregulated PI3K signaling. Notably, combinations were largely effective, with 6 strategies exhibiting stronger efficacy than corresponding single agents in most cases (58-77%). This study identifies HGG vulnerabilities and associated biomarkers, resistance mechanisms, and effective combination strategies that warrant further clinical validation. Graphical Abstract

BACKGROUND AND OBJECTIVES: Surgeon-team familiarity is a critical factor that affects surgical outcomes. The relationships between familiarity and surgical outcomes are varied, and an operational definition of this measure remains underdeveloped. This study creates an effective time-based measure of surgeon-team familiarity and assesses its association with clinical and operational outcomes for neurosurgery. METHODS: Retrospective analysis of 9049 neurosurgery cases performed at 2 campuses of a tertiary academic medical center over a 3-year timeframe was conducted. This study measures normalized case duration as a proxy for operational performance and 30-day postoperative complications for clinical outcomes. Multivariate linear regression and logistic regression were used to analyze relationships between surgeon-team familiarity and surgical outcomes, with risk factors as control variables for case mix. RESULTS: For normalized case duration, the coefficient of surgeon-team familiarity is negative (β = −0.015, P = .03), but the squared term exhibits a positive relationship (β = 0.049, P = .003). The overall regression is statistically significant ( R 2 = 0.046, adjusted R 2 = 0.045, P < .001). The logistic regression shows that surgeon-team familiarity scores are negatively correlated (odds ratio = 0.356, 95% CI [0.126, 0.987]) with the risks of postoperative complications. It is statistically significant and explains between 2.4% (Cox & Snell R Square) and 6.0% (Nagelkerke R Square) of the variance for postoperative complications. CONCLUSION: This study found that surgeon-team familiarity is positively associated with neurosurgery outcomes. Teams familiar with the surgeons will likely improve operational performance and reduce the risk of postoperative complications, whereas too much familiarity may lengthen the case duration. Surgical practice leaders can use electronic health record data to define appropriate familiarity scores and incorporate key metrics when developing surgical team assignments for optimal operating room performance.

OBJECTIVE The aim of this study was to compare 3 electrode designs—a novel 22-contact circular grid, standard 6-contact strip, and high-density (HD) grid between 32 and 64 contacts—for the detection of epileptiform activity during awake craniotomy. METHODS This study included patients who underwent functional brain mapping with and without direct electrical stimulation during awake craniotomy. Demographic, clinical, and electrocorticography (ECoG) data were collected. RESULTS A total of 194 patients were included, with 264 instances of electrode use: 113 circular grid, 96 strip electrode, and 55 HD grid. The HD grid (15%) was used less to record ECoG during direct electrical stimulation than the circular grid (80%, p < 0.001) and strip electrodes (69%, p < 0.001). Sporadic interictal epileptiform activity was better detected with circular (45%, p < 0.001) and HD (40%, p = 0.006) grids compared with strip electrodes (16%). Spontaneous seizures were recorded more frequently with the circular grid (16%, p = 0.018) compared with the strip electrode (9.4%) and HD grid (1.8%). Afterdischarges were more frequently detected by the circular grid (69%, p = 0.031) and with circular and HD grids (combined) compared with strip electrodes (67% vs 48%, p = 0.024), at lower median intensity (3 mA vs 5 mA, p < 0.001). Multivariable analyses demonstrated circular grids (p < 0.001) to be more sensitive in detecting spontaneous epileptiform activity than strip and HD grid electrodes, and grids (circular and HD) to be better in recording stimulus-induced epileptiform activity (p = 0.01). CONCLUSIONS This study demonstrates a higher rate of detection of epileptiform activity with circular and standard grids when compared with strip electrodes. The standard HD grid was used less during electrical stimulation, demonstrating the importance of both the number of contacts and design array when considering optimal conditions for ECoG and functional brain mapping.

Abstract NF2-related schwannomatosis is a genetic condition characterized by mutation in the NF2 gene resulting in tumor formation throughout the nervous system. The most common tumors in these patients include bilateral vestibular schwannomas and multiple meningiomas which, despite their benign classification, lead to significant neurologic deficits including hearing loss, ataxia, hydrocephalus, and brainstem compression. Loss of NF2, which encodes the protein Merlin, is also the most common mutation in spontaneous meningiomas and schwannomas. Current treatment consists of resection followed by radiation for more aggressive tumors. Unfortunately, these treatments are not curative and are associated with significant risk due to tumor location, involvement of neurovasculature, cognitive impairment, and radiation-induced tumor induction. Therefore, identifying additional therapeutics for these patients is critical. Molecular profiling across large cohorts of sporadic meningiomas have identified molecular signatures associated with NF2 mutation, indicating upregulation of Wnt5a/b and the alternative Wnt5a/b-YAP/TAZ signaling pathway. In NF2 knock-out human arachnoid and Schwann cells, we find a significant upregulation of YAP in NF2-null lines compared to controls. Additionally, when stimulated with Wnt5a/b, controls upregulate both beta catenin (canonical Wnt) and YAP (alternative Wnt). However, in NF2-null lines only YAP is increased, indicating a preference for the alternative pathway in the absence of canonical Wnt signaling. In primary NF2-mutant meningioma lines, targeting this pathway via blocking Wnt secretion with the inhibitor LGK974 or YAP signaling with verteporfin, which is FDA approved, results in decreased cell viability and proliferation in vitro. These results indicate activation of the Wnt5a/b-YAP/TAZ alternative signaling pathway in NF2-mutant meningeal and Schwann cells, and a potential therapeutic effect of blocking this pathway in NF2-mutant meningiomas with a previously-FDA approved inhibitor. Additional research is needed on the receptors and molecular mediators playing a role in this pathway and how these drugs may have therapeutic benefits in vivo

Abstract Background Glioblastoma (GBM) is the most common high-grade primary malignant brain tumor, characterized by a notably poor prognosis. Current treatments for GBM have shown limited effectiveness in improving patient survival, highlighting the urgent need for novel therapeutic strategies. Combination therapy offers significant potential in overcoming resistance by targeting multiple signaling pathways; however, it often comes with increased toxicity compared to monotherapy. Co-encapsulating multiple therapeutic agents into a tumor-targeted drug delivery platform holds promise for overcoming these limitations and improving treatment outcomes. Methods We developed a tumor-targeted liposomal nanoformulation (TTL) using phospholipids, cholesterol, DSPE-(PEG)2000-OMe, and a proprietary tumor-targeting peptide (TTP). The TTL was loaded with everolimus (TTL-E), vinorelbine (TTL-V), rapamycin (TTL-R), a combination (TTL-EV), or (TTL-RV). These formulations were tested in vivo on orthotopic GBM mice, combined with temozolomide and radiation. RNA sequencing was performed to identify molecular and transcriptome changes post-treatment. Results TTL demonstrated tumor-specific uptake, effectively delivering drugs to GBM tumors. TTL-EV and TTL-RV outperformed single-drug formulations. Radiation combined with TTL-EV/RV improved tumor growth inhibition and survival, while temozolomide provided minimal benefit. Transcriptome analysis revealed differentially expressed genes (DEGs) linked to DNA damage repair, cell cycle, metabolism, and extracellular matrix pathways. Conclusion TTL crossed the blood-brain barrier, targeting tumors effectively. Radiation plus TTL-EV/RV enhanced tumor suppression and survival in GBM models. Gene expression analysis identified DEGs related to DNA damage and cell death. Mechanistic studies suggest TTL-EV plus radiation inhibits mTOR/MAPK pathways and sensitizes tumors to radiation. These findings offer a potential approach for improving GBM treatment.

Background: Progressive heart failure cardiogenic shock (HFCS) often requires escalation to temporary or durable mechanical circulatory support (MCS) as a bridge to transplant (BTT). Following the 2018 UNOS allocation changes, our center revised its BTT strategy to optimize support and shorten wait times. At our institution, the Impella 5.5 with SmartAssist via the axillary approach was selectively used for patients who remained refractory to guideline-directed medical therapy, failed single-inotrope therapy, and were not considered suitable durable LVAD candidates by our multidisciplinary heart team. We compared transplant-related outcomes of BTT patients supported with Impella 5.5 versus durable LVAD. Methods: We performed a single-center retrospective review of all heart and heart/kidney transplant candidates at Mayo Clinic Florida from October 2018 to February 2021. INTERMACS profile, baseline characteristics, and perioperative data were collected at the time of device implantation and throughout the transplant hospitalization. Results: A total of 87 heart and 4 heart–kidney transplants were completed. Forty-five patients (49%) required MCS as BTT: 27 (60%) with a durable LVAD and 18 (40%) with an Impella 5.5. All eighteen patients with Impella 5.5 as BTT (100%) were transplanted compared to nineteen patients with durable LVAD (70%), p = 0.001. The median time from listing to transplant was substantially shorter with Impella (32 vs. 696 days, p < 0.001), and this difference persisted across INTERMACS profiles. UNOS status at transplant was more urgent for Impella than LVAD (p < 0.001). Transplant surgery following Impella support required shorter cardiopulmonary bypass time (181 vs. 219 min, p < 0.001) and resulted in lower postoperative vasoactive-inotropic requirements (7.9 vs. 13, p = 0.003). No patients in the Impella group died or were delisted while awaiting transplant, whereas 5 LVAD patients (26%) died or were removed due to LVAD complications (p < 0.001). Conclusions: Our data demonstrates that the use of the Impella 5.5 as BTT was associated with significantly shorter waitlist time, higher transplantation rates, reduced perioperative morbidity, and lower postoperative vasoactive support compared with durable LVAD as BTT. These benefits were achieved despite a higher severity of illness at transplantation in the Impella cohort.

Abstract Intravital microscopy enables dynamic and real‐time visualisation of microscopic structures in living tissues without the need for fixation, with real‐life applicability being illustrated by several first‐in‐human studies in different cancers. Its use in preclinical models has yielded important observations of the microvasculature of both healthy and diseased tissues. It has further enabled the observation of the interactions between important components of the tissue microenvironment such as immune cells and neighbouring microvessels. Important recent technological advances, however, have enabled the translation of this technology to human use. Here, we review the main advances in intravital microscopy and some of the most recent uses in different human disease settings.