Citations

Treatment guidelines for Clostridioides difficile infection (CDI) have been published by infectious disease and gastroenterology professional societies; however, adherence in clinical practice remains poorly characterized, particularly for recurrent disease. We conducted a retrospective chart review of 100 patients with CDI (350 episodes: 115 initial, 235 recurrent) referred to a tertiary complicated CDI clinic between 2018 and 2023. Guideline adherence was assessed by comparing treatment with IDSA/SHEA and ACG recommendations, and referring diagnoses were compared with final specialist diagnoses. Guideline adherence was significantly higher in initial compared to recurrent episodes (70.4% vs. 41.3%, p < 0.0001). Among guideline non-adherent recurrent episodes, 51.3% used standard antibiotic regimens inappropriate for the recurrence tier. Specialist review reclassified 12.0% of episodes, with colonization increasing from 2.6% to 8.9%. Misdiagnosed colonization cases had a 6.2-fold higher treatment failure rate than confirmed CDI (39.3% vs. 6.3%, p < 0.0001). Guideline non-adherence showed a non-significant trend toward treatment failure (10.0% vs. 6.7%, p = 0.31). Guideline adherence for recurrent CDI is inadequate in pre-referral settings, and diagnostic misclassification is common. Early specialist involvement may improve both diagnostic accuracy and treatment appropriateness for patients with recurrent CDI.

OBJECTIVE Dural arteriovenous fistulas (dAVFs) are rare cerebrovascular anomalies. Tentorial dAVFs (TDAVFs) have more aggressive features, making them prone to symptomatic presentations and hemorrhage. TDAVFs are heterogenous and require tailored surgical approaches. Presented is a multicenter analysis of TDAVF surgical outcomes. METHODS The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) consortium compiled data on dAVFs from 16 international centers from 1990 to 2021 retrospectively. Microsurgical treatment success was defined as angiographically confirmed complete obliteration of the fistula or discontinuation of cortical venous drainage (CVD) in high-grade TDAVFs. TDAVF subtypes and tailored surgical approaches were reviewed. RESULTS Of 1360 patients in CONDOR, 161 had TDAVFs and 27% (44/161) of these patients underwent surgical management, with the majority (52% [23/44]) receiving surgery as a salvage treatment following failed embolization. The mean age (SD) of this cohort was 56 (15) years, and 68% (30/44) were male. In total, 91% (40/44) of surgically treated patients presented with aggressive symptoms: 64% (28/44) presented with hemorrhage and 27% (12/44) with nonhemorrhagic neurological deficit (NHND). The median (IQR) duration from symptom onset to diagnosis was 1 (1–4) day. The median time (IQR) between diagnosis and surgery was 15 (3–80) days. Surgical approaches varied across the cohort, with the retrosigmoid being the most common (44% [18/41]), followed by the midline suboccipital (24% [10/41]) and occipital (15% [6/41]) approaches. Perioperative complications occurred in 11% (5/44) of cases, as well as permanent neurological deficits in 2% (1/44). Surgical success was achieved in 90% of patients (38/42). During the mean 3-year follow-up, 2 patients experienced a recurrence of their fistula including representation of CVD (2/38 [5%]) and 1 patient had a new NHND (1/43 [2%]). Shorter symptom duration was significantly associated with success (15.6 vs 181.5 days, p = 0.001). Primary versus salvage microsurgery showed no difference in outcomes. Both patients with recurrent fistula were effectively treated with Gamma Knife radiosurgery. CONCLUSIONS Resection is safe and durable for the treatment of TDAVF not otherwise amenable to embolization. It can achieve a high degree of success with a low rate of perioperative complications and permanent neurological deficits, benefits far exceeding the risks associated with TDAVF natural history or management with less effective modalities.

OBJECTIVE Neuromuscular choristoma (NMC) is a rare developmental lesion that may give rise to desmoid-type fibromatosis (DTF) within the same nerve territory (NMC-DTF). While MRI features of NMC are well established, the natural history of progression to NMC-DTF has not been systematically described. This study aimed to define radiological groups from NMC to NMC-DTF using serial MRI and a literature review. METHODS Following IRB approval, the authors retrospectively analyzed 28 patients with NMC from their institutional database. Diagnosis was based on pathology or classic clinicoradiological features. Sequential MR images were reviewed to evaluate nerve enlargement, enhancement patterns, low T1/T2 foci, and NMC-DTF formation. Cases were classified into 3 radiological groups: 1) classic NMC with typical MRI features (group I), 2) NMC plus, with atypical features (foci of low T1/T2 signal intensity and/or at least moderate postcontrast enhancement; group II), and 3) NMC-DTF with a mass outside of the epineurium (group III). Data were correlated with pathology results and prior reports from the literature. RESULTS Of the 28 patients, 24 underwent serial MRI. Eleven patients presented with group I features, 4 with group II, and 9 with group III. Among group I patients with follow-up imaging, 4 (36.4%) progressed to group III over a mean of 6.2 years and 1 (9.1%) to group II. All 4 group II patients (100%) developed NMC-DTF within a mean of 3.0 years. All group III patients demonstrated NMC-DTF extending beyond the epineurium. No prior cases in the literature documented radiological progression from NMC to NMC-DTF on serial MR images. CONCLUSIONS The authors propose a framework for NMC progression based on radiological features, identifying group II as being high risk and a potential transitional phase for the formation of DTF. Structured surveillance with serial MRI is essential to prevent iatrogenic triggers and improve management strategies in patients with NMC.

OBJECTIVE Essential tremor (ET) is common and disabling in older adults. Many patients aged ≥ 80 years are ineligible for deep brain stimulation due to medical comorbidities. Data on noninvasive alternatives, such as MR-guided high-intensity focused ultrasound (MRgHIFU), remain limited in this population. The aim of this study was to evaluate the safety and efficacy of unilateral MRgHIFU thalamotomy targeting the ventral intermediate nucleus (VIM) for the treatment of ET in patients ≥ 80 years of age. METHODS This retrospective multicenter cohort study included consecutive patients aged ≥ 80 years with medically refractory ET treated with unilateral MRgHIFU VIM thalamotomy between 2016 and 2023 at five academic neurosurgical centers. All patients met skull density ratio criteria and underwent standardized targeting. Clinical assessments were conducted at baseline, immediately posttreatment, and at the 3-month follow-up. The primary outcome was change in tremor severity assessed by using the Tremor Research Group Essential Tremor Rating Assessment Scale (TETRAS). Secondary outcomes included the Clinical Rating Scale for Tremor (CRST) score, Dynamic Gait Index score, patient-reported tremor relief, and adverse events. RESULTS One hundred twenty-nine patients (76 male, mean age 84 years) were included. At 3 months, the mean TETRAS score improved by 9.2 points (p < 0.001). CRST scores also showed significant improvement. The mean patient-reported tremor relief was 81%. Adverse events were mild and transient, with a 1.6% rate of nonsurgical adverse events. Subgroup analysis comparing patients 80–84 years versus those ≥ 85 years of age showed no significant differences in treatment response. Gait outcomes improved modestly but were not significant in the age ≥ 85 years group. CONCLUSIONS Unilateral MRgHIFU thalamotomy is a safe and effective noninvasive treatment for ET in patients ≥ 80 years of age. It results in significant improvements in tremor and disability, with a low complication rate. These findings support its consideration for older patients who are ineligible for invasive procedures and highlight the importance of age-specific metrics in neuromodulation outcomes research.

Summary Longitudinal plasma cell-free DNA profiling from the phase 3 Alliance A031201 trial revealed divergent resistance trajectories in metastatic castration-resistant prostate cancer. Rapid progressors harbored non–androgen receptor (AR) alterations suggesting intrinsic resistance, whereas delayed progressors showed progressive AR amplifications, structural rearrangements, and extrachromosomal DNA–associated evolution. These findings support biomarker-guided strategies targeting AR-dependent and AR-independent disease states. See related article by Valentín López et al., p. 2413

Abstract Purpose: Immune checkpoint blockade (ICB) induces frequent and durable responses in metastatic deficient DNA mismatch repair (dMMR) colorectal cancer, yet substantial molecular heterogeneity and resistance remain. We sought to identify candidate tumor- and immune-related biomarkers associated with clinical outcomes following anti–PD-1 therapy. Experimental Design: Consecutive patients with metastatic dMMR colorectal cancer (N = 39) treated with anti–PD-1 therapy underwent tumor profiling using a validated immune-enhanced exome and transcriptome platform. Microsatellite instability (MSI) burden was quantified as the percentage of unstable microsatellite loci using MSIsensor-pro. Associations with objective response were evaluated, and progression-free survival (PFS) and overall survival (OS) were analyzed using Cox proportional hazards models. Results: Higher MSI burden was associated with improved objective response (P = 0.018) and survival. The dichotomized MSI level (Q2–4 vs. Q1) was associated with longer PFS [hazard ratio (HR), 0.18; 95% confidence interval (CI), 0.06–0.56; P = 0.003] and OS (HR, 0.20; 95% CI, 0.07–0.58; P = 0.003), with similar results when modeled continuously. MSI burden correlated with neoantigen clonality but not burden (R = 0.53, P = 0.01). Responders exhibited significantly greater T-cell receptor repertoire diversity; both T- and B-cell receptor diversities were associated with survival. Although human leukocyte antigen (HLA) A, HLA-B, and HLA-C expression was not prognostic, the HLA-B*07:02 allele was associated with the best overall response. In contrast, overexpression of immune exhaustion–related genes and cytotoxic T-cell and natural killer cell exhaustion phenotypes were associated with ICB resistance and poorer prognosis. Conclusions: Integrated exome/transcriptome profiling with MSI quantification identified MSI burden and adaptive immune repertoire diversity as potential correlates of response and survival following ICB. These findings suggest a mechanistic link among genomic instability, antigen recognition diversity, and immunotherapy benefit.

BACKGROUND AND OBJECTIVES: The prospective single-arm nonrandomized SCENT (Surpass Intracranial Aneurysm Embolization System Pivotal) trial on flow diverter treatment of large and giant intracranial aneurysms (IA) was analyzed for patients' age and IA characteristics affecting stroke and occlusion rates over 5 years (Trial registration NCT01716117). METHODS: Impact on major ipsilateral stroke and IA occlusion was studied by stratifying age as 65 years and younger vs older than 65. Kaplan–Meier estimates of time to both endpoints, stratified by age, were created. Univariate predictors of time-to-stroke were analyzed using univariable proportional hazards regression models. Limited bivariable modeling was also attempted. RESULTS: Of 180 patients with large or giant IA enrolled, 119 were 65 years and younger, whereas 61 were older than 65 years. The 3-year risk of stroke for the older than 65 years group (19.7%) was more than double that of the 65 years and younger group (9.2%), P = .047. No new strokes were reported between 3 and 5 years. Four patients (2.2%) experienced aneurysm rupture within the first week post-treatment, 3 being 65 years and younger and the fourth older than 65 (>.99). Complete IA occlusion within age strata at 1 year was: older than 65 60% (33/55), 65 years and younger 79.1% (87/110), P = .009, 3 years: older than 65 67.6% (25/37), 65 years and younger 82.5% (66/80), P = .071, and 5 years: older than 65 85.7% (18/21), 65 years and younger 91.8% (56/61), P = .417. CONCLUSION: Age older than 65 was associated with an increased risk of stroke and predictive of incomplete healing and increased time to healing.

Abstract Background Interpretation of multi-analyte laboratory profiles, such as lupus anticoagulant (LAC) testing, requires integration of numerous test results and clinical information. However, this process is time-consuming, requires domain knowledge, and has limited scalability. Given that rule-based systems are rigid and difficult to maintain and large language models pose risks of “hallucinations,” we developed and evaluated a novel retrieval-based approach to automate LAC profile interpretation to improve efficiency while maintaining fidelity and reliability for clinical use. Methods Our method processes laboratory values through ensemble random forest (RF) models to retrieve the most similar expert interpretation from a curated database of 347 previously interpreted LAC profiles. The system's performance was assessed through technical accuracy metrics, a work flow efficiency timing study, and expert review of interpretation accuracy for held-out cases. Results Technical validation demonstrated high accuracy in retrieving correct interpretative elements (median: 93% accuracy, interquartile range [IQR]: 67% to 100%). Retrieval accuracy was highly correlated with the prevalence of a given element (ρ = 0.8307). In a timing study of 93 consecutive LAC profiles, ensemble-assisted interpretation achieved a median time of 22 s per report (IQR: 16 s to 31 s), representing a 78.6% total reduction compared to manual interpretation (median: 118 s, IQR: 96 s to 172 s; t = 18.61, P &lt; 0.001). Furthermore, 92.5% of AI-assisted interpretations were completed within 60 s, exceeding the target of 85%. Expert review confirmed 100% concordance for LAC presence/absence. Conclusions The proposed approach significantly improves efficiency of complex laboratory interpretation for LAC profiles, while maintaining consistency and high fidelity. Future studies will explore the method’s inherent extensibility to the interpretation of other multi-analyte laboratory profiles.

ABSTRACT Extracellular vesicles (EVs) are non‐replicating, lipid membrane‐bound nanoparticles released by most eukaryotic cells into the extracellular space. When derived from platelets, a subset of EVs can exhibit remarkable anti‐inflammatory and antioxidant properties, making them attractive candidates to attenuate sterile inflammatory states such as limb skeletal muscle ischaemia‐reperfusion injury (IRI). Peripheral extremity IRI complicating acute limb revascularisation procedures, replantation of major traumatic amputations and limb allotransplants can trigger a life‐threatening reperfusion syndrome that leads to multi‐organ system failure and death. In this study, we used a platelet‐derived EVs‐enriched preparation as a therapeutic strategy for extremity IRI. To allow for a clinically translatable drug delivery strategy, we established and validated a catheter‐directed regional intra‐arterial limb infusion (RLI) delivery approach that permitted selective and effective targeting of pEVs to limb skeletal muscles and soft tissues in the vascularly isolated rodent extremity simulating pre‐reperfusion preservation and revascularisation conditions of the ischaemic or amputated extremity. In addition to being safe and feasible, we demonstrated robust retention of EVs by skeletal muscles of the operative limb during the early critical phase of reperfusion injury following RLI. We also show that pretreatment of ischaemic skeletal muscles using an pEVs‐enriched formulation just before reestablishing extremity blood flow alleviated metabolic derangements and suppressed the systemic and localised proinflammatory cytokine response associated with skeletal muscle reperfusion and reduced histologic markers of myofibre injury without adverse effects on serum chemistries. This work opens a new perspective to investigate novel approaches for regional delivery of therapeutic pEVs to skeletal muscle to mitigate limb IRI in vivo, and to achieve both in situ and ex vivo targeted delivery of nanocarriers to the isolated limb tissue for other therapeutic applications.