Citations

Abstract The epileptic network hypothesis and epileptogenic zone hypothesis are two theories of ictogenesis. The network hypothesis posits that coordinated activity among interconnected nodes produces seizures. The epileptogenic zone hypothesis posits that distinct regions are necessary and sufficient for seizure generation. High-frequency oscillations, and particularly fast ripples, are thought to be biomarkers of the epileptogenic zone. We sought to test these theories by comparing high-frequency oscillation rates and networks in surgical responders and non-responders, with no appreciable change in seizure frequency or severity, within a retrospective cohort of 48 patients implanted with stereo-EEG electrodes. We recorded inter-ictal activity during non-rapid eye movement sleep and semi-automatically detected and quantified high-frequency oscillations. Each electrode contact was localized in normalized coordinates. We found that the accuracy of seizure onset zone electrode contact classification using high-frequency oscillation rates was not significantly different in surgical responders and non-responders, suggesting that in non-responders the epileptogenic zone partially encompassed the seizure onset zone(s) (P > 0.05). We also found that in the responders, fast ripple on oscillations exhibited a higher spectral content in the seizure onset zone compared with the non-seizure onset zone (P < 1 × 10−5). By contrast, in the non-responders, fast ripple had a lower spectral content in the seizure onset zone (P < 1 × 10−5). We constructed two different networks of fast ripple with a spectral content >350 Hz. The first was a rate–distance network that multiplied the Euclidian distance between fast ripple-generating contacts by the average rate of fast ripple in the two contacts. The radius of the rate–distance network, which excluded seizure onset zone nodes, discriminated non-responders, including patients not offered resection or responsive neurostimulation due to diffuse multifocal onsets, with an accuracy of 0.77 [95% confidence interval (CI) 0.56–0.98]. The second fast ripple network was constructed using the mutual information between the timing of the events to measure functional connectivity. For most non-responders, this network had a longer characteristic path length, lower mean local efficiency in the non-seizure onset zone, and a higher nodal strength among non-seizure onset zone nodes relative to seizure onset zone nodes. The graphical theoretical measures from the rate–distance and mutual information networks of 22 non- responsive neurostimulation treated patients was used to train a support vector machine, which when tested on 13 distinct patients classified non-responders with an accuracy of 0.92 (95% CI 0.75–1). These results indicate patients who do not respond to surgery or those not selected for resection or responsive neurostimulation can be explained by the epileptic network hypothesis that is a decentralized network consisting of widely distributed, hyperexcitable fast ripple-generating nodes.

Abstract Objective Anterior temporal lobectomy (ATL) is a widely performed and successful intervention for drug‐resistant temporal lobe epilepsy (TLE). However, up to one third of patients experience seizure recurrence within 1 year after ATL. Despite the extensive literature on presurgical electroencephalography (EEG) and magnetic resonance imaging (MRI) abnormalities to prognosticate seizure freedom following ATL, the value of quantitative analysis of visually reviewed normal interictal EEG in such prognostication remains unclear. In this retrospective multicenter study, we investigate whether machine learning analysis of normal interictal scalp EEG studies can inform the prediction of postoperative seizure freedom outcomes in patients who have undergone ATL. Methods We analyzed normal presurgical scalp EEG recordings from 41 Mayo Clinic (MC) and 23 Cleveland Clinic (CC) patients. We used an unbiased automated algorithm to extract eyes closed awake epochs from scalp EEG studies that were free of any epileptiform activity and then extracted spectral EEG features representing (a) spectral power and (b) interhemispheric spectral coherence in frequencies between 1 and 25 Hz across several brain regions. We analyzed the differences between the seizure‐free and non–seizure‐free patients and employed a Naïve Bayes classifier using multiple spectral features to predict surgery outcomes. We trained the classifier using a leave‐one‐patient‐out cross‐validation scheme within the MC data set and then tested using the out‐of‐sample CC data set. Finally, we compared the predictive performance of normal scalp EEG‐derived features against MRI abnormalities. Results We found that several spectral power and coherence features showed significant differences correlated with surgical outcomes and that they were most pronounced in the 10–25 Hz range. The Naïve Bayes classification based on those features predicted 1‐year seizure freedom following ATL with area under the curve (AUC) values of 0.78 and 0.76 for the MC and CC data sets, respectively. Subsequent analyses revealed that (a) interhemispheric spectral coherence features in the 10–25 Hz range provided better predictability than other combinations and (b) normal scalp EEG‐derived features provided superior and potentially distinct predictive value when compared with MRI abnormalities (>10% higher F1 score). Significance These results support that quantitative analysis of even a normal presurgical scalp EEG may help prognosticate seizure freedom following ATL in patients with drug‐resistant TLE. Although the mechanism for this result is not known, the scalp EEG spectral and coherence properties predicting seizure freedom may represent activity arising from the neocortex or the networks responsible for temporal lobe seizure generation within vs outside the margins of an ATL.

ObjectiveThe aim of this study was to determine whether selection of treatment for children with infantile spasms (IS) varies by race/ethnicity.MethodsThe prospective US National Infantile Spasms Consortium database includes children with IS treated from 2012 to 2018. We examined the relationship between race/ethnicity and receipt of standard IS therapy (prednisolone, adrenocorticotropic hormone, vigabatrin), adjusting for demographic and clinical variables using logistic regression. Our primary outcome was treatment course, which considered therapy prescribed for the first and, when needed, the second IS treatment together.ResultsOf 555 children, 324 (58%) were non‐Hispanic white, 55 (10%) non‐Hispanic Black, 24 (4%) non‐Hispanic Asian, 80 (14%) Hispanic, and 72 (13%) other/unknown. Most (398, 72%) received a standard treatment course. Insurance type, geographic location, history of prematurity, prior seizures, developmental delay or regression, abnormal head circumference, hypsarrhythmia, and IS etiologies were associated with standard therapy. In adjusted models, non‐Hispanic Black children had lower odds of receiving a standard treatment course compared with non‐Hispanic white children (odds ratio [OR], 0.42; 95% confidence interval [CI], 0.20–0.89; p = 0.02). Adjusted models also showed that children with public (vs. private) insurance had lower odds of receiving standard therapy for treatment 1 (OR, 0.42; CI, 0.21–0.84; p = 0.01).InterpretationNon‐Hispanic Black children were more often treated with non‐standard IS therapies than non‐Hispanic white children. Likewise, children with public (vs. private) insurance were less likely to receive standard therapies. Investigating drivers of inequities, and understanding the impact of racism on treatment decisions, are critical next steps to improve care for patients with IS. ANN NEUROL 2022;92:32–44

AbstractMicroglia have fundamental roles in health and disease; however, effects of age, sex, and genetic factors on human microglia have not been fully explored. We applied bulk and single‐cell approaches to comprehensively characterize human microglia transcriptomes and their associations with age, sex, and APOE. We identified a novel microglial signature, characterized its expression in bulk tissue and single‐cell microglia transcriptomes. We discovered microglial co‐expression network modules associated with age, sex, and APOE‐ε4 that are enriched for lipid and carbohydrate metabolism genes. Integrated analyses of modules with single‐cell transcriptomes revealed significant overlap between age‐associated module genes and both pro‐inflammatory and disease‐associated microglial clusters. These modules and clusters harbor known neurodegenerative disease genes including APOE, PLCG2, and BIN1. Meta‐analyses with published bulk and single‐cell microglial datasets further supported our findings. Thus, these data represent a well‐characterized human microglial transcriptome resource and highlight age, sex, and APOE‐related microglial immunometabolism perturbations with potential relevance in neurodegeneration.

Human genetic studies support an inverse causal relationship between leukocyte telomere length (LTL) and coronary artery disease (CAD), but directionally mixed effects for LTL and diverse malignancies. Clonal hematopoiesis of indeterminate potential (CHIP), characterized by expansion of hematopoietic cells bearing leukemogenic mutations, predisposes both hematologic malignancy and CAD. TERT (which encodes telomerase reverse transcriptase) is the most significantly associated germline locus for CHIP in genome-wide association studies. Here, we investigated the relationship between CHIP, LTL, and CAD in the Trans-Omics for Precision Medicine (TOPMed) program ( n = 63,302) and UK Biobank ( n = 47,080). Bidirectional Mendelian randomization studies were consistent with longer genetically imputed LTL increasing propensity to develop CHIP, but CHIP then, in turn, hastens to shorten measured LTL (mLTL). We also demonstrated evidence of modest mediation between CHIP and CAD by mLTL. Our data promote an understanding of potential causal relationships across CHIP and LTL toward prevention of CAD.

Abstract Background The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O). Methods Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence‐based review, or evidence‐based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus. Results The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies. Conclusion This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

AbstractFrontline arsenic trioxide (ATO)–based treatment regimens achieve high rates of long-term relapse-free survival in treating acute promyelocytic leukemia (APL) and form the current standard of care. Refining prognostic estimates for newly diagnosed patients treated with ATO-containing regimens remains important in continuing to improve outcomes and identify patients who achieve suboptimal outcomes. We performed a pooled analysis of exclusively ATO-treated patients at a single academic institution and from the ALLG APML4 and Alliance C9710 studies to determine the prognostic importance of additional cytogenetic abnormalities and/or complex karyotype. We demonstrated inferior event-free survival for patients harboring complex karyotype (hazard ratio [HR], 3.74; 95% confidence interval [CI], 1.63-8.56; P = .002), but not for patients harboring additional cytogenetic abnormalities (HR, 2.13; 95% CI, 0.78-5.82; P = .142). These data support a role for full karyotypic analysis of all patients with APL and indicate a need for novel treatment strategies to overcome the adverse effect of APL harboring complex karyotype.

Introduction: Obesity is common in heart failure with preserved ejection fraction (HFpEF) and is directly linked with lower levels of physical activity (PA). Visceral adiposity (VAT) is more common in HFpEF than controls and may play a role in its pathogenesis, characterized by impaired exercise capacity (peak VO 2 ). The direct relationship between VAT and PA in HFpEF is unknown. Hypothesis: Compared to controls, HFpEF patients will have excess regional adiposity (VAT, subcutaneous (SAT), and intramuscular (IMAT)), and these fat depots will be associated with lower levels of chronic physical activity. Methods: HFpEF patients (n=51; age 70±9) and non-HFpEF controls (n=49; age 65±5) prospectively underwent body composition measurement by dual-energy x-ray absorptiometry and magnetic resonance imaging. Peak VO 2 was measured by standard cardiopulmonary exercise testing. PA was monitored continuously via accelerometry over two weeks. Data were binned in arbitrary accelerometry units, averaged and stored in 30-second epochs (counts per epoch, CPE). Models were adjusted for age, sex, and ideal body weight. Results: HFpEF were less active overall (3.15±0.80 vs 3.59±0.73 CPE), had less moderate intensity PA (10.13±0.04 vs 10.15±0.03 CPE), and less morning (3.83±1.15 vs 4.24±1.09 CPE) and afternoon (3.84± 1.20 vs 4.53± 0.97 CPE) (p<0.05 for all) PA. Patients with HFpEF spent a greater proportion of time sedentary (0.71±0.08 vs 0.67±0.08 CPE) and less time in moderate (0.04±0.03 vs 0.06±0.03 CPE) and vigorous (0.02±0.01 vs 0.03±0.03 CPE) PA (p<0.01 for all). Chronic PA was significantly associated with regional fat depots (VAT β= -0.003, 95% CI: -0.004-0.001; SAT β= -0.003, 95%CI: -0.004-0.001; IMAT β=-0.02, 95% CI: -0.04—0.01) as a combined cohort (p<0.01 for all). Muscle quality (β=0.28, 95%CI: 0.15-0.40), peak VO 2 (β=0.08, 95% CI: 0.03-0.13), and peak watts (β=0.01, 95% CI: -0.004-0.02) were associated with PA in HFpEF only (p≤0.01 for all). Conclusions: The amount and pattern of PA differs between HFpEF and controls, as do relationships between regional fat depots and PA, and the relationship of PA and peak VO 2 . Further investigation is needed to better understand the temporality and mechanisms related to the pathophysiology and severity of HFpEF.

Introduction: Elevated lipoprotein(a) [Lp(a)] is associated with atherosclerotic cardiovascular disease (ASCVD), yet little is known about Lp(a) testing patterns in real-world practice. We hypothesized that Lp(a) testing occurs in a different population than calculated low density lipoprotein (LDL-C) testing alone, and that elevated Lp(a) is associated with greater lipid-lowering therapy (LLT) initiation and cardiovascular (CV) events. Methods: We used data from 11 health systems participating in the National Patient-Centered Clinical Research Network. We created two cohorts based on lab tests from Jan 1, 2015 to Dec 31, 2019: 1) the Lp(a) cohort, of adults with an Lp(a) test and 2) the LDL-C cohort, of 4:1 date- and site-matched adults with an LDL-C test, but no Lp(a) test. We used logistic regression to assess the relationship between Lp(a) levels (< 50, 50-100, and > 100mg/dL) and initiation of LLT within 3 months; and cox proportional hazards to evaluate Lp(a) levels and time to all-cause hospitalization and the composite of MI, revascularization and ischemic stroke hospitalization. Results: Overall, 20,551 patients (0.06% per year) had Lp(a) tests, with median Lp(a) value 17.5mg/dL (Q1, Q3: 7.0, 56.0). Compared with the LDL-C cohort (N=82,204), the Lp(a) cohort more frequently had ASCVD (24.3% vs. 8.5%) or multiple prior CV events (8.6% vs. 2.6%). Elevated Lp(a) was associated with greater odds of LLT initiation (Figure 1). Elevated Lp(a) was not significantly associated with all-cause hospitalization; however, Lp(a) > 100mg/dL was correlated with composite CV hospitalization compared with Lp(a) < 50mg/dL [adj HR (95% CI): 1.24 (1.06-1.44), p=0.006]. Conclusions: Lp(a) testing occurs more often in adults with ASCVD and multiple CV events, but testing is infrequent. Elevated Lp(a) was associated with LLT initiation, including niacin, despite lack of evidence of CV benefit. There was an association between elevated Lp(a) and CV hospitalization outcomes.

Although hypothermia has shown to protect against ischemic and traumatic neuronal death, its potential role in neurologic recovery following traumatic spinal cord injury (TSCI) remains incompletely understood. Herein, we systematically review the safety and efficacy of hypothermia therapy for TSCI. The English medical literature was reviewed using PRISMA guidelines to identify preclinical and clinical studies examining the safety and efficacy of hypothermia following TSCI. Fifty-seven articles met full-text review criteria, of which twenty-eight were included. The main outcomes of interest were neurological recovery and postoperative complications. Among the 24 preclinical studies, both systemic and local hypothermia significantly improved neurologic recovery. In aggregate, the 4 clinical studies enrolled 60 patients for treatment, with 35 receiving systemic hypothermia and 25 local hypothermia. The most frequent complications were respiratory in nature. No patients suffered neurologic deterioration because of hypothermia treatment. Rates of American Spinal Injury Association (AIS) grade conversion after systemic hypothermia (35.5%) were higher when compared to multiple SCI database control studies (26.1%). However, no statistical conclusions could be drawn regarding the efficacy of hypothermia in humans. These limited clinical trials show promise and suggest therapeutic hypothermia to be safe in TSCI patients, though its effect on neurological recovery remains unclear. The preclinical literature supports the efficacy of hypothermia after TSCI. Further clinical trials are warranted to conclusively determine the effects of hypothermia on neurological recovery as well as the ideal means of administration necessary for achieving efficacy in TSCI.