Thalamic epileptic spikes disrupt sleep spindles in patients with epileptic encephalopathy.

In severe epileptic encephalopathies, epileptic activity contributes to progressive cognitive dysfunction. Epileptic encephalopathies share the trait of spike-wave activation during non-rapid eye movement sleep (EE-SWAS), a sleep stage dominated by sleep spindles, brain oscillations known to coordinate offline memory consolidation. Epileptic activity has been proposed to hijack the circuits driving these thalamocortical oscillations, thereby contributing to cognitive impairment. Using a unique dataset of simultaneous human thalamic and cortical recordings in subjects with and without EE-SWAS, we provide evidence for epileptic spike interference of thalamic sleep spindle production in patients with EE-SWAS. First, we show that epileptic spikes and sleep spindles are both predicted by slow oscillations during stage two sleep (N2), but at different phases of the slow oscillation. Next, we demonstrate that sleep activated cortical epileptic spikes propagate to the thalamus (thalamic spike rate increases after a cortical spike, p≈0). We then show that epileptic spikes in the thalamus increase the thalamic spindle refractory period (p≈0). Finally, we show that in three patients with EE-SWAS, there is a downregulation of sleep spindles for 30 seconds after each thalamic spike (p<0.01). These direct human thalamocortical observations support a proposed mechanism for epileptiform activity to impact cognitive function, wherein epileptic spikes inhibit thalamic sleep spindles in epileptic encephalopathy with spike and wave activation during sleep.

Photothrombosis induced cortical stroke produces electrographic epileptic biomarkers in mice.

Objective: Interictal epileptiform spikes, high-frequency ripple oscillations, and their co-occurrence (spike ripples) in human scalp or intracranial voltage recordings are well-established epileptic biomarkers. While clinically significant, the neural mechanisms generating these electrographic biomarkers remain unclear. To reduce this knowledge gap, we introduce a novel photothrombotic stroke model in mice that reproduces focal interictal electrographic biomarkers observed in human epilepsy. Methods: We induced a stroke in the motor cortex of C57BL/6 mice unilaterally (N=7) using a photothrombotic procedure previously established in rats. We then implanted intracranial electrodes (2 ipsilateral and 2 contralateral) and obtained intermittent local field potential (LFP) recordings over several weeks in awake, behaving mice. We evaluated the LFP for focal slowing and epileptic biomarkers - spikes, ripples, and spike ripples - using both automated and semi-automated procedures. Results: Delta power (1-4 Hz) was higher in the stroke hemisphere than the non-stroke hemisphere in all mice ( p <0.001). Automated detection procedures indicated that compared to the non-stroke hemisphere, the stroke hemisphere had an increased spike ripple ( p =0.006) and spike rates ( p =0.039), but no change in ripple rate ( p =0.98). Expert validation confirmed the observation of elevated spike ripple rates ( p =0.008) and a trend of elevated spike rate ( p =0.055) in the stroke hemisphere. Interestingly, the validated ripple rate in the stroke hemisphere was higher than the non-stroke hemisphere ( p =0.031), highlighting the difficulty of automatically detecting ripples. Finally, using optimal performance thresholds, automatically detected spike ripples classified the stroke hemisphere with the best accuracy (sensitivity 0.94, specificity 0.94). Significance: Cortical photothrombosis-induced stroke in commonly used C57BL/6 mice produces electrographic biomarkers as observed in human epilepsy. This model represents a new translational cortical epilepsy model with a defined irritative zone, which can be broadly applied in transgenic mice for cell type specific analysis of the cellular and circuit mechanisms of pathologic interictal activity. Key Points: Cortical photothrombosis in mice produces stroke with characteristic intermittent focal delta slowing.Cortical photothrombosis stroke in mice produces the epileptic biomarkers spikes, ripples, and spike ripples.All biomarkers share morphological features with the corresponding human correlate.Spike ripples better lateralize to the lesional cortex than spikes or ripples.This cortical model can be applied in transgenic mice for mechanistic studies.

Phytic acid promotes high glucose-mediated bone marrow mesenchymal stem cells osteogenesis via modulating circEIF4B that sponges miR-186-5p and complexes with IGF2BP3.

Diabetes-related hyperglycemia inhibits bone marrow mesenchymal stem cell (BMSC) function, thereby disrupting osteoblast capacity and bone regeneration. Dietary supplementation with phytic acid (PA), a natural inositol phosphate, has shown promise in preventing osteoporosis and diabetes-related complications. Emerging evidence has suggested that circular (circ)RNAs implicate in the regulation of bone diseases, but their specific regulatory roles in BMSC osteogenesis in hyperglycemic environments remain elucidated. In this study, in virto experiments demonstrated that PA treatment effectively improved the osteogenic capability of high glucose-mediated BMSCs. Differentially expressed circRNAs in PA-induced BMSCs were identified using circRNA microarray analysis. Here, our findings highlight an upregulation of circEIF4B expression in BMSCs stimulated with PA under a high-glucose microenvironment. Further investigations demonstrated that circEIF4B overexpression promoted high glucose-mediated BMSC osteogenesis. In contrast, circEIF4B knockdown exerted the opposite effect. Mechanistically, circEIF4B sequestered microRNA miR-186-5p and triggered osteogenesis enhancement in BMSCs by targeting FOXO1 directly. Furthermore, circEIF4B inhibited the ubiquitin-mediated degradation of IGF2BP3, thereby stabilizing ITGA5 mRNA and promoting BMSC osteogenic differentiation. In vivo experiments, circEIF4B inhibition attenuated the effectiveness of PA treatment in diabetic rats with cranial defects. Collectively, our study identifies PA as a novel positive regulator of BMSC osteogenic differentiation through the circEIF4B/miR-186-5p/FOXO1 and circEIF4B/IGF2BP3/ITGA5 axes, which offers a new strategy for treating high glucose-mediatedBMSCosteogenic dysfunction and delayed bone regeneration in diabetes.

Spike ripples localize the epileptogenic zone best: an international intracranial study.

We evaluated whether spike ripples, the combination of epileptiform spikes and ripples, provide a reliable and improved biomarker for the epileptogenic zone (EZ) compared to other leading interictal biomarkers in a multicenter, international study. We first validated an automated spike ripple detector on intracranial EEG recordings. We then applied this detector to subjects from four centers who subsequently underwent surgical resection with known 1-year outcomes. We evaluated the spike ripple rate in subjects cured after resection (ILAE 1 outcome) and those with persistent seizures (ILAE 2-6) across sites and recording types. We also evaluated available interictal biomarkers: spike, spike-gamma, wideband high frequency oscillation (HFO, 80-500 Hz), ripple (80-250 Hz), and fast ripple (250-500 Hz) rates using previously validated automated detectors. The proportion of resected events was computed and compared across subject outcomes and biomarkers. 109 subjects were included. Most spike ripples were removed in subjects with ILAE 1 outcome (P < 0.001), and this was qualitatively observed across all sites and for depth and subdural electrodes (P < 0.001, P < 0.001). Among ILAE 1 subjects, the mean spike ripple rate was higher in the RV (0.66/min) than in the non-removed tissue (0.08/min, P < 0.001). A higher proportion of spike ripples were removed in subjects with ILAE 1 outcomes compared to ILAE 2-6 outcomes (P = 0.06). Among ILAE 1 subjects, the proportion of spike ripples removed was higher than the proportion of spikes (P < 0.001), spike-gamma (P < 0.001), wideband HFOs (P < 0.001), ripples (P = 0.009) and fast ripples (P = 0.009) removed. At the individual level, more subjects with ILAE 1 outcomes had the majority of spike ripples removed (79%, 38/48) than spikes (69%, P = 0.12), spike-gamma (69%, P = 0.12), wideband HFOs (63%, P = 0.03), ripples (45%, P = 0.01), or fast ripples (36%, P < 0.001) removed. Thus, in this large, multicenter cohort, when surgical resection was successful, the majority of spike ripples were removed. Further, automatically detected spike ripples have improved specificity for epileptogenic tissue compared to spikes, spike-gamma, wideband HFOs, ripples, and fast ripples.

A gel-coated air-liquid-interface culture system with tunable substrate stiffness matching healthy and diseased lung tissues.

Since its invention in the late 1980s, the air-liquid-interface (ALI) culture system has been the standard in vitro model for studying human airway biology and pulmonary diseases. However, in a conventional ALI system, cells are cultured on a porous plastic membrane that is much stiffer than human airway tissues. Here, we develop a gel-ALI culture system by simply coating the plastic membrane with a thin layer of hydrogel with tunable stiffness matching that of healthy and fibrotic airway tissues. We determine the optimum gel thickness that does not impair the transport of nutrients and biomolecules essential to cell growth. We show that the gel-ALI system allows human bronchial epithelial cells (HBECs) to proliferate and differentiate into pseudostratified epithelium. Furthermore, we discover that HBECs migrate significantly faster on hydrogel substrates with stiffness matching that of fibrotic lung tissues, highlighting the importance of mechanical cues in human airway remodeling. The developed gel-ALI system provides a facile approach to studying the effects of mechanical cues in human airway biology and in modeling pulmonary diseases.NEW & NOTEWORTHY In a conventional ALI system, cells are cultured on a plastic membrane that is much stiffer than human airway tissues. We develop a gel-ALI system by coating the plastic membrane with a thin layer of hydrogel with tunable stiffness matching that of healthy and fibrotic airway tissues. We discover that human bronchial epithelial cells migrate significantly faster on hydrogel substrates with pathological stiffness, highlighting the importance of mechanical cues in human airway remodeling.

Untargeted Metabolomics Analysis of Gingival Tissue in Patients with Severe Periodontitis.

The purpose of this study was to determine potential metabolic biomarkers and therapeutic drugs in the gingival tissue of individuals with periodontitis. Liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) were used to analyze the gingival tissue samples from 20 patients with severe periodontitis and 20 healthy controls. Differential metabolites were identified using variable important in projection (VIP) values from the orthogonal partial least squares discrimination analysis (OPLS-DA) model and then verified for significance between groups using a two-tailed Student's t test. In total, 65 metabolites were enriched in 33 metabolic pathways, with 40 showing a significant increase and 25 expressing a significant decrease. In addition, it was found that patients with severe periodontitis have abnormalities in metabolic pathways, such as glucose metabolism, purine metabolism, amino acid metabolism, and so on. Furthermore, based on a multidimensional analysis, 12 different metabolites may be the potential biomarkers of severe periodontitis. The experiment's raw data have been uploaded to the MetaboLights database, and the project number is MTBLS8357. Moreover, osteogenesis differentiation characteristics were detected in the selected metabolites. The findings may provide a basis for the study of diagnostic biomarkers and therapeutic metabolites in severe periodontitis.

Cardiovascular Risk Stratification of Patients Undergoing Hematopoietic Stem Cell Transplantation: The CARE-BMT Risk Score.

BACKGROUND: Evidence guiding the pre-hematopoietic stem cell transplantation (HSCT) cardiovascular evaluation is limited. We sought to derive and validate a pre-HSCT score for the cardiovascular risk stratification of HSCT candidates. METHODS AND RESULTS: We leveraged the CARE-BMT (Cardiovascular Registry in Bone Marrow Transplantation) study, a contemporary multicenter observational study of adult patients who underwent autologous or allogeneic HSCT between 2008 and 2019 (N=2435; mean age at transplant of 55 years; 4.9% Black). We identified the subset of variables most predictive of post-HSCT cardiovascular events, defined as a composite of cardiovascular death, myocardial infarction, heart failure, stroke, atrial fibrillation or flutter, and sustained ventricular tachycardia. We then developed a point-based risk score using the hazard ratios obtained from Cox proportional hazards modeling. The score was externally validated in a separate cohort of 919 HSCT recipients (mean age at transplant 54 years; 20.4% Black). The risk score included age, transplant type, race, coronary artery disease, heart failure, peripheral artery disease, creatinine, triglycerides, and prior anthracycline dose. Risk scores were grouped as low-, intermediate-, and high-risk, with the 5-year cumulative incidence of cardiovascular events being 4.0%, 10.3%, and 22.4%, respectively. The area under the receiver operating curves for predicting cardiovascular events at 100 days, 5 and 10 years post-HSCT were 0.65 (95% CI, 0.59-0.70), 0.73 (95% CI, 0.69-0.76), and 0.76 (95% CI, 0.69-0.81), respectively. The model performed equally well in autologous and allogeneic recipients, as well as in the validation cohort. CONCLUSIONS: The CARE-BMT risk score is easy to calculate and could help guide referrals of high-risk HSCT recipients to cardiovascular specialists before transplant and guide long-term monitoring.

Bomidin attenuates inflammation of periodontal ligament stem cells and periodontitis in mice via inhibiting ferroptosis.

AIM: Periodontitis is a prevalent oral immunoinflammatory condition that is distinguished by the compromised functionality of periodontal ligament stem cells (PDLSCs). Bomidin, a new recombinant antimicrobial peptide (AMP), exhibits antibacterial properties and modulates immune responses. Nevertheless, the precise anti-inflammatory impact of bomidin in periodontitis has yet to be fully elucidated. Thus, the study aimed to clarified the role of bomidin in modulating inflammation and its underlying mechanisms. METHODS: TNF-α was applied to treating PDLSCs for establishing a cell model of periodontitis. Bomidin, RSL3, ML385 and cycloheximide were also used to treat PDLSCs. Transcriptome sequencing, RT-qPCR, western blot, immunofluorescence, immunohistochemistry, Fe2+ detection probe, molecular docking, Co-IP assay, ubiquitination assay and murine models of periodontitis were used. RESULTS: Our study demonstrated that bomidin effectively suppressed inflammation in PDLSCs stimulated by TNF-α, through down-regulating the MAPK and NF-κB signaling pathways. Furthermore, bomidin exerted inhibitory effects on ferroptosis and activated the Keap1/Nrf2 pathway in the TNF-α group. There is a strong likelihood of bonding bomidin with Keap1 protein, which facilitated the degradation of Keap1 protein via the ubiquitin-proteasome pathway, leading to an enhanced translocation of Nrf2 protein to the nucleus. CONCLUSIONS: Bomidin can directly bond to Keap1 protein, resulting in the degradation of Keap1 through the ubiquitin-proteasome pathway, thereby further activating the Keap1/Nrf2 pathway. The upregulation of the Keap1/Nrf2 signaling pathway was found to contribute to the suppression of ferroptosis, ultimately alleviating inflammation in treatment of periodontitis.

Epilepsy Surgery for Cognitive Improvement in Epileptic Encephalopathy.

Epileptic encephalopathies are defined by the presence of frequent epileptiform activity that causes neurodevelopmental slowing or regression. Here, we review evidence that epilepsy surgery improves neurodevelopment in children with epileptic encephalopathies. We describe an example patient with epileptic encephalopathy without drug refractory seizures, who underwent successful diagnostic and therapeutic surgeries. In patients with epileptic encephalopathy, cognitive improvement alone is a sufficient indication to recommend surgical intervention in experienced centers.

The association of aldehyde exposure with the risk of periodontitis: NHANES 2013-2014.

OBJECTIVES: Three distinct models were utilized to investigate the combined impacts of serum aldehyde exposure and periodontitis. MATERIALS AND METHODS: We performed a cross-sectional analysis using data from 525 participants in the 2013-2014 National Health and Nutrition Examination Survey (NHANES). The directed acyclic graphs (DAG) were used to select a minimal sufficient adjustment set of variables (MSAs). To investigate the relationship between aldehydes and periodontitis, we established three models including multiple logistic regression model, restricted cubic spline (RCS) model, and Bayesian kernel machine regression (BKMR) model. RESULTS: After taking all covariates into account, the multiple logistic regression model revealed that elevated concentrations of isopentanaldehyde and propanaldehyde were strongly associated with periodontitis (isopentanaldehyde: OR: 2.38, 95% CI: 1.34-4.23; propanaldehyde: OR: 1.51, 95% CI: 1.08-2.13). Furthermore, the third tertile concentration of isopentanaldehyde was associated with a 2.04-fold increase in the incidence of periodontitis (95% CI: 1.05-3.95) compared to the first tertile concentration, with a P for trend = 0.04. RCS models showed an "L"-shaped relationship between isopentanaldehyde and periodontitis (P for nonlinear association < 0.01), with inflection point of 0.43 ng/mL. BKMR identified a strong connection between mixed aldehydes and periodontitis, with isopentanaldehyde exhibiting the greatest posterior inclusion probability (PIP) with 0.901 and propanaldehyde exhibiting a PIP with 0.775. CONCLUSIONS: Isopentanaldehyde and propanaldehyde are positively associated with the risk of periodontitis. CLINICAL RELEVANCE: Periodontitis may be associated with exposure to mixed aldehyde. This study emphasizes the important role of aldehydes in primary prevention of periodontitis.

Different Methods to Estimate the Phase of Neural Rhythms Agree But Only During Times of Low Uncertainty.

Rhythms are a common feature of brain activity. Across different types of rhythms, the phase has been proposed to have functional consequences, thus requiring its accurate specification from noisy data. Phase is conventionally specified using techniques that presume a frequency band-limited rhythm. However, in practice, observed brain rhythms are typically nonsinusoidal and amplitude modulated. How these features impact methods to estimate phase remains unclear. To address this, we consider three phase estimation methods, each with different underlying assumptions about the rhythm. We apply these methods to rhythms simulated with different generative mechanisms and demonstrate inconsistency in phase estimates across the different methods. We propose two improvements to the practice of phase estimation: (1) estimating confidence in the phase estimate, and (2) examining the consistency of phase estimates between two (or more) methods.

Feeding and developmental outcomes after neonatal seizures-A prospective observational study.

Objective: Among neonates with acute symptomatic seizures, we evaluated whether inability to take full feeds at time of hospital discharge from neonatal seizure admission is associated with worse neurodevelopmental outcomes, after adjusting for relevant clinical variables. Methods: This prospective, 9-center study of the Neonatal Seizure Registry (NSR) assessed characteristics of infants with seizures including: evidence of brainstem injury on MRI, mode of feeding upon discharge, and developmental outcomes at 12, 18, and 24 months. Inability to take oral feeds was identified through review of medical records. Brainstem injury was identified through central review of neonatal MRIs. Developmental outcomes were assessed with the Warner Initial Developmental Evaluation of Adaptive and Functional Skills (WIDEA-FS) at 12, 18, and 24 months corrected age. Results: Among 276 infants, inability to achieve full oral feeds was associated with lower total WIDEA-FS scores (160.2±25.5 for full oral feeds vs. 121.8±42.9 for some/no oral feeds at 24 months, p<0.001). At 12 months, a G-tube was required for 23 of the 49 (47%) infants who did not achieve full oral feeds, compared with 2 of the 221 (1%) who took full feeds at discharge (p<0.001). Conclusions: Inability to take full oral feeds upon hospital discharge is an objective clinical sign that can identify infants with acute symptomatic neonatal seizures who are at high risk for impaired development at 24 months.

Different methods to estimate the phase of neural rhythms agree, but only during times of low uncertainty.

Rhythms are a common feature of brain activity. Across different types of rhythms, the phase has been proposed to have functional consequences, thus requiring its accurate specification from noisy data. Phase is conventionally specified using techniques that presume a frequency band-limited rhythm. However, in practice, observed brain rhythms are typically non-sinusoidal and amplitude modulated. How these features impact methods to estimate phase remains unclear. To address this, we consider three phase estimation methods, each with different underlying assumptions about the rhythm. We apply these methods to rhythms simulated with different generative mechanisms and demonstrate inconsistency in phase estimates across the different methods. We propose two improvements to the practice of phase estimation: (1) estimating confidence in the phase estimate, and (2) examining the consistency of phase estimates between two (or more) methods.

Neonatal brain MRI and short-term outcomes after acute provoked seizures.

OBJECTIVE: We investigated how diagnosis and injury location on neonatal brain MRI following onset of acute provoked seizures was associated with short term outcome. STUDY DESIGN: A multicenter cohort of neonates with acute provoked seizures enrolled in the Neonatal Seizure Registry. MRIs were centrally evaluated by a neuroradiologist for location of injury and radiologic diagnosis. Clinical outcomes were determined by chart review. Multivariate logistic regression was used to examine the association between MRI findings and outcomes. RESULTS: Among 236 newborns with MRI at median age 4 days (IQR 3-8), 91% had abnormal MRI. Radiologic diagnoses of intracranial hemorrhage (OR 3.2 [1.6-6.5], p < 0.001) and hypoxic-ischemic encephalopathy (OR 2.7 [1.4-5.4], p < 0.003) were associated with high seizure burden. Radiologic signs of intracranial infection were associated with abnormal neurologic examination at discharge (OR 3.9 [1.3-11.6], p < 0.01). CONCLUSION: Findings on initial MRI can help with expectant counseling on short-term outcomes following acute provoked neonatal seizures.

Decreased thalamocortical connectivity in resolved Rolandic epilepsy.

OBJECTIVE: Median nerve somatosensory evoked fields (SEFs) conduction times reflect the integrity of neural transmission across the thalamocortical circuit. We hypothesized median nerve SEF conduction time would be abnormal in children with Rolandic epilepsy (RE). METHODS: 22 children with RE (10 active; 12 resolved) and 13 age-matched controls underwent structural and diffusion MRI and median nerve and visual stimulation during magnetoencephalography (MEG). N20 SEF responses were identified in contralateral somatosensory cortices. P100 were identified in contralateral occipital cortices as controls. Conduction times were compared between groups in linear models controlling for height. N20 conduction time was also compared to thalamic volume and Rolandic thalamocortical structural connectivity inferred using probabilistic tractography. RESULTS: The RE group had slower N20 conduction compared to controls (p = 0.042, effect size 0.6 ms) and this difference was driven by the resolved RE group (p = 0.046). There was no difference in P100 conduction time between groups (p = 0.83). Ventral thalamic volume positively correlated with N20 conduction time (p = 0.014). CONCLUSIONS: Children with resolved RE have focally decreased Rolandic thalamocortical connectivity. SIGNIFICANCE: These results identify a persistent focal thalamocortical circuit abnormality in resolved RE and suggest that decreased Rolandic thalamocortical connectivity may support symptom resolution in this self-limited epilepsy.

Macrophages induce gingival destruction via Piezo1-mediated MMPs-degrading collagens in periodontitis.

Macrophages are an integral part of the innate immune response in periodontal tissue and play a crucial role in the progression of periodontitis. Here we reported that macrophages also provoke periodontitis-induced gingival destruction through Piezol-mediated collagen degradation. We discovered that the PIEZO1 expression was markedly elevated in patients with periodontitis through transcriptomic profiling. Moreover, Piezo1 promoted macrophage polarization toward the M1 type in response to lipopolysaccharide (LPS) and induced production of proinflammatory cytokines, which in turn stimulated production of matrix metalloproteinases (MMPs) leading to collagen degradation. Our study suggests that Piezol might be a potential therapeutic target for treating periodontitis-induced gingival destruction.

Distinguishing between different percolation regimes in noisy dynamic networks with an application to epileptic seizures.

In clinical neuroscience, epileptic seizures have been associated with the sudden emergence of coupled activity across the brain. The resulting functional networks-in which edges indicate strong enough coupling between brain regions-are consistent with the notion of percolation, which is a phenomenon in complex networks corresponding to the sudden emergence of a giant connected component. Traditionally, work has concentrated on noise-free percolation with a monotonic process of network growth, but real-world networks are more complex. We develop a class of random graph hidden Markov models (RG-HMMs) for characterizing percolation regimes in noisy, dynamically evolving networks in the presence of edge birth and edge death. This class is used to understand the type of phase transitions undergone in a seizure, and in particular, distinguishing between different percolation regimes in epileptic seizures. We develop a hypothesis testing framework for inferring putative percolation mechanisms. As a necessary precursor, we present an EM algorithm for estimating parameters from a sequence of noisy networks only observed at a longitudinal subsampling of time points. Our results suggest that different types of percolation can occur in human seizures. The type inferred may suggest tailored treatment strategies and provide new insights into the fundamental science of epilepsy.

Preliminary evidence of a relationship between sleep spindles and treatment response in epileptic encephalopathy.

OBJECTIVE: Epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS) is a challenging neurodevelopmental disease characterized by abundant epileptiform spikes during non-rapid eye movement (NREM) sleep accompanied by cognitive dysfunction. The mechanism of cognitive dysfunction is unknown, but treatment with high-dose diazepam may improve symptoms. Spike rate does not predict treatment response, but spikes may disrupt sleep spindles. We hypothesized that in patients with EE-SWAS: (1) spikes and spindles would be anti-correlated, (2) high-dose diazepam would increase spindles and decrease spikes, and (3) spindle response would be greater in those with cognitive improvement. METHODS: Consecutive EE-SWAS patients treated with high-dose diazepam that met the criteria were included. Using a validated automated spindle detector, spindle rate, duration, and percentage were computed in pre- and post-treatment NREM sleep. Spikes were quantified using a validated automated spike detector. The cognitive response was determined from a chart review. RESULTS: Spindle rate was anti-correlated with the spike rate in the channel with the maximal spike rate (p = 0.002) and averaged across all channels (p = 0.0005). Spindle rate, duration, and percentage each increased, and spike rate decreased, after high-dose diazepam treatment (p ≤ 2e-5, all tests). Spindle rate, duration, and percentage (p ≤ 0.004, all tests) were increased in patients with cognitive improvement after treatment, but not those without. Changes in spindle rate but not changes in spike rate distinguished between groups. INTERPRETATION: These findings confirm thalamocortical disruption in EE-SWAS, identify a mechanism through which benzodiazepines may support cognitive recovery, and introduce sleep spindles as a promising mechanistic biomarker to detect treatment response in severe epileptic encephalopathies.