Faculty Bibliography

The gut microbiome can influence brain health by modulating neuroinflammation through various mechanisms, including immune regulation, the production of metabolites that affect neural function, gut and blood-brain barrier integrity, upstream effects via the vagus nerve, upstream migration of gut-resident lymphocytes to the brain, bile acid signalling, and endocrine activity. Changes in gut microbiota have been observed in demyelinating conditions, autoimmune encephalitis, and epilepsy. Gut microbiota composition changes can affect neuroinflammation, disease progression, and treatment outcomes. Advances in microbiome research have improved the potential for clinical translation of findings; but limitations persist, driven by the largely correlational nature of clinical studies and the complexity of microbiome sequencing and interpretation. At present, only the ketogenic diet is routinely recommended by clinicians, whereas other microbiome-based interventions remain investigational. Multiple strategies for manipulating the gut microbiome, including dietary changes, prebiotics, probiotics, postbiotics, and faecal microbiota transplantation, might be used as disease-modifying therapies in the future.

OBJECTIVE:This study was undertaken to examine acute and chronic electroencephalographic (EEG) and seizure characteristics in new onset refractory status epilepticus (NORSE). METHODS:Multicenter inpatient and follow-up clinical and EEG data were analyzed using International League Against Epilepsy definitions and American Clinical Neurophysiology Society (ACNS) EEG terminology. RESULTS:Forty-four patients were included from the Yale NORSE/FIRES Biorepository (median age = 29 years, 33 female, 38 cryptogenic). Nine hundred twenty inpatient EEG days were reviewed (median = 13.5 days/patient). Presenting status epilepticus (SE) types included 24 convulsive SE (CSE), five focal-motor (FMSE), and 15 nonconvulsive (NCSE). Of 39 patients with post discharge follow-up (median = 14.7 months), 61.5% (n = 24) had seizures and required more antiseizure medications than seizure-free patients (median = 4 vs. 1, p < .001). Inpatient EEG captured epileptiform discharges in all and periodic discharges in 38 patients. Seizures were captured in 38 patients: 33 electrographic (11 only electrographic) and 27 electroclinical. Total seizure burden ranged 6.5-29 615.0 min (median = 50.7). Seizures fulfilling ACNS EEG criteria for SE were captured in 20 patients; two had CSE and the remainder NCSE with coma, nine of whom also had FMSE. Inpatient seizure days (median = 50.0 vs. 15.5%, p = .004) and seizure burden (median = 42.9 vs. 0 min, p = .009) were higher in the first half of monitored days. Interictal findings were equally present and did not predict postdischarge seizures, whereas electroclinical seizures (90.9% vs. 45.5%, p = .037), seizure burden (median = 116.8 vs. 32.5 min, p = .045), and proportion of seizure days (36.3% vs. 20.0%, p = .037) did. Among 12 patients with follow-up EEGs (median = 19.6 months post onset), posterior-dominant rhythm (PDR) returned in nine; five had periodic discharges, and three had seizure captured. SIGNIFICANCE/CONCLUSIONS:Seizures are most commonly convulsive upon presentation and nonconvulsive or clinically subtle throughout the inpatient course in NORSE. Inpatient seizures, but not interictal abnormalities, occur earlier in the inpatient course and presence of electroclinical seizures, seizure burden, and proportion of seizure days but not interictal findings are associated with postdischarge seizures. Although return of PDR reflects neurological recovery, seizure persistence and EEG abnormalities post-NORSE are common.

Rasmussen syndrome (RS) includes a well-described constellation of refractory focal seizures, often including epilepsia partialis continua, hemiplegia with progressive unilateral cortical atrophy, and cognitive/language decline. However, the precise early pathogenesis and reliable biomarkers remain elusive. In addition, we lack operational management guidelines, including diagnostic evaluation, disease-monitoring assessments, and medical and surgical treatment approaches. We aimed to create an expert consensus statement to guide and standardize the treatment of RS, with the goal of providing recommendations applicable to a global population. An expert panel was convened to complete three rounds of a modified Delphi procedure given the lack of high-level evidence, with a focus on workup to exclude mimicking diagnoses, disease-activity metrics, and treatment. Consensus was defined as ≥75% of responses being agree/strongly agree in either two subsequent rounds or in the third and final round. A total of 122 of 143 statements met consensus. Proposed diagnostic evaluation in patients with possible RS is outlined, including physical examination, blood/cerebrospinal fluid analyses, neuroimaging, electroencephalography (EEG), and biopsy. Suggested disease-monitoring assessments include neuropsychological testing and serial magnetic resonance imaging (MRI). Intravenous corticosteroids are recommended as first-line, acute immunotherapy for seizure exacerbations and status epilepticus, with or without the addition of intravenous immunoglobulin. Options for maintenance immunotherapy are outlined, with lack of evidence noted for comparing efficacy of these treatments. Hemispheric disconnection remains the most effective seizure treatment, with parameters including age, function, seizure burden, and patient values influencing candidacy for surgery. This consensus statement offers a guideline to standardize management, as well as suggests future directions to further elucidate underlying pathophysiology and target more-effective, better-tolerated treatments.

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.

Acute symptomatic seizures are a well recognized symptom of myelin oligodendrocyte antibody-associated disease (MOGAD), but long-term seizure outcomes and risk of epilepsy are understudied. In a retrospective cohort of 135 consecutive patients meeting consensus criteria for MOGAD without a prior diagnosis of epilepsy or concurrent NMDA-R Ab positivity, 19 developed seizures after MOGAD onset (16 %). Of these 19 patients, 7 patients (37 % of those with seizures, and 5 % of the total cohort). experienced one or more seizure recurrence during MOGAD remission (i.e. outside of an acute attack). Five of the 7 patients with recurrent seizures remained on antiseizure medication (ASM) (four on monotherapy and one on two ASMs) at last follow-up (median duration of follow up: 92 months). We discuss phenotypes of recurrent seizures in patients with MOGAD in the context of the conceptual framework of acute symptomatic seizures versus autoimmune encephalitis associated epilepsy (AEAE).

OBJECTIVE:This study aims to better characterize the long-term neurological quality of life (QOL) outcomes (using the Neuro-QOL scale) in survivors of new onset refractory status epilepticus (NORSE), including its subtype febrile infection-related epilepsy syndrome (FIRES), and provide guidance for psychological and social support strategies. METHODS:Utilizing data from a multicenter prospective study of NORSE/FIRES led by Yale University, we enrolled patients who completed the validated, patient-reported Neuro-QOL scale at least once at 3-6 months (n = 37), 12 months (n = 29), 24 months (n = 23), or ≥36 months (n = 9) following discharge. The Neuro-QOL scale assesses physical, mental, and social health in patients with neurological disorders. QOL impairment (QOL-I) scores were calculated, with higher scores indicating greater impairment. T-scores enabled comparisons with reference populations. RESULTS:In adults, median QOL-I improved from 44.1% at 3-6 months to 37.6% at 36+ months. Paired analysis showed significant improvement in QOL-I between 3-6 and 24 months (p = .016), with specific improvements in communication, satisfaction with social roles, fatigue, and mobility. Greater improvement was also observed for participation in social roles (5.5-point T-score gain) compared to the reference population, suggesting meaningful change. A gradual improvement in overall QOL-I scores was also observed in pediatric participants, despite a modest sample size (n = 5 with data at 3-6 and 12 months). Measures of fatigue and anxiety persisted in adults, and cognitive difficulties persisted in both adults and children. In adults, longer status epilepticus duration and intensive care unit stay were associated with poorer QOL. Additionally, a higher number of antiseizure medications was associated with more depression, cognitive impairments, and perceived stigma. SIGNIFICANCE/CONCLUSIONS:These findings highlight the potential for recovery following an acute episode of NORSE, although many patients continue to face challenges requiring ongoing support, and the clinical meaning of the reported QOL improvement remains unclear. Furthermore, the findings underscore the importance of strategic multidisciplinary support systems in the years following discharge.

We present two cases of adult-onset temporal lobe epilepsy (TLE) who underwent stereo-EEG and, within weeks of explantation, experienced subacute encephalopathy and in one patient, seizure exacerbation. Diagnostic investigations revealed low titer GAD antibodies in serum and evidence of GAD intrathecal synthesis. Immunotherapy led to improvement in one patient. We posit a role for blood brain barrier disruption in the setting of a neurosurgical procedure leading to inflammation and intrathecal synthesis of GAD antibodies. Investigations for autoimmune causes of epilepsy should be undertaken prior to SEEG in patients with no known cause of epilepsy and a suggestive electroclinical phenotype.

OBJECTIVE:Encephalitis is brain parenchyma inflammation, frequently resulting in seizures which worsens outcomes. Early anti-seizure medication could improve outcomes but requires identifying patients at greatest risk of acute seizures. The SEIZURE (SEIZUre Risk in Encephalitis) score was developed in UK cohorts to stratify patients by acute seizure risk. A 'basic score' used Glasgow Coma Scale (GCS), fever and age; the 'advanced score' added aetiology. This study aimed to evaluate the score internationally to determine its global applicability. DESIGN/METHODS:Patients were retrospectively analysed regionally, and by country, in this international evaluation study. Univariate analysis was conducted between patients who did and did not have inpatient seizures, followed by multivariable logistic regression, hierarchical clustering and analysis of the area under the receiver operating curves (AUROC) with 95% CIs. PARTICIPANTS AND SETTING/METHODS:2032 patients across 13 countries were identified, among whom 1324 were included in SEIZURE score calculations and 970 were included in regression modelling. The involved countries comprised 19 organisations spanning all WHO regions. OUTCOME MEASURES/METHODS:The primary outcome was measuring inpatient seizure rates. RESULTS:Autoantibody-associated encephalitis, low GCS and presenting with a seizure were frequently associated with inpatient seizures; fever showed no association. Globally, the score had limited discriminatory ability (basic AUROC 0.58 (95% CI 0.55 to 0.62), advanced AUROC 0.63 (95% CI 0.60 to 0.66)). The scoring system performed acceptably in western Europe, excluding Spain, with the best performance in Portugal (basic AUROC 0.82 (95% CI 0.69 to 0.94), advanced AUROC 0.83 (95% CI 0.72 to 0.95)). CONCLUSIONS:The SEIZURE score performed best in several countries in Western Europe but performed poorly elsewhere, partly due to differing and unknown aetiologies. In most regions, the score did not reach a threshold to be clinically useful. The Western European results could aid in designing clinical trials assessing primary anti-seizure prophylaxis in encephalitis following further prospective trials. Beyond Western Europe, there is a need for tailored, localised scoring systems and future large-scale prospective studies with optimised aetiological testing to accurately identify high-risk patients.

Neuroinflammation involving glial cell activation and BBB dysfunction has increasingly been recognized as a key feature of neuropsychiatric disorders. In vivo imaging methods, particularly translocator protein positron emission tomography (TSPO-PET) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), have advanced our understanding of glial activation and BBB permeability in conditions such as Alzheimer's disease, Parkinson's disease, epilepsy, multiple sclerosis, Huntington's disease, schizophrenia, and depression. We present key findings from the clinical application of these imaging modalities and highlight critical methodological challenges-including variability in study protocols, tracer selection, input function derivation, and parameter estimation-that currently limit cross-study comparability and clinical translation. TSPO-PET and DCE-MRI provide valuable clinical insights on the inflammatory mechanisms contributing to CNS disease at various disease stages. Future methodological standardization, co-localization studies, and longitudinal multi-modal applications will be crucial for using these tools as markers of disease in the context of immune interventions in at-risk populations.