Sands, Tristan T.

Abstract Objective Dravet syndrome (DS) is a developmental and epileptic encephalopathy. Diagnosis is clinical, but ~90% of patients have pathogenic variants in SCN1A . ATP6V0C has recently been proposed as a novel candidate gene for epilepsy, with or without developmental delay. Here we describe two adult patients with a clinical diagnosis of DS associated with ATP6V0C variants. Methods Patients with developmental and epileptic encephalopathies were evaluated by physicians who are experts in DS, and their clinical diagnosis was correlated with genetic findings. A subgroup of those patients with DS but without known genetic causes were evaluated through gene panels, whole exome sequencing, and chromosome microarray. Phenotype was determined by pediatric and adult chart reviews, interviews, and physical examinations. Results Of 753 patients with DS, two unrelated individuals with classic features of DS during childhood and adulthood were identified with heterozygous de novo missense variants in ATP6V0C (c.319G > C, p.(Gly107Arg) and c.284C > T, p.(Ala95Val), respectively). Both variants were absent in normal populations and computational prediction algorithms suggested deleterious effects on protein structure and/or function. No disease‐causing variants in other genes previously associated with DS were found. Significance Here we describe two adult patients with Dravet‐like syndrome and pathogenic/likely pathogenic variants in ATP6V0C . We propose that abnormal ATP6V0C function can, at the severe end of the clinical spectrum, be associated with Dravet‐like phenotype. This is relevant, as these patients would not qualify for disease‐modifying antisense nucleotide or gene therapies targeting SCN1A .

Abstract Objective This study was undertaken to evaluate benzodiazepine (BZD) administration patterns before transitioning to non‐BZD antiseizure medication (ASM) in pediatric patients with refractory convulsive status epilepticus (rSE). Methods This retrospective multicenter study in the United States and Canada used prospectively collected observational data from children admitted with rSE between 2011 and 2020. Outcome variables were the number of BZDs given before the first non‐BZD ASM, and the number of BZDs administered after 30 and 45 min from seizure onset and before escalating to non‐BZD ASM. Results We included 293 patients with a median (interquartile range) age of 3.8 (1.3–9.3) years. Thirty‐six percent received more than two BZDs before escalating, and the later the treatment initiation was after seizure onset, the less likely patients were to receive multiple BZD doses before transitioning (incidence rate ratio [IRR] = .998, 95% confidence interval [CI] = .997–.999 per minute, p = .01). Patients received BZDs beyond 30 and 45 min in 57.3% and 44.0% of cases, respectively. Patients with out‐of‐hospital seizure onset were more likely to receive more doses of BZDs beyond 30 min (IRR = 2.43, 95% CI = 1.73–3.46, p < .0001) and beyond 45 min (IRR = 3.75, 95% CI = 2.40–6.03, p < .0001) compared to patients with in‐hospital seizure onset. Intermittent SE was a risk factor for more BZDs administered beyond 45 min compared to continuous SE (IRR = 1.44, 95% CI = 1.01–2.06, p = .04). Forty‐seven percent of patients ( n = 94) with out‐of‐hospital onset did not receive treatment before hospital arrival. Among patients with out‐of‐hospital onset who received at least two BZDs before hospital arrival ( n = 54), 48.1% received additional BZDs at hospital arrival. Significance Failure to escalate from BZDs to non‐BZD ASMs occurs mainly in out‐of‐hospital rSE onset. Delays in the implementation of medical guidelines may be reduced by initiating treatment before hospital arrival and facilitating a transition to non‐BZD ASMs after two BZD doses during handoffs between prehospital and in‐hospital settings.

AbstractObjectiveThis study was undertaken to describe long‐term clinical and developmental outcomes in pediatric refractory status epilepticus (RSE) and identify factors associated with new neurological deficits after RSE.MethodsWe performed retrospective analyses of prospectively collected observational data from June 2011 to March 2020 on pediatric patients with RSE. We analyzed clinical outcomes from at least 30 days after RSE and, in a subanalysis, we assessed developmental outcomes and evaluated risk factors in previously normally developed patients.ResultsFollow‐up data on outcomes were available in 276 patients (56.5% males). The median (interquartile range [IQR]) follow‐up duration was 1.6 (.9–2.7) years. The in‐hospital mortality rate was 4% (16/403 patients), and 15 (5.4%) patients had died after hospital discharge. One hundred sixty‐six (62.9%) patients had subsequent unprovoked seizures, and 44 (16.9%) patients had a repeated RSE episode. Among 116 patients with normal development before RSE, 42 of 107 (39.3%) patients with available data had new neurological deficits (cognitive, behavioral, or motor). Patients with new deficits had longer median (IQR) electroclinical RSE duration than patients without new deficits (10.3 [2.1–134.5] h vs. 4 [1.6–16] h, p = .011, adjusted odds ratio = 1.003, 95% confidence interval = 1.0008–1.0069, p = .027). The proportion of patients with an unfavorable functional outcome (Glasgow Outcome Scale‐Extended score ≥ 4) was 22 of 90 (24.4%), and they were more likely to have received a continuous infusion.SignificanceAbout one third of patients without prior epilepsy developed recurrent unprovoked seizures after the RSE episode. In previously normally developing patients, 39% presented with new deficits during follow‐up, with longer electroclinical RSE duration as a predictor.

OBJECTIVES: To characterize the pediatric super-refractory status epilepticus population by describing treatment variability in super-refractory status epilepticus patients and comparing relevant clinical characteristics, including outcomes, between super-refractory status epilepticus, and nonsuper-refractory status epilepticus patients. DESIGN: Retrospective cohort study with prospectively collected data between June 2011 and January 2019. SETTING: Seventeen academic hospitals in the United States. PATIENTS: We included patients 1 month to 21 years old presenting with convulsive refractory status epilepticus. We defined super-refractory status epilepticus as continuous or intermittent seizures lasting greater than or equal to 24 hours following initiation of continuous infusion and divided the cohort into super-refractory status epilepticus and nonsuper-refractory status epilepticus groups. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We identified 281 patients (157 males) with a median age of 4.1 years (1.3–9.5 yr), including 31 super-refractory status epilepticus patients. Compared with nonsuper-refractory status epilepticus group, super-refractory status epilepticus patients had delayed initiation of first nonbenzodiazepine-antiseizure medication (149 min [55–491.5 min] vs 62 min [33.3–120.8 min]; p = 0.030) and of continuous infusion (495 min [177.5–1,255 min] vs 150 min [90–318.5 min]; p = 0.003); prolonged seizure duration (120 hr [58–368 hr] vs 3 hr [1.4–5.9 hr]; p < 0.001) and length of ICU stay (17 d [9.5–40 d] vs [1.8–8.8 d]; p < 0.001); more medical complications (18/31 [58.1%] vs 55/250 [22.2%] patients; p < 0.001); lower return to baseline function (7/31 [22.6%] vs 182/250 [73.4%] patients; p < 0.001); and higher mortality (4/31 [12.9%] vs 5/250 [2%]; p = 0.010). Within the super-refractory status epilepticus group, status epilepticus resolution was attained with a single continuous infusion in 15 of 31 patients (48.4%), two in 10 of 31 (32.3%), and three or more in six of 31 (19.4%). Most super-refractory status epilepticus patients (30/31, 96.8%) received midazolam as first choice. About 17 of 31 patients (54.8%) received additional treatments. CONCLUSIONS: Super-refractory status epilepticus patients had delayed initiation of nonbenzodiazepine antiseizure medication treatment, higher number of medical complications and mortality, and lower return to neurologic baseline than nonsuper-refractory status epilepticus patients, although these associations were not adjusted for potential confounders. Treatment approaches following the first continuous infusion were heterogeneous, reflecting limited information to guide clinical decision-making in super-refractory status epilepticus.

AbstractCSNK2B has recently been implicated as a disease gene for neurodevelopmental disability (NDD) and epilepsy. Information about developmental outcomes has been limited by the young age and short follow‐up for many of the previously reported cases, and further delineation of the spectrum of associated phenotypes is needed. We present 25 new patients with variants in CSNK2B and refine the associated NDD and epilepsy phenotypes. CSNK2B variants were identified by research or clinical exome sequencing, and investigators from different centers were connected via GeneMatcher. Most individuals had developmental delay and generalized epilepsy with onset in the first 2 years. However, we found a broad spectrum of phenotypic severity, ranging from early normal development with pharmacoresponsive seizures to profound intellectual disability with intractable epilepsy and recurrent refractory status epilepticus. These findings suggest that CSNK2B should be considered in the diagnostic evaluation of patients with a broad range of NDD with treatable or intractable seizures.