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Peggy O Clark,1 Patricia A Gibson2 1Cincinnati Children’s Hospital Medical Center, The University of Cincinnati College of Medicine, Cincinnati, OH, 2Epilepsy Information Service, Wake Forest University School of Medicine, Winston-Salem, NC, USA Objectives: Lennox–Gastaut syndrome (LGS) is an epileptic encephalopathy with an onset at the age of ~4 years. LGS is notoriously difficult to manage, as most patients experience multiple seizures per day, despite their concomitant use of several antiepileptic drugs (AEDs). Rufinamide (BANZEL®) is an AED approved by the US Food and Drug Administration for the adjunctive treatment of seizures associated with LGS in pediatric patients aged ≥1 year and in adults. The expert care of nurses knowledgeable in the treatment options for LGS is valuable to patients and caregivers. This review summarizes the existing knowledge on LGS and data from clinical and real-world studies on the use of rufinamide in patients with LGS.Methods: Recent review articles and information from the Epilepsy Foundation Website were reviewed for data on LGS treatment. Primary articles on rufinamide were also selected for review.Results and conclusion: The efficacy and safety of rufinamide have been evaluated in children and adults by using double-blind, open-label, and observational studies. In general, these studies indicate that rufinamide effectively reduces the frequency and severity of multiple seizure types associated with LGS and has tolerable side effects, the most common being vomiting and somnolence. Dosing modifications based on age, weight, and concomitant AED usage are recommended for patients using rufinamide. Keywords: Lennox–Gastaut syndrome, anticonvulsants, rufinamide

Identifying genetic risk factors for highly heterogeneous disorders like epilepsy remains challenging. Here, we present the largest whole-exome sequencing study of epilepsy to date, with >54,000 human exomes, comprising 20,979 deeply phenotyped patients from multiple genetic ancestry groups with diverse epilepsy subtypes and 33,444 controls, to investigate rare variants that confer disease risk. These analyses implicate seven individual genes, three gene sets, and four copy number variants at exome-wide significance. Genes encoding ion channels show strong association with multiple epilepsy subtypes, including epileptic encephalopathies, generalized and focal epilepsies, while most other gene discoveries are subtype-specific, highlighting distinct genetic contributions to different epilepsies. Combining results from rare single nucleotide/short indel-, copy number-, and common variants, we offer an expanded view of the genetic architecture of epilepsy, with growing evidence of convergence among different genetic risk loci on the same genes. Top candidate genes are enriched for roles in synaptic transmission and neuronal excitability, particularly postnatally and in the neocortex. We also identify shared rare variant risk between epilepsy and other neurodevelopmental disorders. Our data can be accessed via an interactive browser, hopefully facilitating diagnostic efforts and accelerating the development of follow-up studies., Competing Interests: Competing Interests B.M.N is a member of the scientific advisory board at Deep Genomics and Neumora. No other authors have competing interests to declare

Ethosuximide was identified as the optimal option for new-onset childhood absence epilepsy (CAE) in a randomized, two-phase dose escalation comparative effectiveness trial of ethosuximide, lamotrigine, and valproic acid. However, 47% of ethosuximide initial monotherapy participants experienced short-term treatment failure. This study aimed to characterize the initial monotherapy ethosuximide exposure-response relationship and to propose model-informed precision dosing guidance. Dose titration occurred over a 16-20-week period until patients experienced seizure freedom or intolerable side effects. Subjects with initial monotherapy failure were randomized to one of the other two medications and dose escalation was repeated. A population pharmacokinetic model was created using plasma concentration data (n = 1,320), collected at 4-week intervals from 211 unique participants during both the initial and second monotherapy phases. A logistic regression analysis was performed on the initial monotherapy cohort (n = 103) with complete exposure-response data. Eighty-four participants achieved seizure freedom with a wide range of ethosuximide area under the curves (AUC) ranging from 420 to 2,420 μg·h/mL. AUC exposure estimates for achieving a 50% and 75% probability of seizure freedom were 1,027 and 1,489 μg·h/mL, respectively, whereas the corresponding cumulative frequency of intolerable adverse events was 11% and 16%. Monte Carlo Simulation indicated a daily dose of 40 and 55 mg/kg to achieve 50% and 75% probability of seizure freedom in the overall population, respectively. We identified the need for adjusted mg/kg dosing in different body weight cohorts. This ethosuximide proposed model-informed precision dosing guidance to achieve seizure freedom carries promise to optimize initial monotherapy success for patients with CAE., (© 2023 The Authors. Clinical Pharmacology & Therapeutics © 2023 American Society for Clinical Pharmacology and Therapeutics.)

Objective: To determine whether common polymorphisms in CACNA1G, CACNA1H, CACNA1I, and ABCB1 are associated with differential short-term seizure outcome in childhood absence epilepsy (CAE)., Methods: Four hundred forty-six CAE children in a randomized double-blind trial of ethosuximide, lamotrigine, and valproate had short-term seizure outcome determined. Associations between polymorphisms (minor allele frequency ≥ 15%) in 4 genes and seizure outcomes were assessed. In vitro electrophysiology on transfected CACNA1H channels determined impact of 1 variant on T-type calcium channel responsiveness to ethosuximide., Results: Eighty percent (357 of 446) of subjects had informative short-term seizure status (242 seizure free, 115 not seizure free). In ethosuximide subjects, 2 polymorphisms (CACNA1H rs61734410/P640L, CACNA1I rs3747178) appeared more commonly among not-seizure-free participants (p = 0.011, odds ratio [OR] = 2.63, 95% confidence limits [CL] = 1.25-5.56; p = 0.026, OR = 2.38, 95% CL = 1.11-5.00). In lamotrigine subjects, 1 ABCB1 missense polymorphism (rs2032582/S893A; p = 0.015, OR = 2.22, 95% CL = 1.16-4.17) was more common in not-seizure-free participants, and 2 CACNA1H polymorphisms (rs2753326, rs2753325) were more common in seizure-free participants (p = 0.038, OR = 0.52, 95% CL = 0.28-0.96). In valproate subjects, no common polymorphisms were associated with seizure status. In vitro electrophysiological studies showed no effect of the P640L polymorphism on channel physiology in the absence of ethosuximide. Ethosuximide's effect on rate of decay of Ca V 3.2 was significantly less for P640L channel compared to wild-type channel., Interpretation: Four T-type calcium channel variants and 1 ABCB1 transporter variant were associated with differential drug response in CAE. The in vivo P640L variant's ethosuximide effect was confirmed by in vitro electrophysiological studies. This suggests that genetic variation plays a role in differential CAE drug response. Ann Neurol 2017;81:444-453., (© 2017 American Neurological Association.)

Objective: To determine optimal second monotherapy for children with childhood absence epilepsy (CAE) experiencing initial treatment failure., Methods: Children with CAE experiencing treatment failure during the double-blind phase of a randomized controlled trial comparing ethosuximide, valproic acid, and lamotrigine were randomized to open-label second monotherapy with one of the 2 other study therapies. Primary study outcome was freedom from failure proportion at week 16-20 and month 12 visits after randomization. Secondary study outcome was percentage of participants experiencing attentional dysfunction at these visits., Results: A total of 208 children were enrolled, randomized, and received second therapy. At both week 16-20 visit and month 12 visit, ethosuximide's (63%, 57%) and valproic acid's (65%, 49%) freedom from failure proportions were similar to each other and higher than lamotrigine's (45%, 36%, p = 0.051 and p = 0.062). At both time points, ethosuximide and valproic acid had superior seizure control compared to lamotrigine (p < 0.0001). At both the week 16-20 and month 12 visits, attentional dysfunction was numerically more common with valproic acid than with ethosuximide or lamotrigine. For each medication, second monotherapy freedom from failure proportions demonstrated noninferiority to initial monotherapy freedom from failure proportions., Conclusions: As second monotherapy, ethosuximide and valproic acid, demonstrated higher freedom from failure proportions and greater efficacy than lamotrigine; valproic acid was associated with more attentional dysfunction. Ethosuximide is the optimal second monotherapy for children with CAE not responding to initial therapy with other medications., Clinicaltrialsgov Identifier: NCT00088452., Classification of Evidence: This study provides Class III evidence that for children with CAE experiencing initial treatment failure, second monotherapy with ethosuximide or valproic acid is superior to lamotrigine., (© 2016 American Academy of Neurology.)

Purpose: Determine the optimal initial monotherapy for children with newly diagnosed childhood absence epilepsy (CAE) based on 12 months of double-blind therapy., Methods: A double-blind, randomized controlled clinical trial compared the efficacy, tolerability, and neuropsychological effects of ethosuximide, valproic acid, and lamotrigine in children with newly diagnosed CAE. Study medications were titrated to clinical response, and subjects remained in the trial unless they reached a treatment failure criterion. Maximal target doses were ethosuximide 60 mg/kg/day or 2,000 mg/day, valproic acid 60 mg/kg/day or 3,000 mg/day, and lamotrigine 12 mg/kg/day or 600 mg/day. Original primary outcome was at 16-20 weeks and included a video-electroencephalography (EEG) assessment. For this report, the main effectiveness outcome was the freedom from failure rate 12 months after randomization and included a video-EEG assessment; differential drug effects were determined by pairwise comparisons. The main cognitive outcome was the percentage of subjects experiencing attentional dysfunction at the month 12 visit., Key Findings: A total of 453 children were enrolled and randomized; 7 were deemed ineligible and 446 subjects comprised the overall efficacy cohort. There were no demographic differences between the three cohorts. By 12 months after starting therapy, only 37% of all enrolled subjects were free from treatment failure on their first medication. At the month 12 visit, the freedom-from-failure rates for ethosuximide and valproic acid were similar (45% and 44%, respectively; odds ratio [OR]with valproic acid vs. ethosuximide 0.94; 95% confidence interval [CI] 0.58-1.52; p = 0.82) and were higher than the rate for lamotrigine (21%; OR with ethosuximide vs. lamotrigine 3.08; 95% CI 1.81-5.33; OR with valproic acid vs. lamotrigine 2.88; 95% CI 1.68-5.02; p < 0.001 for both comparisons). The frequency of treatment failures due to lack of seizure control (p < 0.001) and intolerable adverse events (p < 0.037) was significantly different among the treatment groups. Almost two thirds of the 125 subjects with treatment failure due to lack of seizure control were in the lamotrigine cohort. The largest subgroup (42%) of the 115 subjects discontinuing due to adverse events was in the valproic acid group. The previously reported higher rate of attentional dysfunction seen at 16-20 weeks in the valproic acid group compared with the ethosuximide or lamotrigine groups persisted at 12 months (p < 0.01)., Significance: As initial monotherapy, the superior effectiveness of ethosuximide and valproic acid compared to lamotrigine in controlling seizures without intolerable adverse events noted at 16-20 weeks persisted at 12 months. The valproic acid cohort experienced a higher rate of adverse events leading to drug discontinuation as well as significant negative effects on attentional measures that were not seen in the ethosuximide cohort. These 12-month outcome data coupled with the study's prespecified decision-making algorithm indicate that ethosuximide is the optimal initial empirical monotherapy for CAE. This is the first randomized controlled trial meeting International League Against Epilepsy (ILAE) criteria for class I evidence for CAE (or for any type of generalized seizure in adults or children). (NCT00088452.)., (Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.)

Background: Childhood absence epilepsy, the most common pediatric epilepsy syndrome, is usually treated with ethosuximide, valproic acid, or lamotrigine. The most efficacious and tolerable initial empirical treatment has not been defined., Methods: In a double-blind, randomized, controlled clinical trial, we compared the efficacy, tolerability, and neuropsychological effects of ethosuximide, valproic acid, and lamotrigine in children with newly diagnosed childhood absence epilepsy. Drug doses were incrementally increased until the child was free of seizures, the maximal allowable or highest tolerable dose was reached, or a criterion indicating treatment failure was met. The primary outcome was freedom from treatment failure after 16 weeks of therapy; the secondary outcome was attentional dysfunction. Differential drug effects were determined by means of pairwise comparisons., Results: The 453 children who were randomly assigned to treatment with ethosuximide (156), lamotrigine (149), or valproic acid (148) were similar with respect to their demographic characteristics. After 16 weeks of therapy, the freedom-from-failure rates for ethosuximide and valproic acid were similar (53% and 58%, respectively; odds ratio with valproic acid vs. ethosuximide, 1.26; 95% confidence interval [CI], 0.80 to 1.98; P=0.35) and were higher than the rate for lamotrigine (29%; odds ratio with ethosuximide vs. lamotrigine, 2.66; 95% CI, 1.65 to 4.28; odds ratio with valproic acid vs. lamotrigine, 3.34; 95% CI, 2.06 to 5.42; P<0.001 for both comparisons). There were no significant differences among the three drugs with regard to discontinuation because of adverse events. Attentional dysfunction was more common with valproic acid than with ethosuximide (in 49% of the children vs. 33%; odds ratio, 1.95; 95% CI, 1.12 to 3.41; P=0.03)., Conclusions: Ethosuximide and valproic acid are more effective than lamotrigine in the treatment of childhood absence epilepsy. Ethosuximide is associated with fewer adverse attentional effects. (ClinicalTrials.gov number, NCT00088452.), (2010 Massachusetts Medical Society)

Purpose: The long-term effectiveness of topiramate (TPM) was evaluated in children with West syndrome previously refractory to antiepileptic drug (AED) therapy., Methods: Children with infantile spasms who completed a pilot study were eligible to enter a long-term extension phase in which the dosages of TPM and other AEDs could be adjusted to optimal response (maximum, 50 mg/kg/day TPM). The mean duration of long-term therapy was 18 months in the 11 children who were followed; the mean TPM dosage was 29 mg/kg/day., Results: Eight (73%) children were continuing TPM therapy at the time data were analyzed; four (50%) children were spasm free, seven (88%) had experienced a > or =50% reduction in spasms, and three (38%) were able to achieve TPM monotherapy., Conclusions: TPM was well tolerated in that no patients discontinued because of adverse events. The response achieved with TPM during the pilot study was maintained in most children.

Purpose: West syndrome is a rare epileptic syndrome associated with infantile spasms, a specific abnormal electroencephalographic pattern (termed hypsarrhythmia), and mental retardation. Management of this disorder is difficult because current treatment regimens, including many anticonvulsants and hormones, are often ineffective. Topiramate (TPM) is a new antiepileptic drug that may be effective in pediatric epilepsies. We conducted a pilot study to test the effects of rapid TPM dosing in patients with refractory infantile spasms., Methods: Eleven children with refractory infantile spasms were given an initial dose of 25 mg TPM per day in addition to their current therapy. Dosage was increased by 25 mg every 2-3 days until spasms were controlled, the maximal tolerated dose was reached, or the maximal dose of 24 mg/kg/day was achieved. Efficacy was primarily assessed by video EEG and secondarily by parental count of spasm frequency., Results: Five (45%) subjects became spasm free during the study, with absence of infantile spasms and hypsarrhythmia (either classic or modified) proven by video EEG. Nine subjects, including the five spasm free, achieved a spasm reduction of > or =50%. Spasm frequency decreased from 25.6+/-19.3 to 6.9+/-5.9 spasms/day. Sixty-four percent of the subjects were able to achieve TPM monotherapy., Conclusions: Results in this cohort of 11 patients with refractory disease show TPM to be a promising new agent for the treatment of infantile spasms.

Addition of spermidine in millimolar concentrations to Bacillus subtilis cells curing competence development increases transformability. The spermidine must be added at least 30 min before DNA for maximum stimulation. An incubation period of about 30 minutes is also required for the maximum uptake of labeled spermidine. The amount of DNA initially attached and the rate of DNA uptake are increased to the same extent as transformation. The rate of protein synthesis is also equivalently increased. These observations are consistent with an increase in the number of competent cells in the cell population; this increase is mediated by a spermidine-stimulated protein synthesis.

Platelet-activating factor secreted by stimulated human neutrophils and monocytes and rabbit neutrophils and basophils was isolated, purified and chemically and physically characterized. All four preparations had identical thin layer chromatographic behavior in a variety of solvent systems, identical solubility behavior in various organic and aqueous solvents and responded comparably to a variety of chemical and physical agents designed to reveal the presence functional groups. These findings indicate that human neutrophil and monocyte, and rabbit neutrophil and basophil derived platelet-activating factor preparations are indistinguishable, and support the conclusion that platelet-activating factor is a neutral, polar lipid molecule whose functional activity is dependent upon the presence of a carboxylic acid ester.

Extracellular Ca2+ regulated the synthesis and release of platelet-activating factor (PAF) from human polymorphonuclear leukocytes (PMN) stimulated with N'-formyl-methionyl-leucyl-phenylalanine (FMLP) in the presence of cytochalasin B. Maximum PAF synthesis and release required the presence of 0.14 mM Ca2+ whereas 1.4 mM Ca2+ was necessary for maximum lysosomal enzyme secretion. The synthesis of PAF occurred within 2.5 min after PMN stimulation in the presence of 1.4 mM Ca2+; however, PAF release did not occur until 5 min after stimulation. Peak PAF release occurred by 7.5 min but accounted for only 30-40% of the total amount of PAF synthesized, the remainder being retained on or within the PMN. Stimulation of PMN in the presence of 0.01 M EDTA or EGTA decreased PAF synthesis and release by greater than 95%. In the absence of extracellular Ca2+, stimulated PMN synthesized PAF in amounts that were 10-30% of maximum, but there was no release of the newly synthesized PAF. At Ca2+ concentrations greater than 0.01 mM, there was a dose-dependent (up to 0.14 mM) increase in PAF synthesis that was associated with the initiation and concomitant increase in the amount of PAF released. These data suggest the presence of a PAF synthesis-release coupling mechanism in which the extracellular Ca2+-dependent release of PAF stimulates additional PAF synthesis.

Treatment of competent Bacillus subtilis in a Waring Blendor for 10 s increases transformability of the culture about twofold while reducing the attachment of DNA to competent cells by 80%. The effectiveness of attached DNA in producing transformants is increased 10-fold by this treatment. The uptake of transforming DNA into a DNase-resistant state is progressively reduced by 70% during a 120-s blending treatment. Blending for 30-45 s diminishes transformability to about 10% of the original nonblended value without affecting the viable cell titer. No effect is produced by 30 s of blending on transformability if the irreversible uptake of DNA has been completed. Thus, the inhibition occurs at an early step in the transformation sequence. Treatment of the competent culture for 60 s or longer in the Waring Blendor reduces both the number of transformants obtained and the total number of viable cells.