Concise approach to γ-(het)aryl- and γ-alkenyl-γ-aminobutyric acids. Synthesis of vigabatrin.

γ-Aminobutyric acid (GABA) and GABA derivatives have attracted increased attention over the years in the fields of medicinal chemistry and chemical biology due to their interesting biological properties and synthetic relevance. Here, we report a short synthetic route to γ-(het)aryl- and γ-alkenyl-γ-aminobutyric acids, including the antiepileptic drug vigabatrin, from readily available donor-acceptor cyclopropanes and ammonia or methylamine. This protocol includes a facile synthesis of 2-oxopyrrolidine-3-carboxamides and their acid hydrolysis to γ-aryl- or γ-alkenyl-substituted GABAs, which can serve as perspective building blocks for the synthesis of various GABA-based N-heterocycles and bioactive compounds.

Treatment modalities for infantile spasms: current considerations and evolving strategies in clinical practice.

Infantile spasms, newly classified as infantile epileptic spasm syndrome (IESS), occur in children under 2 years of age and present as an occur as brief, symmetrical, contractions of the musculature of the neck, trunk, and extremities. When infantile spasms occur with a concomitant hypsarrhythmia on electroencephalogram (EEG) and developmental regression, it is known as West Syndrome. There is no universally accepted mainstay of treatment for this condition, but some options include synthetic adrenocorticotropic hormone (ACTH), repository corticotropin injection (RCI/Acthar Gel), corticosteroids, valproic acid, vigabatrin, and surgery. Without effective treatment, infantile spasms can cause an impairment of psychomotor development and/or cognitive and behavioral functions. The first-line treatment in the USA is ACTH related to high efficacy for cessation of infantile spasms long-term and low-cost profile. Acthar Gel is a repository corticotropin intramuscular injection that became FDA-approved for the treatment of IESS in 2010. Though it is believed that ACTH, Acthar Gel, and corticosteroids all work via a negative feedback pathway to decrease corticotropin-releasing hormone (CRH) release, their safety and efficacy profiles all vary. Vigabatrin and valproic acid are both anti-seizure medications that work by increasing GABA concentrations in the CNS and decreasing excitatory activity. Acthar Gel has been shown to have superior efficacy and a diminished side effect profile when compared with other treatment modalities.

Fifteen years of real-world data on the use of vigabatrin in individuals with infantile epileptic spasms syndrome.

OBJECTIVE: This study was undertaken to evaluate our treatment algorithm for infantile epileptic spasms syndrome (IESS) used between 2000 and 2018. We initiated vigabatrin (VGB), and steroids were added if the electroclinical response (spasms and electroencephalogram [EEG]) to VGB was not obtained or incomplete. METHODS: Individuals with IESS treated with VGB were recruited from our hospital clinical data warehouse based on electronic health records (EHRs) generated since 2009 and containing relevant keywords. We confirmed the diagnosis of IESS. Clinical, EEG, imaging, and biological data were extracted from the EHRs. We analyzed factors associated with short-term response, time to response, relapse, time to relapse of spasms, and the presence of spasms at last follow-up. RESULTS: We collected data from 198 individuals (female: 46.5%, IESS onset: 6 [4.5-10.3] months, follow-up: 4.6 [2.5-7.6] years, median [Q1-Q3]) including 129 (65.2%) with identifiable etiology. VGB was started 17 (5-57.5) days after IESS diagnosis. A total of 113 individuals were responders (57.1% of the cohort), 64 with VGB alone and 38 with VGB further combined with steroids (56.6% and 33.6% of responders, respectively). Among responders, 33 (29%) experienced relapses of spasms, mostly those with later onset of spasms (p = .002) and those who received VGB for <24 months after spasms cessation compared to a longer duration on VGB (45% vs. 12.8%, p = .003). At follow-up, 92 individuals were seizure-free (46.5% of the whole cohort), including 26 free of therapy (13.1%). One hundred twelve individuals (56.6%) were still receiving VGB, with a duration of 3.2 (1.75-5.7) years. SIGNIFICANCE: Our sequential protocol introducing VGB then adding steroids is an effective alternative to a combined VGB-steroids approach in IESS. It avoids steroid-related adverse events, as well as those from VGB-steroid combination. According to our data, a period of 7 days seems sufficient to assess VGB response and enables the addition of steroids rapidly if needed. Continuing VGB for 2 years may balance the risk of relapse and treatment-induced adverse events.

Chronic intermittent convection-enhanced delivery of vigabatrin to the bilateral subthalamic nucleus in an acute rat seizure model.

Targeted intracerebral drug delivery is an attractive experimental approach for the treatment of drug-resistant epilepsies. In this regard, the subthalamic nucleus (STN) represents a focus-independent target involved in the remote modulation and propagation of seizure activity. Indeed, acute and chronic pharmacological inhibition of the STN with vigabatrin (VGB), an irreversible inhibitor of GABA transaminase, has been shown to produce antiseizure effects. This effect, however, is lost over time as tolerance develops with chronic, continuous intracerebral pharmacotherapy. Here we investigated the antiseizure effects of chronic intermittent intra-STN convection-enhanced delivery of VGB in an acute rat seizure model focusing on circumventing tolerance development and preventing adverse effects. Timed intravenous pentylenetetrazol (PTZ) seizure threshold testing was conducted before and after implantation of subcutaneous drug pumps and bilateral intra-STN cannulas. Drug pumps infused vehicle or VGB twice daily (0.4 µg) or once weekly (2.5 µg, 5 µg) over three weeks. Putative adverse effects were evaluated and found to be prevented by intermittent compared to previous continuous VGB delivery. Clonic seizure thresholds were more clearly raised by intra-STN VGB compared to myoclonic twitch. Both twice daily and once weekly intra-STN VGB significantly elevated clonic seizure thresholds depending on dose and time point, with responder rates of up to 100% observed at tolerable doses. However, tolerance could not be completely avoided, as tolerance rates of 40-75% were observed with chronic VGB treatment. Results indicate that the extent of tolerance development after intermittent intra-STN VGB delivery varies depending on infusion dose and regimen.

The vigabatrin-associated brain abnormalities on MRI and their differential diagnosis.

Vigabatrin is an anti-epileptic drug that inhibits the enzyme γ-aminobutyric acid (GABA)-transaminase. The anticonvulsant effect of vigabatrin involves increasing GABA levels and attenuating glutamate-glutamine cycling. Vigabatrin indications include infantile spasms and refractory focal seizures. Despite having a significant role in paediatric epileptology, vigabatrin has adverse effects, such as retinal toxicity, in up to 30% of patients after 1 year of use and brain abnormalities on magnetic resonance imaging (MRI). The percentage of patients with brain abnormalities on MRI varies between 22-32% of children using vigabatrin to treat infantile spasms. Risk factors for presenting these imaging abnormalities are cryptogenic infantile spasms, age <12 months old, high dosage, and possible concomitant hormonal therapy. Clinically, these abnormalities are usually asymptomatic. Histopathological analysis reveals white matter vacuolation and intramyelinic oedema. The typical findings of vigabatrin-associated brain abnormalities on MRI are bilateral and have a symmetrical hyperintense signal on T2-weighted imaging, with diffusion restriction, that often compromise the globi pallidi, thalami, subthalamic nuclei, cerebral peduncles, midbrain, dorsal brainstem, including the medial longitudinal fasciculi, and dentate nuclei of the cerebellum. In this article, the authors intend to review the clinical manifestations, histopathological features, imaging aspects, and differential diagnosis of vigabatrin-associated brain abnormalities on MRI.

Societal costs of illness for infantile epileptic spasms syndrome and evolutionary cost prediction in the era of WHO's IGAP.

BACKGROUND: To achieve the goal of improving the quality of life for persons with epilepsy within the framework of the WHO's Intersectoral Global Action Plan (IGAP), our study aimed to assess the societal financial burden linked to infantile epileptic spasms syndrome (IESS), ensuring that children afflicted with IESS receive high-quality healthcare without enduring substantial financial constraints. METHODS: Between August 2022 and March 2023, 92 children with IESS (male: female: 2:1), recently diagnosed or previously followed-up, were recruited. We gathered costs for drugs, tests, and medical services, along with legal guardians' monthly income. Total expenditure was determined by multiplying unit costs by the yearly service usage commencing from the onset. Time series analysis was utilised to forecast the financial burden from 2022 to 2032. RESULTS: Clinicians' first choice of treatment was ACTH (n = 60, 65·2%), prednisolone (n = 25, 27·2%), and vigabatrin (n = 7, 7·6%) and the median cost of treatment during the initial year was INR 39,010 [USD 479·2]. The median direct medical, direct non-medical, and indirect cost were INR 31,650 [USD 388·4], INR 6581 [USD 80·8], and INR 10,100 [USD 124·07], respectively. Families lost a median of 12 days of work annually. Drug costs and loss of wages were the key factors in the financial burden. The projected and adjusted figures exhibited an incremental growth rate of 2·6% tri-annually. INTERPRETATION: This pioneering study in developing countries, the first of its kind, evaluates the societal cost, financial hardship, and trajectory of incremental cost in IESS. The primary drivers of the financial burden were pharmacological treatment and family work adjustments. The government shoulders 62% of the financial burden, and projected a triannual growth of 2·6% from 2022 to 2032. Our results rationalize policymakers' focus on incorporating IESS into social security programs, particularly in developing countries.

Discovery of GABA Aminotransferase Inhibitors via Molecular Docking, Molecular Dynamic Simulation, and Biological Evaluation.

γ-Aminobutyric acid aminotransferase (GABA-AT) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that degrades γ-aminobutyric (GABA) in the brain. GABA is an important inhibitory neurotransmitter that plays important neurological roles in the brain. Therefore, GABA-AT is an important drug target that regulates GABA levels. Novel and potent drug development to inhibit GABA-AT is still a very challenging task. In this study, we aimed to devise novel and potent inhibitors against GABA-AT using computer-aided drug design (CADD) tools. Since the crystal structure of human GABA-AT was not yet available, we utilized a homologous structure derived from our previously published paper. To identify highly potent compounds relative to vigabatrin, an FDA-approved drug against human GABA-AT, we developed a pharmacophore analysis protocol for 530,000 Korea Chemical Bank (KCB) compounds and selected the top 50 compounds for further screening. Preliminary biological analysis was carried out for these 50 compounds and 16 compounds were further assessed. Subsequently, molecular docking, molecular dynamics (MD) simulations, and binding free energy calculations were carried out. In the results, four predicted compounds, A07, B07, D08, and H08, were found to be highly potent and were further evaluated by a biological activity assay to confirm the results of the GABA-AT activity inhibition assay.

Molecular EPISTOP, a comprehensive multi-omic analysis of blood from Tuberous Sclerosis Complex infants age birth to two years.

We present a comprehensive multi-omic analysis of the EPISTOP prospective clinical trial of early intervention with vigabatrin for pre-symptomatic epilepsy treatment in Tuberous Sclerosis Complex (TSC), in which 93 infants with TSC were followed from birth to age 2 years, seeking biomarkers of epilepsy development. Vigabatrin had profound effects on many metabolites, increasing serum deoxycytidine monophosphate (dCMP) levels 52-fold. Most serum proteins and metabolites, and blood RNA species showed significant change with age. Thirty-nine proteins, metabolites, and genes showed significant differences between age-matched control and TSC infants. Six also showed a progressive difference in expression between control, TSC without epilepsy, and TSC with epilepsy groups. A multivariate approach using enrollment samples identified multiple 3-variable predictors of epilepsy, with the best having a positive predictive value of 0.987. This rich dataset will enable further discovery and analysis of developmental effects, and associations with seizure development in TSC.

Teratogenic impacts of Antiepileptic drugs on development, behavior and reproduction in Drosophila melanogaster.

Clobazam (CLB) and Vigabatrin (VGB) are the two widely used Antiepileptic drugs, which may have teratogenic potentiality and it has been evaluated in the fruit fly Drosophila melanogaster. These different concentrations of CLB (0.156, 0.25, and 0.312 µg/ml) and VGB (17.6, 22, and 44 µg/ml) were used to evaluate the life-history parameters, developmental, and behavioral abnormalities. The results revealed that life-history parameters (fecundity, fertility, larval and pupal mortality) were significantly affected along with varied developmental duration, and pupal and adult deformities in flies on exposure of CLB and VGB in concentration dependent manner. The present study demonstrated that the prenatal treatment of CLB and VGB has displayed clear teratogenic potentiality with various deformities in the fruit fly. The findings could be correlated with the various abnormalities in human caused by the use of AEDs.

Brazilian experts' consensus on the treatment of infantile epileptic spasm syndrome in infants.

BACKGROUND: Infantile epileptic spasms syndrome (IESS) is a rare but severe condition affecting children early and is usually secondary to an identifiable brain disorder. It is related to psychomotor deterioration in childhood and epilepsy in adult life. Treatment is challenging as infantile spasms may not respond to most antiseizure medication, and relapse is frequent. OBJECTIVE: To evaluate the literature regarding treatment of IESS and provide a practical guidance to a healthcare system with limited resources. METHODS: An expert committee from the Brazilian Society of Child Neurology reviewed and discussed relevant scientific evidence in the treatment of IESS regarding the drugs available in Brazil. RESULTS: Oral prednisolone and vigabatrin are the most common drugs used as first-line therapy; they are efficient and affordable therapy as both are available in the Brazilian unified health system (SUS, in the Portuguese acronym). Intramuscular adrenocorticotropic hormone (ACTH) presents similar efficacy as oral prednisolone but has a higher cost and is not available in Brazil. Other antiseizure medications such as topiramate, levetiracetam, or benzodiazepines have limited response and are prescribed as adjuvant therapy. If the health service has nutritionists, a ketogenic diet should be implemented for those not responding to hormonal and vigabatrin treatment. Epilepsy surgery is mainly indicated for patients with focal lesions that do not respond to pharmacological therapy. CONCLUSION: Early treatment of IESS with efficient drugs is feasible in our country. Using standard protocols increases the odds of achieving complete cessation in a shorter time and decreases relapse.

ANTECEDENTES: A síndrome do espasmo epiléptico infantil (IESS) é uma condição rara, mas grave, que afeta crianças precocemente e geralmente é secundária a um distúrbio cerebral identificável, estando relacionada a deterioração psicomotora na infância e a epilepsia na vida adulta. O tratamento é desafiador, pois os espasmos infantis podem não responder à maioria dos medicamentos anticrises e as recidivas são frequentes. OBJETIVO: Avaliar a literatura sobre o tratamento de IESS e fornecer uma orientação prática para um sistema de saúde com recursos limitados. MéTODOS: Um comitê de especialistas da Sociedade Brasileira de Neurologia Infantil revisou e discutiu evidências científicas relevantes no tratamento da IESS em relação aos medicamentos disponíveis no Brasil. RESULTADOS: Prednisolona oral e vigabatrina são os fármacos mais comumente usados como terapia de primeira linha; são eficientes e acessíveis, já que ambos estão disponíveis no sistema único de saúde brasileiro (SUS). O ACTH intramuscular apresenta eficácia semelhante à prednisolona oral, mas tem custo mais elevado e não está disponível no Brasil. Outros medicamentos anticonvulsivos, como topiramato, levetiracetam ou benzodiazepínicos, têm resposta limitada e são prescritos como terapia adjuvante. Se o serviço de saúde tiver nutricionista, deve-se implementar dieta cetogênica para aqueles que não respondem ao tratamento hormonal e vigabatrina. A cirurgia de epilepsia é indicada principalmente para pacientes com lesões focais que não respondem à terapia farmacológica. CONCLUSãO: O tratamento precoce da IESS com fármacos eficazes é factível em nosso meio. O uso de protocolos padronizados aumenta as chances de alcançar a cessação completa em um tempo menor e diminui a recaída.

Encefalopatia toxica secundaria a vigabatrina: Reporte de caso / Toxic encephalopathy secondary to vigabatrin: Case report

El síndrome de West es una encefalopatía epiléptica caracterizada por espasmos en flexión, hipsarritmia en el electroencefalograma y retraso en el neurodesarrollo. Reportamos el caso de una paciente de 11 meses con diagnóstico de Síndrome de West y encefalopatía tóxica secundaria al uso de vigabatrina

West syndrome is an epileptic encephalopathy characterized by flexing spasms, hypsarritmia in the electroencephalogram and delayed neurodevelopment. We report an 11-month-old patient with a diagnosis of West syndrome and toxic encephalopathy secondary to the use of vigabatrin

Retinal and Systemic Toxicity of Vigabatrin Is Driven by the S-Enantiomer in the Long Evans Rat.

In this study, we assessed the toxicity and toxicokinetics of racemic vigabatrin and its S- and R-enantiomers (vigabatrin consists of 50:50% of the two enantiomers) by administering doses of the three test articles to male Long Evans rats via oral gavage. The animals were housed under high-intensity light conditions and the study consisted of an escalating dose phase and a 21-day fixed-dose phase. Systemic toxicity of vigabatrin appears to be due to the Vig-S-enantiomer only, as increasing doses of Vig-S or Vig-RS caused body weight loss, decreased food consumption, and affected activity. Administration of the Vig-R-enantiomer did not cause any such effects. Systemic exposure to R- and S-enantiomers was approximately linear with dose. Compared to administration of the racemate, there appeared to be a tendency for animals to take up higher amounts of Vig-R and lower amounts of Vig-S when administered as enantiomer. Bilateral retinal atrophy was observed in the fixed-dose phase in rats receiving Vig-S (either alone or as part of Vig-RS) and was characterized by irregular thinning and disorganization of the outer nuclear layer and thinning of the photoreceptor layer. The administration of the R-enantiomer alone did not cause any microscopic retinal change.

Physician experiences with and perceptions of risk evaluation and mitigation strategy programs with elements to assure safe use.

PURPOSE: The US Food and Drug Administration (FDA) Amendments Act of 2007 authorized the FDA to require risk evaluation and mitigation strategy (REMS) programs for drugs with important safety concerns. REMS can have elements to assure safe use (ETASU), such as patient registries, dispensing restrictions, and physician training and certification requirements. We aimed to understand physician experiences with and perceptions of a selection of ETASU REMS. METHODS: Physicians prescribing 1 of 4 ETASU REMS-covered drugs: natalizumab, riociguat, sodium oxybate, and vigabatrin. STUDY DESIGN: Descriptive phenomenological study based on semi-structured phone interviews. DATA COLLECTION/EXTRACTION METHODS: Qualitative content analysis to summarize physician responses to open-ended questions. RESULTS: Of 31 physicians (14 female), 6 prescribed riociguat, 6 vigabatrin, 7 sodium oxybate, and 12 natalizumab (5 for Crohn's disease, 7 for multiple sclerosis), most demonstrated good understanding of the rationale for and requirements of the ETASU REMS but believed that the programs had limited effect on clinical practice. Some physicians reported that the ETASU REMS made them more comfortable with prescribing covered drugs due to heightened oversight, facilitated discussions about treatment, and were likely more beneficial for non-specialists. Concerns were raised about the administrative effort needed to comply with the programs and the potential misuse of patient health information transmitted to manufacturers. CONCLUSIONS: Physicians are generally aware of ETASU REMS and get reassurance from the additional oversight, but the programs can be better integrated into clinical workflows and can be designed to better protect patient health information.

Infantile spasms caused by NEXMIF mutation: A case report and literature review.

BACKGROUND: Infantile spasms are rare epileptic syndromes associated with neurodevelopment and genes. The NEXMIF gene, identified as KIDLIA, KIAA2022 or Xpn, is a gene of unknown biological identity located on the q13.2 X chromosome. CASE DESCRIPTION: We presented a 4-month-old infant with a diagnosis of infantile spasms with NEXMIF mutation. Clinical manifestations include psychomotor retardation, loss of consciousness, and seizures. After oral therapy with vigabatrin, sodium valproate, and levetiracetam, the syndrome was alleviated and no recurrence was observed during one month of follow-up. CONCLUSIONS: A loss-of-function mutation in the NEXMIF gene has been reported. There are few reports on this mutation worldwide. This study provides a new idea for the clinical treatment of infantile spasms.

Inaccuracies in Parental Reporting of Treated Epileptic Spasms: Both Under- and Over-Reporting.

BACKGROUND: The purpose of this study was to evaluate the accuracy of parental reporting of epileptic spasms (ES) after 14 days of appropriate medical therapy for new-onset ES by comparison with extended video electroencephalography (vEEG) monitoring results. METHODS: Fifty-eight patients were identified from August 2019 to February 2021 with new-onset ES, confirmed on vEEG. Patients were initiated on appropriate treatment (high-dose steroids or vigabatrin). After two weeks of therapy, patients underwent overnight (18 to 24 hours) vEEG monitoring in the epilepsy monitoring unit. Parental reporting of presence or absence of ES on admission was compared with results of vEEG monitoring. RESULTS: The 58 patients ranged in age from three to 20 months (average 7.8 months). An underlying etiology was identified in 78%, whereas 22% patients had unknown etiology. The overall accuracy of parental reporting was 74% (43 of 58) when compared with results of vEEG within 14 to 18 days of starting therapy. Of these, 65% (28 of 43) reported ES resolution and 35% (15 of 43) reported continued ES. Of the 26% (15 of 58) families who were incorrect at two-week follow-up, 67% (10 of 15) reported resolution of ES. However, a minority of families, 33% (five of 15), who continued to report spasms clinically, were inaccurate. CONCLUSIONS: Although a majority of inaccurate parental reports at two weeks of treatment were due to unrecognized ES (a widely known phenomenon), a minority were conversely inaccurate due to persistent over-reporting of ES. This fact highlights the importance of correlating parental history with objective vEEG monitoring, to prevent inappropriate escalation of medication therapy.

Newer Antiseizure Medications and Suicidality: Analysis of the Food and Drug Administration Adverse Event Reporting System (FAERS) Database.

BACKGROUND: The association between antiseizure medications (ASMs) and suicidality remains controversial. Analyses of additional datasets are needed to further elucidate the complex relationship between antiseizure medications and suicidality. OBJECTIVE: The aim of this study was to compare the safety profile of newer ASMs with older ASMs through an analysis of the US Food and Drug Administration Adverse Event Reporting System (FAERS) database, with a focus on suicidality. METHODS: We queried over 17 million reports in the FAERS database from 2012 to 2021 and identified cases involving ASMs. After removing incomplete and duplicate reports, the study cohort consisted of lacosamide (n = 7593), perampanel (n = 1813), clobazam (n = 3827), brivaracetam (n = 1166), and vigabatrin (n = 5293) compared with a control group of older ASMs (topiramate, lamotrigine, valproic acid, carbamazepine, levetiracetam; n = 71,535). Cases of suicidality (completed suicide, suicidal ideation, attempted suicide, suicidal behavior, suicidal depression) were identified in each group. Adjusted (age and sex) odds ratios (aOR) and associated 95% confidence intervals (CI) were calculated using logistic regression analysis for each new drug when compared with the control group of older ASM drugs. RESULTS: A total of 6309 cases of suicidality were identified among reports with ASMs. Most reports were sourced from healthcare professionals (5516, 87.4%). The proportion of reports involving suicidality were 210/7593 (2.8%) for lacosamide, 185/1813 (10.2%) for perampanel, 108/3827 (2.8%) for clobazam, 57/1166 (4.9%) for brivaracetam, 14/5293 (0.3%) for vigabatrin, and 5735/71,535 (8.0%) for older ASMs. Compared with older ASMs, the aOR for suicidality was 0.33 (95% CI 0.28-0.38) for lacosamide, 1.34 (95% CI 1.15-1.56) for perampanel, 0.35 (95% CI 0.29-0.43) for clobazam, 0.60 (95% CI 0.45-0.77) for brivaracetam, and 0.03 (95% CI 0.02-0.05) for vigabatrin. CONCLUSION: When compared with older ASMs, four newer ASMs (lacosamide, clobazam, brivaracetam, and vigabatrin) were found to have significantly lower odds of suicidality, while perampanel was found to significantly increase the odds of suicidality. Pronounced variability (greater than 30 fold) in the proportion of FAERS reports associated with suicidality among the drugs studied was identified. The results of this case control study of FDA adverse event reports spanning 10 years and 6309 cases of suicidality expand our understanding of the safety profile of newer ASMs.