Infantile spasms: A U.S. consensus report

Factors predictive of prognosis of infantile spasms. A retrospective study in a low-income country

PURPOSE

To describe the management of infants with epileptic spasms (ESs) in a low-income country and identify factors predictive of their prognosis.

MATERIAL AND METHODS

We conducted a retrospective study in a university hospital in Tunis, Tunisia, over a period of 10 years. We included infants with recurrent ESs.

RESULTS

Thirty-eight patients were included. The median age at onset of ESs was 5 months. Typical hypsarrhythmia was found in 21 patients (55%). Brain MRI was done in 32 patients (84%) and metabolic work-up in 34 patients (89%). ESs were categorized as symptomatic in 58% of the patients. Vigabatrin was prescribed as the first-line drug in almost half of the patients. At the last follow-up, 63% of the patients were seizure-free and 82% had a psychomotor delay. The presence of other types of seizures was associated with uncontrolled epilepsy at the last follow-up (P=0.020). The persistence of spasms after the first-line treatment was associated with abnormal final psychomotor development (P=0.047).

CONCLUSIONS

Investigation practices and final outcomes of our patients were comparable to data from high-income countries. Treatment practices have been standardized to be in line with international guidelines.

Treatment of infantile spasms

The treatment of infantile spasms is challenging, especially in the context of the following: (1) a severe phenotype with high morbidity and mortality; (2) the urgency of diagnosis and successful early response to therapy; and (3) the paucity of effective, safe, and well-tolerated therapies. Even after initially successful treatment, relapse risk is substantial and the most effective therapies pose considerable risk with long-term administration. In evaluating any treatment for infantile spasms, the key short-term outcome measure is freedom from both epileptic spasms and hypsarrhythmia. In contrast, the most important long-term outcomes are enduring seizure-freedom and measures of intellectual performance in later childhood and adulthood. First-line treatment options-namely hormonal therapy and vigabatrin-display moderate to high efficacy but also exhibit substantial side-effect burdens. Data on efficacy and safety of each class of therapy, as well as the combination of these therapies, are reviewed in detail. Specific hormonal therapies (adrenocorticotropic hormone and various corticosteroids) are contrasted. Those etiologies that prompt specific therapies are reviewed briefly, as are an array of second-line therapies supported by less-compelling data. The ketogenic diet is discussed in greater detail, with a focus on the limitations of numerous available studies that generally suggest that it is efficacious. Special discussion is allocated to cannabidiol-the investigational therapy that has received the most attention, and which is already in use in the form of various artisanal cannabis extracts. Finally, a treatment algorithm reflecting the concepts and controversies discussed in this review is presented.

Longitudinal brain functional and structural connectivity changes after hemispherotomy in two pediatric patients with drug-resistant epilepsy

The main focus of the present study was to explore the longitudinal changes in the brain executive control system and default mode network after hemispherotomy. Resting-state functional magnetic resonance imaging and diffusion tensor imaging were collected in two children with drug-resistnt epilepsy underwent hemispherotomy. Two patients with different curative effects showed different trajectories of brain connectivity after surgery. The failed hemispherotomy might be due to the fact that the synchrony of epileptic neurons in both hemispheres is preserved by residual neural pathways. Loss of interhemispheric correlations with increased intrahemispheric correlations can be considered as neural marker for evaluating the success of hemispherotomy.

Acquired parvalbumin-selective interneuronopathy in the multiple-hit model of infantile spasms: A putative basis for the partial responsiveness to vigabatrin analogs?

West syndrome, an age-specific epileptic encephalopathy, manifests with infantile spasms (IS) and impaired neurodevelopmental outcomes and epilepsy. The multiple-hit rat model of IS is a chronic model of IS due to structural etiology, in which spasms respond partially to vigabatrin analogs. Using this model, we investigated whether IS due to structural etiology may have deficits in parvalbumin (PRV) and somatostatin (SST) immunoreactive (-ir) interneurons, and calretinin-ir (CR-ir) neurons of the primary somatosensory cortex of postnatal day (PN) 20-24 rats, using specific immunohistochemical assays. PN3 Sprague-Dawley male rats underwent the multiple-hit induction protocol, were monitored until PN20-24, and were transcardially perfused to collect brains for histology. Age-matched sham and naive control male rats were also used. Coronal brain cryosections were stained with anti-PRV, anti-CR, and anti-SST antibodies, and regions of interest (ROIs) from the primary somatosensory cortices were selected to determine PRV-, CR-, and SST-ir cell counts and cortical ROI volumes, with blinding to experimental group. Statistical analyses were done using a linear mixed model accounting for repeated measures. We found PRV-ir interneuronal selective reduction, sparing of the CR-ir and SST-ir neurons, and bilateral cortical atrophy. Our findings provide evidence for acquired PRV-selective interneuronopathy, possibly underlying the pathogenesis of IS, neurodevelopmental deficits, and epilepsy, and potentially contributing to the partial response to vigabatrin analogs in this model.

High vigabatrin dosage is associated with lower risk of infantile spasms relapse among children with tuberous sclerosis complex

After initially successful treatment of infantile spasms, the long-term cumulative risk of relapse approaches 50%, and there is no established protocol to mitigate this risk. Although vigabatrin may be an effective means to prevent relapse, there is little guidance as to ideal duration and dosage. Using a cohort of children with infantile spasms and tuberous sclerosis complex (TSC), we evaluated the potential association of post-response VGB treatment and the rate of infantile spasms relapse. Patients with infantile spasms and clinical response to vigabatrin were identified among a multicenter prospective observational cohort of children with TSC. For each patient we recorded dates of infantile spasms onset, response to vigabatrin, relapse (if any), and quantified duration and dosage of vigabatrin after response. Time to relapse as a function of vigabatrin exposure was evaluated using survival analyses. We identified 50 children who responded to VGB. During a median follow-up of 16.6 months (IQR 10.3-22.9), 12 (24%) patients subsequently relapsed after a median of 7.8 months (IQR 3.1-9.6). Relapse occurred after VGB discontinuation in four patients, and during continued VGB treatment in the remaining eight cases. In survival analyses, risk of relapse was unaffected by the presence or absence of VGB treatment (HR 0.31, 95%CI 0.01-28.4, P =  0.61), but weighted-average dosage was associated with marked reduction in relapse risk: Each 50 mg/kg/d increment in dosage was associated with 61% reduction in risk (HR 0.39, 95%CI 0.17 - 0.90, P =  0.026). This study suggests that the risk of infantile spasms relapse in TSC may be reduced by high-dose vigabatrin treatment.

Treating Infantile Spasms with High-Dose Oral Corticosteroids: A Retrospective Review of 87 Children

BACKGROUND

Hormonal therapy is the treatment of choice in most patients with infantile spasms, but the optimal way to provide this therapy is unclear. Intramuscular adrenocorticotropic hormone (ACTH) has historically used first-line; however, there are significant logistical and financial issues. Our institution has used high-dose prednisolone as the first-line hormonal treatment of infantile spasms since 2006 and published our early experience with 15 infants in 2009. This study updates our institutional experience over more than 10 years of continuous use.

METHODS

Charts of infants who presented to the Johns Hopkins Hospital with infantile spasms and were treated with high-dose oral prednisolone (40-60 mg/day) from January, 2006 through December, 2016 were reviewed. Electroclinical response was defined as clinical spasm-freedom and resolution of hypsarrhythmia within two weeks of initiation of therapy. Presence of infantile spasms at three months and adverse effects throughout treatment were evaluated.

RESULTS

Over the 10-year period, 87 infants with new-onset infantile spasms were treated. Electroclinical response occurred in 64% infants within two weeks; 62% were spasm-free at three months. Fifty-two percent had side effects, primarily irritability, weight gain, and gastroesophageal reflux. Five percent had major adverse events, including gastrointestinal bleeding (n = 2), herpes simplex virus reactivation (n = 1), and necrotizing enterocolitis (n = 1).

CONCLUSIONS

Our results continue to demonstrate that high-dose oral prednisolone is very effective for the treatment of new-onset infantile spasms, with few major adverse effects. Oral prednisolone represents a less expensive, readily available alternative to adrenocorticotropic hormone injections.

Vitamin B12 Deficiency in Children With Infantile Spasms: A Case-Control Study

There have been few case reports showing association of vitamin B₁₂ deficiency with infantile spasms. We planned this study to see if there was an association of serum vitamin B₁₂ deficiency in children with development of infantile spasms. Cases included children with infantile spasms of ages 6 months to 3 years. The controls were children in the same age group who had global developmental delay but no history of epileptic spasms. Mean serum vitamin B₁₂, serum homocysteine, and urinary methylmalonic acid levels were measured in both groups and compared. Children with infantile spasms had lower mean serum vitamin B₁₂ levels (354.1 pg/mL; standard deviation 234.1 pg/mL) as compared to children with global developmental delay without spasms (466.7 pg/mL; standard deviation 285.5 pg/mL) ( P value < .05). Mean serum homocysteine level (13.9 vs 7.8 μmol/L, P = .02) and mean urinary methylmalonic acid level (68.1 mmol/mol of creatinine vs 26.1 mmol/mol of creatinine, P = .03) were elevated in children with infantile spasms than in controls. Fourteen children (35.0%) with infantile spasms were vitamin B₁₂ deficient compared with 3 (7.50%) controls ( P = .005). Thus, vitamin B₁₂ deficiency may have an association with infantile spasms. More studies are needed before recommending routine measurement of serum B₁₂ levels in children with infantile spasms.

Strength and stability of EEG functional connectivity predict treatment response in infants with epileptic spasms

OBJECTIVE

Epileptic spasms (ES) are associated with pathological neuronal networks, which may underlie characteristic EEG patterns such as hypsarrhythmia. Here we evaluate EEG functional connectivity as a quantitative marker of treatment response, in comparison to classic visual EEG features.

METHODS

We retrospectively identified 21 ES patients and 21 healthy controls. EEG data recorded before treatment and after ≥10 days of treatment underwent blinded visual assessment, and functional connectivity was measured using cross-correlation techniques. Short-term treatment response and long-term outcome data were collected.

RESULTS

Subjects with ES had stronger, more stable functional networks than controls. After treatment initiation, all responders (defined by cessation of spasms) exhibited decreases in functional connectivity strength, while an increase in connectivity strength occurred only in non-responders. There were six subjects with unusually strong pre-treatment functional connectivity, and all were responders. Visually assessed EEG features were not predictive of treatment response.

CONCLUSIONS

Changes in network connectivity and stability correlate to treatment response for ES, and high pre-treatment connectivity may predict favorable short-term treatment response. Quantitative measures outperform visual analysis of the EEG.

SIGNIFICANCE

Functional networks may have value as objective markers of treatment response in ES, with potential to facilitate rapid identification of personalized, effective treatments.

Current concepts on epilepsy management in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disease affecting approximately 1 in 6,000 people, and represents one of the most common genetic causes of epilepsy. Epilepsy affects 90% of the patients and appears in the first 2 years of life in the majority of them. Early onset of epilepsy in the first 12 months of life is associated with high risk of cognitive decline and neuropsychiatric problems including autism. Prenatal or early infantile diagnosis of TSC, before the onset of epilepsy, provides a unique opportunity to monitor EEG before the onset of clinical seizures, thus enabling early intervention in the process of epileptogenesis. In this review, we discuss the current status of knowledge on epileptogenesis in TSC, and present recommendations of American and European experts in the field of epilepsy.

Evolution and course of early life developmental encephalopathic epilepsies: Focus on Lennox-Gastaut syndrome

OBJECTIVES

Developmental encephalopathic epilepsies (DEEs) are characterized by refractory seizures, disability, and early death. Opportunities to improve care and outcomes focus on West syndrome/infantile spasms (WS/IS). Lennox-Gastaut syndrome (LGS) is almost as common but receives little attention. We examined initial presentations of DEEs and their evolution over time to identify risk and indicators of developing LGS.

METHODS

Data are from the Connecticut Study of Epilepsy, a prospective, longitudinal study of 613 children with newly diagnosed epilepsy recruited in 1993-1997. Central review of medical records permitted classification of epilepsy syndromes at diagnosis and at reclassification 2, 5, and 9 years later. DEEs were compared to other epilepsies for seizure and cognitive outcomes and mortality. Analyses examined the evolution of DEE syndromes after initial presentation, with specific comparisons made between WS/IS and LGS. Statistical analyses were performed with t tests and chi-square tests.

RESULTS

Fifty-eight children (9.4%) had DEEs, median onset age = 1.1 years (interquartile range ([IQR] 0.3-1.3) in DEEs and 6.0 years (IQR 3.0-9.0) in other epilepsies (P < 0.001). DEEs vs other epilepsies had more pharmacoresistance (71% vs 18%), intellectual disability (84% vs 11%), and mortality (21% vs <1%; all P < 0.001). During follow-up, the form of epilepsy evolved in 33 children. WS/IS was the most common initial diagnosis (N = 23) and in 5 children WS/IS evolved later. LGS was diagnosed initially in 4 children (1 later revised) and in 22 by the end of follow-up, including 7 evolving from WS/IS and 12 from nonsyndromic generalized, focal, or undetermined epilepsies. Evolution to LGS took a median of 1.9 years. LGS developed in 13% of infants, including 9% of those who did not present initially with WS/IS.

SIGNIFICANCE

DEEs account for disproportionate amounts of pharmacoresistance, disability, and early mortality. LGS often has a window between initial presentation and full expression. LGS should become targeted for early detection and prevention.

Neuroinflammatory Nexus of Pediatric Epilepsy

A rapidly growing body of evidence supports the premise that neuroinflammation plays an important role in initiating and sustaining seizures in a range of pediatric epilepsies. Clinical and experimental evidence indicate that neuroinflammation is both an outcome and a contributor to seizures. In this manner, seizures that arise from an initial insult (e.g. infection, trauma, genetic mutation) contribute to an inflammatory response that subsequently promotes recurrent seizures. This cyclical relationship between seizures and neuroinflammation has been described as a 'vicious cycle.' Studies of human tissue resected for surgical treatment of refractory epilepsy have reported activated inflammatory and immune signaling pathways, while animal models have been used to demonstrate that key inflammatory mediators lead to increased seizure susceptibility. Further characterization of the molecular mechanisms involved in this cycle may ultimately enable the development of new therapeutic approaches for the treatment of epilepsy. In this brief review we focus on key inflammatory mediators that have become prominent in recent literature of epilepsy, including newly characterized microRNAs and their potential role in neuroinflammatory signaling.

Validating an Algorithm to Identify Patients With Infantile Spasms Using Medical Claims

An infantile spasm is a brief seizure type that is characteristic of West syndrome. Many infants present with infantile spasms between 3-12 months of age. Early diagnosis and proper treatment of patients with infantile spasms can lead to improved clinical outcomes. However, proper identification of these patients using claims data with validation has not been performed. The authors developed and tested several algorithms using claims data. Claims data consisted of using International Classification of Disease (ICD), Current Procedural Terminology (CPT), and prescription codes. Access to the claims database was from an accountable care organization. The algorithm using the specific ICD code for infantile spasms only performed the best with high sensitivity and specificity. This algorithm can be used to perform additional research in claims data for patients with infantile spasms.

Epileptic Encephalopathies

PURPOSE OF REVIEW

This article reviews the manifestations and treatment of the epileptic encephalopathies, which are a heterogeneous group of disorders characterized by both seizures and neurocognitive impairment.

RECENT FINDINGS

Next-generation (exome- and genome-based) sequencing technologies are revolutionizing the identification of single-gene causes of epileptic encephalopathy but have only had a modest impact on patient-specific treatment decisions. The treatment of most forms of epileptic encephalopathy remains a particularly challenging endeavor, with therapeutic decisions chiefly driven by the electroclinical syndrome classification. Most antiseizure drugs are ineffective in the treatment of these disorders, and treatments that are effective often entail significant risk and cost.

SUMMARY

The epileptic encephalopathies continue to pose a major challenge in diagnosis and treatment, with most patients experiencing very poor outcomes, although a significant minority of patients respond to, or are even cured by, specific therapies.

Everolimus in infants with tuberous sclerosis complex-related West syndrome: First results from a single-center prospective observational study

Tuberous sclerosis complex (TSC) is the most common cause of West syndrome (WS). Currently available treatment options are ineffective in the majority of affected infants and/or associated with potential serious side effects. Based on the assumption that mTOR overactivation results in increased neuroexcitability in TSC, mTOR inhibitors have been studied as antiseizure therapy. As a result, everolimus recently received approval for the adjunctive treatment of patients aged ≥2 years with refractory TSC-associated focal and secondary generalized seizures. However, efficacy and safety data for infants with TSC-associated WS are still lacking. Therefore, a prospective open-label observational study was initiated at our center, to evaluate everolimus add-on treatment in infants with TSC-associated WS, previously refractory to standard treatment. For this preliminary report, data from four male infants with TSC2 and a median observation period of 13 (range = 8-42) months after treatment initiation were analyzed. Two infants showed electroclinical remission until day 14 after everolimus treatment initiation. In one additional infant, hypsarrhythmia resolved. No relapse after initial response was documented. Developmental progress improved in three infants. Tolerability was similar to that described in older children. According to our preliminary results, everolimus appears to have the potential to treat successfully both spasms and hypsarrhythmia in infants with TSC-associated WS, contributing to better developmental progress.

Metabolic etiologies in West syndrome

West syndrome (WS) is an early life epileptic encephalopathy associated with infantile spasms, interictal electroencephalography (EEG) abnormalities including high amplitude, disorganized background with multifocal epileptic spikes (hypsarrhythmia), and often neurodevelopmental impairments. Approximately 64% of the patients have structural, metabolic, genetic, or infectious etiologies and, in the rest, the etiology is unknown. Here we review the contribution of etiologies due to various metabolic disorders in the pathology of WS. These may include metabolic errors in organic molecules involved in amino acid and glucose metabolism, fatty acid oxidation, metal metabolism, pyridoxine deficiency or dependency, or acidurias in organelles such as mitochondria and lysosomes. We discuss the biochemical, clinical, and EEG features of these disorders as well as the evidence of how they may be implicated in the pathogenesis and treatment of WS. The early recognition of these etiologies in some cases may permit early interventions that may improve the course of the disease.

Detailed Magnetic Resonance Imaging (MRI) Analysis in Infantile Spasms

PURPOSE

To evaluate initial magnetic resonance imaging (MRI) abnormalities in infantile spasms, correlate them to clinical characteristics, and describe repeat imaging findings.

METHODS

A retrospective review of infantile spasm patients was conducted, classifying abnormal MRI into developmental, acquired, and nonspecific subgroups.

RESULTS

MRIs were abnormal in 52 of 71 infantile spasm patients (23 developmental, 23 acquired, and 6 nonspecific) with no correlation to the clinical infantile spasm characteristics. Both developmental and acquired subgroups exhibited cortical gray and/or white matter abnormalities. Additional abnormalities of deep gray structures, brain stem, callosum, and volume loss occurred in the structural acquired subgroup. Repeat MRI showed better definition of the extent of existing malformations.

CONCLUSION

In structural infantile spasms, developmental/acquired subgroups showed differences in pattern of MRI abnormalities but did not correlate with clinical characteristics.

In Vivo Multimodal Magnetic Resonance Imaging Changes After N-Methyl-d-Aspartate-Triggered Spasms in Infant Rats

Objective

Despite the serious neurodevelopmental sequelae of epileptic encephalopathy during infancy, the pathomechanisms involved remain unclear. To find potential biomarkers that can reflect the pathogenesis of epileptic encephalopathy, we explored the neurometabolic and microstructural sequelae after infantile spasms using a rat model of infantile spasms and in vivo magnetic resonance imaging techniques.

Methods

Rats prenatally exposed to betamethasone were subjected to three rounds of intraperitoneal N-methyl-d-aspartate (NMDA) triggering of spasms or received saline injections (controls) on postnatal days (P) 12, 13, and 15. Chemical exchange saturation transfer imaging of glutamate (GluCEST) were performed at P15 and 22 and diffusion tensor imaging and additional spectroscopy (1H-MRI/MRS) of the cingulate cortex were serially done at P16, 23, and 30 and analyzed. Pathological analysis and western blotting were performed with rats sacrificed on P35.

Results

Within 24 h of the three rounds of NMDA-induced spasms, there was an acute increase in the GluCEST (%) in the cortex, hippocampus, and striatum. When focused on the cingulate cortex, mean diffusivity (MD) was significantly decreased during the acute period after multiple spasms with an increase in γ-aminobutyric acid (GABA), glutamate, and glutamine N-acetylaspartate-plus-N-acetylaspartylglutamate (tNAA), total choline, and total creatine. The juvenile rats also showed decreased MD on diffusion tensor imaging and significant decreases in taurine, tNAA, and macromolecules-plus-lipids in the cingulate cortex. Pathologically, there was a significant reduction in glial fibrillary acidic protein, myelin basic protein, and neuronal nuclei expression in the cingulate cortex of rats with NMDA-induced spasms.

Significance

These neurometabolic and microstructural alterations after NMDA-triggered spasms might be potential imaging biomarkers of epileptic encephalopathy.

Why West? Comparisons of clinical, genetic and molecular features of infants with and without spasms

Infantile spasms are the defining seizures of West syndrome, a severe form of early life epilepsy with poorly-understood pathophysiology. We present a novel comparative analysis of infants with spasms versus other seizure-types and identify clinical, etiological, and molecular-genetic factors preferentially predisposing to spasms. We compared ages, clinical etiologies, and associated-genes between spasms and non-spasms groups in a multicenter cohort of 509 infants (<12months) with newly-diagnosed epilepsy. Gene ontology and pathway enrichment analysis of clinical laboratory-confirmed pathogenic variant-harboring genes was performed. Pathways, functions, and cellular compartments between spasms and non-spasms groups were compared. Spasms onset age was similar in infants initially presenting with spasms (6.1 months) versus developing spasms as a later seizure type (6.9 months) but lower in the non-spasms group (4.7 months, p<0.0001). This pattern held across most etiological categories. Gestational age negatively correlated with spasms onset-age (r = -0.29, p<0.0001) but not with non-spasm seizure age. Spasms were significantly preferentially associated with broad developmental and regulatory pathways, whereas motor functions and pathways including cellular response to stimuli, cell motility and ion transport were preferentially enriched in non-spasms. Neuronal cell-body organelles preferentially associated with spasms, while, axonal, dendritic, and synaptic regions preferentially associated with other seizures. Spasms are a clinically and biologically distinct infantile seizure type. Comparative clinical-epidemiological analyses identify the middle of the first year as the time of peak expression regardless of etiology. The inverse association with gestational age suggests the preterm brain must reach a certain post-conceptional, not just chronological, neurodevelopmental stage before spasms manifest. Clear differences exist between the biological pathways leading to spasms versus other seizure types and suggest that spasms result from dysregulation of multiple developmental pathways and involve different cellular components than other seizure types. This deeper level of understanding may guide investigations into pathways most critical to target in future precision medicine efforts.

Cytotoxic edema at onset in West syndrome of unknown etiology: A longitudinal diffusion tensor imaging study

OBJECTIVE

To clarify longitudinal changes in white matter microstructures from the onset of disease in patients with West syndrome (WS) of unknown etiology.

METHODS

Diffusion tensor imaging (DTI) was prospectively performed at onset and at 12 and 24 months old in 17 children with WS of unknown etiology. DTI was analyzed using tract-based spatial statistics (TBSS) and tract-specific analysis (TSA) of 13 fiber tracts, and fractional anisotropy (FA) and mean diffusivity (MD) were compared with those of 42 age-matched controls. Correlations of FA and MD with developmental quotient (DQ) at age 24 months were analyzed. Multiple comparisons were adjusted for using the false discovery rate (q-value).

RESULTS

TBSS analysis at onset showed higher FA and lower MD in the corpus callosum and brainstem in patients. TSA showed lower MD in bilateral uncinate fasciculi (UF) (right: q < 0.001; left: q = 0.03) at onset in patients. TBSS showed a negative correlation between FA at onset and DQ in the right frontal lobe, whereas FA at 24 months old exhibited a positive correlation with DQ in the diffuse white matter. MD for bilateral UF at 24 months old on TSA correlated positively with DQ (q = 0.04, both).

SIGNIFICANCE

These findings may indicate the existence of cytotoxic edema in the immature white matter and dorsal brainstem at onset, and subsequent alterations in the diffuse white matter in WS of unknown etiology. Microstructural development in the UF might play important roles in cognitive development in WS.

Treatment of Epileptic Encephalopathies: Current State of the Art

Childhood epileptic encephalopathies are age-dependent disorders of the brain whose hallmarks include loss of neurologic function over time, abnormal electroencephalographic findings, and seizures. Ictal and interictal electrographic activity are conjointly thought to be at the root of the often devastating neuropsychological deterioration, which is specific to the maturing brain. The goals of treatment are not only to control seizures, but also to prevent or reverse neurologic loss of function. In general, time is of the essence in diagnosis, and experienced specialists should promptly design a treatment plan. Hormonal and immune therapies are at the forefront of treatment in many cases, with traditional antiepileptic drugs and surgery (when an identifiable lesion is present) playing a limited role. However, gold standard evidence for treatment of epileptic encephalopathies remains limited. Ongoing clinical and basic research may lead to better understanding of these catastrophic conditions and to better and more effective therapies.

Efficacy and safety of vigabatrin in Japanese patients with infantile spasms: Primary short-term study and extension study

Vigabatrin was approved for the treatment of infantile spasms by the US Food and Drug Administration, but not in Japan at the time of initiating this clinical study because of concerns about irreversible peripheral visual field defects (VFDs). This study evaluated the efficacy and safety of vigabatrin for Japanese patients with infantile spasms. Of 15 patients (aged ≥4weeks and <2years) enrolled, with the exception of two patients who did not receive vigabatrin, 13 were treated with a titrated dosage of vigabatrin (50-150mg/kg/day; limited to 3000mg/day). Twelve out of 13 patients receiving vigabatrin had spasms that were treatment refractory; these patients were concurrently treated with at least one other antiepileptic drug. One patient received vigabatrin monotherapy. Eight of the 13 patients (61.5% [95% CI: 31.6-86.1%]) had a ≥50% reduction during the dose-adjustment phase compared with baseline in the frequency of spasms, with efficacy maintained through a 2-week maintenance phase. Spasms disappeared in six out of nine patients (66.7% [95% CI: 29.9-92.5%]) who transitioned to the maintenance phase and hypsarrhythmia on electroencephalography also resolved in four patients. Hypsarrhythmia was improved in another two patients. Six out of seven patients who continued treatment through Week 32 of an extension study reported ongoing efficacy for vigabatrin. The most common adverse events (AEs) were psychiatric disorders and nervous system disorders (n=8; 61.5%) that were generally mild in severity. No treatment-related peripheral VFDs were observed. No severe AEs or AEs resulting in discontinuation of vigabatrin therapy were reported. An abnormality in magnetic resonance images was observed in one patient during the extension period. Vigabatrin was deemed to be clinically effective and well tolerated in Japanese patients with infantile spasms.

Fast oscillation dynamics during hypsarrhythmia as a localization biomarker

Hypsarrhythmia in West syndrome, although hard to define, is characterized by chaotic and disorganized electrical activity of the brain and is often regarded as a generalized EEG pattern without any localization value. Using event-related spectral perturbation (ERSP), we tried to determine the brain dynamics during hypsarrhythmia. Routine 1-h scalp EEGs were retrieved from 31 patients with infantile spasms and 20 age-matched controls. Using the EEGLAB toolbox of MATLAB 2015b, the ERSPs of fast oscillations (FOs; 20-100 Hz) of selected channels were analyzed and compared among groups according to their MRI lesions. FO-ERSP cutoff values for predicting the pathologic foci were estimated. The mean FO-ERSPs across all analyzed electrodes of patients with spasms were significantly higher than those of controls. When the patients were categorized into nonlesional, focal/multifocal, or diffuse lesional groups, the FO-ERSP of patients in the focal/multifocal lesional group was significantly lower than that of those in the nonfocal or diffuse lesional groups. In the focal/multifocal lesional group, seven patients (7/9, 77.8%) showed that the locations of channels with high FO-ERSPs were matched to the pathologic MRI lesions. Thus, the localization of high FO-ERSPs is closely associated with the location of pathologic brain lesions. Further research is required to prove the value of the FO-ERSP as an important quantitative localizing biomarker of West syndrome. NEW & NOTEWORTHY The locations of high fast oscillation-event-related spectral perturbations (FO-ERSPs) are closely associated with brain pathologic lesions, and high FO-ERSPs can be used as a localization biomarker of pathologic brain lesions in patients with hypsarrhythmia. With further validation, FO-ERSP might be useful as a biomarker for the localization of hidden pathologies in conditions with generalized epileptiform activities such as West syndrome.

The impact of hypsarrhythmia on infantile spasms treatment response: Observational cohort study from the National Infantile Spasms Consortium

OBJECTIVE

The multicenter National Infantile Spasms Consortium prospective cohort was used to compare outcomes and phenotypic features of patients with infantile spasms with and without hypsarrhythmia.

METHODS

Patients aged 2 months to 2 years were enrolled prospectively with new-onset infantile spasms. Treatment choice and categorization of hypsarrhythmia were determined clinically at each site. Response to therapy was defined as resolution of clinical spasms (and hypsarrhythmia if present) without relapse 3 months after initiation.

RESULTS

Eighty-two percent of patients had hypsarrhythmia, but this was not associated with gender, mean age, preexisting developmental delay or epilepsy, etiology, or response to first-line therapy. Infants with hypsarrhythmia were more likely to receive standard treatment (adrenocorticotropic hormone, prednisolone, or vigabatrin [odds ratio (OR) 2.6, 95% confidence interval (CI) 1.4-4.7] and preexisting epilepsy reduced the likelihood of standard treatment (OR 3.2, 95% CI 1.9-5.4). Hypsarrhythmia was not a determinant of response to treatment. A logistic regression model demonstrated that later age of onset (OR 1.09 per month, 95% CI 1.03-1.15) and absence of preexisting epilepsy (OR 1.7, 95% CI 1.06-2.81) had a small impact on the likelihood of responding to the first-line treatment. However, receiving standard first-line treatment increased the likelihood of responding dramatically: vigabatrin (OR 5.2 ,95% CI 2-13.7), prednisolone (OR 8, 95% CI 3.1-20.6), and adrenocorticotropic hormone (ACTH; OR 10.2, 95% CI 4.1-25.8) .

SIGNIFICANCE

First-line treatment with standard therapy was by far the most important variable in determining likelihood of response to treatment of infantile spasms with or without hypsarrhythmia.

INTERNEURONOPATHIES AND THEIR ROLE IN EARLY LIFE EPILEPSIES AND NEURODEVELOPMENTAL DISORDERS

GABAergic interneurons control the neural circuitry and network activity in the brain. The advances in genetics have identified genes that control the development, maturation and integration of GABAergic interneurons and implicated them in the pathogenesis of epileptic encephalopathies or neurodevelopmental disorders. For example, mutations of the Aristaless-Related homeobox X-linked gene (ARX) may result in defective GABAergic interneuronal migration in infants with epileptic encephalopathies like West syndrome (WS), Ohtahara syndrome or X-linked lissencephaly with abnormal genitalia (XLAG). The concept of "interneuronopathy", i.e. impaired development, migration or function of interneurons, has emerged as a possible etiopathogenic mechanism for epileptic encephalopathies. Treatments that enhance GABA levels, may help seizure control but do not necessarily show disease modifying effect. On the other hand, interneuronopathies can be seen in other conditions in which epilepsy may not be the primary manifestation, such as autism. In this review, we plan to outline briefly the current state of knowledge on the origin, development, and migration and integration of GABAergic interneurons, present neurodevelopmental conditions, with or without epilepsy, that have been associated with interneuronopathies and discuss the evidence linking certain types of interneuronal dysfunction with epilepsy and/or cognitive or behavioral deficits.

Effectiveness and Safety of Different Once-Daily Doses of Adrenocorticotropic Hormone for Infantile Spasms

INTRODUCTION

Adrenocorticotropic hormone (ACTH) has been commonly used as a first-line treatment for infantile spasms (IS), but its optimal dose and duration are still unclear. This study is the largest retrospective cohort to document the therapeutic efficacy and tolerability for three gradient doses of ACTH in IU/kg/day units in Chinese patients.

OBJECTIVE

The aim of our study was to elucidate the effectiveness and safety of three different low doses and duration of ACTH treatment for IS in China.

METHODS

We conducted a retrospective, chart review of IS cases that were treated with biologic short-acting ACTH and followed up for at least 6 months at a single center in China between June 2010 and June 2016. In total, 200 children met the inclusion criteria. Cases were divided into three groups according to dosage (1, 1.1-1.9, and 2-4 IU/kg/day). Furthermore, we divided the 2-4 IU/kg/day group into 2-3 and 3.1-4 IU/kg/day subgroups. All groups were evaluated for response rates, relapse rates, and adverse effects.

RESULTS

Electroclinical remission by day 14 occurred in 41.4% of infants given 2-4 IU/kg/day and 36.4% of infants given 1.1-1.9 IU/kg/day, compared with only 14.7% of patients given 1 IU/kg/day (p = 0.004 and 0.03, respectively). Prolonging ACTH treatment for up to 28 days improved response by 24% in all 200 infants. Overall, 73.9% of infants receiving 2-4 IU/kg/day responded, significantly higher than the 52.7% responding to 1.1-1.9 IU/kg/day and the 23.5% responding to 1 IU/kg/day (p < 0.01). There was no significant difference in the number of relapses or adverse effects in the three groups. Moreover, in the 2-4 IU/kg/day group, 74.7% of children receiving 2-3 IU/kg/day of ACTH responded, compared with 70% who responded to 3.1-4 IU/kg/day (p = 0.78).

CONCLUSIONS

ACTH at a dosage of 2-3 IU/kg/day is superior to 1.1-1.9 and 1 IU/kg/day dosages, is as good as a 3.1-4 IU/kg/day dosage in terms of response rate, and causes no more adverse effects or relapses than other dosages. In addition, prolonging the duration of ACTH treatment can improve response.

Clinical and Economic Evaluation of Repository Corticotropin Injection: A Narrative Literature Review of Treatment Efficacy and Healthcare Resource Utilization for Seven Key Indications

INTRODUCTION

Repository corticotropin injection (RCI; H.P. Acthar® Gel; Mallinckrodt Pharmaceuticals Inc., Hampton, NJ) is a highly purified, prolonged-release porcine preparation of adrenocorticotropic hormone (ACTH) analogue that is FDA-approved for treatment of 19 autoimmune and inflammatory disorders. The diverse physiological actions of RCI at the melanocortin receptors (MCRs) affect processes involved in inflammation, pigmentation, steroidogenesis, and immunomodulation. Although RCI has been approved to treat inflammatory and autoimmune diseases for more than 60 years, recent progress in understanding both MCRs and the effects of RCI in modulating immune responses has led to increased interest in RCI as a therapeutic choice. The objective of this narrative literature review is to summarize key clinical and economic data on RCI treatment of seven disorders: infantile spasms (IS), multiple sclerosis (MS) relapses, proteinuria in nephrotic syndrome, rheumatoid arthritis (RA), dermatomyositis/polymyositis (DM/PM), systemic lupus erythematosus (SLE), and symptomatic sarcoidosis based on published literature and product information. An extended report is available as the Academy of Managed Care Pharmacy (AMCP) Formulary dossier for H.P. Acthar® Gel.

METHODS

Key studies of clinical efficacy and healthcare utilization and cost from 1956 to 2016 are summarized.

RESULTS

The evidence supports the efficacy of RCI across the seven indications. RCI is effective as a first-line therapy for IS. For the other six conditions, RCI may improve clinical outcomes during exacerbations or when the condition is resistant to conventional treatments. Use of RCI is associated with reduced use of biologics, corticosteroids, and disease-modifying antirheumatic drugs. Initiation of RCI therapy in patients with IS, MS, RA, SLE, or DM/PM has been associated with lower post-therapy healthcare utilization and medical costs, including decreases in hospitalizations, hospital length of stay, outpatient visits, and emergency department visits.

CONCLUSION

The evidence suggests that RCI may improve inflammatory and autoimmune disease control and patient quality of life, particularly in complex patients, and yield healthcare cost savings that demonstrate the medicine's value.

FUNDING

Mallinckrodt Pharmaceuticals Inc.

Altered Default Mode Network on Resting-State fMRI in Children with Infantile Spasms

Infantile spasms (IS) syndrome is an age-dependent epileptic encephalopathy, which occurs in children characterized by spasms, impaired consciousness, and hypsarrhythmia. Abnormalities in default mode network (DMN) might contribute to the loss of consciousness during seizures and cognitive deficits in children with IS. The purpose of the present study was to investigate the changes in DMN with functional connectivity (FC) and amplitude of low-frequency fluctuation (ALFF), the two methods to discover the potential neuronal underpinnings of IS. The consistency of the two calculate methods of DMN abnormalities in IS patients was also our main focus. To avoid the disturbance of interictal epileptic discharge, our testing was performed within the interictal durations without epileptic discharges. Resting-state fMRI data were collected from 13 patients with IS and 35 sex- and age-matched healthy controls. FC analysis with seed in posterior cingulate cortex (PCC) was used to compare the differences between two groups. We chose PCC as the seed region because PCC is the only node in the DMN that directly interacts with virtually all other nodes according to previous studies. Furthermore, the ALFF values within the DMN were also calculated and compared between the two groups. The FC results showed that IS patients exhibited markedly reduced connectivity between posterior seed region and other areas within DMN. In addition, part of the brain areas within the DMN showing significant difference of FC had significantly lower ALFF signal in the patient group than that in the healthy controls. The observed disruption in DMN through the two methods showed that the coherence of brain signal fluctuation in DMN during rest was broken in IS children. Neuronal functional impairment or altered integration in DMN would be one neuroimaging characteristic, which might help us to understand the underlying neural mechanism of IS. Further studies are needed to determine whether the disturbed FC and ALFF observed in the DMN are related to cognitive performance in IS patients.

Preclinical Screening for Treatments for Infantile Spasms in the Multiple Hit Rat Model of Infantile Spasms: An Update

Infantile spasms are the typical seizures of West syndrome, an infantile epileptic encephalopathy with poor outcomes. There is an increasing need to identify more effective and better tolerated treatments for infantile spasms. We have optimized the rat model of infantile spasms due to structural etiology, the multiple-hit rat model, for therapy discovery. Here, we test three compounds administered after spasms induction in the multiple hit model for efficacy and tolerability. Specifically, postnatal day 3 (PN3) male Sprague-Dawley rats were induced by right intracerebral injections of doxorubicin and lipopolysaccharide. On PN5 p-chlorophenylalanine was given intraperitoneally (i.p.). Daily monitoring of weights and developmental milestones was done and rats were intermittently video monitored. A blinded, randomized, vehicle-controlled study design was followed. The caspase 1 inhibitor VX-765 (50-200 mg/kg i.p.) and the GABA_B receptor inhibitor CGP35348 (12.5-100 mg/kg i.p.) each was administered in different cohorts as single intraperitoneal injections on PN4, using a dose- and time-response design with intermittent monitoring till PN5. 17β-estradiol (40 ng/g/day subcutaneously) was given daily between PN3-10 and intermittent monitoring was done till PN12. None of the treatments demonstrated acute or delayed effects on spasms, yet all were well tolerated. We discuss the implications for therapy discovery and challenges of replication trials.

Scalp EEG Ictal gamma and beta activity during infantile spasms: Evidence of focality

OBJECTIVE

We investigated temporal and spatial characteristics of ictal gamma and beta activity on scalp EEG during spasms in patients with West syndrome (WS) to evaluate potential focal cortical onset.

METHODS

A total of 1,033 spasms from 34 patients with WS of various etiologies were analyzed on video-electroencephalography (EEG) using time-frequency analysis. Ictal gamma (35-90 Hz) and beta (15-30 Hz) activities were correlated with visual symmetry of spasms, objective EMG (electromyography) analysis, and etiology of WS.

RESULTS

Prior to the ictal motor manifestation, focal ictal gamma activity emerged from one hemisphere (71%, 24/34) or from midline (26%, 9/34), and was rarely simultaneously bilateral (3%, 1/34). Focal ictal beta activity emerged from either one hemisphere (68%, 23/34) or from midline (32%, 11/34). Onsets of focal ictal gamma and beta activity were most commonly observed around the parietal areas. Focal ictal gamma activity propagated faster than ictal beta activity to adjacent electrodes (median: 65 vs. 170 msec, p < 0.01), and to contralateral hemisphere (median: 100 vs. 170 msec, p = 0.01). Asymmetric peak amplitude of ictal gamma activity in the centroparietal areas (C3-P3 vs. C4-P4) correlated with asymmetric semiology. On the other hand, most of the visually symmetric spasms showed asymmetry in peak amplitude and interhemispheric onset latency difference in both ictal gamma and beta activity.

SIGNIFICANCE

Spasms may be a seizure with focal electrographic onset regardless of visual symmetry. Asymmetric involvement of ictal gamma activity to the centroparietal areas may determine the motor manifestations in WS. Scalp EEG ictal gamma and beta activity may be useful to demonstrate localized seizure onset in infants with WS.

Identification of De Novo DNMT3A Mutations That Cause West Syndrome by Using Whole-Exome Sequencing

Epileptic encephalopathies (EEs) are a group of severe neurodevelopmental disorders with extreme genetic heterogeneity. Recent trio-based whole-exome sequencing (WES) studies have demonstrated that de novo mutations (DNMs) play prominent roles in severe EE. In this study, we searched for potential causal DNMs by using high-coverage WES of four unrelated Chinese parent-offspring trios affected by West syndrome. Through extensive bioinformatic analysis, we identified three novel DNMs in DNMT3A, CDKL5, and MAMDC2 in three trios and two compound heterozygous mutations in KMT2A in one trio. The DNMs in CDKL5 and DNMT3A were considered to be deleterious on the basis of the consensus of several genetic damage prediction tools. In addition, spatiotemporal expression patterns revealed a high level of DNMT3A expression during the early embryonic stage in nearly all brain regions. We also observed that certain high-confidence genes for epilepsy were shared among the co-expression and genetic interaction networks of DNMT3A, CDKL5, and KMT2A. Furthermore, all the candidate epilepsy genes in the co-expression network of DNMT3A were significantly enriched in the early developmental stages of the brain according to a rank-based enrichment test. In particular, we found that the DNMs of DNMT3A were shared among EE, autism spectrum disorder (ASD), and intellectual disability (ID) and mainly occurred in the functional domain of DNMT3A. Together, our findings support an association between DNMT3A mutations and EE susceptibility and suggest a shared molecular pathophysiology among EE and other neuropsychiatric disorders.

Tuberous Sclerosis Complex: A Review

Tuberous sclerosis complex (TSC) is a neurocutaneous syndrome that can present at any age and can affect multiple organ systems. This disorder is usually identified in infants and children based on characteristic skin lesions, seizures, and cellular overgrowth or hamartomas in the heart, brain, and kidneys. Tuberous sclerosis complex is a genetic disorder caused by a mutation in either the TSC1 or TSC2 gene leading to dysfunction of hamartin or tuberin, respectively. Hamartin and tuberin form a protein complex that helps regulate cellular hyperplasia. Accurate diagnosis is essential in implementing appropriate surveillance and treatment to patients with this disorder. Specific guidelines for diagnosis, surveillance, and management have been proposed by the International Tuberous Sclerosis Complex Consensus Group. Treatment of tuberous sclerosis complex is in part symptomatic; however, for certain clinical manifestations, specific treatments may be indicated. [Pediatr Ann. 2017;46(4):e166-e171.].

Inflammation in Epileptic Encephalopathies

West syndrome (WS) is an infantile epileptic encephalopathy that manifests with infantile spasms (IS), hypsarrhythmia (in ~60% of infants), and poor neurodevelopmental outcomes. The etiologies of WS can be structural-metabolic pathologies (~60%), genetic (12%-15%), or of unknown origin. The current treatment options include hormonal treatment (adrenocorticotropic hormone and high-dose steroids) and the GABA aminotransferase inhibitor vigabatrin, while ketogenic diet can be given as add-on treatment in refractory IS. There is a need to identify new therapeutic targets and more effective treatments for WS. Theories about the role of inflammatory pathways in the pathogenesis and treatment of WS have emerged, being supported by both clinical and preclinical data from animal models of WS. Ongoing advances in genetics have revealed numerous genes involved in the pathogenesis of WS, including genes directly or indirectly involved in inflammation. Inflammatory pathways also interact with other signaling pathways implicated in WS, such as the neuroendocrine pathway. Furthermore, seizures may also activate proinflammatory pathways raising the possibility that inflammation can be a consequence of seizures and epileptogenic processes. With this targeted review, we plan to discuss the evidence pro and against the following key questions. Does activation of inflammatory pathways in the brain cause epilepsy in WS and does it contribute to the associated comorbidities and progression? Can activation of certain inflammatory pathways be a compensatory or protective event? Are there interactions between inflammation and the neuroendocrine system that contribute to the pathogenesis of WS? Does activation of brain inflammatory signaling pathways contribute to the transition of WS to Lennox-Gastaut syndrome? Are there any lead candidates or unexplored targets for future therapy development for WS targeting inflammation?

Epileptic spasms - 175 years on: Trying to teach an old dog new tricks

PURPOSE

This text provides an overview of how the condition "infantile spasms" has evolved in the last 175 years.

METHOD

Key references are summarised to assimilate this review.

RESULTS

Infantile spasms, first described by Dr West in 1841, has undergone extensive investigation to understand the pathogenesis, aetiologies, optimal intervention and most likely prognosis for the affected child. The terminology has recently evolved such that the preferred term for the condition is now "epileptic spasms" in recognition of the fact that cases can present outside infancy. The aetiologies are diverse and can be structural, genetic, metabolic or acquired. Increasing numbers of presumed causative genetic mutations are now being identified. The condition is an epileptic encephalopathy such that without adequate control of the clinical seizures and correction of the abnormal EEG, ongoing neurological damage occurs. In some cases neuroregression is inevitable despite intervention. First-line treatments are either hormonal therapies, adrenocortcotrophic hormone or prednisolone, or vigabatrin. In the sub-group of patients with tuberous sclerosis complex, vigabatrin is the preferred treatment. High dose prednisolone may be a more viable option in resource limited settings. Recent research has suggested that combining hormonal therapies with vigabatrin will result in more patients achieving spasm cessation.

CONCLUSIONS

Despite extensive study, the pathogenic mechanisms remain an area of debate and in need of further exploration. The enigma, however, may be explained as the role of resting state and dysfunctional brain networks are elucidated further.

[Hormonal treatment in West syndrome]

West syndrome is one of the most well-known epileptic encephalopathies, a catastrophic epilepsy syndrome with onset in the first year of life. Prognosis of this condition depends on the etiology and adequate treatment. The authors review the hormonal treatment of West syndrome. Adrenocorticotrophic hormone (ACTH) is used in USA and its synthetic analogue tetracosactide is used in Europe. Both of the drugs are not registered in the Russian Federation. The data on the efficacy of corticosteroids, including prednisolone, are contradictory. Recent results have demonstrated the high efficacy of prednisolone in the treatment of West syndrome. The authors discuss different aspects of hormonal treatment of West syndrome: possible mechanisms, choice of medication, hormone doses, its duration, efficacy ant tolerability.

Evaluation of ten prognostic factors affecting the outcome of West syndrome

The aim of this study is to assess the seizure and developmental outcome and to determine the prognostic factors affecting the outcome of West syndrome in an etiologically well-defined large cohort. Demographic features, treatment modalities, etiology, seizure and developmental outcome of 216 cases with West syndrome were recorded retrospectively. Ten prognostic factors possibly affecting the outcome of West syndrome including (1) gender, (2) age at the onset (3) presence of seizures prior to spasms, (4) presence of asymmetric spasm, (5) presence of abnormal neurological signs, (6) treatment lag, (7) etiology, (8) drug chosen as the initial treatment, (9) response to initial treatment regardless of the kind, (10) development of other seizure types after spasms were evaluated in terms of seizure and developmental outcome. Twelve percent of the cases were developmentally normal at the end of 2-year follow-up. Ongoing seizures requiring antiepileptic drug medication at the last follow-up were noted in 90 % of the cases. Hypoxia (29 %), metabolic disorders (11 %), infectious diseases (9 %) and cerebral developmental disorders (8 %) were the most frequent etiological factors. Five of the ten prognostic factors (presence of seizures prior to spasms, presence of abnormal neurological signs, response to initial treatment regardless of the kind, etiology and development of other seizure types after spasms) were found to be statistically significant prognostic factors predicting the outcome. In conclusion, West syndrome is still a catastrophic epileptic encephalopathy. Preventable causes still constitute a substantial portion of the etiological causes of West syndrome. Therefore, the prevention of avoidable causes is at least as important as the treatment.

Antibodies against peptides of NMDA-type GluR in cerebrospinal fluid of patients with epileptic spasms

OBJECTIVE

We investigated the contribution of antibodies against N-methyl-d-aspartate (NMDA)-type glutamate receptor (GluR) in cerebrospinal fluid (CSF) to the clinical features of patients with epileptic spasms (ES).

METHODS

CSF samples were collected from 33 patients with ES with median (range) age 1.8 (0.2-8.5) years. Thirty patients without ES with 3.5 (0.5-7.0) years were also studied as disease controls. The CSF levels of antibodies against peptides of NMDA-type GluR subunits (GluN2B & GluN1) were measured by enzyme-linked immunosorbent assay.

RESULTS

The levels of antibodies against the n-terminal of GluN2B (GluN2B-NT2), c-terminal of GluN2B (GluN2B-CT) and n-terminal of GluN1 (GluN1-NT), were significantly higher in patients with ES than in disease controls (p < 0.01, p < 0.01 & p = 0.03). Levels of antibodies to GluN2B-NT2 & CT were not related with ACTH therapy nor conventional CSF factors (cell counts, protein level, etc). Levels of antibodies to GluN2B-NT2 & CT showed evidence of correlation within a linear regression model with intervals from the onset to the examination of CSF until 25 months (p = 0.01 & p = 0.01). The correlation was significant in patients with unknown cause (p = 0.01). Five of 33 patients (four unknown cause & one chromosomal anomaly) had higher level of antibodies to GluN2B-NT2 exceeding mean + 1 SD of all ES patients, and they had poor motor (score 0) and cognitive outcomes (score 0 or 1).

CONCLUSION

The CSF level of antibodies against GluN2B in ES patients with unknown cause was estimated to increase after onset. We hypothesize that some ES patients may have immune process after the onset of ES.

Not all that glitters is gold: A guide to critical appraisal of animal drug trials in epilepsy

Preclinical studies have produced numerous drugs with antiseizure properties that currently are the standard of care. One third of the human population with epilepsy still continues to have seizures despite the ongoing discoveries. The recognized clinical gaps of care that need to be addressed are the identification of antiepileptogenic and disease‐modifying treatments, and treatments for refractory seizures or for seizures and epilepsies with limited or unsatisfactory treatments, such as early life epileptic encephalopathies. In this invited review, we provide a historical summary of the international efforts to reevaluate the strategies adopted in preclinical epilepsy therapy discovery studies. We discuss issues that may affect the quality, interpretation, and validation of preclinical studies and their translation to successful therapies for humans affected with epilepsy. These include the selection of animal models and the study design; research practices that affect rigor (such as appropriate use of statistics and reporting of study methods and results, their validation across models, labs, and preclinical‐clinical studies); the need to harmonize research methods and outcome assessment; and the importance of improving translation to clinically appropriate situations. The epilepsy research community is incrementally adopting collaborative research, including consortia or multicenter studies to meet these needs. Improving the infrastructure that can support these efforts will be instrumental in future success.

Vigabatrin Therapy for Infantile Spasms in a Case of Cardiofaciocutaneous Syndrome with Cardiac Hypertrophy Developing during Adrenocorticotropic Hormone Treatment

In a patient with cardiofaciocutaneous syndrome complicated by intractable infantile spasms (West syndrome), cardiac hypertrophy developed during adrenocorticotropic hormone treatment. Various types of antiepileptic drugs, intravenous immunoglobulin, thyrotropin releasing hormone, and a ketogenic diet were ineffective in this case. However, vigabatrin both decreased clinical seizures and improved electroencephalogram findings. Although vigabatrin has not been approved for use in Japan, the results in the present case suggest that this drug should be considered as an alternative therapy for cases of infantile spasms associated with syndromes involving cardiomyopathy or its potential risk factors, such as cardiofaciocutaneous syndrome.

A case report on the efficacy of vigabatrin analogue (1S, 3S)-3-amino-4-difluoromethylenyl-1-cyclopentanoic acid (CPP-115) in a patient with infantile spasms

West Syndrome is characterized by infantile spasms, a hypsarrhythmic electroencephalogram (EEG) pattern, and a poor neurodevelopmental prognosis. First-line treatments include adrenocorticotrophic hormone (ACTH) and vigabatrin, but adverse effects often limit their use. CPP-115 is a high-affinity vigabatrin analogue developed to increase therapeutic potency and to limit retinal toxicity. Here, we present a child treated with CPP-115 through an investigational new drug protocol who experienced a marked reduction of seizures with no evidence of retinal dysfunction. Given the potential consequences of ongoing infantile spasms and the limitations of available treatments, further assessment of CPP-115 is warranted.