Safety and effectiveness of hormonal treatment versus hormonal treatment with vigabatrin for infantile spasms (ICISS): a randomised, multicentre, open-label trial

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.

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.

West Syndrome: A Review and Guide for Paediatricians

West syndrome (WS), also known as infantile spasms, occurs in infancy with a peak between 4 and 7 months. Spasms, neurodevelopmental regression and hypsarrhythmia on electroencephalogram (EEG) basically define WS. The International League Against Epilepsy commission classifies the aetiologies of WS into genetic, structural, metabolic and unknown. Early diagnosis and a shorter lag time to treatment are essential for the overall outcome of WS patients. These goals are feasible with the addition of brain magnetic resonance imaging (MRI) and genetic and metabolic testing. The present work analysed the medical literature on WS and reports the principal therapeutic protocols of its management. Adrenocorticotropic hormone (ACTH), vigabatrin (VGB) and corticosteroids are the first-line treatments for WS. There is no unique therapeutic protocol for ACTH, but most of the evidence suggests that low doses are as effective as high doses for short-term treatment, which is generally 2 weeks followed by dose tapering. VGB is generally administered at doses from 50 to 150 mg/kg/day, but its related retinal toxicity, which occurs in 21-34% of infants, is most frequently observed when treatment periods last longer than 6 months. Among corticosteroids, a treatment of 14 days of oral prednisolone (40-60 mg/day) has been considered effective and well tolerated. Considering that an early diagnosis and a shorter lag time to treatment are essential for successful outcomes in these patients, further studies on efficacy of the different therapeutic approaches with evaluation of final outcome after cessation of therapy are needed.

Kcnj6(GIRK2) trisomy is not sufficient for conferring the susceptibility to infantile spasms seen in the Ts65Dn mouse model of down syndrome

OBJECTIVE

Infantile spasms (IS) is a catastrophic childhood seizure disorder that is characterized by extensor and/or flexor spasms, cognitive deterioration and a characteristic EEG abnormality. The latter consists of a pattern of a spike-wave followed by an electrodecremental response (EDR), which is a flattening of the EEG waveform amplitude. The mechanism/circuitry that underpins IS is unknown. Children with Down Syndrome (DS) are particularly vulnerable to IS. The standard mouse model of DS is the Ts65Dn mutant mouse (Ts). Using the Ts mouse, we have created an animal model of IS in DS. This model entails the treatment of Ts mice with a GABA_BR agonist with a resultant recapitulation of the semiological, electrographic, and pharmacological phenotype of IS. One of the genes triplicated in Ts mice is the kcnj6 gene which codes for the G-protein inwardly rectifying potassium channel 2 (GIRK2) protein. We have shown that over expression of GIRK2 in Ts brain is necessary for the production of the GABA_BR agonist induced IS phenotype in the Ts mouse. Here, we ask the question whether the excess GIRK2 is sufficient for the production of the GABA_BR agonist induced IS phenotype.

METHODS

To address this question, we used kcnj6 triploid mice, and compared the number of spasms via video analysis and EDR events via EEG to that of the WT mice.

RESULTS

We now show that GABA_RR agonist-treated kcnj6 triploid mice failed to show susceptibility to the IS phenotype. Therefore, over expression of GIRK2 in the brain is necessary, but not sufficient to confer susceptibility to the GABA_BR agonist-induced IS phenotype in the Ts model of DS.

SIGNIFICANCE

It is therefore likely that GIRK2 is working in concert with another factor or factors that are altered in the Ts brain in the production of the GABA_BR agonist-induced IS phenotype.

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.

Comparative efficacy of antiepileptic drugs in children and adolescents: A network meta-analysis

OBJECTIVE

To estimate the comparative efficacy among antiepileptic drugs in the pediatric population (0-18 years).

METHODS

Using the Embase and MEDLINE databases, we updated to February 2017 the search strategy of the National Institute for Health and Care Excellence guidelines for epilepsy. We only included randomized clinical trials conducted in children and mixed-age populations. According to the PRISMA network meta-analysis guideline, the study-level quality assessment was made with the Cochrane risk-of-bias tool. Three investigators independently selected articles. The efficacy outcome was considered to be seizure freedom or ≥50% seizure reduction.

RESULTS

We selected 46 randomized clinical trials. A total of 5652 individuals were randomized to 22 antiepileptic drugs and placebo. The point estimates of carbamazepine and lamotrigine efficacy showed their superiority with respect to all comparator antiepileptic drugs for the treatment of newly diagnosed focal epilepsy. In refractory focal epilepsy, levetiracetam (odds ratio [OR] = 3.3, 95% credible interval [CrI] = 1.3-7.6) and perampanel (OR = 2.5, 95% CrI = 1.1-5.8) were more effective compared to placebo. Ethosuximide and valproic acid were both superior to lamotrigine against absence seizures. The OR point estimate showed the superiority of adrenocorticotropic hormone over all comparators in infantile spasms. A wide heterogeneity in the length of follow-up was observed among the studies.

SIGNIFICANCE

This network meta-analysis suggests that the quality of studies should be improved through the use of comparative designs, relevant outcomes, appropriate follow-up length, and more reliable inclusion criteria.

Drug Treatment of Seizures and Epilepsy in Newborns and Children

The mainstay of treatment of childhood epilepsy is to administer antiepileptic drugs (AEDs). This article provides an overview of the clinical approach to drug treatment of childhood epilepsy, focusing on general principles of therapy and properties of recently introduced medications. Initiation and cessation of therapy, adverse medication effects, drug interactions, indications for the various AEDs, and off-label use of AEDs are reviewed. The distinct challenges in treatment of epileptic spasms and neonatal seizures are addressed. Finally, ideas for the future of drug treatment of childhood epilepsy are presented, with particular attention to precision medicine.

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.

[Immunological mechanism of prednisone in the treatment of infantile spasm]

OBJECTIVE

To investigate the immunological mechanism of prednisone in the treatment of infantile spasm (IS) by evaluating the immune function of IS children before and after treatment.

METHODS

Thirty children with IS were enrolled as IS group. Thirty healthy infants who underwent physical examination were enrolled as healthy control group. Fasting venous blood was collected for both groups before and after prednisone treatment. Chemiluminescence was used to measure serum levels of interleukin-1B (IL-1B), interleukin-2R (IL-2R), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α). Immunoturbidimetric assay was used to measure serum levels of immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG). Flow cytometry was used to measure the percentages of T lymphocyte subsets (CD3⁺, CD4⁺, and CD8⁺). The clinical outcome and electroencephalographic findings were evaluated for all IS children after prednisone treatment.

RESULTS

The IS group had significantly higher serum levels of IL-2R, IL-8, and TNF-α than the healthy control group before treatment (P<0.05). The mean number of daily ictal clusters was positively correlated with the levels of IL-2R, IL-8, and TNF-α in IS children, the mean number of total daily seizures was positively correlated with IL-8 level, and any two indices out of IL-2R, IL-8, and TNF-α were positively correlated with each other (P<0.05). Among the 30 IS children treated with prednisone, 19 achieved seizure control; electroencephalography showed that 18 children achieved complete remission of hyperarrhythmia. After treatment, the IS group had significant reductions in the numbers of daily ictal clusters and total daily seizures, significant improvement in developmental quotient (P<0.05), and significant reductions in serum levels of IL-2R, L-8, and TNF-α, the percentage of CD4⁺ T lymphocytes, and CD4⁺/CD8⁺ ratio (P<0.05), as well as a significant increase in the percentage of CD8⁺ T lymphocytes (P<0.05).

CONCLUSIONS

IS children have immune dysfunction. Prednisone can control seizures in IS children, possibly by regulating and improving immune dysfunction.

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.

Planning interventional trials in childhood arterial ischaemic stroke using a Delphi consensus process

AIM

There is a paucity of data from randomized controlled treatment trials in childhood arterial ischaemic stroke. Our objectives were to identify and plan a trial through use of a Delphi consensus process.

METHOD

The Delphi panel consisted of Australian, New Zealand, and European paediatric neurologists with interests in childhood stroke. Four rounds were conducted using a REDCap (Research Electronic Data Capture) Web-based application: the first consisted of open-ended questions; the second evaluated agreement for the most important trial; the third and fourth reached consensus on design.

RESULTS

Forty-seven out of 66 neurologists answered the first round. Eight areas of research for important and feasible trials were identified. In the second round, 43 paediatric neurologists ranked the three highest rated trials: (1) aspirin versus aspirin plus steroids in focal arteriopathy (n=31); (2) heparin versus aspirin (n=6); and (3) heparin versus aspirin versus modern anticoagulation (n=6). The third and fourth surveys reached consensus among 43 out of 44 respondents on design of the highest ranked trial, and allowed agreement on inclusion/exclusion criteria, clinical/neuroimaging data, and treatment protocols.

CONCLUSION

The Delphi consensus process is an efficient method of identifying and planning paediatric stroke trials. An international, multicentre trial is now in preparation.

New insights into the pathogenesis and prevention of tuberous sclerosis-associated neuropsychiatric disorders (TAND)

Tuberous sclerosis complex (TSC) is a multi-system disorder resulting from mutations in either the TSC1 or TSC2 genes leading to hyperactivation of mechanistic target of rapamycin (mTOR) signaling. TSC is commonly associated with autism (61%), intellectual disability (45%), and behavioral, psychiatric, intellectual, academic, neuropsychological, and psychosocial difficulties that are collectively referred to as TSC-associated neuropsychiatric disorders (TAND). More than 90% of children with TSC have epilepsy, including infantile spasms, and early onset of seizures, especially infantile spasms, is associated with greater impairment in intellectual development compared with individuals with TSC without seizures. Development of the mTOR inhibitors everolimus and sirolimus has led to considerable progress in the treatment of renal angiomyolipomata, pulmonary lymphangioleiomyomatosis, and subependymal giant cell astrocytomas in the brain. However, similar therapeutic progress is needed in the treatment of TAND.

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.