Infantile spasms in Down syndrome--effects of delayed anticonvulsive treatment

Identification and treatment of surgically-remediable causes of infantile epileptic spasms syndrome

INTRODUCTION

Infantile epileptic spasms syndrome (IESS) is a common developmental and epileptic encephalopathy with poor long-term outcomes. A substantial proportion of patients with IESS have a potentially surgically remediable etiology. Despite this, epilepsy surgery is underutilized in this patient group. Some surgically remediable etiologies, such as focal cortical dysplasia and malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE), are under-diagnosed in infants and young children. Even when a surgically remediable etiology is recognised, for example, tuberous sclerosis or focal encephalomalacia, epilepsy surgery may be delayed or not considered due to diffuse EEG changes, unclear surgical boundaries, or concerns about operating in this age group.

AREAS COVERED

In this review, the authors discuss the common surgically remediable etiologies of IESS, their clinical and EEG features, and the imaging techniques that can aid in their diagnosis. They then describe the surgical approaches used in this patient group, and the beneficial impact that early epilepsy surgery can have on developing brain networks.

EXPERT OPINION

Epilepsy surgery remains underutilized even when a potentially surgically remediable cause is recognized. Overcoming the barriers that result in under-recognition of surgical candidates and underutilization of epilepsy surgery in IESS will improve long-term seizure and developmental outcomes.

Early Response, Long-Term Seizure Outcome, and Very-Low-Dose Adrenocorticotrophic Hormone Therapy for Infantile Epileptic Spasms Syndrome With Down Syndrome

BACKGROUND

Infantile epileptic spasms syndrome (IESS) with Down syndrome has good treatment response and good seizure outcomes with high-dose adrenocorticotrophic hormone (ACTH) therapy. We investigated the early treatment response of epileptic spasms (ES), long-term seizure outcome, and efficacy of very-low-dose ACTH therapy for IESS with Down syndrome.

METHODS

We retrospectively investigated patients with Down syndrome and IESS between April 1983 and January 2023. We defined response to treatment as clinical remission and electrographic resolution of hypsarrhythmia after treatment for more than one month and early treatment as any treatment for ES within three months of initiation of treatment. Long-term seizure outcomes were determined by the presence of any type of seizure within one year of the last visit. We investigated the dosage and efficacy of very-low-dose ACTH therapy.

RESULTS

Thirty patients were enrolled with a median follow-up period of 7.7 years (range: 1.3 to 19.1). The response and relapse rates in the early treatment were 83.3% and 16.0%, respectively. The seizure-free rate of long-term seizure outcomes was 80.0%. Long-term seizure outcomes correlated with early treatment response to ES. The response rate of very-low-dose ACTH therapy was 59.3%. The efficacy of ACTH therapy tended to be dose-dependent (P = 0.055).

CONCLUSIONS

Early treatment response to ES may be useful in predicting long-term seizure outcomes of IESS with Down syndrome. Very-low-dose ACTH therapy was the most effective treatment for ES and could exhibit dose-dependent efficacy. Depending on the IESS etiology, the ACTH dose could be reduced to minimize its side effects.

Timing the clinical onset of epileptic spasms in infantile epileptic spasms syndrome: A tertiary health center's experience

OBJECTIVE

Lead time to treatment (clinical onset of epileptic spasms [ES] to initiation of appropriate treatment) is known to predict outcomes in infantile epileptic spasms syndrome (IESS). Timing the clinical onset of ES is crucial to establish lead time. We investigated how often ES onset could be established to the nearest week. We aimed to (1) ascertain the exact date or estimate the nearest week of ES onset and (2) compare clinical/demographic factors between patients where date of ES onset was determined or estimated to the nearest week and patients whose date of ES onset could not be estimated to the nearest week. Reasons for difficulties in estimating date of ES onset were explored.

METHODS

Retrospective chart review of new onset IESS patients (January 2019-May 2022) extracted the date or week of the clinical onset of ES. Predictors of difficulty in date of ES onset estimation to the nearest week were examined by regression analysis. Sources contributing to difficulties determining date of ES onset were assessed after grouping into categories (provider-, caregiver-, disease-related).

RESULTS

Among 100 patients, date of ES onset was estimated to the nearest week in 47%. On univariable analysis, age at diagnosis (p = .021), development delay (p = .007), developmental regression/stagnation (p = .021), ES intermixed with other seizures (p = .011), and nonclustered ES at onset (p = .005) were associated with difficulties estimating date of ES onset. On multivariable analysis, failure to establish date of ES onset was related to ES intermixed with other seizures (p = .004) and nonclustered ES at onset (p = .003). Sources contributing to difficulties determining date of ES onset included disease-related factors (ES characteristics, challenges interpreting electroencephalograms) and provider/caregiver-related factors (delayed diagnosis).

SIGNIFICANCE

Difficulties with estimation of lead time (due to difficulties timing ES onset) can impact clinical care (prognostication), as even small increments in lead time duration can have adverse developmental consequences.

Epilepsy and Encephalopathy

BACKGROUND

Epilepsy encompasses more than the predisposition to unprovoked seizures. In children, epileptic activity during (ictal) and between (interictal) seizures has the potential to disrupt normal brain development. The term "epileptic encephalopathy (EE)" refers to the concept that such abnormal activity may contribute to cognitive and behavioral impairments beyond that expected from the underlying cause of the epileptic activity.

METHODS

In this review, we survey the concept of EE across a diverse selection of syndromes to illustrate its broad applicability in pediatric epilepsy. We review experimental evidence that provides mechanistic insights into how epileptic activity has the potential to impact normal brain processes and the development of neural networks. We then discuss opportunities to improve developmental outcomes in epilepsy now and in the future.

RESULTS

Epileptic activity in the brain poses a threat to normal physiology and brain development.

CONCLUSION

Until we have treatments that reliably target and effectively treat the underlying causes of epilepsy, a major goal of management is to prevent epileptic activity from worsening developmental outcomes.

Children with Down syndrome who experience developmental skill loss, characterization, and phenomenology: A case series

Loss of previously acquired developmental skills in children with Down syndrome (DS) is not a well characterized phenomenon. We identified 20 confirmed cases of childhood-onset skill loss for descriptive analysis. Eligible participants were recruited from a specialty clinic for persons with DS at a large medical center. Age and gender-matched participants also with DS but without skill loss were used as a comparison group. Case and control participants were between 3 and 14 years (mean 7.6 yr) at the time of evaluation. Loss of previously acquired communication, social-communication, and play skills was experienced by all cases, as well as new-onset or intensification of pre-existing maladaptive behaviors. The Aberrant Behavior Checklist (ABC)-community was helpful in distinguishing group differences in maladaptive behavior among cases and controls. All cases met DSMIV criteria for autism. Developmental skill loss associated with autism is an extreme example of within-group phenotypic variability and needs to be the focus of further research.

The Effect of Smartphone Video on Lead Time to Diagnosis of Infantile Spasms

OBJECTIVE

To assess whether access to smartphone video capture of infantile spasms at initial presentation is associated with improved time to diagnosis and treatment.

METHODS

We conducted a collaborative retrospective cohort study of 80 consecutive infants with confirmed infantile epileptic spasms syndrome initially presenting from 2015 to 2021 at 2 US pediatric centers. Statistical methods used included Mann-Whitney U test to assess the difference in lead times to electroencephalogram (EEG), diagnosis, and treatment between groups with and without video capture. A χ2 analysis was used to assess differences in demographics, clinical characteristics, and treatment outcomes between groups. Multivariate regression analysis was used to account for etiology types and infantile spasms capture on EEG.

RESULTS

Patients with smartphone video infantile spasms capture initially presented a median of 9 days earlier (P = .02), had their first EEG 16 days earlier (P = .007), and were diagnosed and started treatment 17 days earlier (P = .006 and P = .008, respectively) compared with the nonvideo group. The video group had a 25% greater response to initial standard treatment (P = .02) and a 21% greater freedom from infantile spasms at long-term follow-up (P = .03), although this long-term outcome lost statistical significance after adjustment for etiology type (P = .07) and EEG capture of infantile spasms (P = .059).

CONCLUSION

Our findings suggest a benefit of smartphone video capture of infantile spasms in reduced time to diagnosis and initial standard treatment, which are associated with improved treatment response rates. Substantial differences in lead times and treatment response highlight the clinical importance of pediatricians recommending caregivers to obtain smartphone video of events concerning for infantile spasms.

A Retrospective Cohort Study of Combined Therapy in West Syndrome associated with Trisomy 21

Background: West syndrome (WS) is a frequent epileptic encephalopathy associated with Down syndrome (DS). This study evaluated an outpatient protocol for WS in patients with DS who received vigabatrin (VGB) or VGB plus adrenocorticotrophic hormone. Methods: We analyzed infants treated in two neuropediatric centers from 2001-2021. We reviewed perinatal and familial history of epilepsy, spasm onset, treatment lag, electroencephalogram, neuroimaging, progression to epilepsy, and other neurological conditions. The outcomes were electroclinical resolution (ECR), relapses, and epilepsy progression. Results: Nineteen infants were included; 57.8% were male. The average spasm onset, follow-up, and treatment lag were 6.4 months, 8.15 years, and 2.33 months, respectively. Almost 74% had ECR after protocol intervention and minor epilepsy progression. Relapses occurred during combined therapy. Conclusions: The treatment protocol, especially combined therapy, was effective for WS in DS, impacting epilepsy progression and indicating the effectiveness of combined therapy to treat WS in patients with trisomy 21.

Brain circuit pathology in Down syndrome: from neurons to neural networks

Down syndrome (DS), a genetic pathology caused by triplication of chromosome 21, is characterized by brain hypotrophy and impairment of cognition starting from infancy. While studies in mouse models of DS have elucidated the major neuroanatomical and neurochemical defects of DS, comparatively fewer investigations have focused on the electrophysiology of the DS brain. Electrical activity is at the basis of brain functioning. Therefore, knowledge of the way in which brain circuits operate in DS is fundamental to understand the causes of behavioral impairment and devise targeted interventions. This review summarizes the state of the art regarding the electrical properties of the DS brain, starting from individual neurons and culminating in signal processing in whole neuronal networks. The reported evidence derives from mouse models of DS and from brain tissues and neurons derived from individuals with DS. EEG data recorded in individuals with DS are also provided as a key tool to understand the impact of brain circuit alterations on global brain activity.

Treatment of Infantile Spasm Syndrome: Update from the Interdisciplinary Guideline Committee Coordinated by the German-Speaking Society of Neuropediatrics

OBJECTIVES

The manuscript serves as an update on the current management practices for infantile spasm syndrome (ISS). It includes a detailed summary of the level of current evidence of different treatment options for ISS and gives recommendations for the treatment and care of patients with ISS.

METHODS

A literature search was performed using the Cochrane and Medline Databases (2014 to July 2020). All studies were objectively rated using the Scottish Intercollegiate Guidelines Network. For recommendations, the evidence from these studies was combined with the evidence from studies used in the 2014 guideline.

RECOMMENDATIONS

If ISS is suspected, electroencephalography (EEG) should be performed within a few days and, if confirmed, treatment should be initiated immediately. Response to first-line treatment should be evaluated clinically and electroencephalographically after 14 days. The preferred first-line treatment for ISS consists of either hormone-based monotherapy (AdrenoCorticoTropic Hormone [ACTH] or prednisolone) or a combination of hormone and vigabatrin. Children with tuberous sclerosis complex and those with contraindications against hormone treatment should be treated with vigabatrin. If first-line drugs are ineffective, second-line treatment options such as ketogenic dietary therapies, sulthiame, topiramate, valproate, zonisamide, or benzodiazepines should be considered. Children refractory to drug therapy should be evaluated early for epilepsy surgery, especially if focal brain lesions are present. Parents should be informed about the disease, the efficacy and adverse effects of the medication, and support options for the family. Regular follow-up controls are recommended.

Response to treatment and outcomes of infantile spasms in Down syndrome

AIM

To estimate the prevalence, and evaluate presentation, treatment response, treatment side effects, and long-term seizure outcomes in all known cases of children with Down syndrome and infantile spasms on the island of Ireland.

METHOD

This was a 10-year retrospective multicentre review of clinical records and investigations, focusing on treatment response, side effects, and long-term outcomes.

RESULTS

The prevalence of infantile spasms in Down syndrome was 3.0% during the study period. Fifty-four infants were identified with median age of spasm onset at 201 days (interquartile range [IQR] 156-242). Spasm cessation was achieved in 88% (n=46) at a median of 110 days (IQR 5-66). The most common first-line medications were prednisolone (n=20, 37%), vigabatrin (n=18, 33.3%), and sodium valproate (n=9, 16.7%). At follow-up (median age 23.7mo; IQR 13.4-40.6), 25% had ongoing seizures and 85% had developmental concerns. Treatment within 60 days did not correlate with spasm cessation. Seventeen children (31%) experienced medication side effects, with vigabatrin accounting for 52%.

INTERPRETATION

Prednisolone is an effective and well-tolerated medication for treating infantile spasms in Down syndrome. Despite the high percentage of spasm cessation, developmental concerns and ongoing seizures were common.

Clinical profile, treatment modalities, and outcomes in patients with infantile spasms: A retrospective study from the United Arab of Emirates (UAE)

BACKGROUND

Infantile spasms (IS) are an epileptic encephalopathy where the prognosis is generally poor, with most patients exhibiting psychomotor retardation or intractable epilepsy. However, it is claimed that early and aggressive treatment is related to better response rate and outcome, especially in patients with idiopathic IS.

OBJECTIVE

To investigate different treatment modalities and outcomes in patients with IS attending a pediatric neurology clinic at a specialized neurology center in Abu Dhabi, United Arab Emirates.

METHODS

Retrospective chart review was done for detailed history, demographic data, etiology, neuro-diagnostic workup, treatment modalities, and the outcomes for all patients diagnosed with IS from September 2014 to September 2019.

RESULTS

Three treatment modalities were identified as 1st line- Prednisolone United Kingdom Infantile Spasms Study (UKISS) (N = 15, 46.8%), Anti-Seizure Medications (ASMs) (N = 12, 37.5%), and Vigabatrin (N = 5, 15.6%). The complete response rate to Vigabatrin as a 1st line treatment showed the highest statistical significance (X² = 7.34, p = 0.007). Patients with idiopathic IS showed a comparable response to treatment to those with symptomatic IS. Additional response to 2nd line treatment with Prednisolone UKISS protocol (25%) and Vigabatrin (15%) was noted in patients who showed partial or no response to the 1st line treatment. None of our patients received Adrenocorticotropic Hormone as treatment. All patients with desirable final outcomes were with idiopathic IS and none were symptomatic.

CONCLUSION

More than a third of our patients showed poor treatment response whenever they were not offered treatment according to the current available protocols. This indicates an urgent need for having a unified treatment protocol that takes into consideration the availability of medications, professional expertise as well as diagnostic workup outside major tertiary care centers in our region.

Treatment outcomes for infantile spasms in Japanese children with Down syndrome

BACKGROUND

The aim of this study was to assess the treatment response to conventional antiepileptic drugs and low-dose adrenocorticotropic hormone therapy for infantile spasms in children with Down syndrome.

METHODS

We retrospectively investigated the response and relapse rates, electroencephalography findings, patient characteristics during drug withdrawal, and developmental outcome in 10 children with Down syndrome treated for infantile spasms in our hospital.

RESULTS

All patients showed cessation of infantile spasms and achieved electroencephalographic normalization. Spasm relapse occurred in one of 10 patients (10%). Antiepileptic drugs have been withdrawn for seven of 10 patients (70%), none of whom have experienced seizure relapse since drug withdrawal. The median developmental quotient (n = 8) was 20.5, which shows that the developmental outcome was unfavorable. Low-dose adrenocorticotropic hormone therapy achieved a low seizure remission rate of 28.6%.

CONCLUSIONS

Elucidation of the optimal treatment for infantile spasms in children with Down syndrome is needed to reduce the duration of infantile spasms and improve the developmental outcome.

Comparative Effectiveness of Initial Treatment for Infantile Spasms in a Contemporary US Cohort

OBJECTIVE

To compare the effectiveness of initial treatment for infantile spasms.

METHODS

The National Infantile Spasms Consortium prospectively followed up children with new-onset infantile spasms that began at age 2 to 24 months at 23 US centers (2012-2018). Freedom from treatment failure at 60 days required no second treatment for infantile spasms and no clinical spasms after 30 days of treatment initiation. We managed treatment selection bias with propensity score weighting and within-center correlation with generalized estimating equations.

RESULTS

Freedom from treatment failure rates were as follows: adrenocorticotropic hormone (ACTH) 88 of 190 (46%), oral steroids 42 of 95 (44%), vigabatrin 32 of 87 (37%), and nonstandard therapy 4 of 51 (8%). Changing from oral steroids to ACTH was not estimated to affect response (observed 44% estimated to change to 44% [95% confidence interval 34%-54%]). Changing from nonstandard therapy to ACTH would improve response from 8% to 39% (17%-67%), and changing to oral steroids would improve response from 8% to 38% (15%-68%). There were large but not statistically significant estimated effects of changing from vigabatrin to ACTH (29% to 42% [15%-75%]), from vigabatrin to oral steroids (29% to 42% [28%-57%]), and from nonstandard therapy to vigabatrin (8% to 20% [6%-50%]). Among children treated with vigabatrin, those with tuberous sclerosis complex (TSC) responded more often than others (62% vs 29%; p < 0.05).

DISCUSSION

Compared to nonstandard therapy, ACTH and oral steroids are superior for initial treatment of infantile spasms. The estimated effectiveness of vigabatrin is between that of ACTH/oral steroids and nonstandard therapy, although the sample was underpowered for statistical confidence. When used, vigabatrin worked best for TSC.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for children with new-onset infantile spasms, ACTH or oral steroids were superior to nonstandard therapies.

Medication selection, health services outcomes, and cost trajectories for Medicaid beneficiaries with infantile spasms

OBJECTIVE

There are three recommended first-line treatments for infantile spasms, adrenocorticotropic hormone (ACTH), oral corticosteroids, and vigabatrin, though non-standard treatments such as topiramate are sometimes selected. Is it uncertain how treatment selection influences health services outcomes.

METHODS

We conducted a retrospective cohort study of Medicaid beneficiaries newly diagnosed with infantile spasms from 2009-2010. We included infants with a new diagnosis of infantile spasms between age 2-9 months who filled ACTH (reference), prednisolone, vigabatrin, or topiramate prescriptions. Multivariable Cox proportional hazards regression compared time to first emergency department (ED) visit or hospitalization across treatment groups during 2 years of follow-up. Monthly costs for each treatment were examined in 6-month intervals and compared in a multivariable generalized linear model.

RESULTS

Among 256 children with infantile spasms, 116 received ACTH, 62 prednisolone, 15 vigabatrin, and 63 topiramate. The rate of ED visit or hospitalization per person-year did not differ significantly for prednisolone (0.9 [95 % CI 0.7-1.2]; adjusted hazard ratio [aHR] 0.84, 95 % CI 0.57-1.24), vigabatrin (0.8 [95 % CI 0.4-1.5]; aHR 0.91, 95% CI 0.45-1.84), or topiramate (1.7 [95 % CI 1.3-2.3]; aHR 1.15, 95 % CI 0.80-1.65), when compared to ACTH (1.1 [95 % CI 0.9-1.3]). The median payment for ACTH was $96,406 (interquartile range 70,742-138,476) during the first 6 months. The adjusted mean total payment in the first 6 months was 73% lower for prednisolone (95% CI -82, -61), 69% lower for vigabatrin (95% CI -84, -40), and 73% lower for topiramate (95% CI -82, -59). However, in subsequent 6-month intervals, costs associated with ACTH were not significantly different compared to other treatments.

SIGNIFICANCE

Compared to other treatments for infantile spasms, use of ACTH was associated with greater cost in the first 6 months of treatment, but not with reduced ED visits or hospitalizations. The cost effectiveness of ACTH depends on its relative clinical efficacy, and merits additional research.

Infantile Spasms and Trisomy 21: Unfavorable Outcomes with First-line Vigabatrin Therapy

Introduction:

Among children with infantile spasms (ISs), those with trisomy 21 (T21) and those with normal development at onset and no identifiable etiology (previously referred to as “idiopathic”) are expected to have relatively favorable outcomes. The study objective is to determine if differences exist in treatment response, relapse, and subsequent epilepsy between these two groups when vigabatrin is used as first-line treatment.

Methods:

In this retrospective study, patients were classified into the following groups and clinical features were compared: T21 (n = 24) and IS with normal development at onset and no identified etiology (n = 40; control group).

Results:

There was no significant difference in the age of IS onset, sex distribution, or treatment lag between the groups. The T21 compared to the control group required a higher mean number of anti-seizure therapies (3.6 vs. 1.9, p < 0.001), had more relapses [10 (42%) vs. 4 (10%), p < 0.005)], and had higher risk of subsequent epilepsy [11 (46%) vs. 8 (20%), p < 0.003]. Relapses were often delayed in the T21 group, with a mean of 8 months after IS cessation.

Conclusion:

Our results differ from most studies using steroids as first-line treatment where the groups were shown to have similar treatment response and T21 patients had a low risk of relapse and subsequent epilepsy. Therefore, our results suggest that vigabatrin as first-line treatment in T21 with IS may be less favorable than steroids.

Risk for infantile spasms after acute symptomatic neonatal seizures

OBJECTIVE

Infantile spasms (IS) is a severe epilepsy in early childhood. Early treatment of IS provides the best chance of seizure remission and favorable developmental outcome. We aimed to develop a prediction rule to accurately predict which neonates with acute symptomatic seizures will develop IS.

METHODS

We used data from the Neonatal Seizure Registry, a prospective, multicenter cohort of infants with acute symptomatic neonatal seizures born from July 2015 to March 2018. Neonates with acute symptomatic seizures who received clinical electroencephalography (EEG) and magnetic resonance imaging (MRI) and were younger than 2 years of age at the time of enrollment were included. We evaluated the association of neonatal EEG, MRI, and clinical factors with subsequent IS using bivariate analysis and best subsets logistic regression. We selected a final model through a consensus process that balanced statistical significance with clinical relevance.

RESULTS

IS developed in 12 of 204 infants (6%). Multiple potential predictors were associated with IS, including Apgar scores, EEG features, seizure characteristics, MRI abnormalities, and clinical status at hospital discharge. The final model included three risk factors: (a) severely abnormal EEG or ≥3 days with seizures recorded on EEG, (b) deep gray or brainstem injury on MRI, and (c) abnormal tone on discharge exam. The stratified risk of IS was the following: no factors 0% (0/82, 95% confidence interval [CI] 0%-4%), one or two factors 4% (4/108, 95% CI 1%-9%), and all three factors 57% (8/14, 95% CI 29%-83%).

SIGNIFICANCE

IS risk after acute symptomatic neonatal seizures can be stratified using commonly available clinical data. No child without risk factors, vs >50% of those with all three factors, developed IS. This risk prediction rule may be valuable for clinical counseling as well as for selecting participants for clinical trials to prevent post-neonatal epilepsy. This tailored approach may lead to earlier diagnosis and treatment and improve outcomes for a devastating early life epilepsy.

Impact of predictive, preventive and precision medicine strategies in epilepsy

Over the last decade, advances in genetics, neuroimaging and EEG have enabled the aetiology of epilepsy to be identified earlier in the disease course than ever before. At the same time, progress in the study of experimental models of epilepsy has provided a better understanding of the mechanisms underlying the condition and has enabled the identification of therapies that target specific aetiologies. We are now witnessing the impact of these advances in our daily clinical practice. Thus, now is the time for a paradigm shift in epilepsy treatment from a reactive attitude, treating patients after the onset of epilepsy and the initiation of seizures, to a proactive attitude that is more broadly integrated into a 'P4 medicine' approach. This P4 approach, which is personalized, predictive, preventive and participatory, puts patients at the centre of their own care and, ultimately, aims to prevent the onset of epilepsy. This aim will be achieved by adapting epilepsy treatments not only to a given syndrome but also to a given patient and moving from the usual anti-seizure treatments to personalized treatments designed to target specific aetiologies. In this Review, we present the current state of this ongoing revolution, emphasizing the impact on clinical practice.

Neurologic complications of Down syndrome: a systematic review

Down syndrome (DS) is one of the most well-recognized genetic disorders. Persons with DS are known to have a variety of co-morbid medical problems, affecting nearly all organ systems. Improved healthcare interventions and research have allowed for increased life span of persons with DS, although disorders of the neurologic system remain underexplored. The purpose of this systematic review is to provide clinically pertinent information on the neurological phenotypes of frequently occurring or clinically relevant conditions. A retrospective review of MEDLINE, Scopus, and Pubmed were used to identify sources among seventeen, clinically relevant, search categories. MeSH terms all contained the phrase "Down Syndrome" in conjunction with the topic of interest. 'Frequently-occurring' was defined as prevalent in more than 10% of persons with DS across their lifespan, whereas 'clinically-relevant' was defined as a disease condition where early diagnosis or intervention can augment the disease course. In total, 4896 sources were identified with 159 sources meeting criteria for inclusion. Seventeen clinical conditions were grouped under the following subjects: hypotonia, intellectual and learning disability, cervical instability, autism spectrum disorder, epilepsy, cerebrovascular disease, Alzheimer's disease and neuropsychiatric disease. The results of this review provide a blueprint for the clinical neurologist taking care of persons with DS across the age spectrum and indicate that there are many underrecognized and misdiagnosed co-occurring conditions in DS, highlighting the need for further research.

Epileptic spasms in individuals with Down syndrome: A review of the current literature

Epilepsy can occur in individuals with Down syndrome (DS), with epileptic spasms representing the most frequent seizure type in this population. Epileptic spasms can have devastating consequences on the development of individuals with the condition. This review sought to explore the lifetime prevalence and underlying mechanism of epileptic spasms in this population. We also aimed to review the response rate to various treatments, the relapse rate, and the development of subsequent epilepsy or autism in this population. A comprehensive literature search was conducted for articles discussing the lifetime prevalence, diagnosis, treatment, outcomes, or underlying etiology of epileptic spasms in animal models or individuals with DS. According to available literature, the global clinic-based lifetime prevalence of epilepsy in individuals with DS ranged from 1.6% to 23.1%, with epileptic spasms representing 6.7%-66.7% of these cases. Response rate to treatment with adrenocorticotropic hormone/corticosteroids was highest (81%) and has the most literature supporting its use, with other regimens, including vigabatrin and other antiepileptic drugs, having lower response rates. Epileptic spasms occur more frequently in children with DS than in the general population, though more studies are needed to determine the true lifetime prevalence of epileptic spasms in this population. Generally, children with DS and epileptic spasms tend to be more responsive to treatment and have better outcomes than children with epileptic spasms of unknown etiology (ie, without DS), in terms of response and relapse rates as well as the development of intractable epilepsy (eg, Lennox-Gastaut syndrome).

Treatment of Epilepsy Associated with Common Chromosomal Developmental Diseases

Chromosomal diseases are heterogeneous conditions with complex phenotypes, which include also epileptic seizures. Each chromosomal syndrome has a range of specific characteristics regarding the type of seizures, EEG findings and specific response to antiepileptic drugs, significant in the context of the respective genetic etiology. Therefore, it is very important to know these particularities, in order to avoid an exacerbation of seizures or some side effects. In this paper we will present a review of the epileptic seizures and antiepileptic treatment in some of the most common chromosomal syndromes.

Outcomes of High-Dose Steroid Therapy for Infantile Spasms in Children With Trisomy 21

OBJECTIVE

We performed a retrospective chart review of patients with trisomy 21 and infantile spasms in our university-based pediatric epilepsy center between 2002 and 2016 in order to describe the clinical characteristics of children with these diagnoses as well as to evaluate their response to first-line treatments.

METHODS

Patients with infantile spasms were identified via the neurophysiology database. Charts were reviewed with attention to infantile spasms diagnosis, presence of trisomy 21, age of reported clinical onset, treatment lag, treatments used, response to treatment, imaging findings, electroencephalography (EEG) data, and developmental outcomes.

RESULTS

Of the 310 patients with infantile spasms, 24 also had trisomy 21. Three patients did not meet inclusion criteria. Ten of the 21 patients received nonstandard therapies first line; 2 of the 10 (20%) achieved spasm control, and 4 of the 8 who failed therapy (50%) progressed to Lennox-Gastaut syndrome. Eleven of the 21 patients received standard therapies as first-line treatments (10 with prednisolone according to the protocol in the United Kingdom Infantile Spasms Study [UKISS] and 1 with adrenocorticotrophic hormone [ACTH]). Nine of the 10 patients (90%) who received prednisolone achieved spasm resolution, 6 (60%) of these without relapse. The final patient (10%) failed prednisolone as well as ACTH. One patient received ACTH first line with success.

CONCLUSION

This is the only series to follow children with trisomy 21 and infantile spasms in which a significant proportion received UKISS-protocol prednisolone. It adds to current knowledge about safety, tolerability, and effectiveness of prednisolone in this group.

Epilepsy in tuberous sclerosis complex: Findings from the TOSCA Study

OBJECTIVE

To present the baseline data of the international TuberOus SClerosis registry to increase disease Awareness (TOSCA) with emphasis on the characteristics of epilepsies associated with tuberous sclerosis complex (TSC).

METHODS

Retrospective and prospective patients' data on all aspects of TSC were collected from multiple countries worldwide. Epilepsy variables included seizure type, age at onset, type of treatment, and treatment outcomes and association with genotype, seizures control, and intellectual disability. As for noninterventional registries, the study protocol did not specify any particular clinical instruments, laboratory investigations, or intervention. Evaluations included those required for diagnosis and management following local best practice.

RESULTS

Epilepsy was reported in 83.6% of patients (1852/2216) at baseline; 38.9% presented with infantile spasms and 67.5% with focal seizures. The mean age at diagnosis of infantile spasms was 0.4 year (median <1 year; range <1-30 years) and at diagnosis of focal seizures was 2.7 years (median 1 year; range <1-66 years). A total of 1469 patients (79.3%) were diagnosed with epilepsy <2 years. The rate of infantile spasms was higher in patients with a TSC 2 mutation than in patients with a TSC1 mutation (47.3% vs 23%). ɣ-aminobutyric acid (GABA)ergic drugs were the most common treatment modality for both infantile spasms (78.7%) and focal seizures (65.5%). Infantile spasms and focal seizures were controlled in 76.3% and 58.2% of patients, respectively. Control of seizures was associated with lower rates of intellectual disability in both groups.

SIGNIFICANCE

This registry reports the largest international cohort of patients with TSC. Findings confirmed the typical onset pattern of infantile spasms and other focal seizures in the first 2 years of life, and the high rates of infantile spasms in patients with TSC2 mutation. Our results underscored the occurrence of focal seizures at all ages, including an onset that preceded emergence of infantile spasms. Seizure control was shown to be associated with lower rates of intellectual disability but did not preclude the presence of intellectual disability.

The epileptic encephalopathy jungle - from Dr West to the concepts of aetiology-related and developmental encephalopathies

PURPOSE OF REVIEW

We aim to further disentangle the jungle of terminology of epileptic encephalopathy and provide some insights into the current understanding about the aetiology and pathophysiology of this process. We cover also the key features of epilepsy syndromes of infancy and childhood which are considered at high risk of developing an epileptic encephalopathy.

RECENT FINDINGS

The concept of 'epileptic encephalopathy' has progressively been elaborated by the International League Against Epilepsy according to growing clinical and laboratory evidence. It defines a process of neurological impairment caused by the epileptic activity itself and, therefore, potentially reversible with successful treatment, although to a variable extent. Epileptic activity interfering with neurogenesis, synaptogenesis, and normal network organization as well as triggering neuroinflammation are among the possible pathophysiological mechanisms leading to the neurological compromise. This differs from the newly introduced concept of 'developmental encephalopathy' which applies to where the epilepsy and developmental delay are both because of the underlying aetiology and aggressive antiepileptic treatment may not be helpful.

SUMMARY

The understanding and use of correct terminology is crucial in clinical practice enabling appropriate expectations of antiepileptic treatment. Further research is needed to elucidate underlying pathophysiological mechanisms, define clear outcome predictors, and find new treatment targets.

Infantile Spasms in Children With Down Syndrome: Identification and Treatment Response

Objectives. To evaluate infantile spasms in children with Down syndrome including assessment of efficacy of treatments, presence of treatment lag, and to identify risk factors that may predict the occurrence of infantile spasms in this population. Methods. Medical charts, electroencephalograms, and brain magnetic resonance images were evaluated in 37 children treated for infantile spasms at a single institution from 2005 to 2015. Results. Mean age at diagnosis was 9.16 months, with an average 1.38-month lag from spasms onset to start of medication. Prevalence of heart defects and pulmonary hypertension were significantly higher in those with infantile spams compared with those without. Eighty-one percent receiving adrenocorticotropic hormone as initial treatment experienced remission within 2 weeks, 94.1% had remission at 3 months compared with 18.8% at 2 weeks and 35.3% at 3 months for other first-line treatments. Type of treatment was the only predictor of good outcome. Conclusions. Results stress the importance of early recognition and adrenocorticotropic hormone treatment for this seizure disorder in children with Down syndrome.

Intellectual Disability and Psychotropic Medications

Andrew is a 17-year-old male with trisomy 21, commonly known as Down syndrome, and accompanying severe intellectual disability who presents to your primary care office with his father for the first time to establish care and assistance with transition. Andrew has a history of a complete atrioventricular canal that was repaired as an infant and poorly controlled infantile spasms. Currently, he struggles with constipation, esophageal strictures, medullary nephrocalcinosis, urinary retention, sleep dysregulation, G-tube dependency, and hip dysplasia.Andrew walked at 11 to 12 years of age. Currently, he ambulates on his feet at home and in a wheelchair out in the community. He is nonverbal but can imprecisely sign for "more" and understands a few words. His father reports that his main concern is long-standing nonsuicidal self-injury (NSSI) and aggression. His self-injury consists of head banging against hard objects such as concrete floors and biting or scratching himself to the point of bleeding. Over the past 13 years, he has been prescribed over 10 different psychotropic medications, including various typical and atypical antipsychotics, selective serotonin reuptake inhibitors, benzodiazepines, mood stabilizers, and alpha agonists, all of which were discontinued because of the perception of undesirable side effects or lack of efficacy. His current medications include aripiprazole, olanzapine, levetiracetam, clorazepate, and trazodone. To rule out causes of irritability, you order a brain and spine magnetic resonance imaging, metabolic testing (for causes of NSSI such as Lesch-Nyhan), an autoimmune workup (for causes of pain or inflammation such as juvenile idiopathic arthritis), and hearing/vision testing, which are all normal. Previous testing by subspecialists (he is followed by gastroenterology, sleep medicine, orthopedics, nephrology, neurology, cardiology, and psychiatry) included normal renal ultrasound and no clear sources of gastrointestinal pain. However, key providers are spread among multiple institutions and do not regularly communicate.Andrew lives with his parents, who are highly educated and very dedicated to his health and wellness. His mother travels frequently for work, and his father is Andrew's full-time caregiver. Despite remaining ostensibly positive, his father reports significant caregiver burnout and fatigue.Over the next several months, Andrew continues to experience worsening NSSI necessitating medication changes despite active involvement in applied behavior analysis therapy. During this time, he presents to the emergency department multiple times for irritability and self-injury. On examination, he is aggressive, irritable, has bruises on his forehead and scratches on his skin, and has intermittent vertical gaze deviation that was noticeable to parents. The rest of his physical and neurological examination was unremarkable and revealed no asymmetry, clonus, hyperreflexia, or changes in muscle tone. While examining his extremities, joints, and abdomen, there was no obvious source of pain.What are your next steps? How would you support this family, both in the immediate management of his self-injury and long-term care needs for this medically and behaviorally complex adolescent?

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.

Early-Life Epilepsies and the Emerging Role of Genetic Testing

IMPORTANCE

Early-life epilepsies are often a consequence of numerous neurodevelopmental disorders, most of which are proving to have genetic origins. The role of genetic testing in the initial evaluation of these epilepsies is not established.

OBJECTIVE

To provide a contemporary account of the patterns of use and diagnostic yield of genetic testing for early-life epilepsies.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective cohort, children with newly diagnosed epilepsy with an onset at less than 3 years of age were recruited from March 1, 2012, to April 30, 2015, from 17 US pediatric hospitals and followed up for 1 year. Of 795 families approached, 775 agreed to participate. Clinical diagnosis of the etiology of epilepsy were characterized based on information available before genetic testing was performed. Added contributions of cytogenetic and gene sequencing investigations were determined.

EXPOSURES

Genetic diagnostic testing.

MAIN OUTCOMES AND MEASURES

Laboratory-confirmed pathogenic variant.

RESULTS

Of the 775 patients in the study (367 girls and 408 boys; median age of onset, 7.5 months [interquartile range, 4.2-16.5 months]), 95 (12.3%) had acquired brain injuries. Of the remaining 680 patients, 327 (48.1%) underwent various forms of genetic testing, which identified pathogenic variants in 132 of 327 children (40.4%; 95% CI, 37%-44%): 26 of 59 (44.1%) with karyotyping, 32 of 188 (17.0%) with microarrays, 31 of 114 (27.2%) with epilepsy panels, 11 of 33 (33.3%) with whole exomes, 4 of 20 (20.0%) with mitochondrial panels, and 28 of 94 (29.8%) with other tests. Forty-four variants were identified before initial epilepsy presentation. Apart from dysmorphic syndromes, pathogenic yields were highest for children with tuberous sclerosis complex (9 of 11 [81.8%]), metabolic diseases (11 of 14 [78.6%]), and brain malformations (20 of 61 [32.8%]). A total of 180 of 446 children (40.4%), whose etiology would have remained unknown without genetic testing, underwent some testing. Pathogenic variants were identified in 48 of 180 children (26.7%; 95% CI, 18%-34%). Diagnostic yields were greater than 15% regardless of delay, spasms, and young age. Yields were greater for epilepsy panels (28 of 96 [29.2%]; P < .001) and whole exomes (5 of 18 [27.8%]; P = .02) than for chromosomal microarray (8 of 101 [7.9%]).

CONCLUSIONS AND RELEVANCE

Genetic investigations, particularly broad sequencing methods, have high diagnostic yields in newly diagnosed early-life epilepsies regardless of key clinical features. Thorough genetic investigation emphasizing sequencing tests should be incorporated into the initial evaluation of newly presenting early-life epilepsies and not just reserved for those with severe presentations and poor outcomes.

Stiripentol and vigabatrin current roles in the treatment of epilepsy

INTRODUCTION

Stiripentol and vigabatrin are the two anticonvulsant drugs currently approved in severe infantile-onset epilepsies, respectively Dravet syndrome and infantile spasms.

AREAS COVERED

For both, the indication was discovered by chance thanks to an exploratory study. Both demonstrated indisputable efficacy through randomized-controlled trials. Stiripentol as adjunctive therapy to clobazam and valproate performed better than placebo, and vigabatrin as first-line monotherapy better than the reference steroid therapy in spasms due to tuberous sclerosis. At one-year treatment vigabatrin and steroids were equally efficient in the other etiologies of spasms. However, it took more than 20 years for both drugs to be approved world-wide.

EXPERT OPINION

Stiripentol suffered from pharmacokinetic potentiation of clobazam, thus raising the question whether it was efficient per se. Finally, animal models and pharmacogenetic data on CYP2C19 confirmed its specific anticonvulsant effect. Stiripentol (in comedication with clobazam and valproate) is therefore to be recommended for Dravet patients. Vigabatrin was found to have a frequent and irreversible retinal toxicity, which required an alternative visual testing to be detected in young children. Today the benefit/risk ratio of vigabatrin as first-line is considered to be positive in infantile spasms, given the severity of this epilepsy and the lack of a safer alternative therapy.

Investigations in West Syndrome: Which, When and Why

Investigators from the National Infantile Spasms Consortium (NISC) in the USA studied the etiology of new-onset infantile spasms (IS) in 251 infants (mean age at onset, 7.1, range, 0.1-22.7 months).

Epilepsy in children with Down syndrome: not so benign as generally accepted

Down syndrome (DS) is one of the most common causes of mental retardation in children. Many children with DS suffer from neurologic problems, including seizures. Epileptic spasms (ES) are the most frequently reported seizure type. As in the general epilepsy population, ES are rather difficult to control with anti-epileptic drugs. Different treatment regimens have been proposed in the literature, most of them containing vigabatrin or steroids. We present 12 children with DS, who were seen and treated at the Antwerp University Hospital because of seizures. Eight of them presented with ES. Different treatment regimens were used, with varying outcome. This article summarizes our experience with epilepsy in children with DS, describing the different treatment options that were used. We found a poor outcome in these children, compared to most previous reports. Although steroids play an important role in the treatment of ES worldwide, we found a low success rate (8.3 %) of these drugs.

Cerebal overinhibition could be the basis for the high prevalence of epilepsy in persons with Down syndrome

Down syndrome (DS) is the most common cause of genetic intellectual disability, and the trisomy 21 is associated with more than 80 clinical traits, including higher risk for epilepsy. Several hypotheses have been put forward to explain the mechanisms underlying increased seizure susceptibility in DS: inherent structural brain abnormalities, abnormal cortical lamination, disruption of normal dendritic morphology, and underdeveloped synaptic profiles. A deficiency or loss of GABA inhibition is hypothesized to be one of the main alterations related to the epileptogenic process. Paradoxically, enhanced GABA inhibition has also been reported to promote seizures. One major functional abnormality observed in the brains of individuals and mouse models with DS appears to be an imbalance between excitatory and inhibitory neurotransmission, with excessive inhibitory brain function. This review discusses the GABAergic system in the human DS brain and the possible implication of the GABAergic network circuit in the epileptogenic process in individuals where the pathogenetic basis for epilepsy is unknown.

The Clinical Characteristics and Treatment Response in Children with West Syndrome in a Developing Country: A Retrospective Case Record Analysis

This study describes the clinical characteristics, treatment, and outcome of children with West syndrome in a tertiary care hospital in north India. Overall, 310 case records diagnosed from January 2009 to June 2012 were reviewed. The median age of onset of spasms was 5 months (interquartile range = 2.5-7 months). The predominant underlying etiology was perinatal cerebral ischemia (55%). Adrenocorticotropic hormone or oral steroids were received by 92% children, of whom 43% became seizure free. Median lag time for appropriate treatment initiation was significantly less in patients who became seizure free as compared to those with persisting seizures (11 vs 15 months, P = .001) soon after receiving treatment of choice. Later age at onset of spasms was associated with a favorable seizure outcome (P = .03). In a resource-limited setting, unawareness along with treatment costs and repeated visits to the hospital are significant obstacles to optimum management.

Seizing control of epileptic activity can improve outcome

In epileptic encephalopathy, the seizures and interictal epileptiform activity create additional neurocognitive dysfunction beyond that due to the underlying etiology. Treatment leading to a reduction in seizures or interictal abnormalities may help improve neurocognitive function in these situations. The focus of our discussion is reviewing data that support the concept that treatment can impact outcome independent of the etiology in some cases.

Neurodevelopmental outcomes in children with Down syndrome and infantile spasms

Down syndrome (DS) is the most common genetic cause of intellectual disability in the United States. The prevalence of seizure in individuals with DS is 1-13%, and infantile spasm (IS) occurs in 6-32% of those with seizures. Since IS is relatively common in children with DS, it is important to understand the impact IS has on the neurodevelopmental outcomes in order to provide appropriate anticipatory guidance to help maximize the potential of these children. Our study is the first to compare the neurodevelopmental outcomes of children with DS and IS (DS + IS) to children with DS and no history of seizures (DS - IS). Using the Bayley Scales of Infant and Toddler Development III, we assessed the neurodevelopment of 29 subjects (eight DS + IS and 21 DS - IS). Neurodevelopmental outcome was poor in the DS + IS cohort, but the delay in treatment does not appear to contribute to any differences in their developmental scores. However, when compared to children with DS - IS, the DS + IS cohort scored approximately 20 points less in all domains including cognitive, motor, and language (P < 0.05). Our results indicate that IS may impact the neurodevelopmental outcomes of children with DS + IS; thus, it is important to provide ongoing developmental and educational assessments and potentially additional therapies for children with DS + IS.

Infantile Spasms Respond Poorly to Topiramate

INTRODUCTION

Infantile spasms are seizures typical of an age-related epileptic encephalopathy. Although evidence supporting topiramate for infantile spasms is lacking, many clinicians use it for this indication. The aim of this study was to determine the rate of infantile spasm remission with topiramate at our institution. A low rate of infantile spasm remission was hypothesized.

METHODS

This was a single-center retrospective medical record review of patients treated with topiramate for infantile spasms between January 2009 and September 2013. Records were reviewed for accuracy of diagnosis and outcome. Clinical remission of infantile spasms was defined as resolution for at least 28 days at any time during treatment with topiramate. For patients with clinical remission, posttreatment electroencephalographs were reviewed to assess for electrographic remission. To assess for confounding variables affecting remission rate, demographics and outcomes were compared with patients treated with adrenocorticotropic hormone within the same period using the same criteria for remission.

RESULTS

Three of 31 (9.7%) patients achieved clinical remission with topiramate, two of whom also experienced electrographic remission. The third patient had electrographic remission with previous adrenocorticotropic hormone treatment but infantile spasm remission only after receiving topiramate. All three of these patients experienced subsequent electroclinical relapse during topiramate therapy. Although there were no significant demographic differences between the topiramate and adrenocorticotropic hormone cohorts, more adrenocorticotropic hormone patients achieved clinical remission (9.7% versus 56%; P < 0.001).

DISCUSSION

Remission of infantile spasms with topiramate was uncommon and no patient experienced persistent electroclinical remission. These findings suggest that infantile spasms respond poorly to topiramate.

Assessing cognitive improvement in people with Down syndrome: important considerations for drug-efficacy trials

Experimental research over just the past decade has raised the possibility that learning deficits connected to Down syndrome (DS) might be effectively managed by medication. In the current chapter, we touch on some of the work that paved the way for these advances and discuss the challenges associated with translating them. In particular, we highlight sources of phenotypic variability in the DS population that are likely to impact performance assessments. Throughout, suggestions are made on how to detect meaningful changes in cognitive-adaptive function in people with DS during drug treatment. The importance of within-subjects evaluation is emphasized.

Neurodevelopmental outcome of infantile spasms: A systematic review and meta-analysis

BACKGROUND

The aims of this systematic review and meta-analysis were to assess (i) estimates of good neurodevelopmental outcome in infantile spasms (IS), (ii) if neurodevelopmental outcome has changed since the publication of the first guideline on medical treatment of IS in 2004 and (iii) effect of lead time to treatment (LTTT).

METHODS

The Medline, Embase, Cochrane, PsycINFO, Web of Science and Scopus databases, and reference lists of retrieved articles were searched. Studies inclusion criteria were: (i) >5 patients with IS, (ii) mean/median follow-up of >6 months, (iii) neurodevelopmental outcome, and (iv) randomized and observational studies. The data extracted included proportion of good neurodevelopmental outcome, year of publication, cryptogenic or symptomatic IS and LTTT.

RESULTS

Of the 1436 citations screened, 55 articles were included in final analysis, with a total of 2967 patients. The pooled estimate for good neurodevelopmental outcome was 0.236 (95% CI: 0.193-0.286). There was no difference between the proportions of good neurodevelopmental outcome for the 21 studies published after 2004 [0.264 (95% CI: 0.197-0.344)] compared to the 34 studies published before 2004 [0.220 (95% CI: 0.168-0.283)] (Q value=0.862, p=0.353). The pooled estimate of good neurodevelopmental outcome for cryptogenic IS [0.543 (95% CI: 0.458-0.625)] was higher than symptomatic IS [0.125 (95% CI: 0.09-0.171)] (Q value=69.724, p<0.001). Risk ratio of LTTT <4weeks relative to >4weeks for good neurodevelopmental outcome of 8 studies was 1.519 (95% CI: 1.064-2.169).

CONCLUSION

Neurodevelopmental outcome was overall poor in patients with IS and has not changed since the publication of first guideline on IS. Although cryptogenic IS has better prognosis than symptomatic IS, the outcome for cryptogenic IS remained poor. There was heterogeneity in neurodevelopmental outcome ascertainment methods, highlighting the need for a more standardized and comprehensive assessment of cognitive, behavioural, emotional and functional outcomes.

Seizure-dependent mTOR activation in 5-HT neurons promotes autism-like behaviors in mice

Epilepsy and autism spectrum disorder (ASD) are common comorbidities of one another. Despite the prevalent correlation between the two disorders, few studies have been able to elucidate a mechanistic link. We demonstrate that forebrain specific Tsc1 deletion in mice causes epilepsy and autism-like behaviors, concomitant with disruption of 5-HT neurotransmission. We find that epileptiform activity propagates to the raphe nuclei, resulting in seizure-dependent hyperactivation of mTOR in 5-HT neurons. To dissect whether mTOR hyperactivity in 5-HT neurons alone was sufficient to recapitulate an autism-like phenotype we utilized Tsc1flox/flox;Slc6a4-cre mice, in which mTOR is restrictively hyperactivated in 5-HT neurons. Tsc1flox/flox;Slc6a4-cre mice displayed alterations of the 5-HT system and autism-like behaviors, without causing epilepsy. Rapamycin treatment in these mice was sufficient to rescue the phenotype. We conclude that the spread of seizure activity to the brainstem is capable of promoting hyperactivation of mTOR in the raphe nuclei, which in turn promotes autism-like behaviors. Thus our study provides a novel mechanism describing how epilepsy can contribute to the development of autism-like behaviors, suggesting new therapeutic strategies for autism.

Hereditary neurometabolic causes of infantile spasms in 80 children presenting to a tertiary care center

BACKGROUND

Infantile spasms are a devastating infantile epileptic syndrome with multiple etiologies. Hereditary neurometabolic disorders are rarely recognized causes of infantile spasms. The aim of this study was to identify hereditary neurometabolic disorders when they were the cause of infantile spasms in patients presenting to a tertiary care center in Saudi Arabia.

METHODOLOGY

We conducted a retrospective review of children presenting to the Pediatric Department of King Abdulaziz Medical City in Riyadh, Saudi Arabia over a 15-year interval.

RESULTS

Eighty patients with infantile spasms were identified. A hereditary neurometabolic disorder was diagnosed in 10 patients (12.5%). Of these patients, two had a Leigh-like disorder and one patient had each of the following diagnoses: ethylmalonic aciduria, nonketotic hyperglycinemia, hyperinsulinemic hypoglycemia, leukodystrophy, short-chain acyl-coenzyme A dehydrogenase deficiency, molybdenum cofactor deficiency, primary carnitine deficiency, and neonatal hypoglycemia due to panhypopituitarism. This article is the first to report the association of the last three conditions with infantile spasms. Compared with the other etiologies, the hereditary neurometabolic disorder group had a strong history of similar disease in the same family (P = 0.002), and most of the patients were born of consanguineous parents (P = 0.021). In addition, a typical hypsarrhythmia pattern was more common in the hereditary neurometabolic disorder group (P = 0.003). Furthermore, this group had a poor response to therapy (P = 0.04). Otherwise, there were no significant differences regarding the type of spasms, neuroimaging or outcome; however, there was a trend toward poorer outcomes and death in the hereditary neurometabolic disorder group.

CONCLUSION

Hereditary neurometabolic disorders are relatively common causes of infantile spasms in this subpopulation of Saudi patients. An early diagnosis via proper metabolic and genetic testing has significant implications for applying specific treatments and for facilitating proper family counseling.