Etiologic Classification of 541 Infantile Spasms Cases: A Cohort Study

A review of epilepsy syndromes and epileptogenic mechanism affiliated with brain tumor related genes

Epilepsy is one of the comorbidities often manifested by patients with brain tumors. While there are reviews commenting on the epileptogenicity of brain-tumor-related genes, the reviews are commonly restricted to BRAF, IDH and PIK3CA. According to World Health Organization (WHO), at least 50 genes have been proposed as brain-tumor-related genes. Hence, we aimed to provide a more comprehensive review of the epileptogenicity of the brain-tumor-related genes. We performed an extensive literature search on PubMed, classified the studies, and provided an overview of the associated epilepsy phenotype and epileptogenic mechanism of the brain-tumor-related genes advocated by WHO. Through our analysis, we found a minor overlap between brain-tumor-related genes and epilepsy-associated genes, as some brain-tumor-related genes have been classified as epilepsy-associated genes in earlier studies. Besides reviewing the well-studied genes like TSC1 and TSC2, we identified several under-discovered brain-tumor-related genes, including TP53, CIC, IDH1 and NOTCH1, that warrant future exploration due to the existence of clinical or in vivo evidence substantiating their pathogenic role in epileptogenesis. We also propounded some methodologies that can be applied in future research to enhance the study of the epileptogenic mechanism of brain-tumor-related genes. To date, this article covers the greatest number of brain-tumor-related genes.

Infantile Epileptic Spasms Syndrome: Unveiling clinical and genetic variability in a case series from Argentina

PURPOSE

Infantile Epileptic Spasms Syndrome (IESS) is the most prevalent epileptic encephalopathy (EE) in the first year of life, with approximately 40 % of cases of genetic or unknown origin. This study aims to describe the clinical and molecular characteristics of a group of Argentine patients diagnosed with IESS of unknown etiology.

METHODS

A retrospective analysis was performed on the clinical data of 24 pediatric patients diagnosed with IESS with hypsarrhythmia, who underwent genomic studies between 2019 and 2022.

RESULTS

A genetic etiology was identified in 50 % of cases (eight boys and four girls; median seizure onset age: 3 months). Most of them initiated with IESS and over half evolved into Lennox-Gastaut syndrome. Developmental delay preceded seizure onset in all patients, persisting or worsening thereafter. Notable features included hypotonia, microcephaly, and dysmorphisms. Half of the patients had a family history of epilepsy, and two of EE. Identified variants included 7/13 (53.8 %) single nucleotide variants in KCNQ2, STXBP1, SCN8A, CDKL5, UGDH, and WWOX; 5/13 (38.5 %) copy number variants involving the genes UBE3A-GABRB3-GABRA5, SCN2A-SCN1A-SCN9A, and WWOX; and a short tandem repeat in ARX. Inheritance patterns included autosomal dominant (n = 8), recessive (n = 2), and X-linked (n = 2). Nine variants (69.2 %) were presumed de novo.

CONCLUSION

These findings underscore the extensive genetic heterogeneity of IESS within the Argentine population, enriching the international literature and variant databases with Latin American data. In cases with an unknown cause, genetic testing is crucial in establishing an etiological diagnosis, guiding appropriate treatment, and facilitating genetic counseling.

What is the impact of etiology, lead time to treatment, and parental awareness on outcomes in infantile epileptic spasm syndrome?

OBJECTIVE

Infantile epileptic spasm syndrome (IESS) is a kind of developmental epileptic encephalopathy that can lead to severe outcomes, including drug-resistant epilepsy and impaired neurodevelopment. The underlying etiology, early diagnosis, and adequate treatment impact the outcome. Our study focused on examining the factors that influence the prognosis and the level of knowledge among families regarding IESS.

METHODS

In the Department of Pediatric Neurology at Gazi University Hospital, we examined 62 IESS children's demographics, neuroimaging, metabolic and genetic findings, seizure characteristics, treatment choices, and long-term outcomes. Our study examined family awareness of seizures, lead time to treatment(LTT), and their impact on prognosis.

RESULTS

Forty-two (67.8 %) patients presented with a symptomatic cause, with over half experiencing intraventricular hemorrhage and/or periventricular leukomalacia attributable to prematurity. The hormonal therapy (tetracosactide or oral prednisolone) was the preferred treatment. Treatment was effective for two-thirds of the patients. Nevertheless, hardly 50 % of the families acknowledged the "event" as a seizure. However, 34 (61 %) individuals had sought medical advice from a doctor during the first seven days. The mean time from the start of seizures to seeking medical care was 9.2 ± 5.7 days.

CONCLUSION

Our research revealed that the etiology was the most significant factor influencing the long-term outcomes of IESS. Additionally, we demonstrated that the clinicians who initially encountered the patients promptly referred them to pediatric neurology departments, despite the fact that the families' seizure awareness was poor. To help prevent this circumstance, it is important to provide information about infantile spasms to the families of high-risk infants.

Infantile epileptic spasms syndrome: an etiologic study of 361 patients with infantile epileptic spasms syndrome

Introduction

Infantile Epileptic Spasms Syndrome (IESS) typically has a profound impact on the neurodevelopment of patients. The study on IESS indicates possible geographical variation in etiology and a lack of data from China. Our study intends to summarize the etiology of IESS and analyze its characteristics.

Methods

A retrospective analysis was performed to gather clinical data from patients diagnosed with IESS at the Department of Neurology of Qilu Hospital of Shandong University and the Children's Hospital Affiliated to Shandong University between June 2017 to May 2024.

Results

A total of 361 patients with IESS were included, comprising 115 structural cases (31.9%), 37 genetic cases (10.2%), 32 genetic-structural cases (8.9%), 9 metabolic cases (2.5%), 3 infectious cases (0.8%), and 165 cases with unknown etiology (45.7%). No immunological cause was determined. The primary cause of the condition was linked to hypoxic-ischemic encephalopathy (HIE), with structural brain abnormalities following closely. The predominant pathogenic genes identified were TSC2, NF1, SCN8A, and KCNQ2. Male gender, preterm infants, low birth weight infants, and developmental regression in patients were associated with a higher likelihood of structural etiology. Patients exhibiting developmental regression before the commencement demonstrated inferior outcomes. Patients administered adrenocorticotropic hormone (ACTH) exhibited a higher likelihood of attaining seizure control, and those who responded favorably to the medication saw improved results.

Conclusion

The predominant etiology of IESS is structural, succeeded by genetic factors, with significant pathogenic genes comprising TSC2, NF1, SCN8A, and KCNQ2. The genetic classifications exhibit geographic variability. Genetic and structural etiologies are frequently linked to an unfavorable prognosis. Genetic testing can help clarify the etiology of IESS when metabolic screening and brain MRI results are negative. The advancement of genetic testing is crucial for future targeted and individualized diagnosis and therapy.

Etiology-specific subgroup analysis of initial pharmacotherapy in infantile epileptic spasm syndrome: A single-center cohort study

AIM

To evaluate the efficacy of initial pharmacotherapy for infantile epileptic spasm syndrome (IESS) with electro-clinical outcome characteristics.

METHOD

A retrospective comparative cohort study with 280 IESS patients was designed; I. vigabatrin monotherapy (n = 129, 46 %); II. hormonotherapy (ACTH/oral prednisolone) (n = 73, 26 %); and III. vigabatrin plus early initiation of hormonotherapy in the first 14 days (n = 78, 28 %). Two types of outcomes were defined: (1) short-term outcome with spasm cessation time ≤42 days and resolution of hypsarrhythmia on the EEG on ≤3 months and (2) long-term outcome with spasm relapse rate or evolution to a new epileptic syndrome.

RESULTS

The etiology-specific diagnoses of the IESS cohort were defined according to the ILAE classification: structural (n = 131, 46.8 %), genetic (n = 28, 10 %), metabolic (n = 13, 4.6 %), immune-infectious (n = 10, 3.6 %), and unknown (n = 98, 35 %). Each treatment modalities had similar short- and long-term outcome characteristics. However, hormonotherapy with steroids (ACTH/oral prednisolone) provided "early IESS resolution" with spasm cessation and resolution of hypsarrhythmia (p = 0.042). The relapse rates of IESS were significantly higher in the etiology well-defined group compared to the unknown group (p = 0.005). The genetic-etiology specific group was more likely to have evolved to a new electro-clinical syndrome with a rate of 83.3 % than the others (p = 0.039).

CONCLUSION

We observed that the early initiation of hormonotherapy with VGB (sequential therapy) should be investigated in etiology well-defined subgroup with short- and long-term outcome characteristics.

Diagnostic yields of genetic testing and related benefits in infantile epileptic spasms syndrome: A systematic review and meta-analysis

BACKGROUND

Diagnostic yields for infantile epileptic spasms syndrome (IESS) are notably heterogeneous across different testing modalities and studies. To investigate the proportion of individuals with IESS harboring causative/pathogenic genetic variants identified using whole-exome sequencing (WES), multi-gene panels (MGPs), and chromosomal microarray (CMA), thereby providing evidence to inform guidelines for genetic testing strategies.

METHODS

The study team searched PubMed, Embase, and Cochrane Central Register of Controlled Trials between January 2012- October2023. Data were extracted and synthesized by two investigators following the preferred reporting items for systematic reviews and meta-analyses guideline. The primary outcome was the pooled diagnostic rate of individual WES, MGPs, and CMA across studies. Subgroup analyses were performed based on the inclusion of cases with tuberous sclerosis complex and the number of genes included on MGPs.

RESULTS

Our study included 30 studies, involving 2 738 participants. The diagnostic rates in IESS for WES (13 studies, n = 799), MGPs (13 studies, n = 1 117), and CMA (13 studies, n = 629) were 26 % (95 % CI = 21 %-31 %), 20 % (95 % CI = 15 %-27 %), and 14 % (95 % CI = 11 %-16 %), respectively. WES and MGPs showed comparable diagnostic yields (P = 0.34). Our results indicated that 61.6 % of individuals with genetic IESS may potentially benefit from genetic diagnosis in terms of clinical management.

CONCLUSIONS

Our results showed that WES and MGPs exhibited comparable genetic diagnostic yields. Therefore, either method could be equally recommended as a first-tier testing approach for IESS cases with suspected genetic or unknown etiologies, especially considering the potential clinical benefits derived from genetic diagnosis.

Therapeutic implications of etiology-specific diagnosis of early-onset developmental and epileptic encephalopathies (EO-DEEs): A nationwide Turkish cohort study

OBJECTIVE

To evaluate the etiology-specific diagnosis of early-onset developmental epileptic encephalopathies (EO-DEEs) in a nationwide Turkish cohort to determine the implications for therapeutic management.

METHODS

The cohort comprised 1450 patients who underwent EO-DEE. The utility of genetic testing was assessed with respect to the initial phases of next generation sequencing (NGS) (2005-2013) and the current NGS era (2014-2022). A predefined four-stepwise diagnostic model was evaluated using cost-effectiveness analysis. The diagnostic and potential therapeutic yields of the genetic tests were subsequently determined.

RESULTS

Gene-related EO-DEEs were identified in 48.3 % (n = 701) of the cohort: non-structural genetic (62.6 %), metabolic genetic (15.1 %), and structural genetic (14.1 %). The most common nonstructural genetic variants were SCN1A (n = 132, 18.8 %), CDKL5 (n = 30, 4.2 %), STXBP1 (n = 21, 2.9 %), KCNQ2 (n = 21, 2.9 %), and PCDH19 (n = 17, 2.4 %). The rate of ultra-rare variants (< 0.5 %) was higher in the NGS era (52 %) than that in the initial phase (36 %). The potential therapeutic yields with precision therapy and antiseizure drug modification were defined in 34.5 % and 56.2 % in genetic-EO-DEEs, respectively. The diagnostic model provided an etiology-specific diagnosis at a rate of 78.7 %: structural (nongenetic) (31.4 %), genetic (38.5 %), metabolic (6.1 %), and immune-infectious (2.8 %). Based on a cost-effectiveness analysis, the presented diagnostic model indicated the early implementation of whole-exome sequencing for EO-DEEs.

SIGNIFICANCE

In the present cohort, the higher rate (48.3 %) of gene-related EO-DEE diagnoses in the NGS era provides a potential therapeutic management plan for more patients.

The Utility of Genetic Testing in Infantile Epileptic Spasms Syndrome: A Step-Based Approach in the Next-Generation Sequencing Era

BACKGROUND

To evaluate the utility of genetic testing for etiology-specific diagnosis (ESD) in infantile epileptic spasms syndrome (IESS) with a step-based diagnostic approach in the next-generation sequencing (NGS) era.

METHODS

The study cohort consisted of 314 patients with IESS, followed by the Pediatric Neurology Division of Ege University Hospital between 2005 and 2021. The ESD was evaluated using a step-based approach: step I (clinical phenomenology), step II (neuroimaging), step III (metabolic screening), and step IV (genetic testing). The diagnostic utility of genetic testing was evaluated to compare the early-NGS period (2005 to 2013, n = 183) and the NGS era (2014 to 2021, n = 131).

RESULTS

An ESD was established in 221 of 314 (70.4%) infants with IESS: structural, 40.8%; genetic, 17.2%; metabolic, 8.3%; immune-infectious, 4.1%. The diagnostic yield of genetic testing increased from 8.9% to 41.7% in the cohort during the four follow-up periods. The rate of unknown etiology decreased from 34.9% to 22.1% during the follow-up periods. The genetic ESD was established as 27.4% with genetic testing in the NGS era. The genetic testing in the NGS era increased dramatically in subgroups with unknown and structural etiologies. The diagnostic yields of the epilepsy panels increased from 7.6% to 19.2%. However, the diagnostic yield of whole exome sequencing remained at similar levels during the early-NGS period at 54.5% and in the NGS era at 59%.

CONCLUSIONS

The more genetic ESD (27.4%) was defined for IESS in the NGS era with the implication of precision therapy (37.7%).

Exhaustive clinical examination of etiology and initial response to first-line treatment in 577 children with infantile epileptic spasm syndrome children: A 5-year retrospective observational study

OBJECTIVE

Employing whole-exome sequencing (WES) technology to investigate the etiology of infantile epileptic spasm syndrome (IESS), and determining whether different etiologies exhibit phenotypic variations, while elucidating the potential associated factors, might improve short-term responses to first-line treatment.

METHODS

We retrospectively evaluated patients with IESS admitted for treatment between January 2018 and June 2023. Clinical phenotypic differences among etiological classifications and clinical manifestations were analyzed. Variable selection using the best subset method was performed, followed by logistic regression analysis to identify the factors influencing treatment response.

RESULTS

A total of 577 patients were included; 412 completed trio-WES. Magnetic resonance imaging abnormalities were detected in 387 patients (67.1%). Patients with etiology as structural abnormalities were likelier to have non-spasms at the initial seizure onset. A total of 532 patients completed the first-line treatment; 273 patients received it for the first time at our hospital (initial response rates: 30.1% and 42.1%, respectively). The response group had a lower proportion of early-onset seizures (≤3 months) than the no-response group (11.3% vs. 23.7%, p < 0.01 and 11.3% vs. 21.5%, p = 0.03, respectively). Logistic regression analysis indicated that earlier initiation of first-line treatment was associated with a higher likelihood of an initial response. However, the etiological classification did not have a significant impact on the initial response.

INTERPRETATION

IESS patients with structural abnormalities are more likely to present with non-spasm seizures at initial onset. Early initiation of first-line treatment is crucial; however, initial responses may be less favorable when seizures occur in early infancy.

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.

Common epilepsy variants from the general population are not associated with epilepsy among individuals with tuberous sclerosis complex

Common genetic variants identified in the general population have been found to increase phenotypic risks among individuals with certain genetic conditions. Up to 90% of individuals with tuberous sclerosis complex (TSC) are affected by some type of epilepsy, yet the common variants contributing to epilepsy risk in the general population have not been evaluated in the context of TSC-associated epilepsy. Such knowledge is important to help uncover the underlying pathogenesis of epilepsy in TSC which is not fully understood, and critical as uncontrolled epilepsy is a major problem in this population. To evaluate common genetic modifiers of epilepsy, our study pooled phenotypic and genotypic data from 369 individuals with TSC to evaluate known and novel epilepsy common variants. We did not find evidence of enhanced genetic penetrance for known epilepsy variants identified across the largest genome-wide association studies of epilepsy in the general population, but identified support for novel common epilepsy variants in the context of TSC. Specifically, we have identified a novel signal in SLC7A1 that may be functionally involved in pathways relevant to TSC and epilepsy. Our study highlights the need for further evaluation of genetic modifiers in TSC to aid in further understanding of epilepsy in TSC and improve outcomes.

Genetic Advancements in Infantile Epileptic Spasms Syndrome and Opportunities for Precision Medicine

Infantile epileptic spasms syndrome (IESS) is a devastating developmental epileptic encephalopathy (DEE) consisting of epileptic spasms, as well as one or both of developmental regression or stagnation and hypsarrhythmia on EEG. A myriad of aetiologies are associated with the development of IESS; broadly, 60% of cases are thought to be structural, metabolic or infectious in nature, with the remainder genetic or of unknown cause. Epilepsy genetics is a growing field, and over 28 copy number variants and 70 single gene pathogenic variants related to IESS have been discovered to date. While not exhaustive, some of the most commonly reported genetic aetiologies include trisomy 21 and pathogenic variants in genes such as TSC1, TSC2, CDKL5, ARX, KCNQ2, STXBP1 and SCN2A. Understanding the genetic mechanisms of IESS may provide the opportunity to better discern IESS pathophysiology and improve treatments for this condition. This narrative review presents an overview of our current understanding of IESS genetics, with an emphasis on animal models of IESS pathogenesis, the spectrum of genetic aetiologies of IESS (i.e., chromosomal disorders, single-gene disorders, trinucleotide repeat disorders and mitochondrial disorders), as well as available genetic testing methods and their respective diagnostic yields. Future opportunities as they relate to precision medicine and epilepsy genetics in the treatment of IESS are also explored.

STXBP1-Related Disorders: Clinical Presentation, Molecular Function, Treatment, and Future Directions

In recent years, the affordability and availability of genetic testing have led to its increased use in clinical care. The increased frequency of testing has led to STXBP1 variants being identified as one of the more common variants associated with neurological disorders. In this review, we aim to summarize the common clinical phenotypes associated with STXBP1 pathogenic variants, provide an overview of their known natural history, and discuss current research into the genotype to phenotype correlation. We will also provide an overview of the suspected normal function of the STXBP1-encoded Munc18-1 protein, animal models, and experimental techniques that have been developed to study its function and use this information to try to explain the diverse phenotypes associated with STXBP1-related disorders. Finally, we will explore current therapies for STXBP1 disorders, including an overview of treatment goals for STXBP1-related disorders, a discussion of the current evidence for therapies, and future directions of personalized medications for STXBP1-related disorders.

Clinical and electroencephalographic characteristics of 34 infant with onset of epileptic spasms before three months of age

Epileptic spasms (ES) occur mostly between age 3 months and 24 months. ES beginning before 3 months of age were called early-onset ES in previous studies. The aim of this study was to identify clinical and electroencephalographic characteristics of patients with ES onset before 3 months of age. In total, 34 ES patients were retrospectively identified at Children's Hospital of Chongqing Medical University from January 1, 2020 to October 1, 2022. Our patients had diverse etiologies, including genetic (32.3 %), genetic-structural (11.8 %), structural-acquired (11.8 %), structural-congenital (8.8 %), and metabolic (5.9 %), with 29.4 % of patients having unknown etiology. Some patients experienced ES in clusters (either symmetrical or flexional) that occurred most often during awakening after sleep, and a minority of ES were characterized as isolated or asymmetrical, occurred during sleep, and could also manifest as relatively subtle. Approximately 35.3 % of patients also experienced other seizure types concurrently, including 10 focal seizures and 2 generalized seizures, and only half of the focal seizures had structural causes. The other seizure types occurred alone or sequentially with ES. Interictal electroencephalography revealed hypsarrhythmia or its variants, multifocal discharge, or burst suppression. 18 patients had no seizures lasting for more than 2 months, however, at the last follow-up visit, 5 of them had relapsed. All patients had different degrees of psychomotor retardation.

Electrophysiological network predicts clinical response to vigabatrin in epileptic spasms

PURPOSE

This study aimed to discover electrophysiologic markers correlated with clinical responses to vigabatrin-based treatment in infants with epileptic spasms (ES).

METHOD

The study involved a descriptive analysis of ES patients from a single institution, as well as electroencephalogram (EEG) analyses of 40 samples and 20 age-matched healthy infants. EEG data were acquired during the interictal sleep state prior to the standard treatment. The weighted phase-lag index (wPLI) functional connectivity was explored across frequency and spatial domains, correlating these results with clinical features.

RESULTS

Infants with ES exhibited diffuse increases in delta and theta power, differing from healthy controls. For the wPLI analysis, ES subjects exhibited higher global connectivity compared to control subjects. Subjects who responded favorably to treatment were characterized by higher beta connectivity in the parieto-occipital regions, while those with poorer outcomes exhibited lower alpha connectivity in the frontal regions. Individuals with structural neuroimaging abnormalities exhibited correspondingly low functional connectivity, implying that ES patients who maintain adequate structural and functional integrity are more likely to respond favorably to vigabatrin-based treatments.

CONCLUSION

This study highlights the potential utility of EEG functional connectivity analysis in predicting early response to treatments in infants with ES.

Neurological Phenotypes of IRF2BPL Gene Variants: A Report of Four Novel Variants

IRF2BPL gene variants have recently been associated to developmental disability and epilepsy in children and movement disorders in adults. So far, only few cases have been reported; here we present four novel cases identified by exome sequencing, while investigating developmental delay, adult-onset cerebellar ataxia or regression.

Decreased cerebrospinal fluid kynurenic acid in epileptic spasms: A biomarker of response to corticosteroids

Background

Epileptic (previously infantile) spasms is the most common epileptic encephalopathy occurring during infancy and is frequently associated with abnormal neurodevelopmental outcomes. Epileptic spasms have a diverse range of known (genetic, structural) and unknown aetiologies. High dose corticosteroid treatment for 4 weeks often induces remission of spasms, although the mechanism of action of corticosteroid is unclear. Animal models of epileptic spasms have shown decreased brain kynurenic acid, which is increased after treatment with the ketogenic diet. We quantified kynurenine pathway metabolites in the cerebrospinal fluid (CSF) of infants with epileptic spasms and explored clinical correlations.

Methods

A panel of nine metabolites in the kynurenine pathway (tryptophan, kynurenine, kynurenic acid, 3-hydroxykynurenine, xanthurenic acid, anthranilic acid, 3-hydroxyanthranilic acid, quinolinic acid, and picolinic acid) were measured using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). CSF collected from paediatric patients less than 3 years of age with epileptic spasms (n=34, 19 males, mean age 0.85, median 0.6, range 0.3–3 yrs) were compared with other epilepsy syndromes (n=26, 9 males, mean age 1.44, median 1.45, range 0.3–3 yrs), other non-inflammatory neurological diseases (OND) (n=29, 18 males, mean age 1.47, median 1.6, range 0.1–2.9 yrs) and inflammatory neurological controls (n=12, 4 males, mean age 1.80, median 1.80, range 0.8–2.5 yrs).

Findings

There was a statistically significant decrease of CSF kynurenic acid in patients with epileptic spasms compared to OND (p<0.0001). In addition, the kynurenic acid/kynurenine (KYNA/KYN) ratio was lower in the epileptic spasms subgroup compared to OND (p<0.0001). Epileptic spasms patients who were steroid responders or partial steroid responders had lower KYNA/KYN ratio compared to patients who were refractory to steroids (p<0.005, p<0.05 respectively).

Interpretation

This study demonstrates decreased CSF kynurenic acid and KYNA/KYN in epileptic spasms, which may also represent a biomarker for steroid responsiveness. Given the anti-inflammatory and neuroprotective properties of kynurenic acid, further therapeutics able to increase kynurenic acid should be explored.

Funding

Financial support for the study was granted by Dale NHMRC Investigator grant APP1193648, Petre Foundation, Cerebral Palsy Alliance and Department of Biochemistry at the Children's Hospital at Westmead. Prof Guillemin is funded by NHMRC Investigator grant APP1176660 and Macquarie University.