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

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%).

eDeeplepsy: An artificial neural framework to reveal different brain states in children with epileptic spasms

OBJECTIVE

Despite advances, analysis and interpretation of EEG still essentially rely on visual inspection by a super-specialized physician. Considering the vast amount of data that composes the EEG, much of the detail inevitably escapes ordinary human scrutiny. Significant information may not be evident and is missed, and misinterpretation remains a serious problem. Can we develop an artificial intelligence system to accurately and efficiently classify EEG and even reveal novel information? In this study, deep learning techniques and, in particular, Convolutional Neural Networks, have been used to develop a model (which we have named eDeeplepsy) for distinguishing different brain states in children with epilepsy.

METHODS

A novel EEG database from a homogenous pediatric population with epileptic spasms beyond infancy was constituted by epileptologists, representing a particularly intriguing seizure type and challenging EEG. The analysis was performed on such samples from long-term video-EEG recordings, previously coded as images showing how different parts of the epileptic brain are distinctly activated during varying states within and around this seizure type.

RESULTS

Results show that not only could eDeeplepsy differentiate ictal from interictal states but also discriminate brain activity between spasms within a cluster from activity away from clusters, usually undifferentiated by visual inspection. Accuracies between 86 % and 94 % were obtained for the proposed use cases.

SIGNIFICANCE

We present a model for computer-assisted discrimination that can consistently detect subtle differences in the various brain states of children with epileptic spasms, and which can be used in other settings in epilepsy with the purpose of reducing workload and discrepancies or misinterpretations. The research also reveals previously undisclosed information that allows for a better understanding of the pathophysiology and evolving characteristics of this particular seizure type. It does so by documenting a different state (interspasms) that indicates a potentially non-standard signal with distinctive epileptogenicity at that period.

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.

Intraventricular SEEG and laser ablation for the treatment of infantile spasm: Technical note

OBJECTIVES

Infantile spasm (IS) is an epileptic encephalopathy with ongoing neurological damage due to seizures and epileptiform abnormalities. Epilepsy surgery is considered for children refractory to drug therapy, especially when there is a focal brain lesion. In this study, we investigated the feasibility and efficacy of intraventricular stereotactic electroencephalography (SEEG) and laser ablation for the treatment of IS children with focal brain lesions.

METHODS

We performed the first reported study using ventriculoscopic laser ablation to treat IS. Seven IS children with drug-resistant epilepsy and definite encephalomalacia on brain magnetic resonance imaging scan were included in this study. Ablation was performed after confirmation of epileptiform discharges by SEEG under the surveillance of ventriculoscope.

RESULTS

The median follow-up time for the cohort was 3.1 years and 86% (6/7) of the children had an Engel class ≤III epilepsy at the final follow-up. Five (71%) children had a reduction in seizure medication usage, and the other two were on the same amount as preablation. None of the children experienced serious new neurological deficits. Laser ablation might result in seizure freedom by destroying the local brain network and blocking the spread of abnormal discharges.

CONCLUSIONS

Intraventricular SEEG and laser ablation was feasible and effective for the treatment of IS. Further studies are warranted.

Comparing late-onset epileptic spasm outcomes after corpus callosotomy and subsequent disconnection surgery between post-encephalitis/encephalopathy and non-encephalitis/encephalopathy

OBJECTIVE

We aimed to analyze the efficiency of corpus callosotomy (CC) and subsequent disconnection surgeries in patients with late-onset epileptic spasms (LOES) by comparing post-encephalitis/encephalopathy (PE) and non-encephalitis/encephalopathy (NE). We hypothesized these surgeries can control potential focal onset epileptic spasms (ES) in the NE group but not in the PE group.

METHODS

We retrospectively included 23 patients (12 with PE and 11 with NE) who initially underwent CC and subsequent disconnection surgeries (five NE). We compared the clinical courses, seizure types, MRI, video-EEG, epilepsy surgery, and seizure outcomes between the two groups.

RESULTS

The median age of LOES onset in the PE group was 2.8 (range 1.0-10.1 years) and 2.9 years (range 1.1-12.6) in the NE group. Bilateral MRI abnormalities were observed in both groups (PE, n = 12; NE, n = 3; P < 0.05). The PE group presented ES alone (n = 2), ES + focal seizures (FS) (n = 3), ES + generalized seizures (GS) (n = 3), and ES + FS + GS (n = 4) in addition to stimulus-induced startle seizures (SS) (n = 8) (mean 3.1 seizure types/patient). The NE group presented ES alone (n = 1), ES + FS (n = 2), and ES + FS + GS (n = 8) (mean 2.7 seizure types/patient). In the PE group, CC stopped ES (n = 1) and SS (n = 1) and achieved <50% SS (n = 3). In the NE group, CC achieved immediate ES-free status (n = 2) and < 50% ES (n = 1), and additional disconnection surgeries subsided all seizure types (n = 3) based on lateralized interictal/ictal EEG findings. LOES was significantly remitted by surgery in the NE group (6/11 [55%]) compared with the PE group (1/12 [8%]) (P < 0.05).

SIGNIFICANCE

LOES is a drug-resistant, focal/generalized/unknown onset ES. Lateralization of ES in NE could be achieved after CC and eliminated by further disconnection surgeries because of potential focal onset ES. LOES in PE had little benefit from CC for generalized onset ES. However, CC might reduce SS in patients in the PE group with multiple seizure types.

Discriminating and understanding brain states in children with epileptic spasms using deep learning and graph metrics analysis of brain connectivity

BACKGROUND AND OBJECTIVE

Epilepsy is a brain disorder consisting of abnormal electrical discharges of neurons resulting in epileptic seizures. The nature and spatial distribution of these electrical signals make epilepsy a field for the analysis of brain connectivity using artificial intelligence and network analysis techniques since their study requires large amounts of data over large spatial and temporal scales. For example, to discriminate states that would otherwise be indistinguishable from the human eye. This paper aims to identify the different brain states that appear concerning the intriguing seizure type of epileptic spasms. Once these states have been differentiated, an attempt is made to understand their corresponding brain activity.

METHODS

The representation of brain connectivity can be done by graphing the topology and intensity of brain activations. Graph images from different instants within and outside the actual seizure are used as input to a deep learning model for classification purposes. This work uses convolutional neural networks to discriminate the different states of the epileptic brain based on the appearance of these graphs at different times. Next, we apply several graph metrics as an aid to interpret what happens in the brain regions during and around the seizure.

RESULTS

Results show that the model consistently finds distinctive brain states in children with epilepsy with focal onset epileptic spasms that are indistinguishable under the expert visual inspection of EEG traces. Furthermore, differences are found in brain connectivity and network measures in each of the different states.

CONCLUSIONS

Computer-assisted discrimination using this model can detect subtle differences in the various brain states of children with epileptic spasms. The research reveals previously undisclosed information regarding brain connectivity and networks, allowing for a better understanding of the pathophysiology and evolving characteristics of this particular seizure type. From our data, we speculate that the prefrontal, premotor, and motor cortices could be more involved in a hypersynchronized state occurring in the few seconds immediately preceding the visually evident EEG and clinical ictal features of the first spasm in a cluster. On the other hand, a disconnection in centro-parietal areas seems a relevant feature in the predisposition and repetitive generation of epileptic spasms within clusters.

Mitochondrial encephalomyopathy

Mitochondrial dysfunction, especially perturbation of oxidative phosphorylation and adenosine triphosphate (ATP) generation, disrupts cellular homeostasis and is a surprisingly frequent cause of central and peripheral nervous system pathology. Mitochondrial disease is an umbrella term that encompasses a host of clinical syndromes and features caused by in excess of 300 different genetic defects affecting the mitochondrial and nuclear genomes. Patients with mitochondrial disease can present at any age, ranging from neonatal onset to late adult life, with variable organ involvement and neurological manifestations including neurodevelopmental delay, seizures, stroke-like episodes, movement disorders, optic neuropathy, myopathy, and neuropathy. Until relatively recently, analysis of skeletal muscle biopsy was the focus of diagnostic algorithms, but step-changes in the scope and availability of next-generation sequencing technology and multiomics analysis have revolutionized mitochondrial disease diagnosis. Currently, there is no specific therapy for most types of mitochondrial disease, although clinical trials research in the field is gathering momentum. In that context, active management of epilepsy, stroke-like episodes, dystonia, brainstem dysfunction, and Parkinsonism are all the more important in improving patient quality of life and reducing mortality.

Clinical and electroencephalography characteristics of 41 children with epileptic spasms onset after 1 year of age

The incidence of epileptic spasms (ES) that begin after the first year of life is much lower than that before 1 year of age. The aim of this study was to identify clinical and electroencephalography (EEG) characteristics, etiologies, treatments, and prognoses in pediatric patients with ES onset after 1 year of age. Forty-one children were retrospectively identified in Children's Hospital of Chongqing Medical University between January 1, 2020 and December 1, 2021. ES onset after 1 year of age have diverse presentations. Although most occur in clusters, are symmetrical and flexional, and occur frequently during awakening, some are characterized as isolated and asymmetrical, have a tonic component, and can also occur during sleep. The hypsarrhythmia variants and focal or multifocal discharges occur alternately in the interictal period, and the focal spikes and slow waves predominated in the unilateral temporal or frontotemporal areas. These patients had diverse etiologies, including structural (51.2 % of patients) and genetic (22.0 %) ones, and 11 patients (26.8 %) had an unknown etiology. No patients in our study had an infectious or immune-mediated etiology. Forty-eight percent of patients responded to hydrocortisone and/or adrenocorticotropic hormone. The efficacy of antiepileptic drug therapy was lower in patients who did not receive concurrent steroid therapy. However, ES onset after 1 year of age caused by a tumor, brain malformation, or other focal lesions, may be cured by focal cortical resection despite a lack of clearly localized EEG surface anomalies. Delays in motor, language, and cognitive development, or behavioral problems were observed in all but three patients.

Diffusion tractography predicts propagated high-frequency activity during epileptic spasms

OBJECTIVE

To determine the structural networks that constrain propagation of ictal oscillations during epileptic spasm events, and compare the observed propagation patterns across patients with successful or unsuccessful surgical outcomes.

METHODS

Subdural electrode recordings of 18 young patients (age 1-11 years) were analyzed during epileptic spasm events to determine ictal networks and quantify the amplitude and onset time of ictal oscillations across the cortical surface. Corresponding structural networks were generated with diffusion magnetic resonance imaging (MRI) tractography by seeding the cortical region associated with the earliest average oscillation onset time, and white matter pathways connecting active electrode regions within the ictal network were isolated. Properties of this structural network were used to predict oscillation onset times and amplitudes, and this relationship was compared across patients who did and did not achieve seizure freedom following resective surgery.

RESULTS

Onset propagation patterns were relatively consistent across each patient's spasm events. An electrode's average ictal oscillation onset latency was most significantly associated with the length of direct corticocortical tracts connecting to the area with the earliest average oscillation onset (p < .001, model R2  = .54). Moreover, patients demonstrating a faster propagation of ictal oscillation signals within the corticocortical network were more likely to have seizure recurrence following resective surgery (p = .039). In addition, ictal oscillation amplitude was associated with connecting tractography length and weighted fractional anisotropy (FA) measures along these pathways (p = .002/.030, model R2  = .31/.25). Characteristics of analogous corticothalamic pathways did not show significant associations with ictal oscillation onset latency or amplitude.

SIGNIFICANCE

Spatiotemporal propagation patterns of high-frequency activity in epileptic spasms align with length and FA measures from onset-originating corticocortical pathways. Considering the data in this individualized framework may help inform surgical decision-making and expectations of surgical outcomes.

Disconnection surgery to cure or palliate medically intractable epileptic spasms: a retrospective study

OBJECTIVE

Surgery is a treatment option for medically intractable epileptic spasms (ESs). However, outcomes of ES after surgery are not well understood, especially when surgeries aimed at seizure palliation are included. The purpose of the present study was to 1) investigate the proportion of favorable postoperative ES outcomes, 2) explore the preoperative factors related to favorable postoperative ES outcomes, and 3) examine the timing of ES recurrence after disconnection surgeries, including both curative and palliative indications.

METHODS

This retrospective study included patients who underwent disconnection surgery for medically intractable ES at the authors' institution between May 2015 and April 2021. Patients with suggested focal-onset ES based on preoperative evaluations initially underwent lobar disconnection. Patients with suggested generalized or unknown-onset ES underwent corpus callosotomy (CC). If evaluations after initial CC showed focalized or lateralized change, they were considered secondarily revealed focal-onset ES, and lobar disconnection was performed. ES outcomes were evaluated using the International League Against Epilepsy classification. ES outcomes were divided into classes 1-4 as favorable outcomes and classes 5 and 6 as unfavorable outcomes. The relationship between the favorable postoperative ES outcomes and the following preoperative factors was analyzed: sex, age at onset (< or > 1 year), duration between seizure onset and initial surgery (< or > 2 years), type of seizure at onset (ES or others), presence of other types of seizures, substrate, hypsarrhythmia, and MRI abnormalities. The period between the last surgery and ES recurrence was also analyzed.

RESULTS

A total of 41 patients were included, of whom 75.6% achieved favorable ES outcomes. A longer seizure duration between seizure onset and initial surgery, presence of hypsarrhythmia, and positive MRI findings led to poorer postoperative ES outcomes (p = 0.0028, p = 0.0041, and p = 0.0241, respectively). A total of 60.9% of patients had ES recurrence during the follow-up period, and their ES recurred within 13 months after the last surgery.

CONCLUSIONS

Disconnection surgery is an effective treatment option for medically intractable ES, even when the preoperative evaluation suggests a generalized or unknown onset.

Effectiveness of ACTH in Patients with Infantile Spasms

(1) Background: West syndrome is a severe, refractory, epileptic syndrome that usually appears in infancy or early childhood. ACTH is one of the more effective drugs for treating this condition. (2) Aim of the study and methods: The objective of our study was to examine short-term efficacy (during treatment schedule) and long-term outcome of intramuscular 0.02 mg/kg/day ACTH (tetracosactide) depot, used concomitantly with other antiepileptic drugs (AEDs) in patients with infantile spasms who did not achieve seizure cessation or relapse when taking only the AEDs. The drug efficacy was evaluated in retrospective and prospective analyses of 50 patients diagnosed with infantile spasms. (3) Results: Complete cessation of spasms was achieved in 42 cases (84%). EEG improvement was seen in 41 (82%) patients who responded to ACTH therapy. Information on the clinical course of 28 patients was obtained duringlong-term follow-up. In 17 (60.7%) cases, seizures were still present. Normal or near-normal development was observed in 11 out of 28 children (39%). ACTH used concomitantly with other AEDis a highly effective treatment with acceptable side effects. (4) Conclusion: Randomized controlled clinical trialswith long-term follow-up are needed to compare the effectiveness of ACTH in polytherapy and monotherapy. Dyskinesias as a potential side effect observed in our study group should be investigated in the following studies.

Epilepsy Outcome at Four Years in a Randomized Clinical Trial Comparing Oral Prednisolone and Intramuscular ACTH in West Syndrome

BACKGROUND

This article explores the role of initial treatment on control of spasms and other epilepsies at four years in children previously treated for West syndrome.

METHODS

The Sri Lanka Infantile Spasm Study is a prospective clinical trial evaluating response to intra-muscular adrenocorticotropic hormone (ACTH) versus oral prednisolone. A previous report documented response through age 12 months. This article provides four-year follow-up data.

RESULTS

At age four years, 65 of the original 97 were available for follow-up; another 13 had died, and 19 moved and could not be contacted. Of the 65 children, 37 (57%) continued to have seizures and 28 were seizure free. In the 37 children with ongoing epilepsy, 32.4% continued to have spasms, either alone or in combination with other seizure types. The epilepsy types seen in these children were focal epilepsy (59.4%), mixed focal and generalized epilepsy (24%), generalized epilepsy only (10.8%), and uncertain (5%). The majority of those still having epilepsy (66.7%) were controlled on medication. There was no significant difference in the rate of epilepsy or spasms or their control by medication between those treated with ACTH or oral prednisolone. Spasm control at day 14 did not influence the four-year spasm or epilepsy outcome.

CONCLUSIONS

A majority of children diagnosed with West syndrome continued to have seizures at age four years, although most were controlled on antiseizure medication. The long-term risk of developing epilepsy or its control was the same, regardless of whether ACTH or prednisolone was initially used as treatment.

Phase-amplitude coupling of interictal fast activities modulated by slow waves on scalp EEG and its correlation with seizure outcomes of disconnection surgery in children with intractable nonlesional epileptic spasms

OBJECTIVE

Epileptic spasms (ESs) are classified as focal, generalized, or unknown onset ESs. The classification of ESs and surgery in patients without lesions apparent on MRI is challenging. Total corpus callosotomy (TCC) is a surgical option for diagnosis of the lateralization and possible treatment for ESs. This study investigated phase-amplitude coupling (PAC) of fast activity modulated by slow waves on scalp electroencephalography (EEG) to evaluate the strength of the modulation index (MI) before and after disconnection surgery in children with intractable nonlesional ESs. The authors hypothesize that a decreased MI due to surgery correlates with good seizure outcomes.

METHODS

The authors studied 10 children with ESs without lesions on MRI who underwent disconnection surgeries. Scalp EEG was obtained before and after surgery. The authors collected 20 epochs of 3 minutes each during non-rapid eye movement sleep. The MI of the gamma (30-70 Hz) amplitude and delta (0.5-4 Hz) phase was obtained in each electrode. MIs for each electrode were averaged in 4 brain areas (left/right, anterior/posterior quadrants) and evaluated to determine the correlation with seizure outcomes.

RESULTS

The median age at first surgery was 2.3 years (range 10 months-9.1 years). Two patients with focal onset ESs underwent anterior quadrant disconnection (AQD). TCC alone was performed in 5 patients with generalized or unknown onset ESs. Two patients achieved seizure freedom. Three patients had residual generalized onset ESs. Disconnection surgeries in addition to TCC consisted of TCC + posterior quadrant disconnection (PQD) (1 patient); TCC + AQD + PQD (1 patient); and TCC + AQD + hemispherotomy (1 patient). Seven patients became seizure free with a mean follow-up period of 28 months (range 5-54 months). After TCC, MIs in 4 quadrants were significantly lower in the 2 seizure-free patients than in the 6 patients with residual ESs (p < 0.001). After all 15 disconnection surgeries in 10 patients, MIs in the 13 target quadrants for each disconnection surgery that resulted in freedom from seizures were significantly lower than in the 26 target quadrants in patients with residual ESs (p < 0.001).

CONCLUSIONS

In children with nonlesional ESs, PAC for scalp EEG before and after disconnection surgery may be a surrogate marker for control of ESs. The MI may indicate epileptogenic neuronal modulation of the interhemispheric corpus callosum and intrahemispheric subcortical network for ESs. TCC may be a therapeutic option to disconnect the interhemispheric modulation of epileptic networks.

Epileptic Spasms in a Large Hypothalamic Hamartoma Cohort

INTRODUCTION

Hypothalamic hamartoma is rarely associated with epileptic spasms. We describe epileptic spasms in a large cohort of hypothalamic hamartoma patients.

METHODS

We performed a retrospective chart review between March 2011 and March 2020 to identify patients with hypothalamic hamartoma and epilepsy.

RESULTS

We identified 114 patients with hypothalamic hamartoma and epilepsy, only 3 male patients (2.6%) also had epileptic spasms. The epileptic spasms developed between 6 and 18 months of age. Epileptic spasms resolved with oral prednisolone in 1 and with vigabatrin in the second patient. The third patient continued epileptic spasms despite multiple antiepileptic drugs and partial resection of hypothalamic hamartoma. All 3 patients underwent laser-ablation of hypothalamic hamartoma at the age of 14, 29, and 63 months. The seizure burden decreased by 100%, 84%, and 93% at follow-up (3-47 months).

CONCLUSIONS

Epileptic spasms are rare in hypothalamic hamartoma patients and early laser-ablation could potentially treat epileptic spasms and all other seizure types associated with hypothalamic hamartoma.

Infantile Spasms and West Syndrome - A Clinician's Perspective

Infantile spasms, though long recognised, are still a cause of significant morbidity in children. The knowledge of their etiology and pathogenesis is still evolving. Even the management strategies vary among different centres. Hormonal treatments and vigabatrin have been recognised as effective but controversies prevail on the exact protocols that best balance the risk benefit ratio. Collaborative studies have begun to provide some clarity on some of the management issues but further large scale studies that further standardise protocols are a felt need. This article attempts to provide a clinically relevant summary of the current knowledge.

West syndrome: a comprehensive review

Since its first clinical description (on his son) by William James West (1793-1848) in 1841, and the definition of the classical triad of (1) infantile spasms; (2) hypsarrhythmia, and (3) developmental arrest or regression as "West syndrome", new and relevant advances have been recorded in this uncommon disorder. New approaches include terminology of clinical spasms (e.g., infantile (IS) vs. epileptic spasms (ES)), variety of clinical and electroencephalographic (EEG) features (e.g., typical ictal phenomena without EEG abnormalities), burden of developmental delay, spectrum of associated genetic abnormalities, pathogenesis, treatment options, and related outcome and prognosis. Aside the classical manifestations, IS or ES may present with atypical electroclinical phenotypes (e.g., subtle spasms; modified hypsarrhythmia) and may have their onset outside infancy. An increasing number of genes, proteins, and signaling pathways play crucial roles in the pathogenesis. This condition is currently regarded as a spectrum of disorders: the so-called infantile spasm syndrome (ISs), in association with other causal factors, including structural, infectious, metabolic, syndromic, and immunologic events, all acting on a genetic predisposing background. Hormonal therapy and ketogenic diet are widely used also in combination with (classical and recent) pharmacological drugs. Biologically targeted and gene therapies are increasingly studied. The present narrative review searched in seven electronic databases (primary MeSH terms/keywords included West syndrome, infantile spasms and infantile spasms syndrome and were coupled to 25 secondary clinical, EEG, therapeutic, outcomes, and associated conditions terms) including MEDLINE, Embase, Cochrane Central, Web of Sciences, Pubmed, Scopus, and OMIM to highlight the past knowledge and more recent advances.

Early surgical intervention for structural infantile spasms in two patients under 6 months old: a case report

Background

Infantile spasms (IS) are the most common childhood epileptic encephalopathy. Focal cortical dysplasia (FCD) and gray matter heterotopias (GH) are common structural causes of IS. The recommended first-line treatment for IS patients with structural causes is surgical intervention, according to the International League Against Epilepsy (ILAE) commission guidelines. However, there is currently no consensus on appropriate timings of surgery.

Case presentations

Two structural IS cases are presented here: one was caused by FCD, and the other by GH. Both patients exhibited recurrent seizures at the age of 2 months, had poor responses to various antiepileptic drugs (AEDs) and displayed severe mental and motor developmental retardation. Seizure types included focal seizures and spasms. Brain magnetic resonance imaging showed abnormal gray signal or suspicious FCD lesions that coincided with the origin of the focal seizures. The patients underwent lesion resection before the age of 6 months. Follow-up observation showed that seizures of both patients were completely controlled several days after the surgery. All AEDs were gradually reduced in dosage within 1 year, and the mental and motor development almost returned to normal.

Conclusion

Early resection of lesions in structural IS patients has benefits of effectively controlling convulsions and improving developmental retardation. Infants at several months of age can well tolerate craniotomy, and their cognitive development is more likely to return to normal after early surgery.

A conundrum of West syndrome, behavioural problems and parental expressed emotions: a case report

West syndrome (WS) is the most common epileptic syndrome in infancy characterised by epileptic spasms, hypsarrhythmia and neurodevelopmental problems. Epileptic spasms remain in many ways a conundrum, and the ideal intervention, as well as how to screen patients to provide optimal care and certainly its genetic cause, remains puzzling. It is important to screen infants for early recognition and intervention to achieve the optimal outcome. We hereby discuss the approach to management of a boy aged 4½ years old with WS and behavioural problems and of parental expressed emotions.

Management practices for West syndrome in South Asia: A survey study and meta-analysis

OBJECTIVES

Considering the dearth of literature on West syndrome (WS) from South Asian countries, this study aimed to evaluate the management practices in South Asia by an online survey and meta-analysis.

METHODS

An online questionnaire was sent to 223 pediatric neurologists/pediatricians in India, Pakistan, Myanmar, Sri Lanka, Bhutan, Nepal, and Bangladesh. Their responses were evaluated and supplemented by a meta-analysis.

RESULTS

Of 125 responses received (response rate: 56%), around 60% of responders observed male preponderance and an approximate lead-time-to-treatment (LTTT) of 4-12 weeks. The commonest etiology observed was a static structural insult (88.6% of responders). Most commonly used first-line drug (country-wise) was as follows: India-adrenocorticotropin hormone (ACTH, 50%); Pakistan-oral steroids (45.5%); Myanmar, Sri Lanka, and Nepal-oral steroids (94.4%); Bangladesh-ACTH (2/2); Bhutan-vigabatrin (3/5). ACTH and vigabatrin are not available in Myanmar and Nepal. The most commonly used regime for ACTH was maximal-dose-at-initiation-regime in India, Sri Lanka, and Bangladesh and gradually escalating-regime in Pakistan. Maximum dose of prednisolone was variable-most common response from India: 3-4 mg/kg/d; Pakistan, Bhutan, and Bangladesh: 2 mg/kg/d; Sri Lanka, Nepal, and Myanmar: 5-8 mg/kg/d or 60 mg/d. The total duration of hormonal therapy (including tapering) ranged from 4 to 12 weeks (67/91). Most responders considered cessation of spasms for four weeks as complete response (54/111) and advised electroencephalography (EEG; 104/123) to check for hypsarrhythmia resolution. Difficult access to pediatric EEG in Bhutan and Nepal is concerning. More than 95% of responders felt a need for more awareness. The meta-analysis supported the preponderance of male gender (68%; confidence interval [CI]: 64%-73%), structural etiology(80%; CI 73%-86%), longer LTTT (2.4 months; CI 2.1-2.6 months), and low response rate to hormonal therapy(18% and 28% for ACTH and oral steroids respectively) in WS in South Asia.

SIGNIFICANCE

This study highlights the practices and challenges in the management of WS in South Asia. These include a preponderance of male gender and structural etiology, a longer LTTT, difficult access to pediatric EEG, nonavailability of ACTH and vigabatrin in some countries, and low effectiveness of hormonal therapy in this region.

Spontaneous remission of infantile spasms following rotavirus gastroenteritis

Epileptic seizures might be provoked and/or exacerbated by fever or viral infection in children with epilepsy. However, this is not true for infantile spasms; in this study, we report three cases with infantile spasms became seizure free within 2-5 days following rotavirus gastroenteritis without an exchange or addition of antiepileptic drugs, and hypsarrhythmia evolved to diffuse slow waves or localized spikes on electroencephalography. We propose that the probability regarding the mechanism of spontaneous mitigation is the suppression of immunopathological processes caused by infection, while the possibility of ketogenic effects of diarrhea and intestinal flora recombination after rotavirus gastroenteritis is unlikely. Further study may provide important information concerning the mechanism of seizure control and the applicability to treatment for infantile spasms.

Treatment of infantile spasms: why do we know so little?

INTRODUCTION

Infantile spasm (IS) is an epileptic syndrome with typical onset within the first 2 years of life. This condition might be caused by several etiologies. IS is associated with pathological neuronal networks; however, definite hypotheses on neurobiological processes are awaited.

AREAS COVERED

Changes in NMDA and GABA_B receptors and increase of Ca²⁺ conductance are some of the possible pathophysiological mechanisms. Animal models can help, but most have only some features of IS. Outcome is strongly affected by etiology and the timing of treatment, which relies still on ACTH, oral steroids, and vigabatrin. No significant differences in terms of efficacy have been documented, though a combination of ACTH and vigabatrin seems to be associated with better long-term outcomes. Despite the increasing knowledge about the etiology and pathophysiology of IS, in the last years, no new treatment approaches have been recognized to be able to modify the neurobiological process underlying IS. Precision medicine has far to come in IS.

EXPERT OPINION

Recently, no new therapeutic options for IS have emerged, probably due to the lack of reliable animal models and to the extreme variability in etiologies. Consequently, the outlook for patients and families is poor and early recognition and intervention remain research priorities.

Neutrophil to lymphocyte rate and serum prealbumin maybe predictors for abnormal high blood pressure caused by adrenocorticotropic hormone therapy in children with epileptic spasms: two cases report

Epileptic spasms are a catastrophic form of epilepsy. When epileptic spasms occur under 2-year-old, they may be also called “infantile spasms”. Adrenocorticotropic hormone (ACTH) is recommended as first line intervention for the treatment of epileptic spasms without tuberous sclerosis complex. The chief risks of ACTH therapy are immunosuppression and hypertension. We reported rare cases of abnormal high blood pressure in two male epileptic spasms patients during ACTH therapy. Both patients’ blood pressure reached a high blood pressure stage 2 on the 9th day and 10th day of ACTH treatment, respectively. The blood pressure returned to normal range after the drug dosage was reduced or stopped. The lower level of neutrophil%, neutrophil count, and a higher level of lymphocyte%, lymphocyte count and prealbumin than normal range were observed in both patients before ACTH therapy. The neutrophil to lymphocyte rate might be a predictor for high blood pressure among patients treated with ACTH. The rates of both patients were under 0.50 (0.42 for Case 1 and 0.17 for Case 2). We reported the documented cases in two Chinese pediatric patients who suffered from epileptic spasms treated with ACTH resulted in abnormal high blood pressure, which could be predicted by using neutrophil to lymphocyte rate. We also mentioned serum prealbumin might be another predictor. More clinical data is required to elucidate the relationship between serum prealbumin level and blood pressure.

Genotype-phenotype correlation on 45 individuals with West syndrome

West syndrome is an epilepsy syndrome characterized by repetitive epileptic spasms (ES) and hypsarrhythmia, typically leading to developmental delay/intellectual disability (DD/ID). It is considered a classic epileptic encephalopathy (EE). We designed a diagnostic sequencing panel targeting 131 genes associated with epilepsy and/or EE and screened a cohort of 45 individuals with clinical diagnosis of West syndrome. We identified disease-causing single nucleotide variants in 11 out of 45 individuals affecting genes commonly associated with West syndrome (such as CDKL5, ARX) but also in genes predominantly linked to other epileptic disorders (such as DEPDC5, SCN1A, WDR45, AARS). Panel analysis revealed copy number variants in two additional cases, comprising a 6,7 Mb Duplication on chromosome 2 including SCN2A and SCN3A and a supernumerary marker chromosome 15 leading to an overall diagnostic yield of 29% (13/45). In our cohort, individuals with a disease-causing variant had significantly more severe phenotypes with respect to DD/ID, therapy resistant epilepsy and cerebral atrophy compared to genetically unclarified cases. In addition to investigating the genotypic spectrum of West syndrome, we compared the phenotypic spectrum of clarified versus unclarified cases. Our study illustrates that West syndrome is an electroclinical syndrome caused by various genetic disorders. Individuals without detectable genetic cause might have less encephalopathy leading to a less severe course.

Etiologic classification of infantile spasms using positron emission/magnetic resonance imaging and the efficacy of adrenocorticotropic hormone therapy

PURPOSE

The aim of this study was to investigate if the etiologic classification of infantile spasm (IS) using positron emission tomography/magnetic resonance imaging (PET/MR) is feasible. Based on the classified etiologic groups, we further evaluated the efficacy of adrenocorticotropic hormone (ACTH) therapy in different IS groups.

MATERIALS AND METHODS

One hundred fifty-five children diagnosed with IS were included in this study. A qualitative assessment of the PET/MR images was performed. The abnormal lesions localized with both MR and PET images were considered to be epileptic foci, and the patients with these lesions were classified into the structural-metabolic group. For the remaining patients, quantitative analyses were further performed on whole-brain T1-weighted (T1WI) and PET images, based on the asymmetry index of bilateral volumes and metabolic quantifications. Patients with asymmetry indices above a certain threshold (15%) were classified into the structural-metabolic group. The patients without positive finding from either qualitative or quantitative analyses were assigned to the unknown etiology group. The efficacy of ACTH therapy was evaluated in the different IS groups.

RESULTS

Among the 155 children with IS, 18 genetic cases were first diagnosed by the genetic testing. In the remaining 137 cases, 49 cases were identified with structural-metabolic etiology using qualitative PET/MR assessments. Fifty-two cases were newly diagnosed with quantitative analysis. The remaining 36 cases were classified into the unknown etiology group. The efficacy of ACTH therapy was statistically different for the different etiology groups (p < 0.001). The respective efficacy rates for the genetic, qualitative structural-metabolic, quantitative structural-metabolic, and unknown etiology groups were 27.8% (5/18), 30.61% (15/49), 34.62% (18/52), and 72.22% (26/36), respectively.

CONCLUSIONS

The combination of PET and MR provides additional diagnostic information for IS. Quantitative analysis can further improve patient etiologic classifications and the predication of therapy efficacies.

Early Intervention With Adrenocorticotropin for Acute Encephalopathy-Associated Epileptic Spasms: Report of Two Cases

PURPOSE

Acute encephalopathy with biphasic seizures and reduced diffusion (AESD) is a leading cause of childhood-onset encephalopathy in Japan. Children with AESD frequently develop intractable epilepsy, whereas their treatment options remain to be determined.

METHOD

We present 2 unrelated girls, who developed AESD at 25 months (case 1) and 12 months of age (case 2). Both cases underwent intensive cares from the first day of illness, whereas severe neurological impairments were left on discharge. They showed repeated signs of epileptic spasms at 2 months (case 1) and 8 months (case 2) after the onset of AESD. Video-monitoring electroencephalograms (EEG) detected the recurrent attacks accompanying slow-wave bursts and transient suppressions of the precedent epileptiform discharges, as typically observed in epileptic spasms.

RESULTS

Intramuscular injection of adrenocorticotropic hormone (ACTH, 0.0125 mg/kg/d) was introduced within 1 month from the onset of epileptic spasms and continued for 2 weeks. The ACTH treatment disrupted the paroxysmal activity in EEG, and it has relieved these patients from epileptic seizures for more than 1 year.

CONCLUSION

This report illustrates the potential efficacy of ACTH for a group of children with epileptic spasms after AESD.

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

PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Epileptic spasms: Evidence for oral corticosteroids and implications for low and middle income countries

Implementation of international guidelines for the treatment of epileptic spasms, is challenging when access to adrenocorticotrophic hormone (ACTH) and vigabatrin is restricted, especially in Low and Middle Income Countries (LMIC). Oral corticosteroids are alternative interventions but evidence for the optimal agent, dose, duration, efficacy and long-term effects is lacking. A systematic review of the literature was performed to assess the quality of evidence of prednisone and prednisolone (oral corticosteroids) for the management of epileptic spasms. There is level C recommendation based on class III evidence to support the efficacy of oral corticosteroids for the acute clinical control of epileptic spasms and EEG resolution. Efficacy of oral corticosteroids in comparison to the internationally recommended intervention of ACTH has class IV evidence supporting level U recommendation. Similarly, there is no data on the risk of relapse with oral corticosteroids (class IV, level U), compared to ACTH. There is class IV evidence supporting level U recommendation for the safety of oral corticosteroids and class II evidence for level B recommendation for ACTH. In terms of oral corticosteroids and effects on long-term development there is class IV evidence leading to level U recommendation, compared to class III evidence supporting level C recommendation for ACTH. Randomized controlled studies are needed to compare oral corticosteroids with ACTH, the optimal dosage and regimen as well as the long-term neurodevelopmental outcomes. Based on the limited existing studies a treatment guideline for LMIC is proposed which could be used to standardize interventions permitting clarification of these unmet questions.

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

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

West Syndrome: A Review and Guide for Paediatricians

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

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.

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

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