Three different scenarios for epileptic spasms

Tonic and tonic-clonic seizures in the first year of life: Insights from electrographic features

OBJECTIVE

We studied the electrographic features of tonic seizures (TS) with bilateral contraction and tonic-clonic seizures (TCS) without focal signs occurring during the first year of life to evaluate if there is a correlation with outcome.

METHODS

We retrospectively reviewed patients aged 1 to 12 months with at least one TS or TCS recorded with video-EEG between 2011 and 2021 in our Epilepsy Monitoring Unit. We analyzed the following electrographic features: seizure duration, presence and duration of focal ictal EEG onset, and post-ictal generalized EEG suppression (PGES). Among clinical variables, we collected age at epilepsy onset, age at TS and TCS recording, response to anti-seizure medications, genetic and neuroimaging findings, epileptic syndrome classification.

RESULTS

Overall, we recorded 2577 seizures in 1769 patients. One-hundred-twenty-eight seizures (5%) were clinically labeled either as TS or TCS in 41 patients (2%). Out of 41 patients, 17 (41%) presented with TS, and 24 (59%) with TCS. Thirteen patients (32%) had a Self-limited Epilepsy, and 28 (68%) a Developmental and Epileptic Encephalopathy (DEE). Seventy-two percent of genetically tested patients had pathogenic gene variants. None had structural epilepsy. Mean age at epilepsy onset was 4.48 months (range 3 days-12 months). Age at seizure onset was earlier in patients presenting with TS versus patients presenting with TCS (2.31 months vs. 6.01 months; p = 0.001) and in DEEs versus Self-limited Epilepsies (3.23 months vs. 7.16 months; p = 0.001). TS were exclusively present in DEEs (p = 0.001), and TCS were recorded in both DEEs and Self-limited Epilepsies. Focal ictal EEG onset was evident in 92 % of TCS, and in none of TS. Generalized ictal EEG onset was documented in 100 % of TS, and in 8 % of TCS. Focal ictal EEG onset occurred more frequently (100 % vs. 32 %; p = 0.000) and was significantly longer (30.61 s vs. 16.22 s; p = 0.020) in Self-limited Epilepsies versus DEEs. PGES was observed in 18 out of 41 (44 %) and was more frequent in Self-limited Epilepsies (p = 0.026).

SIGNIFICANCE

This study provides insights into the electroclinical features of TS and TCS in infants that may help distinguish Self-limited Epilepsies from DEEs soon after epilepsy onset.

Predictive modeling based on functional connectivity of interictal scalp EEG for infantile epileptic spasms syndrome

OBJECTIVE

This study aims to delineate the electrophysiological variances between patients with infantile epileptic spasms syndrome (IESS) and healthy controls and to devise a predictive model for long-term seizure outcomes.

METHODS

The cohort consisted of 30 individuals in the seizure-free group, 23 in the seizure-residual group, and 20 in the control group. We conducted a comprehensive analysis of pretreatment electroencephalography, including the relative power spectrum (rPS), weighted phase-lag index (wPLI), and network metrics. Follow-up EEGs at 2 years of age were also analyzed to elucidate physiological changes among groups.

RESULTS

Infants in the seizure-residual group exhibited increased rPS in theta and alpha bands at IESS onset compared to the other groups (all p < 0.0001). The control group showed higher rPS in fast frequency bands, indicating potentially enhanced cognitive function. The seizure-free group presented increased wPLI across all frequency bands (all p < 0.0001). Our predictive model utilizing wPLI anticipated long-term outcomes at IESS onset (area under the curve 0.75).

CONCLUSION

Our findings demonstrated an initial "hypersynchronous state" in the seizure-free group, which was ameliorated following successful treatment.

SIGNIFICANCE

This study provides a predictive model utilizing functional connectivity and insights into the diverse electrophysiology observed among outcome groups of IESS.

Characteristics of malignant brain tumor-associated epileptic spasms

Although epilepsy is the most common comorbidity of brain tumors, epileptic spasms rarely occur. Brain tumors associated with epileptic spasms are mostly low-grade gliomas. To date, few studies in the literature have reported on malignant (Grades 3-4) brain tumors associated with epileptic spasms. Thus, we aimed to investigate the characteristics of malignant brain tumor-associated epileptic spasms. We retrospectively reviewed patients with malignant brain tumors and epileptic spasms in our institution. Data on demographics, tumor histology, magnetic resonance imaging, epileptic spasm characteristics, electroencephalography, and treatment responsiveness were also collected. Six patients were included. In all cases, the brain tumors occurred in infancy in the supratentorial region and epileptic spasm onset occurred after the completion of brain tumor treatment. Anti-seizure medication did not control epileptic spasms; two patients were seizure-free after epileptic surgery. Although all patients had developmental delays caused by malignant brain tumors and their treatment, developmental regression proceeded after epileptic spasm onset. Two patients who achieved seizure-free status showed improved developmental outcomes after cessation of epileptic spasms. This is the first report of the characteristics of malignant brain tumor-associated epileptic spasms. Our report highlights a difficulties of seizure control and possibillity of efficacy of epileptic surgery in this condition. In malignant brain tumor-associated epileptic spasms, it is important to proceed with presurgical evaluation from an early stage, bearing in mind that epileptic spasms may become drug-resistant.

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.

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.

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.

Medical treatment in infants and young children with epilepsy: Off-label use of antiseizure medications. Survey Report of ILAE Task Force Medical Therapies in Children

OBJECTIVE

Antiseizure medications (ASMs) remain the mainstay of epilepsy treatment. These ASMs have mainly been tested in trials in adults with epilepsy, which subsequently led to market authorization (MA). For treatment of - especially young - children with epilepsy, several ASMs do not have a MA and guidelines are lacking, subsequently leading to "off-label" use of ASMs. Even though "off-label" ASM prescriptions for children could lead to more adverse events, it can be clinically appropriate and rational if the benefits outweigh the risks. This could be the case if "on-label" ASM, in mono- or polytherapy, fails to achieve adequate seizure control.

METHODS

The Medical Therapies Task Force of the International League Against Epilepsy (ILAE) Commission for Pediatrics performed a survey to study the current treatment practices in six classic, early life epilepsy scenarios. Our aim was not only to study first- and second-line treatment preferences but also to illustrate the use of "off-label" drugs in childhood epilepsies.

RESULTS

Our results reveal that several ASMs (e.g. topiramate, oxcarbazepine, benzodiazepines) are prescribed "off-label" in distinct scenarios of young children with epilepsy. In addition, recent scientific guidelines were not always adopted by several survey respondents, suggesting a potential knowledge gap.

SIGNIFICANCE

We report the relatively common use of "off-label" prescriptions that underlines the need for targeted and appropriately designed clinical trials, including younger patients, which will also result in the ability to generate evidence-based guidelines.

[Factors influencing the efficacy of initial adrenocorticotropic hormone therapy for infantile epileptic spasms syndrome]

OBJECTIVES

To study the factors influencing the short-term (28 days) efficacy of initial adrenocorticotropic hormone (ACTH) therapy for infantile epileptic spasms syndrome (IESS), as well as the factors influencing recurrence and prognosis.

METHODS

The clinical data were collected from the children with IESS who received ACTH therapy for the first time in the Department of Pediatric Neurology, Xiangya Hospital of Central South University, from April 2008 to January 2018 and were followed up for ≥2 years. The multivariate logistic regression analysis was used to evaluate the factors influencing the short-term efficacy of ACTH therapy, recurrence, and long-term prognosis.

RESULTS

ACTH therapy achieved a control rate of seizures of 55.5% (111/200) on day 28 of treatment. Of the 111 children, 75 (67.6%) had no recurrence of seizures within 12 months of follow-up. The possibility of seizure control on day 28 of ACTH therapy in the children without focal seizures was 2.463 times that in those with focal seizures (P<0.05). The possibility of seizure control on day 28 of ACTH therapy in the children without hypsarrhythmia on electroencephalography on day 14 of ACTH therapy was 2.415 times that in those with hypsarrhythmia (P<0.05). The possibility of recurrence within 12 months after treatment was increased by 11.8% for every 1-month increase in the course of the disease (P<0.05). The possibility of moderate or severe developmental retardation or death in the children without seizure control after 28 days of ACTH therapy was 8.314 times that in those with seizure control (P<0.05). The possibility of moderate or severe developmental retardation or death in the children with structural etiology was 14.448 times that in those with unknown etiology (P<0.05).

CONCLUSIONS

Presence or absence of focal seizures and whether hypsarrhythmia disappears after 14 days of treatment can be used as predictors for the short-term efficacy of ACTH therapy, while the course of disease before treatment can be used as the predictor for recurrence after seizure control by ACTH therapy. The prognosis of IESS children is associated with etiology, and early control of seizures after ACTH therapy can improve long-term prognosis.

Quantitative pretreatment EEG predicts efficacy of ACTH therapy in infantile epileptic spasms syndrome

OBJECTIVE

This study aimed to determine the correlation between outcomes following adrenocorticotrophic hormone (ACTH) therapy and measurements of relative power spectrum (rPS), weighted phase lag index (wPLI), and graph theoretical analysis on pretreatment electroencephalography (EEG) in infants with non-lesional infantile epileptic spasms syndrome (IESS).

METHODS

Twenty-eight patients with non-lesional IESS were enrolled. Outcomes were classified based on seizure recurrence following ACTH therapy: seizure-free (F, n = 21) and seizure-recurrence (R, n = 7) groups. The rPS, wPLI, clustering coefficient, and betweenness centrality were calculated on pretreatment EEG and were statistically analyzed to determine the correlation with outcomes following ACTH therapy.

RESULTS

The rPS value was significantly higher in the delta frequency band in group R than in group F (p < 0.001). The wPLI values were significantly higher in the delta, theta, and alpha frequency bands in group R than in group F (p = 0.007, <0.001, and <0.001, respectively). The clustering coefficient in the delta frequency band was significantly lower in group R than in group F (p < 0.001).

CONCLUSIONS

Our findings demonstrate the significant differences in power and functional connectivity between outcome groups.

SIGNIFICANCE

This study may contribute to an early prediction of ACTH therapy outcomes and thus help in the development of appropriate treatment strategies.

Sleep architecture in neonatal and infantile onset epilepsies in the first six months of life: A scoping review

AIM

Epilepsy occurs in approximately 80 per 100,000 infants in the first year of life, ranging in severity from self-limited and likely to spontaneously resolve, to severe developmental and epileptic encephalopathies. Sleep plays a key role in early brain development and the reciprocal relationship between sleep and seizures is not yet fully understood, particularly in young children. We conducted a Scoping Review to synthesise current knowledge of sleep architecture in neonates and infants with epilepsy.

METHOD

Peer-reviewed publications from 2005 to 2022 describing sleep architecture in infants up to six months of age with unprovoked seizures were included. The analysis set was derived from EMBASE, Web of Science and PubMED using key terms "sleep, epilepsy and infant" and related descriptors. Inclusion criteria were prospectively described in a Scoping Review protocol. Sleep architecture was assessed as macro- and micro-structural elements.

RESULTS

21 publications were included in the qualitative analysis. In self-limited familial and genetic epilepsy, sleep macrostructure was generally preserved. In DEEs and in epileptic encephalopathies of genetic or structural aetiology, sleep architecture was significantly disrupted.

INTERPRETATION

Early identification of infants with epilepsy is important to ensure early and effective treatment. In the DEE spectrum, sleep architecture is significantly impacted, and abnormal sleep architecture may be associated with compromised developmental outcome. Further research is needed to identify the sequence of events in abnormal brain development, epilepsy and sleep disruption and potentially help to predict the course of epilepsy towards a self-limited epilepsy versus a DEE.

Periodic electroencephalographic discharges and epileptic spasms involve cortico-striatal-thalamic loops on Arterial Spin Labeling Magnetic Resonance Imaging

Periodic discharges are a rare peculiar electroencephalogram pattern, occasionally associated with motor or other clinical manifestations, usually observed in critically ill patients. Their underlying pathophysiology remains poorly understood. Epileptic spasms in clusters and periodic discharges with motor manifestations share similar electroencephalogram pattern and some aetiologies of unfavourable prognosis such as subacute sclerosing panencephalitis or herpes encephalitis. Arterial spin labelling magnetic resonance imaging identifies localizing ictal and inter-ictal changes in neurovascular coupling, therefore assumed able to reveal concerned cerebral structures. Here, we retrospectively analysed ictal and inter-ictal arterial spin labelling magnetic resonance imaging in patients aged 6 months to 15 years (median 3 years 4 months) with periodic discharges including epileptic spasms, and compared these findings with those of patients with drug-resistant focal epilepsy who never presented periodic discharges nor epileptic spasms as well as to those of age-matched healthy controls. Ictal electroencephalogram was recorded either simultaneously with arterial spin labelling magnetic resonance imaging or during the close time lapse of patients' periodic discharges, whereas inter-ictal examinations were performed during the patients' active epilepsy but without seizures during the arterial spin labelling magnetic resonance imaging. Ictal arterial spin labelling magnetic resonance imaging was acquired in five patients with periodic discharges [subacute sclerosing panencephalitis (1), stroke-like events (3), West syndrome with cortical malformation (1), two of them also had inter-ictal arterial spin labelling magnetic resonance imaging]. Inter-ictal group included patients with drug-resistant epileptic spasms of various aetiologies (14) and structural drug-resistant focal epilepsy (8). Cortex, striatum and thalamus were segmented and divided in six functional subregions: prefrontal, motor (rostral, caudal), parietal, occipital and temporal. Rest cerebral blood flow values, absolute and relative to whole brain, were compared with those of age-matched controls for each subregion. Main findings were diffuse striatal as well as cortical motor cerebral blood flow increase during ictal examinations in generalized periodic discharges with motor manifestations (subacute sclerosing panencephalitis) and focal cerebral blood flow increase in corresponding cortical-striatal-thalamic subdivisions in lateralized periodic discharges with or without motor manifestations (stroke-like events and asymmetrical epileptic spasms) with straight topographical correlation with the electroencephalogram focus. For inter-ictal examinations, patients with epileptic spasms disclosed cerebral blood flow changes in corresponding cortical-striatal-thalamic subdivisions (absolute-cerebral blood flow decrease and relative-cerebral blood flow increase), more frequently when compared with the group of drug-resistant focal epilepsies, and not related to Vigabatrin treatment. Our results suggest that corresponding cortical-striatal-thalamic circuits are involved in periodic discharges with and without motor manifestations, including epileptic spasms, opening new insights in their pathophysiology and new therapeutical perspectives. Based on these findings, we propose a model for the generation of periodic discharges and of epileptic spasms combining existing pathophysiological models of cortical-striatal-thalamic network dynamics.

Case Report: Hindlimb Ataxia Concurrent With Seizures by Presumed Osmotic Demyelination Syndrome in a Dog

A 6-year-old castrated male Chihuahua dog was presented with hindlimb paresis and ataxia. The dog had hyponatremia and was diagnosed as hypoadrenocorticism 10 days before its visit, and the neurologic signs including generalized tonic seizures and hindlimb paresis occurred 3 days after correction of hyponatremia at a referral hospital. Based on history and clinical findings, osmotic demyelination syndrome (ODS) secondary to rapid correction of hyponatremia was highly suspected. After administration of anti-convulsant and supplements, seizures did not occur, and gait was normalized within 2 weeks. Phenobarbital was tapered and finally discontinued after 3 months, and seizure did not recur. The neurologic signs were completely resolved and the dog continued to be free of neurologic or additional clinical signs over the 19-month follow-up period. ODS should be included among the differential diagnoses in case of any acute neurological dysfunction that occurs with episodes of rapid correction of hyponatremia. To the author's knowledge, this is the rare case report of a dog with hypoadrenocorticism and presumed ODS after rapid correction of hyponatremia leading to neurologic signs including seizures and ataxia.

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.

Different pharmacoresistance of focal epileptic spasms, generalized epileptic spasms, and generalized epileptic spasms combined with focal seizures

Objective

Among standard treatments for infantile spasms, adrenocorticotropic hormone (ACTH) is reported as the best treatment, but ACTH is ineffective in one‐half of the patients. To establish precision medicine, we examined pharmacoresistance of focal epileptic spasms (ES), generalized ES, and generalized ES combined with focal seizures, diagnosed based on the revised seizure classification of ILAE in 2017.

Methods

We conducted a retrospective nationwide study in Japan on the long‐term seizure outcome of ES. Long‐term seizure outcome was evaluated by seizure‐free rate, seizure‐free period, and Kaplan‐Meier curve. Seizure‐free was defined as seizure control for longer than 2 months.

Results

From the medical history of 501 patients, 325 patients had generalized ES only (GES group) at the start of the first treatment, 125 patients had generalized ES after focal seizure onset (FS‐GES group), seven patients had focal ES after focal seizure onset (FS‐FES group), and 24 patients had generalized ES combined with focal seizures after focal seizure onset (FS‐GES + FS group). Seizure‐free period of ES (generalized ES and focal ES) [mean (95% confidence interval)] was 2.7 (0.0‐5.4) months in GES group, 1.1 (0.1‐2.2) months in FS‐GES group, 1.0 (0.2‐1.9) months in FS‐GES + FS group, and 0.1 (−0.2‐0.5) months in FS‐FES group. Seizure‐free rate, seizure‐free period, and Kaplan‐Meier curve of generalized ES were almost the same in GES group and FS‐GES group, with characteristics of superior response to ACTH. Mean seizure‐free period of generalized ES combined with focal seizures was significantly shorter in FS‐GES + FS group than in GES group. Mean seizure‐free period of focal ES in FS‐FES group was extremely short with exceedingly early relapse.

Significance

Pharmacoresistance was different in generalized ES, focal ES, and generalized ES combined with focal seizures. ES with focal features or with focal seizures may have focal lesions, thus consider surgical options earlier in the course.

Case Report: Subtotal Hemispherotomy Modulates the Epileptic Spasms in Aicardi Syndrome

The mechanism of epileptic spasms (ES) in Aicardi syndrome (AS) remains obscure. We compared intraoperative high-frequency oscillations (HFOs) and phase-amplitude coupling (PAC) before and after subtotal hemispherotomy in a 3-month-old girl with drug-resistant ES secondary to AS. Fetal ultrasonography showing corpus callosum agenesis, bilateral ventricular dilatation, and a large choroid plexus cyst confirmed AS diagnosis. Her ES started when she was 1 month old and had ten series of clustered ES per day despite phenobarbital and vitamin B6 treatment. After subtotal hemispherotomy, her ES dramatically improved. We analyzed two intraoperative electrocorticography modalities: (1), occurrence rate (OR) of HFOs; (2), PAC of HFOs and slow wave bands in the frontal, central, and parietal areas. We hypothesized that HFOs and PAC could be the biomarkers for efficacy of subtotal hemispherotomy in AS with ES. PAC in all three areas and OR of HFOs in the frontal and parietal areas significantly decreased, while OR of HFOs in the central area remained unchanged after subtotal hemispherotomy. We have demonstrated the usefulness of evaluating intraoperative HFOs and PAC to assess subtotal hemispherotomy effectiveness in AS patients with ES. Disconnecting the thalamocortical and subcortical pathways in the epileptic network plays a role in controlling ES generation.