Cognitive outcome in children with infantile spasms using a standardized treatment protocol. A five-year longitudinal study

Factors influencing efficacy and relapse of adrenocorticotropic hormone in infantile epileptic spasms syndrome

BACKGROUND

Infantile epileptic spasms syndrome (IESS) is a severe epileptic condition characterized by persistent uncontrolled seizures, with some children experiencing recurrent seizures despite multiple pharmacological therapies. The prognostic risk factorsassociated with IESS remain unclear. This study aimed to evaluate the factors influencing the efficacy and relapse of adrenocorticotropic hormone (ACTH) treatment for IESS in infants, as well as to assess the correlation between the Burden of Amplitudes and Epileptiform Discharges (BASED) score and clinical outcomes.

METHODS

A retrospective analysis was conducted on a cohort of 88 pediatric patients diagnosed with IESS who received ACTH therapy at our hospital from February 2016 to August 2023. Patients were categorized into response (n = 47) and non-response (n = 41) groups based on their treatment response at day 28. Responders were further classified into relapse and non-relapse groups. A modified Poisson regression model and receiver operating characteristic (ROC) curves were employed to evaluate the positive predictive values.

RESULTS

In this study, a total of 47 patients (53.4 %) responded to ACTH treatment. Patients in the response group demonstrated significantly greater reductions in BASED scores by day 14 of ACTH treatment, yielding an area under the curve (AUC) of 0.859 (95 % CI: 0.782-0.937, P＜0.05), with a sensitivity of 68.1 % and a specificity of 95.1 %. The optimal cut-off point was established at ≥ 2, corresponding to a Youden index of 0.632. Notably, patientswho were on anti-seizure medications (ASMs) before ACTH treatment and those with developmental delay prior to the onset of spasms exhibited lower short-term response rates (P＜0.05), although these factors did not demonstrate predictive value. Among the responders, 20 cases (42.6 %) experienced a relapse, with only those patients showing specific abnormalities on cranial magnetic resonance imaging (MRI) exhibiting a statistically higher proportion of relapse.

CONCLUSION

Patients receiving ASMs before ACTH treatment and those with developmental delays prior to the onset of spasms may have a less favorable therapeutic response. A reduction in BASED scores of 2 or greater by day 14 of ACTH treatment may signify a potentially positive treatment response. Additionally, patients with IESS who present with specific abnormalities on cranial MRI may have an increased likelihood of relapse following ACTH treatment.

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.

Increased propensity for infantile spasms and altered neocortical excitation-inhibition balance in a mouse model of down syndrome carrying human chromosome 21

Children with Down syndrome (DS, trisomy of chromosome 21) have an increased risk of infantile spasms (IS). As an epileptic encephalopathy, IS may further impair cognitive function and exacerbate neurodevelopmental delays already present in children with DS. To investigate the pathophysiology of IS in DS, we induced IS-like epileptic spasms in a genetic mouse model of DS that carries human chromosome 21q, TcMAC21, the animal model most closely representing gene dosage imbalance in DS. Repetitive extensor/flexor spasms were induced by the GABA_B receptor agonist γ-butyrolactone (GBL) and occurred predominantly in young TcMAC21 mice (85%) but also in some euploid mice (25%). During GBL application, background electroencephalographic (EEG) amplitude was reduced, and rhythmic, sharp-and-slow wave activity or high-amplitude burst (epileptiform) events emerged in both TcMAC21 and euploid mice. Spasms occurred only during EEG bursts, but not every burst was accompanied by a spasm. Electrophysiological experiments revealed that basic membrane properties (resting membrane potential, input resistance, action-potential threshold and amplitude, rheobase, input-output relationship) of layer V pyramidal neurons were not different between TcMAC21 mice and euploid controls. However, excitatory postsynaptic currents (EPSCs) evoked at various intensities were significantly larger in TcMAC21 mice than euploid controls, while inhibitory postsynaptic currents (IPSCs) were similar between the two groups, resulting in an increased excitation-inhibition (E-I) ratio. These data show that behavioral spasms with epileptic EEG activity can be induced in young TcMAC21 DS mice, providing proof-of-concept evidence for increased IS susceptibility in these DS mice. Our findings also show that basic membrane properties are similar in TcMAC21 and euploid mice, while the neocortical E-I balance is altered to favor increased excitation in TcMAC21 mice, which may predispose to IS generation.

Long-Term Outcome of Adrenocorticotropic Hormone Therapy in Children With New-Onset Infantile Spasms

BACKGROUND

To investigate for pretreatment clinical variables to predict the outcome of new-onset epileptic spasms after adrenocorticotropic hormone (ACTH) therapy and to identify risk factors for poor long-term outcome.

METHODS

We retrospectively studied 129 consecutive patients with infantile spasms syndrome (ISS). These patients received ACTH with antiseizure medication therapy for the first time and were regularly followed up for more than six months at our hospital. The response to treatment was assessed after two weeks of ACTH injection. Kaplan-Meier survival analysis and the multivariate Cox proportional hazard regression model were used.

RESULTS

Among the 129 patients, 61 (47.3%) had a good response after two weeks of ACTH treatment. At the time of the latest follow-up, 71 (55%) patients were seizure-free (International League Against Epilepsy class1). The univariate analysis revealed that normal neurodevelopment (P = 0.018), time lag of less than one month (P = 0.026), no hypsarrhythmia on EEG (P = 0.004), and serum calcium level ≥2.50 mmol/L (P = 0.035) were significantly associated with a good response. Only a good response to ACTH therapy was significantly associated with a positive long-term outcome. The Kaplan-Meier survival analysis showed that serum calcium level ≧2.50 mmol/L was significantly associated with a positive long-term outcome (P = 0.030). Multivariate analysis confirmed that no response to ACTH therapy was an independent variable that predicted long-term seizure recurrence (P < 0.001, hazard ratio = 4.602, confidence interval = 2.252 to 9.406).

CONCLUSIONS

A good response to ACTH therapy had a significant predictive value for long-term seizure outcomes. Calcium may play an important role in the treatment of ISS with ACTH.

Automatic BASED scoring on scalp EEG in children with infantile spasms using convolutional neural network

In recent years, the Burden of Amplitudes and Epileptiform Discharges (BASED) score has been used as a reliable, accurate, and feasible electroencephalogram (EEG) grading scale for infantile spasms. However, manual EEG annotation is, in general, very time-consuming, and BASED scoring is no exception. Convolutional neural networks (CNNs) have proven their great potential in many EEG classification problems. However, very few research studies have focused on the use of CNNs for BASED scoring, a challenging but vital task in the diagnosis and treatment of infantile spasms. This study proposes an automatic BASED scoring framework using EEG and a deep CNN. The feasibility of using CNN for automatic BASED scoring was investigated in 36 patients with infantile spasms by annotating their long-term EEG data with four levels of the BASED score (scores 5, 4, 3, and ≤2). In the validation set, the accuracy was 96.9% by applying a multi-layer CNN to classify the EEG data as a 4-label problem. The extensive experiments have demonstrated that our proposed approach offers high accuracy and, hence, is an important step toward an automatic BASED scoring algorithm. To the best of our knowledge, this is the first attempt to use a CNN to construct a BASED-based scoring model.

Long-Term Health Outcomes of Infantile Spasms Following Prednisolone vs. Adrenocorticotropic Hormone Treatment Characterized Using Phenome-Wide Association Study

Objective

To determine differences in long-term health and neurological outcomes following infantile spasms (IS) in patients treated with adrenocorticotropic hormone (ACTH) vs. prednisolone/prednisone (PRED).

Methods

A retrospective, case-control study of patients with an International Classification of Diseases, Ninth Revision, Clinical Modifications (ICD-9) diagnosis of IS, identified over a 10-year period from a national administrative database, was conducted. IS patients treated with ACTH or PRED were determined and cohorts established by propensity score matching. Outcomes, defined by hospital discharge ICD codes, were followed for each patient for 5 years. Related ICD codes were analyzed jointly as phenotype codes (phecodes). Analysis of phecodes between cohorts was performed including phenome-wide association analysis.

Results

A total of 5,955 IS patients were identified, and analyses were subsequently performed for 493 propensity score matched patients, each in the ACTH and PRED cohorts. Following Bonferroni correction, no phecode was more common in either cohort (p < 0.001). However, assuming an a priori difference, one phecode, abnormal findings on study of brain or nervous system (a category of abnormal neurodiagnostic tests), was more common in the PRED cohort (p <0.05), and was robust to sensitivity analysis. Variability in outcomes was noted between hospitals.

Significance

We found that long-term outcomes for IS patients following ACTH or PRED treatment were very similar, including for both neurological and non-neurological outcomes. In the PRED-treated cohort there was a higher incidence of abnormal neurodiagnostic tests, assuming an a priori statistical model. Future studies can evaluate whether variability in outcomes between hospitals may be affected by post-treatment differences in care models.