The prognostic value of EEG patterns in epilepsies with infantile spasms

Scoring Systems for the Evaluation of Hypsarrhythmia

SUMMARY

Hypsarrhythmia is a well-recognized EEG pattern and it has been long known as a feature of one of the more severe forms of epilepsy early in life with adverse consequences if not recognized and treated promptly. Yet, it has been difficult to objectively quantify its varied manifestations and link them to the clinical severity of epilepsy, implications for treatment, or the overall seizure and developmental outcome of young patients. This is not for want of effort, for there have been several approaches to score hypsarrhythmia ever since its initial recognition as a unique EEG pattern. In this article, we review the different methods proposed to score hypsarrhythmia and highlight the challenges inherent to each one of them.

Resective epilepsy surgery for West syndrome: The Hypsarrhythmic Asymmetric Scoring Scheme is a determining predictor of seizure outcome

OBJECTIVE

It has been suggested that asymmetric hypsarrhythmia is associated with structural etiology. We devised the Hypsarrhythmic Asymmetric Scoring Scheme (HASS) to quantify the degree of hypsarrhythmic asymmetry in a retrospective series of patients who underwent surgical treatment at our center. The present study aimed to investigate the role of HASS in predicting the postsurgical seizure outcomes.

METHODS

We retrospectively analyzed the records of 46 children with hypsarrhythmia who underwent resective epilepsy surgery between 2018 and 2020 and were followed up for at least 1 year after surgery. Hypsarrhythmia severity in each hemisphere was quantified and scored. The HASS score was calculated as the difference between the two hemispheres. Univariate results were submitted to logistic regression models to identify independent predictors for favorable surgical outcomes.

RESULTS

Of the 46 patients who underwent resective surgery, Engel's class I-Ⅱ outcomes were achieved in 34 (73.9%). The Engel I-Ⅱ group had a significantly higher HASS score than the Engel Ⅲ-Ⅳ group (p<0.001). Multivariate analysis showed that the HASS score was the only significant predictor of good outcomes (p = 0.011). Further receiver operating characteristic analysis showed that a threshold of 7 yielded a better seizure outcome with a sensitivity of 97.06% and specificity of 83.33%.

SIGNIFICANCE

As the first hypsarrhythmia scoring system specially designed for presurgical evaluation, the HASS score may contribute to predicting the postsurgical seizure outcome from the electroencephalography perspective.

Standard procedures for the diagnostic pathway of sleep-related epilepsies and comorbid sleep disorders: A European Academy of Neurology, European Sleep Research Society and International League against Epilepsy-Europe consensus review

BACKGROUND

Some epilepsy syndromes (sleep-related epilepsies [SRE]) have a strong link with sleep. Comorbid sleep disorders are common in patients with SRE and can exert a negative impact on seizure control and quality of life.

PURPOSES

To define the standard procedures for the diagnostic pathway of patients with possible SRE (scenario 1) and the general management of patients with SRE and comorbidity with sleep disorders (scenario 2).

METHODS

The project was conducted under the auspices of the European Academy of Neurology (EAN), the European Sleep Research Society (ESRS) and the International League against Epilepsy (ILAE) Europe. The framework of the document entailed the following phases: conception of the clinical scenarios; literature review; statements regarding the standard procedures. For literature search a step-wise approach starting from systematic reviews to primary studies was applied. Published studies were identified from the National Library of Medicine's MEDLINE database and Cochrane Library.

RESULTS

Scenario 1: despite a low quality of evidence, recommendations on anamnestic evaluation, tools for capturing the event at home or in the laboratory are provided for specific SRE. Scenario 2: Early diagnosis and treatment of sleep disorders (especially respiratory disorders) in patients with SRE are likely to be beneficial for seizures control.

CONCLUSIONS

Definitive procedures for evaluating patients with SRE are lacking. We provide advice that could be of help for standardising and improving the diagnostic approach of specific SRE. The importance of identifying and treating specific sleep disorders for the management and outcome of patients with SRE is underlined.

Standard procedures for the diagnostic pathway of sleep-related epilepsies and comorbid sleep disorders: an EAN, ESRS and ILAE-Europe consensus review

BACKGROUND AND PURPOSE

Some epilepsy syndromes (sleep-related epilepsies, SREs) have a strong link with sleep. Comorbid sleep disorders are common in patients with SRE and can exert a negative impact on seizure control and quality of life. Our purpose was to define the standard procedures for the diagnostic pathway of patients with possible SRE (scenario 1) and the general management of patients with SRE and comorbidity with sleep disorders (scenario 2).

METHODS

The project was conducted under the auspices of the European Academy of Neurology, the European Sleep Research Society and the International League Against Epilepsy Europe. The framework entailed the following phases: conception of the clinical scenarios; literature review; statements regarding the standard procedures. For the literature search a stepwise approach starting from systematic reviews to primary studies was applied. Published studies were identified from the National Library of Medicine's MEDLINE database and Cochrane Library.

RESULTS

Scenario 1: Despite a low quality of evidence, recommendations on anamnestic evaluation and tools for capturing the event at home or in the laboratory are provided for specific SREs. Scenario 2: Early diagnosis and treatment of sleep disorders (especially respiratory disorders) in patients with SRE are likely to be beneficial for seizure control.

CONCLUSIONS

Definitive procedures for evaluating patients with SRE are lacking. Advice is provided that could be of help for standardizing and improving the diagnostic approach of specific SREs. The importance of identifying and treating specific sleep disorders for the management and outcome of patients with SRE is underlined.

Prognostic Utility of Clinical Epilepsy Severity Score Versus Pretreatment Hypsarrhythmia Scoring in Children With West Syndrome

This cross-sectional study assessed the impact of clinical epilepsy severity and pretreatment hypsarrhythmia severity on epilepsy and cognitive outcomes in treated children with West syndrome. Thirty-three children, aged 1 to 5 years, with infantile spasms were enrolled if pretreatment EEG records were available, after completion of ≥1 year of onset of spasms. Neurodevelopment was assessed by Development Profile 3 and Gross Motor Function Classification System. Epilepsy severity in the past 1 year was determined by the Early Childhood Epilepsy Severity Score (E-Chess). Kramer Global Score of hypsarrhythmia severity was computed. Kramer Global Score (≤8) and E-Chess (≤9) in the past 1 year were associated with favorable epilepsy outcome but not neurodevelopmental or motor outcome.

Prognostic factors of infantile spasms: role of treatment options including a ketogenic diet

OBJECTIVES

The aim of this study was to provide additional evidences on prognostic factors for infantile spasms and the possible role of a ketogenic diet.

METHODS

A retrospective analysis was performed for patients with infantile spasms who had been followed up for more than 6months between January 2000 and July 2012 at Samsung Medical Center (Seoul, Republic of Korea). We analyzed the association between possible prognostic factors and seizure/developmental outcomes.

RESULTS

Sixty-nine patients were included in this study and their mean follow-up duration was 52.5 (9-147) months. In the patients who had been followed up for more than 2years, 53.6% (n=30/57) remained seizure-free at the last visit. Sixty patients (86.9%) showed developmental delay at last follow-up. Forty-two patients (60.9%) became spasm-free with one or two antiepileptic drugs, one patient with epilepsy surgery for a tumor, and seven patients with a ketogenic diet after the failure of two or more antiepileptic drugs. The etiology and age of seizure onset were the significant prognostic factors.

CONCLUSIONS

In this study, about 60% of the patients became spasm-free with vigabatrin and topiramate. Ketogenic diet increased the rate by 10% in the remaining antiepileptic drug resistant patients. However, 86.9% of the patients showed developmental delay, mostly a severe degree. Early diagnosis and prompt application of treatment options such as antiepileptic drugs, a ketogenic diet or epilepsy surgery can improve outcomes in patients with infantile spasms.

Informative value of magnetic resonance imaging and EEG in the prognosis of infantile spasms

PURPOSE

To investigate the informative value of EEG and cranial magnetic resonance imaging (cMRI) in the prognosis of infantile spasms (ISs); 86 patients with ISs were included in this study.

METHODS

All cases had epileptic spasms, psychomotor retardation, and hypsarrhythmia in at least one of their EEGs. cMRIs and laboratory tests necessary for etiologic diagnosis were completed in all cases. Patients were followed up periodically both clinically and by video-EEGs for >1 year. Clinical information was categorized on the basis of four spheres as epilepsy, psychosocial development, motor development, and overall clinical condition, with each category being evaluated under three levels of involvement as good, moderate, and severe, depending on selected parameters. A similar scale was applied for the EEG results and for the cMRI findings. Clinical parameters were correlated to EEG and cMRI results, by Spearman test. Other statistical tests used were Kruskal-Wallis chi(2) and Mann-Whitney U analysis as multiple comparison by post hoc Bonferroni correction.

RESULTS

A severe overall clinical course was observed in 64% of patients, whereas this incidence was 58% and 44% in the EEG follow-up and cMRI parameters, respectively. In regard to prognosis, a significant correlation was determined between the clinical and the EEG course. This relation was the most prominent in psychosocial developmental parameters and least prominent in the motor development. cMRI findings, however, were correlated only with motor development.

CONCLUSIONS

cMRI and repeated EEG recordings, especially when assessed together, may provide complementary information regarding the prognosis in ISs.