The spectrum of epilepsy with eyelid myoclonia: delineation of disease subtypes from a large multicenter study

Expanding the Mutational Landscape and Clinical Phenotype of CHD2-Related Encephalopathy

Objectives

To present a case series of novel CHD2 variants in patients presenting with genetic epileptic and developmental encephalopathy.

Background

CHD2 gene encodes an ATP-dependent enzyme, chromodomain helicase DNA-binding protein 2, involved in chromatin remodeling. Pathogenic variants in CHD2 are linked to early-onset conditions such as developmental and epileptic encephalopathy, drug-resistant epilepsies, and neurodevelopmental disorders. Approximately 225 diagnosed patients from 28 countries exhibit various allelic variants in CHD2, including small intragenic deletions/insertions and missense, nonsense, and splice site variants.

Results

We present the molecular and clinical characteristics of 17 unreported individuals from 17 families with novel pathogenic or likely pathogenic variants in CHD2. All individuals presented with severe global developmental delay, childhood-onset myoclonic epilepsy, and additional neuropsychiatric features, such as behavioral including autism, ADHD, and hyperactivity. Additional findings include abnormal reflexes, hypotonia and hypertonia, motor impairment, gastrointestinal problems, and kyphoscoliosis. Neuroimaging features included hippocampal signal alterations (4/10), with additional volume loss in 2 cases, inferior vermis hypoplasia (7/10), mild cerebellar atrophy (4/10), and cerebral atrophy (1/10).

Discussion

Our study broadens the geographic scope of CHD2-related phenotypes, providing valuable insights into the prevalence and clinical characteristics of this genetic disorder in previously underrepresented populations.

Drug-resistant generalized epilepsies: Revisiting the frontiers of idiopathic generalized epilepsies

The 2017 International League Against Epilepsy (ILAE) classification suggested that the term "genetic generalized epilepsies" (GGEs) should be used for the broad group of epilepsies with so-called "generalized" seizure types and "generalized" spike-wave activity on EEG, based on a presumed genetic etiology. Within this framework, idiopathic generalized epilepsies (IGEs) are described as a subset of GGEs and include only four epileptic syndromes: childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone. The recent 2022 ILAE definition of IGEs is based on the current state of knowledge and reflects a community consensus and is designed to evolve as knowledge advances. The term "frontiers of IGEs" refers to the actual limits of our understanding of these four syndromes. Indeed, among patients presenting with a syndrome compatible with the 2022 definition of IGEs, we still observe a significant proportion of patients presenting with specific clinical features, refractory seizures, or drug-resistant epilepsies. This leads to the discussion of the boundaries of IGEs and GGEs, or what is accepted within a clinical spectrum of a definite IGE. Here, we discuss several entities that have been described in the literature for many years and that may either constitute rare features of IGEs or a distinct differential diagnosis. Their recognition by clinicians may allow a more individualized approach and improve the management of patients presenting with such entities.

Neuropsychiatric comorbidities and cognition in epilepsy with eyelid myoclonia: A retrospective pediatric case series

OBJECTIVE

Epilepsy with eyelid myoclonia (EEM) is a rare epileptic syndrome classified within the Genetic Generalized Epilepsies of childhood. It is characterized by a high drug resistance, and little is known about prognostic factors and neurodevelopmental comorbidities. The aim of this study was to describe the clinical features, cognitive profile, and prognostic factors in a series of children with EEM.

METHODS

This is a retrospective observational study of patients diagnosed with EEM from 2012 to 2022 in a tertiary pediatric hospital.

RESULTS

Seventeen patients were analyzed (mean age at symptom onset 5.8 years). Neuropsychiatric comorbidities were present in 76.4% (attention deficit hyperactivity disorder 58.8%, behavioral disorder 11.8%, autism spectrum disorder 11.8%, and psychotic outbreaks 11.8%). Neurocognitive assessment was performed in 75%, revealing cognitive impairment in 66.6% (62.5% with borderline intellectual function and 37.5% with -IQ <70-), with predominant difficulties in executive functions, comprehensive language, and motor skills. Cognitive deterioration was observed in one patient in parallel onset with psychotic symptoms. High refractoriness to antiseizure medication (ASM) was observed, with only 23.5% of the patients being seizure-free after a mean follow-up of 7 years. The most effective ASM was valproic acid, and two of them received ketogenic diet with good response. Regarding prognostic factors, psychotic symptoms were associated with a greater number of antiseizure medication (p < .05) implying a more drug-resistant epilepsy.

SIGNIFICANCE

In our study, we found a high rate of cognitive and psychiatric comorbidities and high refractoriness. These data support the concept of EEM as an intermediate entity between idiopathic generalized epilepsy and epileptic and/or neurodevelopmental encephalopathy. Making a proper diagnosis and management of these comorbidities is necessary to improve prognosis and quality of life in EEM.

Management of epilepsy with eyelid myoclonia: Results of an international expert consensus panel

OBJECTIVE

There are limited data about the treatment and management of epilepsy with eyelid myoclonia (EEM). The objective of this study was to determine areas of consensus among an international panel of experts for the management of EEM (formerly known as Jeavons syndrome).

METHODS

An international steering committee was convened of physicians and patients/caregivers with expertise in EEM. This committee summarized the current literature and identified an international panel of experts (comprising 25 physicians and five patients/caregivers). This panel participated in a modified Delphi process, including three rounds of surveys to determine areas of consensus for the treatment, other areas of management, and prognosis for EEM.

RESULTS

There was a strong consensus for valproic acid as the first-line treatment, with levetiracetam or lamotrigine as preferable alternatives for women of childbearing age. There was a moderate consensus that ethosuximide and clobazam are also efficacious. There was a strong consensus to avoid sodium channel-blocking medications, except for lamotrigine, as they may worsen seizure control. There was consensus that seizures typically persist into adulthood, with remission occurring in <50% of patients. There was less agreement about other areas of management, including dietary therapy, lens therapy, candidacy for driving, and outcome.

SIGNIFICANCE

This international expert panel identified multiple areas of consensus regarding the optimal management of EEM. These areas of consensus may inform clinical practice to improve the management of EEM. In addition, multiple areas with less agreement were identified, which highlight topics for further research.