Abnormal gait and motor cortical processing in drug-resistant juvenile myoclonic epilepsy

BACKGROUND

Juvenile myoclonic epilepsy (JME) is characterized by generalized seizures. Nearly 30% of JME patients are drug-resistant (DR-JME), indicating a widespread cortical dysfunction. Walking is an important function that necessitates orchestrated coordination of frontocentral cortical regions. However, gait alterations in JME have been scarcely investigated. Our aim was to assess changes in gait and motor-evoked responses in DR-JME patients.

METHODS

Twenty-nine subjects (11 JME drug-responder, 8 DR-JME, and 10 healthy controls) underwent a gait analyses during usual walking and dual-task walking. Later, subjects underwent 64-channel EEG recordings while performing a simple motor task. We calculated the motor-evoked current source densities (CSD) at a priori chosen cortical regions. Gait and CSD measures were compared between groups and tasks using mixed model analysis.

RESULTS

DR-JME patients demonstrated an altered gait pattern that included slower gait speed (p = .018), reduced cadence (p = .003), and smaller arm-swing amplitude (p = .011). The DR-JME group showed higher motor-evoked CSD in the postcentral gyri compared to responders (p = .049) and both JME groups showed higher CSD in the superior frontal gyri compared to healthy controls (p < .011). Moreover, higher CSD in the superior frontal gyri correlated with worse performance in dual-task walking (r > |-0.494|, p < .008).

CONCLUSIONS

These alterations in gait and motor-evoked responses in DRE-JME patients reflect a more severe dysfunction of motor-cognitive neural processing in frontocentral regions, leading to poorer gait performance. Further studies are needed to investigate the predictive value of altered gait and cortical motor processing as biomarkers for poor response to treatment in JME and other epilepsy syndromes.

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

OBJECTIVE

Epilepsy with eyelid myoclonia (EEM) has been associated with marked clinical heterogeneity. Early epilepsy onset has been recently linked to lower chances of achieving sustained remission and to a less favorable neuropsychiatric outcome. However, much work is still needed to better delineate this epilepsy syndrome.

METHODS

In this multicenter retrospective cohort study, we included 267 EEM patients from 9 countries. Data about electroclinical and demographic features, intellectual functioning, migraine with or without aura, family history of epilepsy and epilepsy syndromes in relatives were collected in each patient. The impact of age at epilepsy onset (AEO) on EEM clinical features was investigated, along with the distinctive clinical characteristics of patients showing sporadic myoclonia over body regions other than eyelids (body-MYO).

RESULTS

Kernel density estimation revealed a trimodal distribution of AEO and Fisher-Jenks optimization disclosed three EEM subgroups: early-onset (EO-EEM), intermediate-onset (IO-EEM) and late-onset subgroup (LO-EEM). EO-EEM was associated with the highest rate of intellectual disability, antiseizure medication refractoriness and psychiatric comorbidities and with the lowest rate of family history of epilepsy. LO-EEM was associated with the highest proportion of body-MYO and generalized tonic-clonic seizures (GTCS), whereas IO-EEM had the lowest observed rate of additional findings. A family history of EEM was significantly more frequent in IO-EEM and LO-EEM compared with EO-EEM. In the subset of patients with body-MYO (58/267), we observed a significantly higher rate of migraine and GTCS but no relevant differences in other electroclinical features and seizure outcome.

SIGNIFICANCE

Based on AEO, we identified consistent EEM subtypes characterized by distinct electroclinical and familial features. Our observations shed new light on the spectrum of clinical features of this generalized epilepsy syndrome and may help clinicians towards a more accurate classification and prognostic profiling of EEM patients.

Omitting Hyperventilation in Electroencephalogram during the COVID-19 Pandemic May Reduce Interictal Epileptiform Discharges in Patients with Juvenile Myoclonic Epilepsy

BACKGROUND

To prevent the spread of coronavirus disease 2019 (COVID-19), hyperventilation (HV) activation has been avoided in electroencephalograms (EEGs) since April 2020. The influence of omitting HV in EEG on epilepsy diagnosis remains uncertain for patients with epilepsies other than child absence epilepsy. We hypothesized that EEGs with HV would show more interictal epileptiform discharges (IEDs) than EEGs without HV in patients with juvenile myoclonic epilepsy (JME).

METHODS

We reviewed the EEGs of seizure-free patients with JME who underwent EEG, both with and without HV, from January 2019 to October 2021, in our institution, and compared IEDs between EEG with and without HV.

RESULTS

This study analyzed 23 JME patients. The IED-positive rate was significantly higher in EEG with HV (65.2%) than in EEG without HV (34.8%, p = 0.016). The mean ± standard deviation number of IEDs per minute was significantly larger during HV (1.61 ± 2.25 × 10^-1) than during non-activation of both first EEG (0.57 ± 0.93 × 10^-1, p = 0.039) and second EEG (0.39 ± 0.76 × 10^-1, p = 0.009).

CONCLUSIONS

In JME patients, performing HV during EEG may increase IEDs and appears to facilitate the accurate diagnosis of epilepsy.

Emotional Word Processing in Patients With Juvenile Myoclonic Epilepsy

Objective

According to Panksepp's hierarchical emotion model, emotion processing relies on three functionally and neuroanatomically distinct levels. These levels comprise subcortical networks (primary level), the limbic system (secondary level), and the neocortex (tertiary level) and are suggested to serve differential emotional processing. We aimed to validate and extend previous evidence of discrete and dimensional emotion processing in patient with juvenile myoclonic epilepsy (JME).

Methods

We recorded brain activity of patients with JME and healthy controls in response to lexical decisions to words reflecting the discrete emotion fear and the affective dimension negativity previously suggested to rely on different brain regions and to reflect different levels of processing. In all study participants, we tested verbal cognitive functions, as well as the relationship of psychiatric conditions, seizure types and duration of epilepsy and emotional word processing.

Results

In support of the hierarchical emotion model, we found an interaction of discrete emotion and affective dimensional processing in the right amygdala likely to reflect secondary level processing. Brain activity related to affective dimensional processing was found in the right inferior frontal gyrus and is suggested to reflect tertiary level processing. Psychiatric conditions, type of seizure nor mono- vs. polytherapy and duration of epilepsy within patients did not have any effect on the processing of emotional words. In addition, no differences in brain activity or response times between patients and controls were observed, despite neuropsychological testing revealed slightly decreased verbal intelligence, verbal fluency and reading speed in patients with JME.

Significance

These results were interpreted to be in line with the hierarchical emotion model and to highlight the amygdala's role in processing biologically relevant stimuli, as well as to suggest a semantic foundation of affective dimensional processing in prefrontal cortex. A lack of differences in brain activity of patients with JME and healthy controls in response to the emotional content of words could point to unaffected implicit emotion processing in patients with JME.

Safety and Efficacy of Clonazepam in the Treatment of Juvenile Myoclonic Epilepsy: A Meta-Analysis

Background

Juvenile myoclonic epilepsy (JME) is referred to as one of the most common epileptic syndromes. Several anti-epilepsy drugs (AEDs) have been developed and remain part of clinical intervention with varying safety and efficacy profiles. Comprehensive synthesis of the scientific evidence examining the safety and efficacy of clonazepam toward the treatment of JME was carried out in the study.

Methods

A detailed scientific literature search was made utilizing the most relevant scientific studies published to date on the intervention of clonazepam in the management of JME. In this study, a detailed search was made in multiple databases, including PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Scielo databases. Confidence intervals among the studies and continuous measures, proportion, and risk factor analysis were determined using the MedCalC tool (Version 20.110) as per PRISMA guidelines.

Results

A total of 6 studies out of 70 were found eligible for meta-analysis, where 186 JME patients were subjected to clonazepam intervention with controls. Clonazepam was reported effective in comparative analysis among six studies where P < 0.001. The result also shows a higher prevalence of JME in the female population compared to males (male versus female; 86/110). Efficacy and safety of clonazepam were reported significant as well.

Conclusion

Clonazepam is effective AEDs for the management of JME. However, more clinical evidence requires for statistical validation of clinical efficacy.