Sleep-Related Epilepsy

Functional seizures and their mimics: a retrospective service review of cases from a tertiary video telemetry database

ABSTRACT

Objective

Identify the proportion of patients referred with putative functional seizures (FS) that were subsequently re-diagnosed as epileptic seizures (ES), or an alternative diagnosis, following video telemetry EEG (VTEEG). In addition, describe the characteristics of those seizures.

Methods

The VTEEG reports from patients admitted to the Chalfont Centre for Epilepsy between 2019 and 2022 were reviewed. Pre-VTEEG and post-VTEEG diagnoses were compared to identify whether a diagnostic revision was made from suspected FS to ES or another diagnosis. Diagnostic revision cases were then grouped into cohorts with associated features and reviewed to characterise and describe FS mimics.

Results

444 VTEEG reports where patients had habitual events were identified. 4.7% of patients were referred with FS and were subsequently diagnosed with ES or another diagnosis. In this group, several cohorts could be identified including frontal lobe epileptic seizures, ES with functional overlay, insular or temporal lobe epileptic seizures associated with autonomic or marked experiential peri-ictal symptoms, and individuals who had both ES and FS but whose ES were revealed on medication withdrawal.

Conclusion

In patients referred to a tertiary epilepsy unit, a small minority of cases had seizures diagnosed as functional and reclassified as epileptic or an alternative diagnosis. It is clinically important to be aware of these FS mimics.

The Clinical Spectrum of the Parasomnias

Parasomnias are defined as abnormal movements or behaviors that occur in sleep or during arousals from sleep. Parasomnias vary in frequency from episodic events that arise from incomplete sleep state transition. The framework by which parasomnias are categorized and diagnosed is based on the International Classification of Sleep Disorders-Third Edition, Text Revision (ICSD-3-TR), published by the American Academy of Sleep Medicine. The recent Third Edition, Text Revision (ICSD-3-TR) of the ICSD provides an expert consensus of the diagnostic requirements for sleep disorders, including parasomnias, based on an extensive review of the current literature.

Continuous Spike-Waves during Slow Sleep Today: An Update

In the context of childhood epilepsy, the concept of continuous spike-waves during slow sleep (CSWS) includes several childhood-onset heterogeneous conditions that share electroencephalograms (EEGs) characterized by a high frequency of paroxysmal abnormalities during sleep, which have negative effects on the cognitive development and behavior of the child. These negative effects may have the characteristics of a clear regression or of a slowdown in development. Seizures are very often present, but not constantly. The above makes it clear why CSWS have been included in epileptic encephalopathies, in which, by definition, frequent EEG paroxysmal abnormalities have an unfavorable impact on cognitive functions, including socio-communicative skills, causing autistic features, even regardless of the presence of clinically overt seizures. Although several decades have passed since the original descriptions of the electroclinical condition of CSWS, there are still many areas that are little-known and deserve to be further studied, including the EEG diagnostic criteria, the most effective electrophysiological parameter for monitoring the role of the thalamus in CSWS pathogenesis, its long-term evolution, the nosographic location of Landau-Kleffner syndrome, standardized neuropsychological and behavioral assessments, and pharmacological and non-pharmacological therapies.

Clinical, Sociodemographic, and Psychological Factors Associated with Transition Readiness in Patients with Epilepsy

BACKGROUND

The transition to adult care for patients with epilepsy is a complicated clinical issue associated with adverse outcomes, including non-adherence to treatment, dropout of medical care, and worse prognosis. Moreover, youngsters with epilepsy are notably prone to emotional, psychological, and social difficulties during the transition to adulthood. Transition needs depend on the type of epilepsy and the epileptic syndrome, as well as on the presence of co-morbidities. Having a structured transition program in place is essential to reduce poor health consequences. A key strategy to optimize outcomes involves the use of transition readiness and associated factors assessment to implement the recognition of vulnerability and protective aspects, knowledge, and skills of these patients and their parents. Therefore, this study aims to provide a comprehensive framework of clinical and psychosocial aspects associated with the transition from pediatric to adult medical care of patients with epilepsy.

METHODS

Measures examining different aspects of transition readiness and associated clinical, socio-demographic, psychological, and emotional factors were administered to 13 patients with epilepsy (Mage = 22.92, SD = 6.56) with (n = 6) or without (n = 7) rare diseases, and a respective parent (Mage = 56.63, SD = 7.36).

RESULTS

patients showed fewer problems in tracking health issues, appointment keeping, and pharmacological adherence as well as low mood symptoms and moderate resiliency. Moreover, they referred to a low quality of sleep. Notably, parents of patients with rare diseases reported a lower quality of sleep as compared to the other group of parents.

CONCLUSIONS

Increasing awareness around transition readiness is essential to promote self-management skills of patients with epilepsy and their parents. Anticipating the period of transition could be beneficial, especially to prevent problematic sleep patterns and promote independence in health care management. Parents of patients with epilepsy and rare diseases should be monitored for their mental status which can affect patients' well-being.

The Association of Nocturnal Seizures and Interictal Cardiac/Central Autonomic Function in Frontal Lobe Epilepsy: Heart Rate Variability and Central Autonomic Network Analysis

Purpose

Patients with epilepsy frequently experience autonomic dysfunction, closely related to sudden unexplained death in epilepsy (SUDEP). SUDEP occurs most often at night or during sleep, and frequent nocturnal seizures are an established risk factor. This study investigated the influence of nocturnal seizures on autonomic dysfunction in epilepsy.

Patients and Methods

This retrospective study enrolled frontal lobe epilepsy (FLE) patients who performed 24-hour EEG monitoring. All participants were divided into nocturnal FLE (NFLE, > 90% of seizures occurring during sleep) or diurnal FLE (DFLE) groups. EEG and ECG signals were simultaneously obtained during waking and sleep stages. EEG current density source and connectivity analysis of the autonomic network were performed. ECG was analyzed across time and frequency domains heart rate variability (HRV) analysis method was used. The obtained parameters were compared between the NFLE and DFLE groups.

Results

Fifteen NFLE and 16 DFLE patients were enrolled with no significant difference in age, sex, disease duration, seizure frequency, or the number of anti-seizure medications between the two groups. During sleep, a decrease in HRV parameters and an increase of the beta-1 (13-22 Hz) current source density power in the bilateral paracentral lobule (BA4,5,6), precuneus (BA7), and cingulate (BA31) were observed in the NFLE group compared to DFLE group. The NFLE group also showed hyperconnectivity in the central autonomic (12 edges distributed over 10 nodes), sympathetic (2 edges distributed over 3 nodes), and parasympathetic (4 edges distributed over 6 nodes) beta-1 frequency band networks during sleep. During wakefulness, central and cardiac autonomic variables were not significantly different between the NFLE and DFLE groups.

Conclusion

Interictal cardiac and central autonomic dysfunction occurred simultaneously and can be attributed to the brain-heart autonomic axis. Our findings suggest that nocturnal seizures may contribute to interictal autonomic dysfunction during sleep in people with epilepsy.

Effectiveness and safety of perampanel as adjunctive therapy among Chinese patients with focal-onset epilepsy: A real-world prospective observational study

OBJECTIVE

Perampanel (PER) has previously been shown to be effective and tolerable when used as an adjunctive therapy for patients with focal-onset seizures (FOS). This study aimed to evaluate the effect of PER as adjunctive therapy for patients with FOS in the Chinese population under real-world conditions for 1 year.

METHODS

A prospective, single-center, 1-year observational study was conducted at Huashan Hospital, enrolling both under age (≥4 years old) and adult patients with FOS. Response to PER was assessed at 3-, 6-, and 12-month checkpoints by analyzing the 50 % responder rate, the seizure-free rate, and reduction in seizure frequency.

RESULTS

One hundred and eight patients (mean age: 26.6 years, 56.5 % males) with FOS were included, with seventy-six patients finishing the 1-year follow-up (retention rate: 70.4 %, mean PER dose: 4.3 mg/day). The seizure frequency was reduced significantly at 3, 6, and 12 months relative to baseline (p < 0.001 for each seizure type). At 12 months, the responder rate was 65.8 %, and the seizure-free rate was 39.5 %. A significantly higher responder rate was found in patients with focal to bilateral tonic-clonic seizures (p = 0.024), among which the percentage of patients with sleep-related epilepsy was significantly high (p = 0.045). Responders had a lower number of concomitant anti-seizure medications (ASMs) than the non-responders (p = 0.009). Drug-related adverse events (AEs) were reported in 37 % of patients, mostly mild or moderate, and the patients who experienced AEs had a higher daily dose of PER than those who did not (p = 0.026).

CONCLUSION

Perampanel, an add-on therapy for focal-onset seizures, was found to be effective and tolerable in Chinese patients at 12 months.

Pretreatment electroencephalographic features in patients with childhood absence epilepsy

OBJECTIVE

To analyze the ictal and interictal electroencephalographic (EEG) features in newly diagnosed childhood absence epilepsy (CAE) and determine the association between seizure onset topography, interictal focal spike-wave discharges (FSWDs) and accompanying clinical features of absence seizures.

METHODS

The authors searched the EEG database for a definite diagnosis of CAE according to ILAE 2017 criteria. Video-EEGs of untreated pediatric patients during sleep and wakefulness were evaluated retrospectively.

RESULTS

The study included 47 patients (25 males, 22 females). Interictal FSWDs were observed in 49% of patients with CAE during wakefulness and in 85.1% during sleep (p = 0.001). Interictal FSWDs were most frequently observed in the frontal regions (awake: 34%; asleep: 74.5%), followed by the posterior temporoparietooccipital region (awake: 21.2%; asleep: 36.1%), and the centrotemporal region (awake: 6.4%; asleep: 8.5%). Eleven patients (23.4%) had polyspikes during sleep. Both bilateral symmetric and asymmetric seizure onset were noted in 32%, whereas focal seizure onset was observed in 14.9% of the patients. Absence seizures with and without motor components were seen in 72.3% and 61.7% of patients, respectively, and in 33% of patients both occurred. There were no associations between the existence of interictal FSWDs, focal/asymmetric seizure onset, and absence seizures with and/or without motor components.

CONCLUSION

Asymmetric and/or focal seizure onset, interictal FSWDs, and absence seizures with motor components are commonly observed in drug-naive CAE. This study found no association between seizure onset topography, interictal FSWDs, and semiological features of absence seizures.

The role of monoaminergic neurons in modulating respiration during sleep and the connection with SUDEP

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among epilepsy patients, occurring even more frequently in cases with anti-epileptic drug resistance. Despite some advancements in characterizing SUDEP, the underlying mechanism remains incompletely understood. This review summarizes the latest advances in our understanding of the pathogenic mechanisms of SUDEP, in order to identify possible targets for the development of new strategies to prevent SUDEP. Based on our previous research along with the current literature, we focus on the role of sleep-disordered breathing (SDB) and its related neural mechanisms to consider the possible roles of monoaminergic neurons in the modulation of respiration during sleep and the occurrence of SUDEP. Overall, this review suggests that targeting the monoaminergic neurons is a promising approach to preventing SUDEP. The proposed roles of SDB and related monoaminergic neural mechanisms in SUDEP provide new insights for explaining the pathogenesis of SUDEP.

Sleep Disruption Worsens Seizures: Neuroinflammation as a Potential Mechanistic Link

Sleep disturbances, such as insomnia, obstructive sleep apnea, and daytime sleepiness, are common in people diagnosed with epilepsy. These disturbances can be attributed to nocturnal seizures, psychosocial factors, and/or the use of anti-epileptic drugs with sleep-modifying side effects. Epilepsy patients with poor sleep quality have intensified seizure frequency and disease progression compared to their well-rested counterparts. A better understanding of the complex relationship between sleep and epilepsy is needed, since approximately 20% of seizures and more than 90% of sudden unexpected deaths in epilepsy occur during sleep. Emerging studies suggest that neuroinflammation, (e.g., the CNS immune response characterized by the change in expression of inflammatory mediators and glial activation) may be a potential link between sleep deprivation and seizures. Here, we review the mechanisms by which sleep deprivation induces neuroinflammation and propose that neuroinflammation synergizes with seizure activity to worsen neurodegeneration in the epileptic brain. Additionally, we highlight the relevance of sleep interventions, often overlooked by physicians, to manage seizures, prevent epilepsy-related mortality, and improve quality of life.

Sleep and Epilepsy, Clinical Spectrum and Updated Review

Electroencephalogram (EEG) recording is essential in the evaluation of complex movement and behaviors during sleep, but in particular for differentiating epileptic versus nonepileptic events. In general, epileptiform discharges occur with greater density in the first few nonerapid eye movement cycles, and approximately 12% to 20% of seizures occur exclusively at night. This review examines the epilepsy types and syndromes whose presentation is strongly influenced by the sleep state, with an appraisal about the role that sleep plays in facilitating seizures, while deleaneatign EEG findings and clinical manifestation. The review will summarize the typical semiology of sleep-related hypermotor seizures and contrasted with those occurring during none/rapid eye movement parasomnias and sleep-related movement disorders.

Ambulatory EEG to Classify the Epilepsy Syndrome

SUMMARY

Recording of interictal epileptiform discharges to classify the epilepsy syndrome is one of the most common indications for ambulatory EEG. Ambulatory EEG has superior sampling compared with standard EEG recordings and advantages in terms of cost-effectiveness and convenience compared with a prolonged inpatient EEG study. Ambulatory EEG allows for EEG recording in all sleep stages and transitional states, which can be very helpful in capturing interictal epileptiform discharges. In the absence of interictal epileptiform discharges or in patients with atypical events, the characterization of an epilepsy syndrome may require recording of the habitual events. Diagnostic ambulatory EEG can be a useful alternative to inpatient video-EEG monitoring in a selected number of patients with frequent events who do not require medication taper or seizure testing for surgical localization.

Electrophysiological and neurochemical evaluation of the adverse effects of REM sleep deprivation and epileptic seizures on rat's brain

AIM

The current study aims to investigate the impact of paradoxical (REM) sleep deprivation and/or epileptic seizures on rat's cortical brain tissues.

MAIN METHODS

Animals were divided into four groups; control, epileptic, REM sleep deprived and epileptic subjected to REM sleep deprivation. Electrocorticogram (ECoG) signals were recorded and quantitatively analyzed for each group. Concentrations of amino acid neurotransmitters; proinflammatory cytokines; and oxidative stress parameters; and acetylcholinesterase activity were determined in the cortex of the animals in different groups.

KEY FINDINGS

Results showed significant variations in the spectral distribution of ECoG waves in the epilepsy model, 24- and 48-hours of REM sleep deprivation and their combined effects indicating a state of cortical hyperexcitability. Significant increases in NO and taurine and significant decrement in glutamine, GABA and glycine were determined. In REM sleep deprived rats significant elevation in glutamate, aspartate, glycine and taurine and a significant lowering in GABA were obtained. This was accompanied by significant reduction in AchE and IL-β. In the cortical tissue of epileptic rats deprived from REM sleep significant increases in lipid peroxidation, TNF-α, IL-1β, IL-6 and aspartate and a significant reduction in AchE were observed.

SIGNIFICANCE

The present data indicate that REM sleep deprivation induces an increase in lipid peroxidation and storming in proinflammatory cytokines in the cortex of rat model of epilepsy during SRS. These changes are associated with a decreased seizure threshold as inferred from the increase in alpha and Beta waves and a decrease in Delta waves of ECoG.

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.

Daylight saving time transitions are not associated with increased seizure incidence

OBJECTIVE

Given the known association of daylight saving time (DST) transitions with increased risk of accidents, heart attack, and stroke, we aimed to determine whether seizures, which are reportedly influenced by sleep and circadian disruption, also increased in frequency following the transition into DST.

METHODS

Using Seizure Tracker's self-reported data from 12 401 individuals from 2008-2016, 932 717 seizures were assessed for changes in incidence in relation to DST transitions. Two methods of standardization-z scores and unit-scaled rate ratios (RRs)-were used to compare seizure propensities following DST transitions to other time periods.

RESULTS

As a percentile relative to all other weeks in a given year, absolute seizure counts in the week of DST fell below the median (DST seizure percentiles mean ± SD: 19.68 ± 16.25, P = 0.01), which was concordant with weekday-specific comparisons. Comparatively, RRs for whole-week (1.06, 95% confidence interval [CI] 1.02-1.10, P = 0.0054) and weekday-to-weekday (RR range 1.04-1.16, all P < 0.001) comparisons suggested a slightly higher incidence of seizures in the DST week compared to all other weeks of the year. However, examining the similar risk of the week preceding and following the DST-transition week revealed no significant weekday-to-weekday differences in seizure incidence, although there was an unexpected, modestly decreased seizure propensity in the DST week relative to the whole week prior (RR 0.94, 95% CI 0.91-0.96, P < 0.001).

SIGNIFICANCE

Despite expectations that circadian and sleep disruption related to DST transitions would increase the incidence of seizures, we found little substantive evidence for such an association in this large, longitudinal cohort. Although large-scale observational/epidemiologic cohorts can be effective at answering such questions, additional covariates (eg, sleep duration, seizure type, and so on) that may underpin the association were not able available, so the association has not definitively been ruled out.

Impact of sleep disorders on the risk of seizure recurrence in juvenile myoclonic epilepsy

OBJECTIVE

The aim of this study was to investigate the presence of sleep disturbances in patients with juvenile myoclonic epilepsy (JME) using sleep questionnaires. Further, we tried to evaluate whether alterations in sleep quality may influence the clinical expression of JME.

METHODS

Sixty-two patients with JME treated with levetiracetam were included. Demographic and clinical variables were collected. Moreover, all patients submitted the Pittsburgh Sleep Quality index (PSQI) and the Epworth Sleepiness Scale (ESS) in order to respectively assess sleep quality during the last month and daytime sleepiness. All patients were followed up for a 6-month period and divided in two groups: seizure-free (Group 1) and seizure recurrence (Group 2). The PSQI and ESS scores were synthesized as binary variables <5/≥5 and <10/≥10, respectively. A comprehensive analysis was performed to evaluate the independent effect of the sleep quality and daytime sleepiness on the risk of having seizures during the follow-up.

RESULTS

Both reduced sleep quality during the last month and daytime sleepiness were associated with an increased risk of suffering from seizures during the follow-up period. In fact, a PSQI score<5 or an ESS score<10 resulted significantly associated with the absence of seizure recurrence (p<0.004 and p<0.001, respectively). Increasing age had a significantly protective effect in the risk of seizure relapse.

CONCLUSIONS

Our findings show that reduced sleep quality and daytime sleepiness in patients with JME increase the risk of seizure occurrence in spite of an appropriate pharmacological treatment. This negative effect seems to be more relevant in younger patients. Sleep disorders and their specific correction should be taken into consideration for the management of patients with JME.

Loss of CLOCK Results in Dysfunction of Brain Circuits Underlying Focal Epilepsy

Because molecular mechanisms underlying refractory focal epilepsy are poorly defined, we performed transcriptome analysis on human epileptogenic tissue. Compared with controls, expression of Circadian Locomotor Output Cycles Kaput (CLOCK) is decreased in epileptogenic tissue. To define the function of CLOCK, we generated and tested the Emx-Cre; Clockflox/flox and PV-Cre; Clockflox/flox mouse lines with targeted deletions of the Clock gene in excitatory and parvalbumin (PV)-expressing inhibitory neurons, respectively. The Emx-Cre; Clockflox/flox mouse line alone has decreased seizure thresholds, but no laminar or dendritic defects in the cortex. However, excitatory neurons from the Emx-Cre; Clockflox/flox mouse have spontaneous epileptiform discharges. Both neurons from Emx-Cre; Clockflox/flox mouse and human epileptogenic tissue exhibit decreased spontaneous inhibitory postsynaptic currents. Finally, video-EEG of Emx-Cre; Clockflox/flox mice reveals epileptiform discharges during sleep and also seizures arising from sleep. Altogether, these data show that disruption of CLOCK alters cortical circuits and may lead to generation of focal epilepsy.

The Cyclic Vomiting Syndrome Threshold: A Framework for Understanding Pathogenesis and Predicting Successful Treatments

Cyclic vomiting syndrome (CVS) is an uncommon, idiopathic disorder defined by recurrent, sudden-onset attacks of repetitive retching and vomiting that are separated by symptom-free intervals. CVS was long regarded as a disorder primarily experienced by children but is now known to present de novo in adulthood. Adult CVS has garnered more research attention over the past 20 years, and these efforts have identified some acute and prophylactic treatments for this disorder. However, CVS still lacks a unifying disease model, and this has hindered the development of new therapies. Here adult CVS is reframed as a neurogenic disorder, driven by various endophenotypic factors that shape patterns of activity within the neural circuits required for disease expression. The concept of the "CVS threshold" is put forth in parallel with exploring the remarkable similarity of adult CVS with features of chronic migraine, epilepsy, and panic disorder. Because of such shared neural mechanisms and overlapping endophenotypes, many therapies that have been developed for these other disorders could also be useful in managing CVS. This review seeks to achieve three primary aims: (1) to develop a comprehensive, explanatory framework for adult CVS pathogenesis, (2) to use this framework for identifying potentially novel therapies for CVS, and (3) to describe future research directions that are needed to move the field forward.