Epilepsy and sleep disturbance

The latency to awake from induced-obstructive sleep apnea is reduced in rats with chronic epilepsy

OSA is known to increase the risk for SUDEP in persons with epilepsy, but the relationship between these two factors is not clear. Also, there is no study showing the acute responses to obstructive apnea in a chronic epilepsy model. Therefore, this study aimed to characterize cardiorespiratory responses to obstructive apnea and chemoreceptor stimulation in rats. In addition, we analyzed respiratory centers in the brain stem by immunohistochemistry. Epilepsy was induced with pilocarpine. About 30-60 days after the first spontaneous seizure, tracheal and thoracic balloons, and electrodes for recording the electroencephalogram, electromyogram, and electrocardiogram were implanted. Intermittent apneas were made by inflation of the tracheal balloon during wakefulness, NREM sleep, and REM sleep. During apnea, respiratory effort increased, and heart rate fell, especially with apneas made during wakefulness, both in control rats and rats with epilepsy. Latency to awake from apnea was longer with apneas made during REM than NREM, but rats with epilepsy awoke more rapidly than controls with apneas made during REM sleep. Rats with epilepsy also had less REM sleep. Cardiorespiratory responses to stimulation of carotid chemoreceptors with cyanide were similar in rats with epilepsy and controls. Immunohistochemical analysis of Phox2b, tryptophan hydroxylase, and NK1 in brain stem nuclei involved in breathing and sleep (retrotrapezoid nucleus, pre-Bötzinger complex, Bötzinger complex, and caudal raphe nuclei) revealed no differences between control rats and rats with epilepsy. In conclusion, our study showed that rats with epilepsy had a decrease in the latency to awaken from apneas during REM sleep, which may be related to neuroplasticity in some other brain regions related to respiratory control, awakening mechanisms, and autonomic modulation.

Circadian changes in aperiodic activity are correlated with seizure reduction in patients with mesial temporal lobe epilepsy treated with responsive neurostimulation

OBJECTIVES

Responsive neurostimulation (RNS) is an established therapy for drug-resistant epilepsy that delivers direct electrical brain stimulation in response to detected epileptiform activity. However, despite an overall reduction in seizure frequency, clinical outcomes are variable, and few patients become seizure-free. The aim of this retrospective study was to evaluate aperiodic electrophysiological activity, associated with excitation/inhibition balance, as a novel electrographic biomarker of seizure reduction to aid early prognostication of the clinical response to RNS.

METHODS

We identified patients with intractable mesial temporal lobe epilepsy who were implanted with the RNS System between 2015 and 2021 at the University of Utah. We parameterized the neural power spectra from intracranial RNS System recordings during the first 3 months following implantation into aperiodic and periodic components. We then correlated circadian changes in aperiodic and periodic parameters of baseline neural recordings with seizure reduction at the most recent follow-up.

RESULTS

Seizure reduction was correlated significantly with a patient's average change in the day/night aperiodic exponent (r = .50, p = .016, n = 23 patients) and oscillatory alpha power (r = .45, p = .042, n = 23 patients) across patients for baseline neural recordings. The aperiodic exponent reached its maximum during nighttime hours (12 a.m. to 6 a.m.) for most responders (i.e., patients with at least a 50% reduction in seizures).

SIGNIFICANCE

These findings suggest that circadian modulation of baseline broadband activity is a biomarker of response to RNS early during therapy. This marker has the potential to identify patients who are likely to respond to mesial temporal RNS. Furthermore, we propose that less day/night modulation of the aperiodic exponent may be related to dysfunction in excitation/inhibition balance and its interconnected role in epilepsy, sleep, and memory.

Cerebral palsy and sleep: nonpharmacological treatment and impact on the life of caregivers - an integrative review

BACKGROUND

 Children with cerebral palsy have a higher prevalence of sleep disorders, with numerous factors associated with a negative impact on the quality of life of caregivers.

OBJECTIVE

 To identify factors related to sleep disorders, nonpharmacological treatment, and the impact on the lives of caregivers.

METHODS

 The present literature review was carried out in the Latin American and Caribbean Center on Health Sciences Information (BIREME), the Cochrane Library, Scopus, PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycInfo, WorldCat, Web of Science, Latin American Literature on Health Sciences (LILACS), and Excerpta Medica Database (EMBASE), with the descriptors sleep, child, cerebral palsy, parents, and nursing. Studies available in Portuguese, English, or Spanish, published between 2010 and 2020, were our inclusion criteria. A total of 29 articles were included in the present review.

RESULTS

 We considered nonpharmacological interventions effective support measures to drug-based treatments. The main sleep disorders in children with cerebral palsy are insomnia, parasomnias, nightmares, sleep bruxism, sleepwalking, sleep talking, disorders of initiation and maintenance of sleep, and sleep hyperhidrosis. Most studies point to a reduction in the quality of life of caregivers whose children have sleep disorders.

CONCLUSION

 Our review suggests the effectiveness of nonpharmacological treatments combined with the use of medications. Measures such as changes in sleep environment and routine are favorable strategies to improve sleep quality. In addition, children with sleep disorders negatively impact the quality of life of their caregivers.

Diurnal circadian clock gene expression is altered in models of genetic and acquired epilepsy

OBJECTIVES

Growing evidence demonstrates a relationship between epilepsy and the circadian system. However, relatively little is known about circadian function in disease states, such as epilepsy. This study aimed to characterize brain and peripheral core circadian clock gene expression in rat models of genetic and acquired epilepsy.

METHODS

For the Genetic Absence Epilepsy Rats from Strasbourg (GAERS) study, we used 40 GAERS and 40 non-epileptic control (NEC) rats. For the kainic acid status epilepticus (KASE) study, we used 40 KASE and 40 sham rats. Rats were housed in a 7 am:7 pm light-dark cycle. Hypothalamus, hippocampus, liver, and small intestine samples were collected every 3 h throughout the light period. We then assessed core diurnal clock gene expression of per1, cry1, clock, and bmal1.

RESULTS

In the GAERS rats, all tissues exhibited significant changes in clock gene expression (P < 0.05) when compared to NEC. In the KASE rats, there were fewer effects of the epileptic condition in the hypothalamus, hippocampus, or small intestine (P > 0.05) compared with shams.

SIGNIFICANCE

These results indicate marked diurnal disruption to core circadian clock gene expression in rats with both generalized and focal chronic epilepsy. This could contribute to epileptic symptomology and implicate the circadian system as a viable target for future treatments.

The prevalence and predictors of poor sleep quality and excessive daytime sleepiness in epilepsy: A single tertiary centre experience in Malaysia

BACKGROUND AND OBJECTIVE

People with epilepsy frequently encounter sleep disruptions that can stem from a variety of complex factors. Epilepsy-related sleep disturbance can lead to reduced quality of life and excessive daytime hypersomnolence. Identification of sleep disturbances may help in the overall management of epilepsy patients. This study was conducted to determine the prevalence and predictors of poor sleep quality and daytime sleepiness in epilepsy.

METHODS

A cross-sectional study on 284 epilepsy patients was performed in a local tertiary centre. The demographic and clinical epilepsy data were collected. The Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) questionnaires were utilised to determine the quality of life and daytime hypersomnolence of epilepsy patients, respectively.

RESULTS

Poor sleep quality was reported in 78 (27.5%) patients while daytime hypersomnolence was present in 17 (6%) patients. The predictors of poor sleep quality include structural causes (OR = 2.749; 95% CI: 1.436, 5.264, p = 0.002), generalised seizures (OR = 1.959, 95% CI: 1.04, 3.689, p = 0.037), and antiseizure medications such as Carbamazepine (OR = 2.34; 95% CI: 1.095, 5.001, p = 0.028) and Topiramate (OR 2.487; 95% CI: 1.028, 6.014, p = 0.043). Females are 3.797 times more likely score higher in ESS assessment (OR 3.797; 95% CI: 1.064, 13.555 p = 0.04).

DISCUSSION

Sleep disturbances frequently coexist with epilepsy. Patients should be actively evaluated using the PSQI and ESS questionnaires. It is imperative to identify the key factors that lead to reduced sleep quality and heightened daytime sleepiness in patients with epilepsy, as this is essential to properly manage their condition.

Prevalence of sleep disorders in children with Congenital Zika Syndrome

Studies have reported that children with Congenital Zika Syndrome (CZS) experience changes in their sleep patterns, which can result in mood disturbances, behavioral issues and delays in growth and development. This systematic review synthesized the available evidence on the prevalence of sleep disorders in children with CZS. Eligible studies were those with an observational design that reported sleep disorders in children with CZS using validated questionnaires, polysomnography/electroencephalographic recording or parent/caregiver reports. Searches were conducted in PubMed, Web of Science, SCOPUS and Embase, as well as a gray literature search using Google Scholar. The Freeman-Tukey double-arcsine transformation with a random-effects model was used to estimate the pooled prevalence of sleep disorders with a 95% confidence interval (CI). Five studies were included and data from 340 Brazilian children with CZS were analyzed. The overall prevalence of sleep disorders was 27.4% (95% CI 16.7-39.4), without differences among studies using validated questionnaires (29.4%, 95% CI 21.4-37.8) or report from parents and caregivers (27.4%, 95% CI 11.5-47.0). Sleep disorders are prevalent in children with CZS, impacting their development and quality of life. It is critical to examine the quality of sleep in these children to develop appropriate interventions that can mitigate these issues.

Characterizing Sleep Phenotypes in Children With Newly Diagnosed Epilepsy

BACKGROUND

Children with epilepsy frequently have sleep, behavior, and cognitive problems at the time of or before the epilepsy diagnosis. The primary goal of this study was to determine if specific sleep disturbance phenotypes exist in a large cohort of children with new-onset epilepsy and if these phenotypes are associated with specific cognitive and behavioral signatures.

METHODS

A total of354 children with new-onset epilepsy, aged six to 16 years, were recruited within six weeks of initial seizure onset. Each child underwent evaluation of their sleep along with self, parent, and teacher ratings of emotional-behavioral status. Two-step clustering using sleep disturbance (Sleep Behavior Questionnaire), naps, and sleep latency was employed to determine phenotype clusters.

RESULTS

Analysis showed three distinct sleep disturbance phenotypes-minimal sleep disturbance, moderate sleep disturbance, and severe sleep disturbance phenotypes. Children who fell into the minimal sleep disturbance phenotype had an older age of onset with the best cognitive performance compared with the other phenotypes and the lowest levels of emotional-behavioral problems. In contrast, children who fell into the severe sleep disturbance phenotype had the youngest age of onset of epilepsy with poor cognitive performance and highest levels of emotional-behavioral problems.

CONCLUSIONS

This study indicates that there are indeed specific sleep disturbance phenotypes that are apparent in children with newly diagnosed epilepsy and are associated with specific comorbidities. Future research should determine if these phenotypic groups persist over time and are predictive of long-term difficulties, as these subgroups may benefit from targeted therapy and intervention.

Chronobiology of epilepsy and sudden unexpected death in epilepsy

Epilepsy is a neurological disease characterized by spontaneous, unprovoked seizures. Various insults render the brain hyperexcitable and susceptible to seizure. Despite there being dozens of preventative anti-seizure medications available, these drugs fail to control seizures in nearly 1 in 3 patients with epilepsy. Over the last century, a large body of evidence has demonstrated that internal and external rhythms can modify seizure phenotypes. Physiologically relevant rhythms with shorter periodic rhythms, such as endogenous circadian rhythms and sleep-state, as well as rhythms with longer periodicity, including multidien rhythms and menses, influence the timing of seizures through poorly understood mechanisms. The purpose of this review is to discuss the findings from both human and animal studies that consider the effect of such biologically relevant rhythms on epilepsy and seizure-associated death. Patients with medically refractory epilepsy are at increased risk of sudden unexpected death in epilepsy (SUDEP). The role that some of these rhythms play in the nocturnal susceptibility to SUDEP will also be discussed. While the involvement of some of these rhythms in epilepsy has been known for over a century, applying the rhythmic nature of such phenomenon to epilepsy management, particularly in mitigating the risk of SUDEP, has been underutilized. As our understanding of the physiological influence on such rhythmic phenomenon improves, and as technology for chronic intracranial epileptiform monitoring becomes more widespread, smaller and less invasive, novel seizure-prediction technologies and time-dependent chronotherapeutic seizure management strategies can be realized.

The Interaction Between Sleep and Epilepsy

PURPOSE OF REVIEW

To review the mutual interactions between sleep and epilepsy, including mechanisms of epileptogenesis, the relationship between sleep apnea and epilepsy, and potential strategies to treat seizures.

RECENT FINDINGS

Recent studies have highlighted the role of functional network systems underlying epileptiform activation in sleep in several epilepsy syndromes, including absence epilepsy, benign focal childhood epilepsy, and epileptic encephalopathy with spike-wave activation in sleep. Sleep disorders are common in epilepsy, and early recognition and treatment can improve seizure frequency and potentially reduce SUDEP risk. Additionally, epilepsy is associated with cyclical patterns, which has led to new treatment approaches including chronotherapy, seizure monitoring devices, and seizure forecasting. Adenosine kinase and orexin receptor antagonists are also promising new potential drug targets that could be used to treat seizures. Sleep and epilepsy have a bidirectional relationship that intersects with many aspects of clinical management. In this article, we identify new areas of research involving future therapeutic opportunities in the field of epilepsy.

Urinary Neurotransmitter Patterns Are Altered in Canine Epilepsy

Epilepsy is the most common chronic neurological disease in humans and dogs. Epilepsy is thought to be caused by an imbalance of excitatory and inhibitory neurotransmission. Intact neurotransmitters are transported from the central nervous system to the periphery, from where they are subsequently excreted through the urine. In human medicine, non-invasive urinary neurotransmitter analysis is used to manage psychological diseases, but not as yet for epilepsy. The current study aimed to investigate if urinary neurotransmitter profiles differ between dogs with epilepsy and healthy controls. A total of 223 urine samples were analysed from 63 dogs diagnosed with idiopathic epilepsy and 127 control dogs without epilepsy. The quantification of nine urinary neurotransmitters was performed utilising mass spectrometry technology. A significant difference between urinary neurotransmitter levels (glycine, serotonin, norepinephrine/epinephrine ratio, ɤ-aminobutyric acid/glutamate ratio) of dogs diagnosed with idiopathic epilepsy and the control group was found, when sex and neutering status were accounted for. Furthermore, an influence of antiseizure drug treatment upon the urinary neurotransmitter profile of serotonin and ɤ-aminobutyric acid concentration was revealed. This study demonstrated that the imbalances in the neurotransmitter system that causes epileptic seizures also leads to altered neurotransmitter elimination in the urine of affected dogs. Urinary neurotransmitters have the potential to serve as valuable biomarkers for diagnostics and treatment monitoring in canine epilepsy. However, more research on this topic needs to be undertaken to understand better the association between neurotransmitter deviations in the brain and urine neurotransmitter concentrations in dogs with idiopathic epilepsy.

Sleep Disorders in Rett Syndrome and Rett-Related Disorders: A Narrative Review

Rett Syndrome (RTT) is a rare and severe X-linked developmental brain disorder that occurs primarily in females, with a ratio of 1:10.000. De novo mutations in the Methyl-CpG Binding protein 2 (MECP2) gene on the long arm of X chromosome are responsible for more than 95% cases of classical Rett. In the remaining cases (atypical Rett), other genes are involved such as the cyclin-dependent kinase-like 5 (CDKL5) and the forkhead box G1 (FOXG1). Duplications of the MECP2 locus cause MECP2 duplication syndrome (MDS) which concerns about 1% of male patients with intellectual disability. Sleep disorders are common in individuals with intellectual disability, while the prevalence in children is between 16 and 42%. Over 80% of individuals affected by RTT show sleep problems, with a higher prevalence in the first 7 years of life and some degree of variability in correlation to age and genotype. Abnormalities in circadian rhythm and loss of glutamate homeostasis play a key role in the development of these disorders. Sleep disorders, epilepsy, gastrointestinal problems characterize CDKL5 Deficiency Disorder (CDD). Sleep impairment is an area of overlap between RTT and MECP2 duplication syndrome along with epilepsy, regression and others. Sleep dysfunction and epilepsy are deeply linked. Sleep deprivation could be an aggravating factor of epilepsy and anti-comitial therapy could interfere in sleep structure. Epilepsy prevalence in atypical Rett syndrome with severe clinical phenotype is higher than in classical Rett syndrome. However, RTT present a significant lifetime risk of epilepsy too. Sleep disturbances impact on child's development and patients' families and the evidence for its management is still limited. The aim of this review is to analyze pathophysiology, clinical features, the impact on other comorbidities and the management of sleep disorders in Rett syndrome and Rett-related syndrome.

Reduced Sleep Quality Is Related to Poor Quality of Life in Patients with Juvenile Myoclonic Epilepsy, a Case-Control Study

Juvenile myoclonic epilepsy (JME) is a primary generalized epilepsy which is closely related to the sleep-wake cycle. This study aimed to investigate whether sleep disturbance is more common among patients with JME and the impact this may have on their quality of life (QOL). Thirty-four patients with JME and age- and gender-matched controls were recruited into this case control study, and assessed using validated sleep questionnaires including the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Stanford Sleepiness Scale (SSS). QOL was assessed using the Quality of Life in Epilepsy Inventory (QOLIE-31). The patients had a significantly higher PSQI score and higher proportion of abnormal PSQI scores than the controls. They also had higher ESS and SSS scores, but without statistical significance. The patients with poor sleep quality had significantly lower overall QOL, emotional well-being, and energy/fatigue subscale scores. The use of a higher number of antiseizure medications, dosage of levetiracetam, and usage of antiseizure medication polytherapy were associated with sleep disorders. Our results showed that sleep disturbance is common in patients with JME, and also that it has an impact on their QOL.

Electrical brain stimulation and continuous behavioral state tracking in ambulatory humans

Objective.Electrical deep brain stimulation (DBS) is an established treatment for patients with drug-resistant epilepsy. Sleep disorders are common in people with epilepsy, and DBS may actually further disturb normal sleep patterns and sleep quality. Novel implantable devices capable of DBS and streaming of continuous intracranial electroencephalography (iEEG) signals enable detailed assessments of therapy efficacy and tracking of sleep related comorbidities. Here, we investigate the feasibility of automated sleep classification using continuous iEEG data recorded from Papez's circuit in four patients with drug resistant mesial temporal lobe epilepsy using an investigational implantable sensing and stimulation device with electrodes implanted in bilateral hippocampus (HPC) and anterior nucleus of thalamus (ANT).Approach.The iEEG recorded from HPC is used to classify sleep during concurrent DBS targeting ANT. Simultaneous polysomnography (PSG) and sensing from HPC were used to train, validate and test an automated classifier for a range of ANT DBS frequencies: no stimulation, 2 Hz, 7 Hz, and high frequency (>100 Hz).Main results.We show that it is possible to build a patient specific automated sleep staging classifier using power in band features extracted from one HPC iEEG sensing channel. The patient specific classifiers performed well under all thalamic DBS frequencies with an average F1-score 0.894, and provided viable classification into awake and major sleep categories, rapid eye movement (REM) and non-REM. We retrospectively analyzed classification performance with gold-standard PSG annotations, and then prospectively deployed the classifier on chronic continuous iEEG data spanning multiple months to characterize sleep patterns in ambulatory patients living in their home environment.Significance.The ability to continuously track behavioral state and fully characterize sleep should prove useful for optimizing DBS for epilepsy and associated sleep, cognitive and mood comorbidities.

The use of rodent models to better characterize the relationship among epilepsy, sleep, and memory

Epilepsy, a neurological disorder characterized by recurrent seizures, is known to be associated with impaired sleep and memory. Although the specific mechanisms underlying these impairments are uncertain, the known role of sleep in memory consolidation suggests a potential relationship may exist between seizure activity, disrupted sleep, and memory impairment. A possible mediator in this relationship is the sleep spindle, the characteristic electroencephalographic (EEG) feature of non-rapid-eye-movement (NREM) sleep in humans and other mammals. Growing evidence supports the idea that sleep spindles, having thalamic origin, may mediate the process of long-term memory storage and plasticity by generating neuronal conditions that favor these processes. To study this potential relationship, a single model in which memory, sleep, and epilepsy can be simultaneously observed is of necessity. Rodent models of epilepsy appear to fulfill this requirement. Not only do rodents express both sleep spindles and seizure-induced sleep disruptions, but they also allow researchers to invasively study neurobiological processes both pre- and post- epileptic onset via the artificial induction of epilepsy (a practice that cannot be carried out in human subjects). However, the degree to which sleep architecture differs between rodents and humans makes direct comparisons between the two challenging. This review addresses these challenges and concludes that rodent sleep studies are useful in observing the functional roles of sleep and how they are affected by epilepsy.

The Relationship Between Sleep, Cognition and Behavior in Children With Newly-Diagnosed Epilepsy Over 36 Months

Introduction

There is substantial evidence that children with epilepsy experience more sleep, behavior and cognitive challenges than children without epilepsy. However, the literature is limited in describing the relationship between sleep, epilepsy, cognition and behavioral challenges and the interactions amongst these factors over time. This study aims to understand the nature and strength of the relationship between sleep, cognition, mood and behavior in children with new-onset epilepsy as assessed by multiple informants at multiple time periods using multiple different dependent measures.

Methods

332 participants (6-16years) were recruited within 6 weeks of their first recognized seizure. The comparison group was comprised of 266 healthy siblings. Participants underwent sleep evaluation by a parent using the Sleep Behavioral Questionnaire (SBQ), cognitive evaluation using a comprehensive neuropsychological test battery, a behavioral evaluation using the Child Behavior Checklist (CBCL from parents and TRF from teachers) and the Children's Depression Inventory (CDI). These evaluations were completed at baseline (B), at 18 months, and at 36 months.

Results

Compared to siblings, children with new-onset epilepsy had more sleep disturbance (SBQ), higher rates of behavioral problems (CBCL and TRF), lower cognitive testing scores, and higher rates of depression; which persisted over the 36-month study. Sleep significantly correlated with behavioral problems, cognitive scores and depression. When divided into categories based of sleep disturbance scores, 39.7% of children with epilepsy experienced "Persistently Abnormal Sleep", while 14.8% experienced "Persistently Normal Sleep". Children with persistently abnormal sleep experienced the highest rates of behavioral problems, depression and cognitive impairment compared to those with persistently normal sleep, regardless of epilepsy syndrome. Younger age of seizure onset, younger age at testing, and lower grade level at baseline were associated with persistently abnormal sleep.

Conclusions

To our knowledge, this is the first demonstration of the nature, strength, reliability, stability and persistence of the relationship between sleep, cognition, and behavioral problems over time in a large cohort of children with newly diagnosed epilepsy, as assessed by multiple informants at different timepoints. The results of this study indicate that children with epilepsy are at a high risk of significant persisting neurobehavioral multimorbidity. Therefore, early screening for these challenges may be essential for optimizing quality of life long-term.

Pharmacoresponsiveness of spontaneous recurrent seizures and the comorbid sleep disorder of epileptic Kcna1-null mice

Drug resistant epilepsy affects ∼30% of people with epilepsy and is associated with epilepsy syndromes with frequent and multiple types of seizures, lesions or cytoarchitectural abnormalities, increased risk of mortality and comorbidities such as cognitive impairment and sleep disorders. A limitation of current preclinical models is that spontaneous seizures with comorbidities take time to induce and test, thus making them low-throughput. Kcna1-null mice exhibit all the characteristics of drug resistant epilepsy with spontaneous seizures and comorbidities occurring naturally; thus, we aimed to determine whether they also demonstrate pharmacoresistanct seizures and the impact of medications on their sleep disorder comorbidity. In this exploratory study, Kcna1-null mice were treated with one of four conventional antiseizure medications, carbamazepine, levetiracetam, phenytoin, and phenobarbital using a moderate throughput protocol (vehicle for 2 days followed by 2 days of treatment with high therapeutic doses selected based on published data in the 6 Hz model of pharmacoresistant seizures). Spontaneous recurrent seizures and vigilance states were recorded with video-EEG/EMG. Carbamazepine, levetiracetam and phenytoin had partial efficacy (67%, 75% and 33% were seizure free, respectively), whereas phenobarbital was fully efficacious and conferred seizure freedom to all mice. Thus, seizures of Kcna1-null mice appear to be resistant to three of the drugs tested. Levetiracetam failed to affect sleep architecture, carbamazepine and phenytoin had moderate effects, and phenobarbital, as predicted, restored sleep architecture. Data suggest Kcna1-null mice may be a moderate throughput model of drug resistant epilepsy useful in determining mechanisms of pharmacoresistance and testing novel therapeutic strategies.

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.

Evaluation of the effects of ketogenic diet therapy on sleep quality in children with drug-resistant epilepsy and their mothers

BACKGROUND

Sleep disorders are common in drug-resistant children with epilepsy and their mothers. Ketogenic diet therapy (KDT) may have positive effects on sleep quality. The aim of this study was to evaluate the sleep quality of children with epilepsy and their mothers after starting KDT.

METHODS

Using a prospective cross-sectional model, pre- and post-KDT questionnaires were given to the study subjects. A children's sleep habits questionnaire was administered to children with epilepsy, and the Pittsburgh sleep questionnaire was administered to their mothers. Sociodemographic and some clinical categorical variables of the patient group were evaluated using descriptive statistics. Evaluation of the data was conducted using the Wilcoxon and paired t-tests as parametric and non-parametric tests.

RESULTS

Of 24 patients scheduled to begin KDT between January 2019 and January 2020, 14 were included in the study. Regarding sleep quality, improvement was reported in 7 (50%) of 14 patients, deterioration in 5 (35.7%) patients, and no change was seen in 2 (14.3%) patients. Sleep quality was reported to improve in all working mothers. Seven (50%) patients reported no seizures and 6 (42.9%) patients reported more than 50% seizure reduction. Although there were improvements in sleep scores in both groups, these improvements were not statistically significant. A significant decrease in sleep anxiety was reported in children after the third month of the KDT (p = 0.09).

CONCLUSIONS

The results of this study determined that three months of KDT offered significant improvement on the sleep anxiety of children with epilepsy. It was thought that paying attention to patient selection may lead to better sleep quality by increasing compliance to KDT. However, a larger scale study and longer term follow-up should be done.

Sleep Abnormalities in the Synaptopathies-SYNGAP1-Related Intellectual Disability and Phelan-McDermid Syndrome

Neurodevelopmental disorders are frequently associated with sleep disturbances. One class of neurodevelopmental disorders, the genetic synaptopathies, is caused by mutations in genes encoding proteins found at the synapse. Mutations in these genes cause derangement of synapse development and function. We utilized a validated sleep instrument, Children's Sleep Habits Questionnaire (CSHQ) to examine the nature of sleep abnormalities occurring in individuals with two synaptopathies-Phelan-McDermid syndrome (PMD) (N = 47, male = 23, female = 24, age 1-46 years) and SYNGAP1-related intellectual disability (SYNGAP1-ID) (N = 64, male = 31, female = 33, age 1-64 years), when compared with unaffected siblings (N = 61, male = 25, female = 36, age 1-17 years). We found that both PMD and SYNGAP1-ID have significant sleep abnormalities with SYNGAP1-ID having greater severity of sleep disturbance than PMD. In addition, sleep disturbances were more severe for PMD in individuals 11 years and older compared with those less than 11 years old. Individuals with either disorder were more likely to use sleep aids than unaffected siblings. In conclusion, sleep disturbances are a significant phenotype in the synaptopathies PMD and SYNGAP1-ID. Improved sleep is a viable endpoint for future clinical trials for these neurodevelopmental disorders.

Relationship between sleep quality and cognitive performance in patients with epilepsy

PURPOSE

To investigate the relationship between self-reported sleep quality and cognitive function in patients with epilepsy (PWE), as well as anxiety and depressive symptoms and patient quality of life (QoL).

METHODS

This multicenter cross-sectional study included PWE aged ≥12 years who were receiving ≥1 anti-seizure medication (ASM) and had not been diagnosed with a sleep disorder. Patients completed the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Montreal Cognitive Assessment test (MoCA), the Hospital Anxiety and Depression Scale (HADS), and the Quality of Life in Epilepsy Inventory-10 (QOLIE-10).

RESULTS

The study enrolled 150 patients aged 16-83 years, mean age (standard deviation [SD]) 40.6 (15.2) years; 58.7% were female and 75.3% had focal epilepsy. Mean (SD) PSQI score was 4.71 (3.08), 44.4% of patients had impaired sleep quality (PSQI score ≥5), 19.9% had pathologic excessive daytime sleepiness (ESS score >12), and 32.7% had mild cognitive impairment (MoCA score <26). Within the PSQI, sleep disturbance (P = 0.036) and use of sleep medication (P = 0.006) scores were significantly higher in patients with mild cognitive impairment. Multiple regression analysis showed older age (regression coefficient [B], -0.086; 95% confidence interval [CI], -0.127, -0.045; P < 0.001) and the use of sleep medication component of the PSQI [B, -1.157; 95% CI, -2.064, -0.220; P = 0.013) were independently associated with lower MoCA score. Poor sleep quality was associated with probable anxiety and depression symptoms, and directly correlated with reduced QoL.

CONCLUSIONS

In PWE, sleep quality was not significantly independently associated with mild cognitive impairment, although poor sleep quality had a negative effect on mood and QoL.

Sleep duration and quality among U.S. adults with epilepsy: National Health Interview Survey 2013, 2015, and 2017

BACKGROUND

Epilepsy is associated with a high prevalence of sleep disturbance. However, population-based studies on the burden of sleep disturbance in people with epilepsy are limited. This study assessed sleep duration and sleep quality by epilepsy status in the general U.S. adult population aged ≥ 18 years.

METHODS

We pooled data of cross-sectional National Health Interview Surveys in 2013, 2015, and 2017 to compare the prevalence of sleep duration and quality among those without epilepsy (N = 93,126) with those with any epilepsy (a history of physician-diagnosed epilepsy) (N = 1774), those with active epilepsy (those with a history of physician-diagnosed epilepsy who were currently taking medication to control it, had one or more seizures in the past year, or both) (N = 1101), and those with inactive epilepsy (those with a history of physician-diagnosed epilepsy who were neither taking medication for epilepsy nor had had a seizure in the past year) (N = 673). We also compared these measures between those with active and those with inactive epilepsy. The prevalences were adjusted for sociodemographics, behaviors, and health covariates, with multivariable logistic regression. We used Z-tests to compare prevalences of sleep duration and quality at the statistical significance level of 0.05.

RESULTS

Adults with any epilepsy reported significantly higher adjusted prevalences of short sleep duration (<7 h) (36.0% vs. 31.8%) and long sleep duration (>9 h per day) (6.7% vs. 3.7%) but a lower prevalence of healthy sleep duration (7-9 h per day) (57.4% vs.64.6%) than those without epilepsy. In the past week, adults with any epilepsy reported significantly higher adjusted prevalences than adults without epilepsy of having trouble falling asleep (25.0% vs. 20.3%), staying asleep (34.4% vs. 26.3%), nonrestorative sleep (adults did not wake up feeling well rested) (≥3days) (50.3% vs. 44.3%), and taking medication to help themselves fall asleep or stay asleep (≥1 times) (20.9% vs. 13.5%). However, adults with active epilepsy did not differ from adults with inactive epilepsy with respect to these sleep duration and quality measures.

CONCLUSIONS

Adults with epilepsy reported more short or long sleep duration and worse sleep quality than those without epilepsy. Neither seizure occurrence nor antiepileptic drug use accounted for these differences in sleep duration and quality. Careful screening for sleep complaints as well as identifying and intervening on the modifiable risk factors associated with sleep disturbances among people with epilepsy could improve epilepsy outcomes and quality of life.

The Good, the Bad, and the Deadly: Adenosinergic Mechanisms Underlying Sudden Unexpected Death in Epilepsy

Adenosine is an inhibitory modulator of neuronal excitability. Neuronal activity results in increased adenosine release, thereby constraining excessive excitation. The exceptionally high neuronal activity of a seizure results in a surge in extracellular adenosine to concentrations many-fold higher than would be observed under normal conditions. In this review, we discuss the multifarious effects of adenosine signaling in the context of epilepsy, with emphasis on sudden unexpected death in epilepsy (SUDEP). We describe and categorize the beneficial, detrimental, and potentially deadly aspects of adenosine signaling. The good or beneficial characteristics of adenosine signaling in the context of seizures include: (1) its direct effect on seizure termination and the prevention of status epilepticus; (2) the vasodilatory effect of adenosine, potentially counteracting postictal vasoconstriction; (3) its neuroprotective effects under hypoxic conditions; and (4) its disease modifying antiepileptogenic effect. The bad or detrimental effects of adenosine signaling include: (1) its capacity to suppress breathing and contribute to peri-ictal respiratory dysfunction; (2) its contribution to postictal generalized EEG suppression (PGES); (3) the prolonged increase in extracellular adenosine following spreading depolarization waves may contribute to postictal neuronal dysfunction; (4) the excitatory effects of A2A receptor activation is thought to exacerbate seizures in some instances; and (5) its potential contributions to sleep alterations in epilepsy. Finally, the adverse effects of adenosine signaling may potentiate a deadly outcome in the form of SUDEP by suppressing breathing and arousal in the postictal period. Evidence from animal models suggests that excessive postictal adenosine signaling contributes to the pathophysiology of SUDEP. The goal of this review is to discuss the beneficial, harmful, and potentially deadly roles that adenosine plays in the context of epilepsy and to identify crucial gaps in knowledge where further investigation is necessary. By better understanding adenosine dynamics, we may gain insights into the treatment of epilepsy and the prevention of SUDEP.

Regulation of microRNA Expression in Sleep Disorders in Patients with Epilepsy

The effects of epilepsy on sleep and the activating effects of sleep on seizures are well documented in the literature. To date, many sleep-related and awake-associated epilepsy syndromes have been described. The relationship between sleep and epilepsy has led to the recognition of polysomnographic testing as an important diagnostic tool in the diagnosis of epilepsy. The authors analyzed the available medical database in search of other markers that assess correlations between epilepsy and sleep. Studies pointing to microRNAs, whose abnormal expression may be common to epilepsy and sleep disorders, are promising. In recent years, the role of microRNAs in the pathogenesis of epilepsy and sleep disorders has been increasingly emphasized. MicroRNAs are a family of single-stranded, non-coding, endogenous regulatory molecules formed from double-stranded precursors. They are typically composed of 21–23 nucleotides, and their main role involves post-transcriptional downregulation of expression of numerous genes. Learning more about the role of microRNAs in the pathogenesis of sleep disorder epilepsy may result in its use as a biomarker in these disorders and application in therapy.

Sleep, neuronal hyperexcitability, inflammation and neurodegeneration: Does early chronic short sleep trigger and is it the key to overcoming Alzheimer's disease?

Evidence links neuroinflammation to Alzheimer's disease (AD); however, its exact contribution to the onset and progression of the disease is poorly understood. Symptoms of AD can be seen as the tip of an iceberg, consisting of a neuropathological build-up in the brain of extracellular amyloid-β (Aβ) plaques and intraneuronal hyperphosphorylated aggregates of Tau (pTau), which are thought to stem from an imbalance between its production and clearance resulting in loss of synaptic health and dysfunctional cortical connectivity. The glymphatic drainage system, which is particularly active during sleep, plays a key role in the clearance of proteinopathies. Poor sleep can cause hyperexcitability and promote Aβ and tau pathology leading to systemic inflammation. The early neuronal hyperexcitability of γ-aminobutyric acid (GABA)-ergic inhibitory interneurons and impaired inhibitory control of cortical pyramidal neurons lie at the crossroads of excitatory/inhibitory imbalance and inflammation. We outline, with a prospective framework, a possible vicious spiral linking early chronic short sleep, neuronal hyperexcitability, inflammation and neurodegeneration. Understanding the early predictors of AD, through an integrative approach, may hold promise for reducing attrition in the late stages of neuroprotective drug development.

Sleep scoring based on video-electroencephalography monitoring in an Epileptology Unit: Comparison with polysomnography

The aim of the study was to compare the performance of video- electroencephalography (EEG) monitoring and standard polysomnography for sleep scoring in an Epileptology Unit. We calculated the level of agreement between two methods of sleep scoring, using either 27-electrode video-EEG or polysomnography for 1 night in 22 patients admitted to our Epileptology Unit. Independent experts manually scored sleep using the American Academy of Sleep Medicine 2017 guidelines. We evaluated the number of sleep cycles and their distribution on hypnogram, total sleep time, sleep efficiency, sleep and rapid eye movement sleep-onset latency, wake after sleep-onset, and sleep stages. We then extracted sub-samples of recordings to examine the agreement in microarousal and rapid eye movement scoring. We used Bland and Altman plots and Cohen's kappa test to measure agreement. Bland and Altman plots showed at least 95% agreement for all studied sleep parameters with the exception of wake after sleep onset, where there was an 11 min difference. Cohen's kappa test showed an agreement for the recognition of microarousal (0.89) and of rapid eye movements (0.96) in sub-samples. Video-EEG represents an acceptable alternative tool for sleep architecture study in patients admitted to an Epileptology Unit.

Evidence of objective sleep impairment in nonepileptic attack disorder: A naturalistic prospective controlled study using actigraphy and daily sleep diaries over six nights

Poor sleep is reported by many with nonepileptic attack disorder (NEAD) with correlations evident between self-reported sleep quality and mood and functional impairment. However, it is contended that self-reported sleep impairment in NEAD is a subjective phenomenon, which represents a general tendency to over-report symptoms or misinterpret bodily states in those with NEAD. The present study was therefore designed to investigate the extent of subjective and objective sleep impairments in those with NEAD. Over six nights we prospectively recorded comparable nightly objective (actigraphy) and subjective (consensus sleep diary) sleep parameters in a sample of 17 people with NEAD, and an age- and gender-matched normative control group (N = 20). Participants recorded daily measures of attacks, dissociation, and mood. Alongside higher subjective sleep impairment, the NEAD group had significantly worse objective sleep on several metrics compared to the normative controls, characterized by disrupted sleep (frequent awakenings and wake after sleep onset, low efficiency). Exploratory analyses using mixed effects models showed that attacks were more likely to occur on days preceded by longer, more restful sleep. This study, which had good ecological validity, evidences the presence of objective sleep impairment in NEAD, suggesting that in patient reports of problems with sleep should be given careful consideration in clinical practice.

Relationship between locomotor activity rhythm and corticosterone levels during HCC development, progression, and treatment in a mouse model

Cancer-related fatigue (CRF) and stress are common symptoms in cancer patients and represent early side effects of cancer treatment which affect the life quality of the patients. CRF may partly depend on disruption of the circadian rhythm. Locomotor activity and corticosterone rhythms are two important circadian outputs which can be used to analyze possible effects on the circadian function during cancer development and treatment. The present study analyzes the relationship between locomotor activity rhythm, corticosterone levels, hepatocellular carcinoma (HCC) development, and radiotherapy treatment in a mouse model. HCC was induced in mice by single injection of diethylnitrosamine (DEN) and chronic treatment of phenobarbital in drinking water. Another group received chronic phenobarbital treatment only. Tumor bearing animals were divided randomly into four groups irradiated at four different Zeitgeber time points. Spontaneous locomotor activity was recorded continuously; serum corticosterone levels and p-ERK immunoreaction in the suprachiasmatic nucleus (SCN) were investigated. Phenobarbital treated mice showed damped corticosterone levels and a less stable 24 hours activity rhythm as well as an increase in activity during the light phase, reminiscent of sleep disruption. The tumor mice showed an increase in corticosterone level during the inactive phase and decreased activity during the dark phase, reminiscent of CRF. After irradiation, corticosterone levels were further increased and locomotor activity rhythms were disrupted. Lowest corticosterone levels were observed after irradiation during the early light phase; thus, this time might be the best to apply radiotherapy in order to minimize side effects.

Sleep profile and Polysomnography in patients with drug-resistant temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) and the effect of epilepsy surgery on sleep-a prospective cohort study

OBJECTIVES

We analyzed changes in sleep profile and architecture of patients with drug-resistant TLE-HS using three validated sleep questionnaires- Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), NIMHANS Comprehensive Sleep Disorders, and polysomnography (PSG). We studied the effect of epilepsy surgery in a subset of patients.

METHODS

In this prospective observational cohort study, sleep profile of 40 patients with drug-resistant TLE-HS was compared to 40 healthy matched controls. Sleep architecture of 22 patients was studied by overnight PSG and compared to 22 matched controls. Sleep profile was reassessed in 20 patients after a minimum period of three months after epilepsy surgery.

RESULTS

The mean PSQI was higher among patients compared to controls(P=0.0004) while mean ESS showed no difference. NCSDQ showed fewer patients feeling refreshed after a night's sleep compared to controls (p=0.006). PSG revealed a higher time in bed (p=0.0001), longer total sleep time (p=0.006) and more time spent in NREM stage 1 (p=0.001) and stage 2 (p=0.005) while spending less time in stage 3 (p=0.039) among TLE patients. Sleep efficiency was worse in patients on ≥3 ASMs compared to those on 2 ASMs (p-0.044). There was no change in mean ESS (p=0.48) or PSQI (p=0.105) after surgery.

CONCLUSIONS

Patients with drug-resistant TLE-HS have an altered sleep profile and architecture. Patients on ≥3 ASMs have a lower sleep efficiency. Reassessment at short intervals after epilepsy surgery did not reveal significant changes in sleep profile.

Fatigue and cognitive functions in epilepsy: A review of the literature

Epilepsy is a common neurological disorder affecting people of all ages and inducing cognitive impairments. While research has advanced in terms of neuropsychological enquiries of the various epileptic syndromes, the understanding of more complex and ill-defined phenomena such as fatigue is still unclear for epilepsy. It is suggested that fatigue is not just physical, but there can also be a cognitive element to it. Although studies in other conditions have been able to identify a relationship between fatigue and particular cognitive components, similar evidence is sparse in patients with epilepsy. This review is an attempt to gather, analyze, integrate, and critically discuss available information on fatigue and its rapport with various aspects of epilepsy, particularly focusing on cognition. Future directions are discussed urging researchers to target cognitive components of fatigue.

Prevalence of sleep disorders in patients with epilepsy: A questionnaire-based cross-sectional study

BACKGROUND

Sleep disturbance is a frequent finding in patients with epilepsy. As evaluation of sleep disorders and quality of sleep in patients with epilepsy may provide better management of these patients, we aimed to assess the prevalence of common sleep disorders in patients with epilepsy.

METHODS

Patients with epilepsy referred to an outpatient epilepsy clinic in Tehran during one year were included. Validated Persian questionnaires were used by an interviewer to assess Excessive daytime sleepiness (EDS), Restless leg syndrome (RLS), and insomnia. Also, patients' demographic features and clinical seizure-related characteristics were recorded.

RESULTS

Seventy patients (35 males) aged between 18 and 75 were enrolled. Among patients, 61.4, 35.7, and 28.6% suffered from insomnia, EDS, and RLS, respectively (mild to severe). When considering seizure characteristics, there was no significant correlation between either seizure frequency or its type and the prevalence of sleep disturbance (although sleep disturbance was more common among patients with higher seizure frequency and patients with generalized seizure). Interestingly, age had a positive correlation with EDS.

CONCLUSION

This study showed that sleep disturbance is a common finding in patients with epilepsy, which may become severe in some cases. Taking this into consideration, we suggest that routine evaluation of sleep disorders may help physicians to boost patients' sleep quality.

Epilepsy-associated neurocognitive disorders (EAND) in an onchocerciasis-endemic rural community in Cameroon: A population-based case-control study

BACKGROUND

Epilepsy affects at least 50 million individuals worldwide, especially in sub-Saharan Africa (sSA). Cognitive impairment is common in people with epilepsy (PWE) yet, little is known on the burden of cognitive impairment in people with epilepsy in sSA. This study was thus designed to assess cognitive impairment in PWE or epilepsy-associated neurocognitive disorders (EAND) in a rural population in Cameroon.

METHODS

This was a case-control study including PWE and age/sex-matched healthy controls from July to September 2017 in Bilomo, a village in the Mbam and Kim Division. The Montreal Cognitive Assessment (MoCA), International HIV Dementia Scale (IHDS), Dubois' Five Word testing, Frontal Assessment Battery (FAB), Isaac's Set Test and the Clock drawing test were administered to the study participants to evaluate global and specific cognitive functions.

RESULTS

Eighty participants were included (40 cases and 40 controls) with a mean age of 25.78 years. Using the MoCA, 87.5% of cases had cognitive impairment, against 37.5% of controls (p < 0.001; OR 11.67; CI 3.40-45.09). Using the IHDS, the prevalence of global cognitive impairment was 84.6% among the cases against 40% for the controls (p = <0.001; OR 7.07; CI 2.29-29.19). Specifically, executive function deficits (92.5% of cases vs 40.0% of controls p = <0.001 OR = 18.50 CI; 4.48-105.08) and decreased verbal fluency (100% of cases against 45% of controls p < 0.001) were the most affected cognitive domains. Longer duration of epilepsy and higher seizure frequency were associated with global cognitive impairment. Low level of education was associated with both decreased verbal fluency and executive dysfunction while a longer stay in Bilomo correlated with poor results on the Isaac's Set Test.

CONCLUSION

The prevalence of cognitive impairment appears to be much higher in PWE in the Mbam valley, particularly decreased executive function and verbal fluency, than in people without epilepsy. Longer disease duration, higher seizure frequency, low level of education and length of stay in Bilomo are associated with poorer cognitive performance. More studies are needed to refine evaluation tools to better characterize and manage EAND in sSA.

Metabolic syndrome and obstructive sleep apnea syndrome among patients with epilepsy on monotherapy

OBJECTIVES

The study aimed to determine the frequency of metabolic syndrome (MetS) and obstructive sleep apnea syndrome (OSAS) in patients with epilepsy receiving monotherapy and the relationship between these syndromes and antiepileptic drugs (AEDs).

METHODS

Two hundred and ninety-seven patients with epilepsy between the ages of 18-65 years receiving monotherapy for at least one year and 50 healthy participants were enrolled. Body mass indices and waist circumferences were measured. Serum fasting glucose levels, high-density lipoprotein (HDL), low density lipoprotein (LDL), total cholesterol (TC), triglyceride, and serum AED concentrations were noted. The frequency of MetS in patients with epilepsy was calculated. The snoring, tiredness, observed apnea, high blood pressure, body mass index, age, neck circumference, and male gender (STOP-Bang) questionnaire was used to determine the risk of OSAS. The relationship between these two syndromes and seizure type, disease duration, AED dosage, and treatment duration was analyzed.

RESULTS

Metabolic syndrome was more frequent in patients with epilepsy compared with healthy participants (32.6% vs. 12.0%), and it was diagnosed in 37.8% of patients receiving valproic acid (VPA), 36.1% of patients receiving carbamazepine (CBZ), 34.9% of patients receiving oxcarbazepine (OXC), and 30.5% of patients on levetiracetam (LEV). There was a positive correlation between VPA treatment duration and MetS existence (p < 0.05). However, MetS frequency did not change because of seizure type, disease duration, or AED dosages in patients with epilepsy receiving monotherapy. The risk for OSAS was higher in patients with epilepsy compared with healthy participants (24.6% vs. 12%), and it was calculated high in 27.7% of patients receiving CBZ, 32.2% of patients receiving LEV, and 30.2% of patients receiving OXC. The OSAS risk was higher in patients who have focal seizures than generalized seizures (p = 0.044). There was no relationship between OSAS risk and duration of epilepsy, duration of treatment, drug doses, and serum drug levels (p > 0.05).

CONCLUSION

Higher frequency of MetS and OSAS risk should be kept in mind on clinical follow-up of patients with epilepsy receiving monotherapy.

Is the glymphatic system the missing link between sleep impairments and neurological disorders? Examining the implications and uncertainties

Until recently, both the purpose of the biological need for sleep and the mechanism by which the central nervous system eliminated metabolic waste products were unknown. The glymphatic system is the recently discovered macroscopic waste clearance system for the CNS, which predominantly functions during sleep states. Important implications for the glymphatic system exist for a significant proportion of neurological disorders, including traumatic brain injury, epilepsy, stroke, migraine, and Alzheimer's disease. Within the limited amount of research pertaining to this novel system there exists controversy regarding several of the key structural and functional aspects of the glymphatic system. In this review we address evidence from both standpoints regarding the prominent debates surrounding the glymphatic system, including the functional differences in wakefulness vs. sleep, the role of glial aquaporin-4 water channels, and whether it reflects a convective flow or a passive diffusion process. The answers that underlie these questions will have crucial and distinct outcomes for the future of the glymphatic system and the disorders it has been implicated in. However, this review also summarizes the potential role of the glymphatic system in the development and progression of the aforementioned neurological disorders. Furthermore, the possible contribution of the orexinergic system to this relationship between the glymphatic system, sleep, and these neurological disorders is also explored. Overall, in order to develop and utilize therapeutic interventions centred around the glymphatic system we must first dedicate further investigation to elucidating these discrepancies and unanswered questions.

Deep Brain Stimulation Increases Seizure Threshold by Altering REM Sleep and Delta Powers During NREM Sleep

We previously demonstrated that seizure occurrences at different zeitgeber times alter sleep and circadian rhythm differently. On the other hand, the synchronized delta wave of electroencephalogram (EEG) during non-rapid eye movement (NREM) sleep facilitates seizure, while the desynchronized EEG of rapid eye movement (REM) sleep suppresses it. We also elucidated that unilateral deep brain stimulation (DBS) of the anterior nucleus of thalamus (ANT) suppresses seizure recurrence. In the present study, we intraperitoneally injected pentylenetetrazol (PTZ, 40 mg/kg) for 14 consecutive days (PTZ kindling) to induce spontaneous seizure in rats, and a 30-min (delivered 10 min before each PTZ injection) or a 3-h DBS of unilateral ANT (delivered 1 h before each PTZ injection) was applied to suppress seizure. The frequency of DBS stimulation was 200 Hz and the electrical current consisted of biphasic square pulses with 50-μA intensity, 100-μs pulse width, and 4.1-ms stimulation interval. Our results found that PTZ-induced spontaneous seizure did not cause a significant change in the quantity of NREM sleep but suppressed the amount of REM sleep. Unilateral ANT DBS prolonged the onset latency of ictal seizure, decreased the spontaneous seizure duration, and increased the survival rate but did not change the amplitude of epileptiform EEGs during ictal period. Unilateral ANT DBS did not significantly alter NREM sleep but increased the amount of REM sleep. An analysis of the spectrograms of fast Fourier transform indicated that the intensities of all frequencies were enhanced during the PTZ-induced ictal period and the subsequent spontaneous seizure. Thirty minutes of unilateral ANT DBS suppressed the augmentation of low-frequency (<10 Hz) intensities during the spontaneous seizure induced by PTZ kindling. We further found that consecutive injections of PTZ progressively increased the enhancement of the delta powers during NREM sleep, whereas unilateral ANT DBS inhibited this progressive enhancement. It was also noticed that 30 min of ANT DBS exhibited a better efficacy in epilepsy suppression than 3 h of ANT DBS. These results elucidated that unilateral ANT DBS enhanced the seizure threshold by increasing the amount of REM sleep and decreasing the progressive enhancement of delta power during NREM sleep to suppress spontaneous seizure recurrences in PTZ kindling-induced epileptic rats.

Sleep Quality and Associated Factors among Peoples with Epilepsy Who Have a Follow-Up at Amanuel Mental Specialized Hospital, Addis Ababa, Ethiopia, 2019: An Institutional Based Cross-Sectional Study

Background

Sleep is an active cyclic biological phenomenon and necessary for survival. Individuals who suffer from sleep disturbance are less productive, decreased performance, and negative effects on mental health. Despite there are different studies on sleep quality in Ethiopia, no studies have been conducted on magnitude and predictors of sleep quality among people with epilepsy in the study setting.

Objective

To assess sleep quality and associated factors among people with epilepsy who have a follow-up at Amanuel Mental Specialized Hospital, Addis Ababa, Ethiopia, 2019.

Method

An institution-based cross-sectional study was employed from May-June 2019. Systematic random sampling following face to face interview technique was employed. Epi-data version 3.1 and SPSS version 25 statistical packages were used for data entry and analysis, respectively. Frequencies, proportions, means, SDs, and cross-tabulations were used to summarize descriptive statistics of the data and tables, texts, and graphs were used for data presentation. To identify association and significant predictor with the outcome variable, binary logistic regression was fitted. The variable which has statistical significance was identified on the basis of p values ≤ 0.05 and AOR with 95% confident intervals.

Results

A total of 423 participants have been enrolled to the study with a response rate of 98.1%. The prevalence of poor sleep quality among peoples live with epilepsy was found 65.4% (95% CI: 61.0, 69.9). Being female (AOR = 2.94; (95% CI; 1.79, 4.85)), having stress full life events (AOR = 2.38; (95% CI; 1.43, 3.97)), nonadherent to AED medication (AOR = 1.86; (95% CI; 1.05, 2.78), poly-therapy treatment (AOR = 2.24; (95% CI; 1.05, 2.78)), poor seizer control (AOR = 2.4; (95% CI; 2.21, 12.46)), comorbid medical illness (AOR = 2.6; (95% CI; 1.18, 5.61)), and anxiety (AOR = 2.54; (95% CI; 1.52,4.24)) were factors significantly associated with poor sleep quality.

Conclusion

This study revealed that more than half of the study participants were found to have poor sleep quality. So, considering the regular assessment of sleep quality and factors associated followed with appropriate intervention is recommended among peoples living with epilepsy.

General side effects and challenges associated with anti-epilepsy medication: A review of related literature

Background

This study is coming against the background of people with epilepsy who are abandoning anti-epilepsy medication in developing countries, such as Zimbabwe.

Aim

The aim of this article was therefore to review the general side effects and challenges associated with these anti-epilepsy medications.

Setting

The researchers reviewed literature related to the general side effects, psychological, social and economic challenges associated with anti- epilepsy medication.

Methods

To answer the research questions, the researchers used a narrative approach.

Results

Findings of the study reflected that the general side effects associated with anti- epilepsy medication include feelings of tiredness, stomach upset, dizziness or blurred vision, which usually happen during the first weeks of taking medicines. Psychologically, an individual with epilepsy may suffer cognitive problems that are associated with thinking, remembering, paying attention or concentrating and finding the right words to use. Socially, people with epilepsy experience social isolation, dependent behaviour, low rates of marriages, unemployment and reduced quality of life. Using anti-epilepsy medication is also associated with economic challenges.

Conclusion

The researchers concluded that some people with epilepsy have discontinued using anti-epilepsy medications because of these side effects and challenges.

Circadian regulation of sleep in a pre-clinical model of Dravet syndrome: dynamics of sleep stage and siesta re-entrainment

STUDY OBJECTIVES

Sleep disturbances are common co-morbidities of epileptic disorders. Dravet syndrome (DS) is an intractable epilepsy accompanied by disturbed sleep. While there is evidence that daily sleep timing is disrupted in DS, the difficulty of chronically recording polysomnographic sleep from patients has left our understanding of the effect of DS on circadian sleep regulation incomplete. We aim to characterize circadian sleep regulation in a mouse model of DS.

METHODS

Here we exploit long-term electrocorticographic recordings of sleep in a mouse model of DS in which one copy of the Scn1a gene is deleted. This model both genocopies and phenocopies the disease in humans. We test the hypothesis that the deletion of Scn1a in DS mice is associated with impaired circadian regulation of sleep.

RESULTS

We find that DS mice show impairments in circadian sleep regulation, including a fragmented rhythm of non-rapid eye movement (NREM) sleep and an elongated circadian period of sleep. Next, we characterize re-entrainment of sleep stages and siesta following jet lag in the mouse. Strikingly, we find that re-entrainment of sleep following jet lag is normal in DS mice, in contrast to previous demonstrations of slowed re-entrainment of wheel-running activity. Finally, we report that DS mice are more likely to have an absent or altered daily "siesta".

CONCLUSIONS

Our findings support the hypothesis that the circadian regulation of sleep is altered in DS and highlight the value of long-term chronic polysomnographic recording in studying the role of the circadian clock on sleep/wake cycles in pre-clinical models of disease.

Sleep disturbances in Italian children and adolescents with epilepsy: A questionnaire study

Sleep and epilepsy interact with each other in a complex bidirectional way. The main objective of this study was to characterize and determine the prevalence of sleep and behavioral disorders among Italian children and adolescents with epilepsy. We asked 84 consecutive parents/caregivers of patients with epilepsy aged between 6 and 17 years old to fill out the Sleep Disturbances Scale for Children (SDSC) and Child Behavior Checklist (CBCL). An abnormal total sleep score was found in 20 subjects with epilepsy (23.8%), compared with 4 (4.4%) of control group (P < .001). Forty-eight patients (57.1%) had an abnormal score in at least one SDSC factor: disorders in initiating and maintaining sleep (DIMS; 13.1%), sleep breathing disorders (SBD; 13.1%), disorders of arousal (DA; 5.9%), sleep-wake transition disorders (SWTD; 15.5%), disorders of excessive somnolence (DOES; 20.2%), and sleep hyperhidrosis (SHY; 5.9%). Patients with epilepsy showed higher prevalence of behavioral/emotional disturbances in all CBCL domains but one compared with patients without epilepsy. The SDSC and CBCL total scores showed a significant correlation (R-square = 0.256; P < .001). Sleep and behavioral/emotional disorders are common in epilepsy during childhood and adolescence. The SDSC could be a valid tool to screen sleep disturbances in this group of patients.

Group-based cognitive behavioral therapy program for improving poor sleep quality and quality of life in people with epilepsy: A pilot study

Sleep difficulties are commonly reported by patients with epilepsy and can have a detrimental impact on overall quality of life. The purpose of this pilot study was to assess the efficacy of a psychotherapeutic approach, namely Cognitive Behavioral Therapy for Insomnia (CBT-I), in improving sleep quality in patients with epilepsy. Twenty outpatients with epilepsy who reported poor sleep quality were randomized to either a control or CBT-I treatment group, which involved four group-based CBT-I sessions, delivered on a weekly basis. In addition to completing a range of standardized measures related to sleep quality and quality of life, participants also monitored their sleep with a self-completed sleep diary over a two-week period, on two separate occasions. Following CBT-I treatment, no between-group difference was found on any sleep or quality of life measure. However, both the treatment and control groups improved on measures of sleep quality, quality of life, sleep hygiene behaviors, and dysfunctional beliefs about sleep. These findings suggest that sleep monitoring alone may have the potential for prompting healthy behavior change in this clinical population.

Automatic sleep stage classification based on subcutaneous EEG in patients with epilepsy

Background

The interplay between sleep structure and seizure probability has previously been studied using electroencephalography (EEG). Combining sleep assessment and detection of epileptic activity in ultralong-term EEG could potentially optimize seizure treatment and sleep quality of patients with epilepsy. However, the current gold standard polysomnography (PSG) limits sleep recording to a few nights. A novel subcutaneous device was developed to record ultralong-term EEG, and has been shown to measure events of clinical relevance for patients with epilepsy. We investigated whether subcutaneous EEG recordings can also be used to automatically assess the sleep architecture of epilepsy patients.

Method

Four adult inpatients with probable or definite temporal lobe epilepsy were monitored simultaneously with long-term video scalp EEG (LTV EEG) and subcutaneous EEG. In total, 11 nights with concurrent recordings were obtained. The sleep EEG in the two modalities was scored independently by a trained expert according to the American Academy of Sleep Medicine (AASM) rules. By using the sleep stage labels from the LTV EEG as ground truth, an automatic sleep stage classifier based on 30 descriptive features computed from the subcutaneous EEG was trained and tested.

Results

An average Cohen’s kappa of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\kappa = 0.78\pm 0.02$$\end{document}κ=0.78±0.02 was achieved using patient specific leave-one-night-out cross validation. When merging all sleep stages into a single class and thereby evaluating an awake–sleep classifier, we achieved a sensitivity of 94.8% and a specificity of 96.6%. Compared to manually labeled video-EEG, the model underestimated total sleep time and sleep efficiency by 8.6 and 1.8 min, respectively, and overestimated wakefulness after sleep onset by 13.6 min.

Conclusion

This proof-of-concept study shows that it is possible to automatically sleep score patients with epilepsy based on two-channel subcutaneous EEG. The results are comparable with the methods currently used in clinical practice. In contrast to comparable studies with wearable EEG devices, several nights were recorded per patient, allowing for the training of patient specific algorithms that can account for the individual brain dynamics of each patient. Clinical trial registered at ClinicalTrial.gov on 19 October 2016 (ID:NCT02946151).

G, Calderon O, Moreno-Gonzalez I. Modifiable Risk Factors for Alzheimer's Disease

Since first described in the early 1900s, Alzheimer's disease (AD) has risen exponentially in prevalence and concern. Research still drives to understand the etiology and pathogenesis of this disease and what risk factors can attribute to AD. With a majority of AD cases being of sporadic origin, the increasing exponential growth of an aged population and a lack of treatment, it is imperative to discover an easy accessible preventative method for AD. Some risk factors can increase the propensity of AD such as aging, sex, and genetics. Moreover, there are also modifiable risk factors-in terms of treatable medical conditions and lifestyle choices-that play a role in developing AD. These risk factors have their own biological mechanisms that may contribute to AD etiology and pathological consequences. In this review article, we will discuss modifiable risk factors and discuss the current literature of how each of these factors interplay into AD development and progression and if strategically analyzed and treated, could aid in protection against this neurodegenerative disease.

Effect of sleep quality on memory, executive function, and language performance in patients with refractory focal epilepsy and controlled epilepsy versus healthy controls - A prospective study

We aimed to evaluate the effect of sleep quality on memory, executive function, and language performance in patients with refractory focal epilepsy and controlled epilepsy and compare these with healthy individuals. We prospectively enrolled 37 adolescent and adult patients with refractory focal epilepsy (Group 1) and controlled epilepsy (Group 2) in each group. History pertaining to epilepsy and sleep were recorded, and all patients underwent overnight polysomnography. Language, memory, and executive function assessments were done using Western Aphasia Battery, Post Graduate Institute (PGI) memory scale, and battery of four executive function tests (Trail Making Test A & B, Digit symbol test, Stroop Task, and Verbal Fluency Test), respectively. Forty age- and sex-matched controls were also included in the study. Significant differences were noted in both objective and subjective sleep parameters among all the groups. On polysomnography, parameters like total sleep time, sleep efficiency, sleep latency, and rapid eye movement (REM) latency were found to be significantly worse in Group 1 as compared with Group 2. Cognitive and executive parameters were significantly impaired in Group 1. Shorter total sleep time, poorer sleep efficiency, and prolonged sleep latencies were observed to be associated with poor memory and executive function in patients with refractory epilepsy. Our study strongly suggests that sleep disturbances, mainly shorter total sleep time, poor sleep efficiency, and prolonged sleep latencies, are associated with impaired memory and executive function in patients with refractory focal epilepsy and to a lesser extent, among those with medically controlled epilepsy.

Sleep and Behavior Problems in Children With Epilepsy

We designed a cross-sectional study to examine the association between sleep and behavior problems in toddlers and preschool-age children with epilepsy. We found that 71 (78.9%) children slept less than 10 hours in a 24-hour period according to the actigraphy, with 75 (83.3%) children waking for more than an hour during nocturnal sleep. Twenty-five (27.8%) children usually or sometimes had an inconsistent bedtime, and 24 (26.7%) did not sleep the same amount each day. Twenty-nine (32.2%) and 18 (20.0%) children had an internalizing and externalizing problem in clinical range, respectively. Sleep anxiety was significantly (p < .01) associated with increased internalizing and externalizing problems, even after the relevant epilepsy variables were controlled for. Findings from our study suggest that screening of sleep and behavior problems should be part of routine epilepsy care to identify children with problematic sleep and unrecognized sleep disorders and those at risk of behavioral dysfunction.

The effects of service dogs on psychosocial health and wellbeing for individuals with physical disabilities or chronic conditions

Purpose: To evaluate the effects of service dogs on psychosocial health and indicators of wellbeing among individuals with physical disabilities or chronic conditions.Materials and methods: A total of 154 individuals participated in a cross-sectional survey including 97 placed with a mobility or medical service dog and 57 on the waitlist to receive one. Hierarchical regression evaluated the effect of having a service dog on standardized measures of psychosocial health (Pediatric Quality of Life Inventory) as well as anger, companionship, and sleep disturbance (Patient Reported Outcome Measurement Information System). Among those with a service dog, the Monash Dog-Owner Relationship Scale quantified the human-animal bond.Results: Results indicated that compared to those on the waitlist, individuals with a service dog exhibited significantly better psychosocial health including higher social, emotional, and work/school functioning. There was no significant effect of having a service dog on anger, companionship, or sleep disturbance. Among those with a service dog, emotional closeness, dog-owner interaction, and amount of time since the service dog was placed were weak correlates of outcomes.Conclusions: Findings suggest that service dogs may have measurable effects on specific aspects of psychosocial health for individuals with physical disabilities or chronic conditions.Implications for rehabilitationHealth care providers should recognize that in addition to the functional benefits service dogs are trained to provide, they can also provide their handlers with psychosocial benefits from their assistance and companionship.Results indicate that having a service dog was related to better emotional functioning, social functioning, and work/school functioning. Areas with no significant relationship with having a service dog included social companionship, sleep, and anger.Although findings are from a large and representative sample of mobility and medical service dogs, there may be individual differences in how service dogs affect the psychosocial health of their handlers.

The impact of sleep characteristics and epilepsy variables on memory performance in patients with focal seizures

Disturbed sleep can negatively affect overnight memory retention as well as new learning the subsequent day. In healthy participants, positive associations between memory performance and sleep characteristics (e.g., time spent in slow-wave sleep [SWS]) have been detected. In a previous study, we found that SWS was much reduced in patients with focal seizures, but when correlations between memory complaints and various sleep characteristics were considered, the only significant relationship was with the time to onset of rapid eye movement (REM) sleep (i.e., REM latency). In this study, we investigated the relationships between sleep, epilepsy, and objective memory performance variables. Twenty-five patients with focal seizures had their memory tested while undergoing a two-day ambulatory electroencephalography (EEG). The sleep variables of interest were the percentage of time spent in SWS (%SWS) and REM latency. Epilepsy variables included the presence of (1) seizures, (2) interictal epileptiform discharges, and/or (3) hippocampal lesions as well as site of seizure origin (temporal vs extratemporal). Overnight retention (of autobiographical events, a story, and a complex geometric figure) and the ability to learn a word list on day 2 were the measures of memory. A significant positive correlation was found between word-list learning and %SWS during the previous night. A significant negative correlation was observed between REM latency and overnight retention of autobiographical events. Overnight retention scores for the story and geometric figure were not related to sleep characteristics but were negatively affected by the presence of epileptiform activity. Story retention was also worse for temporal lobe epilepsy (TLE) than for patients with extratemporal epilepsy (ETE). Those with hippocampal lesions were more impaired than those without lesions on word-list learning, autobiographical events' retention, and story retention. When multiple contributing factors were entered into regression analyses, %SWS was found to be the best predictor of subsequent word-list learning, whereas the presence of a hippocampal lesion was the best predictor of overnight retention of autobiographical events and a story. These findings provide further evidence of the ways in which particular sleep characteristics are associated with memory and suggest that treatment of sleep disturbances in patients with epilepsy might be helpful for improving their performance.

Overnight Video-Polysomnographic Studies in Children with Intractable Epileptic Encephalopathies

Background

The aim of this study was to assess sleep architecture and respiration during sleep in children with intractable epileptic encephalopathies using overnight video-polysomnography (V-PSG).

Material/Methods

Between 2015 to 2017 overnight V-PSG recordings were made for 31 children (22 boys and 9 girls) with intractable epileptic encephalopathy with a mean age of 6.78±3.61 years and a mean body mass index (BMI) of 15.83±3.16 kg/m³. Thirty-one healthy children were matched for sex, age, and BMI as the control group. The phases of sleep studied included rapid eye movement (REM) sleep, and non-REM (NREM) phases NREM 1, NREM 2, and NREM 3. Respiratory function during sleep was evaluated.

Results

Children with epileptic encephalopathies receiving antiepileptic treatment had significantly decreased total sleep time (TST) (p=0.038), significantly increased percentage of NREM1 (p=0.033), and a significantly lower percentage of total REM (p<0.0001), compared with the control group. All children 31/31 (100%) with epileptic encephalopathies had interictal epileptiform discharges, and 4/31 (12.9%) had ictal events. The number of respiratory events did not differ significantly between the two groups (p=0.118), but children in the epileptic encephalopathy group had a significantly shorter average duration (p=0.008) and longest duration (p=0.048) of respiratory events. Average (p=0.006) and least (p=0.0004) oxygen saturation (SatO₂) were significantly lower in children with epileptic encephalopathies compared with the control group.

Conclusions

Children with epileptic encephalopathies had altered sleep architecture and marked oxygen desaturation, which supports the need for referral of children with epileptic encephalopathy for overnight sleep evaluation.

Parental Perception of Comorbidities in Children With Dravet Syndrome

BACKGROUND

We hypothesized that children with Dravet syndrome may have additional common features beyond seizures and cognitive impairment. To address this gap in knowledge, we conducted a survey of caregivers of children with Dravet syndrome to identify and quantify their perception of associated symptoms in this population.

METHODS

An electronic survey was developed in REDcap (Research Electronic Data Capture) and sent via e-mail to the participants on the Dravet Syndrome Foundation e-mail list. Questions focused on eating, sleep, behavior, and other symptoms that might be related to Dravet syndrome. The questions were assessed using a four-point Likert scale (e.g., strongly agree to strongly disagree). Results were later dichotomized for analysis. Logistic regression was used to calculate odds ratios of various demographic factors potentially associated with symptoms. Multivariable models were constructed using backward elimination to assess the relationship among a variety of symptoms.

RESULTS

There were 202 respondents, 96% were parents of a child with Dravet syndrome (the remainder were grandparents or guardians); 90.5% were female. The median age of the affected child was eight years (interquartile range five to 14), 50% were male, and 90.5% were reported to have a known SCN1A mutation. At least one symptom associated with appetite was reported in 99% of respondents, 82% reported a disturbance of sleep, one third reported autonomic symptoms, and 75% reported problems with gait. Inattention and perseveration were reported more commonly than other behavioral disturbances.

SIGNIFICANCE

Caregivers have the perception of many symptoms in children with Dravet syndrome in addition to those that have been previously reported, including appetite, sleep, gait, and behavior. Many of these can significantly affect quality of life for both the child and the caregiver.