Obstructive sleep apnea in refractory epilepsy: A pilot study investigating frequency, clinical features, and association with risk of sudden unexpected death in epilepsy

Impaired post-sleep apnea autonomic arousals in patients with drug-resistant epilepsy

OBJECTIVE

Sudden and unexpected deaths in epilepsy (SUDEP) pathophysiology may involve an interaction between respiratory dysfunction and sleep/wake state regulation. We investigated whether patients with epilepsy exhibit impaired sleep apnea-related arousals.

METHODS

Patients with drug-resistant (N = 20) or drug-sensitive (N = 20) epilepsy and obstructive sleep apnea, as well as patients with sleep apnea but without epilepsy (controls, N = 20) were included. We explored (1) the respiratory arousal threshold based on nadir oxygen saturation, apnea-hypopnea index, and fraction of hypopnea among respiratory events; (2) the cardiac autonomic response to apnea/hypopnea quantified as percentages of changes from the baseline in RR intervals (RRI), high (HF) and low (LF) frequency powers, and LF/HF.

RESULTS

The respiratory arousal threshold did not differ between groups. At arousal onset, RRI decreased (-9.42%) and LF power (179%) and LF/HF ratio (190%) increased. This was followed by an increase in HF power (118%), p < 0.05. The RRI decrease was lower in drug-resistant (-7.40%) than in drug-sensitive patients (-9.94%) and controls (-10.91%), p < 0.05. LF and HF power increases were higher in drug-resistant (188%/126%) than in drug-sensitive patients (172%/126%) and controls (177%/115%), p < 0.05.

CONCLUSIONS

Cardiac reactivity following sleep apnea is impaired in drug-resistant epilepsy.

SIGNIFICANCE

This autonomic dysfunction might contribute to SUDEP pathophysiology.

Sleepiness in neurological disorders

Sleepiness is a frequent and underrecognized symptom in neurological disorders, that impacts functional outcomes and quality of life. Multiple and potentially additive factors might contribute to sleepiness in neurological disorders, including sleep quality alterations, circadian rhythm disorders, drugs, and sleep disorders including sleep apnea or central disorders of hypersomnolence. Physician awareness of the possible symptoms of hypersomnolence, and associated causes is of crucial importance to allow proper identification and treatment of underlying causes. This review first provides a brief overview on clinical aspects of excessive daytime sleepiness, and diagnosis tools, then examines its frequency and mechanisms in various neurological disorders, including neurodegenerative disorders, multiple sclerosis, autoimmune encephalitis, epilepsy, and stroke.

Electroencephalography characteristics related to risk of sudden unexpected death in epilepsy in patients with Dravet syndrome

Objective

To investigate the quantitative electroencephalography (EEG) features associated with a high risk of sudden unexpected death in epilepsy (SUDEP) in patients with Dravet syndrome (DS).

Methods

Patients with DS and healthy controls (HCs) who underwent EEG were included in the study. EEG signals were recorded using a 21 channel digital EEG system, and pre-processed data were analyzed to identify quantitative EEG features associated with a high SUDEP risk. To assess the risk of SUDEP, SUDEP-7 scores were used.

Results

A total of 64 patients with DS [38 males and 26 females, aged: 128.51 ± 75.50 months (range: 23-380 months)], and 13 HCs [7 males and 6 females, aged: 95.46 ± 86.48 months (range: 13-263 months)] were included. For the absolute band power, the theta power was significantly higher in the high-SUDEP group than in the low-SUDEP group in the central brain region. For the relative band power, the theta power was also significantly higher in the high-SUDEP group than in the low-SUDEP group in the central and occipital brain regions. The alpha power was significantly lower in the high-SUDEP group than in the low-SUDEP group in the central and parietal brain regions.

Conclusion

Patients with high SUDEP-7 scores have different EEG features from those with low SUDEP-7 scores, suggesting that EEG may be used as a biomarker of SUDEP in DS.

Significance

Early intervention in patients with DS at a high risk of SUDEP can reduce mortality and morbidity. Patients with high theta band powers warrant high-level supervision.

Epilepsy risk awareness and background factors in patients with epilepsy and family caregivers

OBJECTIVES

Patients with epilepsy are at risk of various injuries throughout their lives. Awareness of patients and family caregivers about risk factors and self-care prevents potential injuries. This study aimed to investigate epilepsy risk awareness and background factors in patients with epilepsy and family caregivers.

METHODS

This descriptive study was conducted with the recruitment of 120 patients with epilepsy and 120 family caregivers who were referred to the Neurological Clinic of Tabriz Razi Hospital in Iran. Data was collected using Persian version of the epilepsy risk awareness questionnaires for patients (3rd Edition) and family caregivers.

RESULTS

The average age of the patients (65.8% women) was 29.2 and of the family caregivers (58.3% women) 41.5 years. The average score of risk awareness in family caregivers was 82.6 ± 8.8 and higher than that in patients with epilepsy 84.9 ± 8.5 (obtainable score: 0-120). Compared to the maximum score, the average scores of both groups in all domains including epilepsy, personal security, physical health, and mental health were low. A statistically significant relationship was observed between the mean scores of risk awareness and some background variables.

CONCLUSION

The results showed that epilepsy risk awareness in patients and family caregivers is low and there is a need for education and support. By developing education programs for the patient and their family and increasing epilepsy risk awareness, patients can be protected from potential risks and their safety and quality of life can be improved.

[Alternative methods of therapy for comorbid sleep disorders as a method of choice in adult patients with epilepsy]

OBJECTIVE

Systematization and generalization of data from domestic and foreign literature on alternative methods of treatment of sleep disorders in epilepsy.

MATERIAL AND METHODS

The search for data from domestic and foreign literary sources was carried out in the electronic databases Medline (PubMed), Scopus, Web of Science, eLibrary, CyberLeninka, Google Scholar.

RESULTS

The data of modern randomized trials, meta-analyzes on the effectiveness of various non-traditional methods as a method of choice for epilepsy with comorbid sleep disorders have been analyzed.

CONCLUSIONS

Complementary (alternative) treatments have many advantages over the classical pharmacotherapy of sleep disorders in epilepsy, in the form of non-invasiveness, low incidence of side-effects, ease of use, and lack of a dose-dependent effect. Of course, the targets of most of the above methods are not focused and not very specific, and the sample size is too small to obtain impartial and meaningful clinical conclusions, but this once again emphasizes the urgent need for large-scale clinical trials, which is necessary to develop evidence-based treatments for comorbid sleep disorders in epilepsy.

[The impact of antiepileptic therapy on sleep disorders in women with epilepsy]

OBJECTIVE

To analyze the frequency of various sleep disorders in patients with epilepsy receiving antiepileptic therapy.

MATERIAL AND METHODS

Sixty-four women were selected from the register of patients with epilepsy and other paroxysmal conditions. The group consisted of young and middle-aged women (36.9±13.5 years), all patients received antiepileptic therapy. To diagnose sleep disorders, we used a sequential algorithm for clinical examination supplemented by instrumental methods according to indications (polysomnography, respiratory monitoring).

RESULTS

The duration of epilepsy was 15.7±7.6 years, the disease was represented by three forms: structural (n=15, 23.4%), genetic (n=32, 50%) and unspecified (n=17, 26.6%). Sleep disorders were common among female patients with epilepsy (43.7%), they are most frequently combined with genetic epilepsy (18.7%), and represented by: insomnia (43%) mild to moderately severe breathing disorders (32%) and sleep movement disorders (25%). Sleep disorders were combined with symptoms of depression in the majority of patients (71%). A 6-month follow-up evaluation of nighttime sleep parameters after treatment showed a decrease in the frequency of sleep disorders to 25%; scores on the Epworth Sleepiness Scale significantly decreased to 6.7±3.6. A change in antiepileptic therapy in patients with sleep breathing disorders resulted in a marked regression of the Apnea-Hypopnea Index (9.2±2.5 points; p=0.003). However, there were no significant changes in the severity of sleep movement disorders.

CONCLUSION

Sleep disorders are common in patients with epilepsy, in most cases they are associated with mood disorders, and may regress after optimization of antiepileptic therapy.

Sleep Disturbances in Neurological Disease: A Target for Intervention

Sleep is a biological function required for neurological and general health, but a significant and under-recognized proportion of the population has disturbed sleep. Here, we briefly overview the biology of sleep, sleep requirements over the lifespan, and common sleep disorders. We then turn our attention to five neurological diseases that significantly contribute to global disease burden and neurology practice makeup: epilepsy, headache, ischemic stroke, Parkinson's disease, and Alzheimer's disease. For each disease, we review evidence that sleep disturbances contribute to disease risk and severity and discuss existing data that addressing sleep disturbances may have disease-modifying effects. We provide recommendations derived from the literature and existing clinical guidelines to facilitate the evaluation and management of sleep disturbances within the context of each neurological disease. Finally, we synthesize identified needs and commonalities into future directions for the field and practical sleep-related recommendations for physicians caring for patients at risk for or currently suffering from neurological disease.

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.

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 and Temporal Lobe Epilepsy – Associations, Mechanisms and Treatment Implications

In this systematic review, we aim to describe the association between temporal lobe epilepsy (TLE) and sleep, with bidirectional links in mechanisms and therapeutic aspects. Sleep stages may variably impact seizure occurrence, secondary generalization and the development, frequency and distribution of interictal epileptiform discharges. Conversely, epilepsy affects sleep micro- and macroarchitecture. TLE, the most frequent form of drug resistant epilepsy (DRE), shares an enduring relationship with sleep, with some intriguing potential mechanisms specific to anatomic localization, linking the two. Sleep characteristics of TLE may also inform localizing properties in persons with DRE, since seizures arising from the temporal lobe seem to be more common during wakefulness, compared to seizures of extratemporal origin. Polysomnographic studies indicate that persons with TLE may experience excessive daytime somnolence, disrupted sleep architecture, increased wake after sleep onset, frequent shifts in sleep stages, lower sleep efficiency, decreased rapid eye movement (REM) sleep, and possibly, increased incidence of sleep apnea. Limited literature suggests that effective epilepsy surgery may remedy many of these objective and subjective sleep-related concerns, via multipronged effects, apart from reduced seizure frequency. Additionally, sleep abnormalities also seem to influence memory, language and cognitive-executive function in both medically controlled and refractory TLE. Another aspect of the relationship pertains to anti-seizure medications (ASMs), which may contribute significantly to sleep characteristics and abnormalities in persons with TLE. Literature focused on specific aspects of TLE and sleep is limited, and heterogeneous. Future investigations are essential to understand the pathogenetic mechanisms linking sleep abnormalities on epilepsy outcomes in the important sub-population of TLE.

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.

Expert Opinion: Managing sleep disturbances in people with epilepsy

Poor sleep and daytime sleepiness are common in people with epilepsy. Sleep disorders can disrupt seizure control and in turn sleep and vigilance problems can be exacerbated by seizures and by antiepileptic treatments. Nevertheless, these aspects are frequently overlooked in clinical practice and a clear agreement on the evidence-based guidelines for managing common sleep disorders in people with epilepsy is lacking. Recently, recommendations to standardize the diagnostic pathway for evaluating patients with sleep-related epilepsies and comorbid sleep disorders have been presented. To build on these, we adopted the Delphi method to establish a consensus within a group of experts and we provide practical recommendations for identifying and managing poor night-time sleep and daytime sleepiness in people with epilepsy. We recommend that a comprehensive clinical history of sleep habits and sleep hygiene should be always obtained from all people with epilepsy and their bed partners. A psychoeducational approach to inform patients about habits or practices that may negatively influence their sleep or their vigilance levels should be used, and strategies for avoiding these should be applied. In case of a suspected comorbid sleep disorder an appropriate diagnostic investigation should be performed. Moreover, the possible presence of sleep fragmentation induced by sleep-related seizures should be ruled out. Finally, the dose and timing of antiepileptic medications and other co-medications should be optimized to improve nocturnal sleep and avoid daytime sedation.

Risk of sudden unexpected death in people with epilepsy and obstructive sleep apnea

This study aimed to determine whether severity of newly diagnosed obstructive sleep apnea (OSA) in people with epilepsy is associated with elevated sudden unexpected death in epilepsy (SUDEP) risk as calculated by the revised SUDEP-7 Inventory (rSUDEP-7). To this aim, a retrospective cross-sectional study was conducted at a single academic center. Adults ≥18 years of age with epilepsy and newly diagnosed OSA were retrospectively identified via electronic health records. Analysis was performed for subjects with confirmed epilepsy, OSA, and complete diagnostic PSG and rSUDEP-7 data. OSA severity was categorized as mild, moderate or severe. Logistic regression analysis was used to determine the association between OSA severity and rSUDEP-7 scores, adjusting for significantly different baseline characteristics. Of 86 subjects, OSA severity was classified as mild 38(44.2 %), moderate 25(29.1 %), and severe 23(26.7 %). Multivariate logistic regression demonstrated that severe OSA was significantly associated with rSUDEP-7 ≥ 5 after adjusting for congestive heart failure and diabetes (OR:4.08,p = 0.046,CI:1.04-16.28), but was attenuated when male gender was added to the model (OR:3.91,p = 0.067,CI:0.91-16.77). In conclusion, severe OSA is associated with elevated SUDEP risk. As a treatable disorder, OSA may thus represent a modifiable SUDEP risk factor. However, future confirmatory studies involving the prospective, longitudinal evaluation of SUDEP from broader populations are required.

Frequency of sleep-disordered breathing in a referral population of Somali-Americans

STUDY OBJECTIVES

To study the frequency of obstructive sleep apnea (OSA) in individuals of Somali ancestry referred to a clinical sleep laboratory.

METHODS

This was a retrospective study using a large registry of patients who underwent diagnostic polysomnography between 17 November 2009 and 15 April 2017. Adult patients self-reporting as being of Somali origin were confirmed using the electronic medical record.

RESULTS

Somali-American patients comprised approximately 0.2% of all patients undergoing polysomnography at the Mayo Clinic Center for Sleep Medicine. The median (interquartile range) age was 52.6 (35, 64) years with 66% males and a median (interquartile range) body mass index of 31.2 (27, 34) kg/m². OSA was diagnosed in 77% of patients, with approximately 50% having moderate to severe OSA. OSA was more frequent in older patients and similar between men and women, and only age predicted an OSA diagnosis while sex and body mass index did not. All patients with diabetes mellitus type 2 (n = 7) and all but one of the hypertensive patients (n = 11) had significant OSA.

CONCLUSIONS

Less than 0.2% of all patients undergoing polysomnography at Mayo Clinic were of Somali origin. Moderate-to-severe OSA was frequent in this select sample of individuals who underwent polysomnography. Hypertension and diabetes were present in most Somali-Americans with OSA. Given the rising prevalence of diabetes and hypertension in Somali-Americans, and the likely high prevalence of undiagnosed OSA, screening Somali-Americans for sleep disorders may contribute importantly to prevention, early detection, and reduction of cardiovascular and metabolic diseases in this population.

Obstructive sleep apnea and sudden unexpected death in epilepsy in unselected patients with epilepsy: are they associated?

PURPOSE

We aimed to determine (1) the frequency of high-risk sudden unexpected death in epilepsy (SUDEP) in patients with epilepsy who have had obstructive sleep apnea (OSA) in different stages of sleep using the revised SUDEP risk inventory (rSUDEP-7) score instrument and (2) the factors associated with high risk SUDEP in patients with epilepsy who have had OSA.

METHODS

We conducted a cross-sectional study of consecutive subjects who are more than 15 years old without known sleep disorders, recruited from a single epilepsy clinic in a tertiary care facility. Participants underwent polysomnography. Scoring was performed by two blinded board-certified sleep physicians. The relationships between rSUDEP-7 scores and OSA measures were evaluated using Wilcoxon rank-sum test, chi-squared test, and quantile regression.

RESULTS

Our study population consisted of 95 participants. Overall median (IQR) apnea-hypopnea index (AHI) of our populations was 2.3 (0.7,7.5) events rate per hour; 12 (75%) patients had moderate OSA and 4 (25%) patients had severe OSA. Nine patients had a rSUDEP-7 score of 5 to 7. There was no significant difference between total rSUDEP-7 score or rSUDEP-7 score of > 5 or < 5 and total AHI, supine AHI, non-supine AHI, NREM AHI, or REM AHI; similarly, (2) there was no significant difference in total rSUDEP-7 score between AHI of < 15 or > 15.

CONCLUSION

Our study reveals no association between AHI score, OSA, and total rSUDEP-7 score or rSUDEP-7 score of > 5. The pathophysiology underlying SUDEP appears complex. We need further studies on SUDEP to help elucidate the cardiorespiratory mechanisms and predisposing factors.

Rapid eye movement sleep disturbance in patients with refractory epilepsy: A polysomnographic study

OBJECTIVE/BACKGROUND

Patients with epilepsy have disrupted sleep architecture and a higher prevalence of sleep disturbance. Moreover, obstructive sleep apnea (OSA) is more common among patients with refractory epilepsy. Few studies have compared subjective sleep quality, sleep architecture, and prevalence of OSA between patients with refractory epilepsy and those with medically controlled epilepsy. Therefore, this study aimed to evaluate the differences in sleep quality, sleep architecture, and prevalence of OSA between patients with refractory epilepsy and patients with medically controlled epilepsy.

PATIENTS

This retrospective case-control study included 38 patients with refractory epilepsy and 96 patients with medically controlled epilepsy. Sleep parameters and indices of sleep-related breathing disorders were recorded by standard in-laboratory polysomnography. The scores from sleep questionnaires on sleep quality and daytime sleepiness were compared between the two groups.

RESULTS

Patients with refractory epilepsy versus medically controlled epilepsy had statistically significantly decreased rapid eye movement (REM) sleep (13.5 ± 6.1% vs. 16.2 ± 6.1%) and longer REM latency (152.2 ± 84.1 min vs. 117.2 ± 61.9 min). Further, no differences were found in the prevalence of sleep-related breathing disorders, subjective sleep quality, prevalence of daytime sleepiness, and quality of life. Although not statistically significant, patients with refractory epilepsy have a lower rate of OSA compared with those with medically controlled epilepsy (21.1% vs. 30.2%).

CONCLUSIONS

Patients with refractory epilepsy had more disrupted REM sleep regulation than those with medically controlled epilepsy. Although patients with epilepsy have a higher risk of OSA, in this study patients with refractory epilepsy were not susceptible to OSA.

Sleep and Epilepsy: a Focused Review of Pathophysiology, Clinical Syndromes, Co-morbidities, and Therapy

A healthy brain requires balancing of waking and sleeping states. The normal changes in waking and sleeping states result in neurophysiological conditions that either increase or decrease the tendency of seizures and interictal discharges to occur. This article reviews the manifold and complex relationships between sleep and epilepsy and discusses treatment of the sleep-related epilepsies. Several forms of epilepsy predominantly or exclusively manifest during sleep and seizures tend to arise especially from light NREM sleep. Diagnostic interictal epileptiform discharges on the electroencephalogram are also most likely to be activated during deep NREM sleep stage N3. Epileptiform discharges and antiepileptic medications may in turn detrimentally impact sleep. Co-morbid sleep disorders also have the potential to worsen seizure control. Sleep has an important key association with sudden unexpected death in epilepsy (SUDEP). Further research is necessary to understand the complex relationships between sleep and epileptic disorders and their treatments.

Obstructive sleep apnea risk in patients with focal versus generalized epilepsy

OBJECTIVE

Obstructive sleep apnea (OSA) is common in patients with epilepsy (PWE), and treatment may improve seizure control. However, OSA is often undiagnosed in PWE, and understanding of the risk profile for OSA is important. In this study, we sought to determine if OSA risk is similar in patients with generalized versus focal epilepsy.

METHODS

We recruited 115 patients presenting to the Rutgers-Robert Wood Johnson Epilepsy Clinic with focal or generalized epilepsy. Obstructive sleep apnea risk was assessed using the Sleep Apnea Scale of the Sleep Disorders Questionnaire (SA-SDQ). Sleepiness was assessed using the Epworth Sleepiness Scale (ESS). Demographic and clinical information was gathered from the electronic medical record. Unadjusted and adjusted analyses were carried out to assess differences in the SA-SDQ between patients with generalized versus focal epilepsy. Further analyses were done to assess the relationship between seizure frequency, epilepsy type, and the SA-SDQ.

RESULTS

Unadjusted mean SA-SDQ scores, as well as scores high enough to represent likely OSA, were similar in patients with generalized versus focal epilepsy. However, in adjusted analyses, patients with generalized epilepsy had a significantly higher mean SA-SDQ score. Older age, higher body mass index (BMI), and a history of hypertension (HTN) were also associated with higher SA-SDQ scores. Sleep Apnea Scale of the Sleep Disorders Questionnaire scores were not significantly affected by the presence of a seizure within the prior one month or six months. Average ESS scores and the percentage of scores consistent with an abnormal degree of sleepiness were statistically similar in patients with generalized versus focal epilepsy.

SIGNIFICANCE

Our study suggests that patients with generalized epilepsy have a higher risk of OSA. Further studies measuring OSA directly as well as assessing potential benefits of treatment are needed.

Sleep-Wake Disorders in Childhood

PURPOSE OF REVIEW

The presentation of sleep issues in childhood differs from the presentation in adulthood and may be more subtle. Sleep issues may affect children differently than adults, and distinct treatment approaches are often used in children.

RECENT FINDINGS

Sodium oxybate was approved by the US Food and Drug Administration (FDA) in October 2018 for an expanded indication of treatment of sleepiness or cataplexy in patients with narcolepsy type 1 or narcolepsy type 2 aged 7 years or older, with side effect and safety profiles similar to those seen in adults. Restless sleep disorder is a recently proposed entity in which restless sleep, daytime sleepiness, and often iron deficiency are observed, but children do not meet the criteria for restless legs syndrome or periodic limb movement disorder.

SUMMARY

Children's sleep is discussed in this article, including normal sleep patterns and effects of insufficient sleep. Sleep disorders of childhood are reviewed, including insomnia, obstructive sleep apnea, restless legs syndrome, parasomnias, narcolepsy, and Kleine-Levin syndrome. Children with neurologic issues or neurodevelopmental disorders frequently have sleep disorders arising from an interaction of heterogeneous factors. Further attention to sleep may often be warranted through a polysomnogram or referral to a pediatric sleep specialist. Sleep disorders may cause indelible effects on children's cognitive functioning, general health, and well-being, and awareness of sleep disorders is imperative for neurologists who treat children.

Epilepsy and Its Interaction With Sleep and Circadian Rhythm

Growing evidence shows the bidirectional interactions between sleep, circadian rhythm, and epilepsy. Comprehending how these interact with each other may help to advance our understanding of the pathophysiology of epilepsy and develop new treatment strategies to improve seizure control by reducing the medication side effects and the risks associated with seizures. In this review, we present the overview of different temporal patterns of interictal epileptiform discharges and epileptic seizures over a period of 24 consecutive hours. Furthermore, we discuss the underlying mechanism of the core-clock gene in periodic seizure occurrences. Finally, we outline the role of circadian patterns of seizures on seizure forecasting models and its implication for chronotherapy in epilepsy.

Prevention of sudden unexpected death in epilepsy: current status and future perspectives

Introduction: Sudden unexpected death in epilepsy (SUDEP) affects about 1 in 1000 people with epilepsy, and even more in medically refractory epilepsy. As most people are between 20 and 40 years when dying suddenly, SUDEP leads to a considerable loss of potential life years. The most important risk factors are nocturnal and tonic-clonic seizures, underscoring that supervision and effective seizure control are key elements for SUDEP prevention. The question of whether specific antiepileptic drugs are linked to SUDEP is still controversially discussed. Knowledge and education about SUDEP among health-care professionals, patients, and relatives are of outstanding importance for preventive measures to be taken, but still poor and widely neglected.Areas covered: This article reviews epidemiology, pathophysiology, risk factors, assessment of individual SUDEP risk and available measures for SUDEP prevention. Literature search was done using Medline and Pubmed in October 2019.Expert opinion: Significant advances in the understanding of SUDEP were made in the last decade which allow testing of novel strategies to prevent SUDEP. Promising current strategies target neuronal mechanisms of brain stem dysfunction, cardiac susceptibility for fatal arrhythmias, and reliable detection of tonic-clonic seizures using mobile health technologies.Abbreviations: AED, antiepileptic drug; CBZ, carbamazepine; cLQTS, congenital long QT syndrome; EMU, epilepsy monitoring unit; FBTCS, focal to bilateral tonic-clonic seizures; GTCS, generalized tonic-clonic seizures; ICA, ictal central apnea; LTG, lamotrigine; PCCA, postconvulsive central apnea; PGES, postictal generalized EEG suppression; SRI, serotonin reuptake inhibitor; SUDEP, sudden unexpected death in epilepsy; TCS, tonic-clonic seizures.

Risks and predictive biomarkers of sudden unexpected death in epilepsy patient

PURPOSE OF REVIEW

The current review updates our knowledge regarding sudden unexpected death in epilepsy patient (SUDEP) risks, risk factors, and investigations of putative biomarkers based on suspected mechanisms of SUDEP.

RECENT FINDINGS

The overall incidence of SUDEP in adults with epilepsy is 1.2/1000 patient-years, with surprisingly comparable figures in children in recently published population-based studies. This risk was found to decrease over time in several cohorts at a rate of -7% per year, for unknown reasons. Well established risk factors include frequency of generalized tonic-clonic seizures, while adding antiepileptic treatment, nocturnal supervision and use of nocturnal listening device appear to be protective. In contrast, recent data failed to demonstrate the predictive value of heart rate variability, periictal cardiorespiratory dysfunction, and postictal generalized electroencephalography suppression. Preliminary findings suggest that brainstem and thalamic atrophy may be associated with a higher risk of SUDEP. Novel experimental and human data support the primary role of generalized tonic-clonic seizure-triggered respiratory dysfunction and the likely contribution of altered brainstem serotoninergic neurotransmission, in SUDEP pathophysiology.

SUMMARY

Although significant progress has been made during the past year in the understanding of SUDEP mechanisms and investigation of numerous potential biomarkers, we are still missing reliable predictors of SUDEP beyond the well established clinical risk factors.

Let's talk SUDEP

Sudden unexplained death in epilepsy (SUDEP) is a devastating complication of epilepsy which was under-recognized in the recent past despite its clear importance. In this review, we examine the definition of SUDEP, revise current pathophysiological theories, discuss risk factors and preventative measures, disclose tools for appraising the SUDEP risk, and last but not least dwell upon announcing and explaining the SUDEP risk to the patients and their caretakers. We aim to aid the clinicians in their responsibility of knowing SUDEP, explaining the SUDEP risk to their patients in a reasonable and sensible way and whenever possible, preventing SUDEP. Future studies are definitely needed to increase scientific knowledge and awareness related to this prioritized topic with malign consequences.

Dead in the Night: Sleep-Wake and Time-Of-Day Influences on Sudden Unexpected Death in Epilepsy

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related death in patients with refractory epilepsy. Convergent lines of evidence suggest that SUDEP occurs due to seizure induced perturbation of respiratory, cardiac, and electrocerebral function as well as potential predisposing factors. It is consistently observed that SUDEP happens more during the night and the early hours of the morning. The aim of this review is to discuss evidence from patient cases, clinical studies, and animal research which is pertinent to the nocturnality of SUDEP. There are a number of factors which might contribute to the nighttime predilection of SUDEP. These factors fall into four categories: influences of (1) being unwitnessed, (2) lying prone in bed, (3) sleep-wake state, and (4) circadian rhythms. During the night, seizures are more likely to be unwitnessed; therefore, it is less likely that another person would be able to administer a lifesaving intervention. Patients are more likely to be prone on a bed following a nocturnal seizure. Being prone in the accouterments of a bed during the postictal period might impair breathing and increase SUDEP risk. Sleep typically happens at night and seizures which emerge from sleep might be more dangerous. Lastly, there are circadian changes to physiology during the night which might facilitate SUDEP. These possible explanations for the nocturnality of SUDEP are not mutually exclusive. The increased rate of SUDEP during the night is likely multifactorial involving both situational factors, such as being without a witness and prone, and physiological changes due to the influence of sleep and circadian rhythms. Understanding the causal elements in the nocturnality of SUDEP may be critical to the development of effective preventive countermeasures.