Sleep apnea and epilepsy: who's at risk?

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.

A polysomnographic study of slow-wave sleep loss in elderly patients with epilepsy

Objective

The primary objective is to explore what causes slow-wave sleep loss in elderly patients with epilepsy. The secondary objective is to identify the PSG characteristics in elderly patients with epilepsy. The clinical demographics, sleep architecture, sleep-related events, and interictal epileptiform discharges are to be evaluated in the objectives.

Methods

The video electroencephalography (VEEG) and polysomnogram (PSG) data from 44 elderly patients with epilepsy and 52 elderly patients with sleep disorders but without definite central nervous system diseases were analysed. This was a case-control study. The differences in the PSG sleep architecture parameters (total sleep time (TST), sleep efficiency, wake after sleep onset, etc.) and sleep-related events (apnea hypopnea index, oxygen desaturation index (ODI), periodic limb movement index, etc.) between the epilepsy and control groups. As Additionally, these parameters were assessed within the elderly patients with epilepsy, comparing the slow-wave sleep existence and slow-wave sleep loss groups, using VEEG and PSG.

Results

The epileptic group exhibited significantly lower TST (343.477 ± 96.3046min vs 389.115 ± 61.5727min, p < 0.05), rapid eye movement (%) (13.011 ± 7.5384 vs 16.992 ± 6.7025, p < 0.05), non-rapid eye movement stage 3 (%) (1.35[0,7.225] vs 3.65[0.425,13.75], p < 0.05), and sleep efficiency (%) (69.482 ± 14.1771% vs 77.242 ± 10.6171%, p < 0.05). Conversely, the ODI (25.6[9.825,51.775] events/hour vs 16.85[5.3,30.425] events/hour, p < 0.05) and spontaneous arousal index (4.0455[2.1805,6.9609] events/hour vs 2.9709[1.4747,5.0554] events/hour, p < 0.05) were significantly higher in elderly patients with epilepsy. The prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) was significantly higher in the slow-wave sleep loss group than in the slow-wave sleep existence group (100% vs 77.8%, p < 0.05). The incidence of slow-wave sleep loss was lower in patients with epilepsy aged between 75 and 85 years compared to those aged between 65 and 75 years.

Conclusion

Elderly patients with epilepsy exhibit higher levels of ODI and spontaneous arousal index. Our findings indicate that OSAHS could be a contributing factor to slow-wave sleep loss in this population. The incidence of slow-wave sleep loss was lower in patients aged above 75 years among elderly patients with epilepsy.

Bi-level VNS therapy with different therapy modes at night and daytime improves seizures and quality of life in a patient with drug-resistant epilepsy

Induction or aggravation of sleep apnea is a known side effect of vagus nerve stimulation (VNS). We report the case of a 44 year old male with drug-resistant epilepsy and depression who did not experience any seizure reduction after 1 year of VNS but a worsening of depression and daytime sleepiness. After confirming VNS-associated sleep apnea we started the first bi-level VNS therapy with standard VNS settings during daytime and reduced settings during nighttime. Anti-seizure medication remained unchanged. Within 12 months his seizure frequency was reduced by 90 % and his depression improved, permitting a cessation of his antidepressant medication. The observations made in this case have contributed to the manufacturer of VNS developing new generator models that can automatically provide bi-level VNS.

Sleep and epilepsy: A clinical and pathophysiological overview

The interaction between sleep and epilepsy is complex. A better understanding of the mechanisms linking sleep and epilepsy appears increasingly important as it may improve diagnosis and therapeutic strategies in patients with epilepsy. In this narrative review, we aim to (i) provide an overview of the physiological and pathophysiological processes linking sleep and epilepsy; (ii) present common sleep disorders in patients with epilepsy; (iii) discuss how sleep and sleep disorders should be considered in new therapeutic approaches to epilepsy such as neurostimulation; and (iv) present the overall nocturnal manifestations and differential diagnosis between epileptic seizures and parasomnia.

Sleep and respiratory abnormalities in adults with developmental and epileptic encephalopathies using polysomnography and video-EEG monitoring

This study evaluated sleep and respiratory abnormalities, and their relationship with seizures, in adults with developmental and epileptic encephalopathies (DEEs). We studied consecutive adults with DEEs undergoing inpatient video-EEG monitoring and concurrent polysomnography between December 2011 and July 2022. Thirteen patients with DEEs were included (median age: 31 years, range: 20-50; 69.2% female): Lennox-Gastaut syndrome (n = 6), Lennox-Gastaut syndrome-like phenotype (n = 2), Landau-Kleffner syndrome (n = 1), epilepsy with myoclonic-atonic seizures (n = 1), and unclassified DEEs (n = 3). Sleep architecture was often fragmented by epileptiform discharges and seizures resulting in arousals (median arousal index: 29.0 per h, range: 5.1-65.3). Moderate-to-severe obstructive sleep apnea (OSA) was observed in seven patients (53.8%). Three patients (23.1%) had tonic seizures that frequently occurred with central apnea; one met criteria for mild central sleep apnea. Of the patients with tonic seizures, two had other identifiable seizure manifestations, but in one patient, central apnea was commonly the only discernable seizure manifestation. Polysomnography during video-EEG is an effective diagnostic tool in detecting sleep and seizure-related respiratory abnormalities. Clinically significant OSA may increase the risk of comorbid cardiovascular disease and premature mortality. Treatment of epilepsy may improve sleep quality, and conversely, improved sleep, may decrease seizure burden.

Management of vagus nerve simulation therapy in the peri-operative period: Guidelines from the Association of Anaesthetists: Guidelines from the Association of Anaesthetists

Vagus nerve stimulation is a well-established treatment option for patients with drug-resistant epilepsy and has an expanding range of other clinical indications. Side effects of vagus nerve stimulation therapy include: cough; voice changes; vocal cord adduction; rarely, obstructive sleep apnoea; and arrhythmia. Patients with implanted vagus nerve stimulation devices may present for unrelated surgery and critical care to clinicians who are unfamiliar with their function and safe management. These guidelines have been formulated by multidisciplinary consensus based on case reports, case series and expert opinion to support clinicians in the management of patients with these devices. The aim is to provide specific guidance on the management of vagus nerve stimulation devices in the following scenarios: the peri-operative period; peripartum period; during critical illness; and in the MRI suite. Patients should be aware of the importance of carrying their personal vagus nerve stimulation device magnet with them at all times to facilitate urgent device deactivation if necessary. We advise that it is generally safer to formally deactivate vagus nerve stimulation devices before general and spinal anaesthesia. During periods of critical illness associated with haemodynamic instability, we also advise cessation of vagus nerve stimulation and early consultation with neurology services.

The mobile sleep medicine model in neurologic practice: Rationale and application

Background

Undiagnosed obstructive sleep apnea (OSA) is prevalent in neurological practice and significantly contributes to morbidity and mortality. OSA is prevalent in US adults and causes poor quality sleep and significant neurocognitive, cardiovascular, and cerebrovascular impairments. Timely treatment of OSA reduces cardio-cerebrovascular risks and improves quality of life. However, most of the US population has limited systematic access to sleep medicine care despite its clinical significance.

Focus

We discuss the importance of systematic screening, testing, and best-practice management of OSA and hypoventilation/hypoxemia syndromes (HHS) in patients with stroke, neurocognitive impairment, and neuromuscular conditions. This review aims to introduce and describe a novel integrated Mobile Sleep Medicine (iMSM) care model and provide the rationale for using an iMSM in general neurological practice to assist with systematic screening, testing and best-practice management of OSA, HHS, and potentially other sleep conditions.

Key points

The iMSM is an innovative, patient-centered, clinical outcome-based program that uses a Mobile Sleep Medicine Unit—a “sleep lab on wheels”—designed to improve access to OSA management and sleep care at all levels of health care system. The protocol for the iMSM care model includes three levels of operations to provide effective and efficient OSA screening, timely testing/treatment plans, and coordination of further sleep medicine care follow-up. The iMSM care model prioritizes effective, efficient, and patient-centered sleep medicine care; therefore, all parties and segments of care that receive and provide clinical sleep medicine services may benefit from adopting this innovative approach.

Insomnia and poor sleep quality are associated with poor seizure control in patients with epilepsy

OBJECTIVES

This study aimed to assess the presence of sleep disorders in patients with epilepsy and to analyse their association with seizure control.

METHODS

We performed a cross-sectional study of patients with epilepsy, recruited consecutively between September 2017 and December 2018. Patients were classified as having good seizure control (no seizures in the last 4 weeks) or poor seizure control (at least one seizure in the last 4 weeks). We performed intergroup comparisons for demographic and clinical data, insomnia (Insomnia Severity Index [ISI]), excessive daytime sleepiness (Epworth Sleepiness Scale [ESS]), sleep quality (Pittsburgh Sleep Quality Index [PSQI]), depression (Beck Depression Inventory-II [BDI-II]), and quality of life (Quality of Life in Epilepsy Inventory-10 [QOLIE-10]).

RESULTS

The sample included a total of 123 patients, of whom 31.7% had excessive daytime sleepiness (ESS≥10), 50.4% had insomnia (ISI≥10), and 53.6% had poor sleep quality (PSQI≥5). According to our multivariate analysis, presence of seizures was associated with unemployment (odds ratio [OR]=4.7; 95% confidence interval [CI], 1.36-19.2; P=.02), a higher number of antiepileptic drugs (OR=5.87; 95% CI, 1.81-27.1; P<.001), insomnia (OR=1.9; 95% CI, 1.1-9.3; P=.04), and poor sleep quality (OR=2.8; 95% CI, 1.9-10.32; P=.01).

CONCLUSIONS

Sleep disorders are common in patients with epilepsy. Insomnia and poor sleep quality were associated with poor seizure control. These findings support the hypothesis that sleep disorders constitute a significant comorbidity of epilepsy, especially in patients with poor seizure control.

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.

Identifying obstructive sleep apnea in patients with epilepsy: A cross-sectional multicenter study

OBJECTIVE

Several screening questionnaires for obstructive sleep apnea (OSA) have been introduced. No study has compared the performance of different questionnaire in the same patients with epilepsy. Herein, we compare the performance characteristics of four common questionnaires for assessing the probability of OSA in patients with epilepsy.

METHODS

This cross-sectional multicenter study was conducted among adult epilepsy patients attending neurology and general medical clinics in Thailand. Before performing full polysomnography (PSG), all participants completed the STOP-BANG, STOP-BAG, SA-SDQ, and NoSAS questionnaires. OSA was defined by apnea/ hypopnea index (AHI) criteria of AHI: ≥ 5, ≥ 15, and ≥ 30. Discriminatory ability was assessed by area under the receiver operating characteristics (ROC) curve (AUC) and likelihood ratio. To improve discriminative ability, we created 3 ranges of the score to predict lower, middle, and higher probability of OSA as defined by each diagnostic criterion.

RESULTS

A total 166 patients with epilepsy were included. OSA prevalence was 38%. Overall, NoSAS had higher AUC at all AHI criteria but not significantly higher than that of other scales. Using prediction cut-points for NoSAS of ≥ 4 and ≥ 8 to predict OSA defined by AHI ≥ 5, the likelihood ratios for the 3 ranges were 0.37, 2.22 and 9.81 respectively.

CONCLUSION

Among the 4 scales, the 2-cut-point NoSAS score had the highest discriminatory ability at each AHI cutoff.

Effects of Obstructive Sleep Apnea on Epilepsy, and Continuous Positive Airway Pressure as a Treatment Option

Purpose: To compare the characteristics of obstructive sleep apnea (OSA) between patients with epilepsy and patients without epilepsy and to investigate CPAP (Continuous Positive Airway Pressure) effect on seizures. Methods: Medical and polysomnography (PSG) data from 235 adult OSA patients with epilepsy (OE; 183 males; mean age, 49.8 years) and 268 age- and sex-matched OSA patients without epilepsy (OSE; 216 males; mean age, 51.3 years), obtained between March 2014 and May 2020 and housed in a database in a university-affiliated hospital, were retrospectively reviewed. All subjects completed surveys addressing comorbidities and medications, and sleep-related questionnaires including the Insomnia Severity Index, Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and Beck Depression Inventory-II. Results: Compared with the OSE group, the OE group reported fewer sleep-related complaints and less severe OSA-related PSG parameters, with a lower apnea-hypopnea index (24.9 vs. 33.4 events/h; p < 0.003), arousal index (23.3 vs. 30.8 events/h; p < 0.001), and oxygen desaturation index (19.6 vs. 28.8; p < 0.002). The OE group had fewer smokers and lower alcohol consumption but a higher body mass index (27.0 vs. 25.9 kg/m2; p < 0.001). No correlations were observed between OSA-related PSG parameters and epilepsy-related factors, such as age at seizure onset, seizure type, frequency of seizures, presence of nocturnal seizures, and number of antiseizure medications, in the OE group. Patients with OE who demonstrated good compliance with CPAP therapy exhibited a decrease in seizure frequency. Conclusions: The OE group exhibited less severe disease characteristics than their age- and sex-matched OSE counterparts. Nevertheless, because the coexistence of OSA and epilepsy is high, CPAP therapy can reduce the frequency of seizures. Therefore, it is important to evaluate the presence of OSA in patients with epilepsy and to treat the conditions concurrently.

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.

Reducing Sudden Unexpected Death in Epilepsy: Considering Risk Factors, Pathophysiology and Strategies

Purpose of Review

Sudden Unexpected Death in Epilepsy (SUDEP) is the commonest cause of epilepsy-related premature mortality in people with chronic epilepsy. It is the most devastating epilepsy outcome. We describe and discuss risk factors and possible pathophysiological mechanisms to elucidate possible preventative strategies to avert SUDEP.

Recent Findings

Sudden death accounts for a significant proportion of premature mortality in people with epilepsy compared to the general population. Unmodifiable risk factors include a history of neurologic insult, younger age of seizure-onset, longer epilepsy duration, a history of convulsions, symptomatic epilepsy, intellectual disability, and non-ambulatory status. Modifiable risk factors include the presence of convulsive seizures, increased seizure frequency, timely and appropriate use of antiseizure medications, polytherapy, alcoholism, and supervision while sleeping. Pathophysiology is unclear, but several possible mechanisms such as direct alteration of cardiorespiratory function, pulmonary impairment, electrocerebral shutdown, adenosine dysfunction, and genetic susceptibility suggested.

Summary

Methods to prevent SUDEP include increasing awareness of SUDEP, augmenting knowledge of unmodifiable risk factors, obtaining full seizure remission, addressing lifestyle factors such as supervision and prone positioning, and enacting protocols to increase the detection of and intervention for SUDEP. Further studies are required to characterize precisely and comprehensively SUDEP risk factors and pathophysiological drivers and develop evidence-based algorithms to minimize SUDEP in people with epilepsy.

Insomnia and poor sleep quality are associated with poor seizure control in patients with epilepsy

OBJECTIVE

This study aimed to assess the presence of sleep disorders in patients with epilepsy and to analyse their association with seizure control.

METHODS

We performed a cross-sectional study of patients with epilepsy, recruited consecutively between September 2017 and December 2018. Patients were classified as having good seizure control (no seizures in the last 4 weeks) or poor seizure control (at least one seizure in the last 4 weeks). We performed intergroup comparisons for demographic and clinical data, insomnia (Insomnia Severity Index [ISI]), excessive daytime sleepiness (Epworth Sleepiness Scale [ESS]), sleep quality (Pittsburgh Sleep Quality Index [PSQI]), depression (Beck Depression Inventory-II [BDI-II]), and quality of life (Quality of Life in Epilepsy Inventory-10 [QOLIE-10]).

RESULTS

The sample included a total of 123 patients, of whom 31.7% had excessive daytime sleepiness (ESS ≥ 10), 50.4% had insomnia (ISI ≥ 10), and 53.6% had poor sleep quality (PSQI ≥ 5). According to our multivariate analysis, presence of seizures was associated with unemployment (odds ratio [OR] = 4.7; 95% confidence interval [CI], 1.36-19.2; P = .02), a higher number of antiepileptic drugs (OR = 5.87; 95% CI, 1.81-27.1; P < .001), insomnia (OR = 1.9; 95% CI, 1.1-9.3; P = .04), and poor sleep quality (OR = 2.8; 95% CI, 1.9-10.32; P = .01).

CONCLUSIONS

Sleep disorders are common in patients with epilepsy. Insomnia and poor sleep quality were associated with poor seizure control. These findings support the hypothesis that sleep disorders constitute a significant comorbidity of epilepsy, especially in patients with poor seizure control.

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.

How much can medical management alone improve the outcome of adult drug-resistant epilepsy? An exploratory study on possibilities and limitations of combining multiple therapeutic actions

PURPOSE

Failure to control epileptic seizures with two medications, adequately chosen and dosed, indicates drug-resistant epilepsy (DRE). The chance of pharmacologically controlling seizures is low for patients with DRE and uncontrolled seizures who are not candidates for surgery, who have already undergone surgery, or who already had a vagus nerve stimulator (VNS) placed. Patients experiencing these conditions must instead rely on medical management of their seizures, and there is no breakthrough solution on the horizon. Medical care of DRE might be optimized by systematically considering factors that promote and inhibit breakthrough seizures. For example, seizure control could be enhanced through measures such as increasing the frequency of follow-up visits, tracking treatment plan compliance, treating sleep disorders, rational polypharmacy, adjusting drug administration to achieve higher levels when seizures are more likely and educating patients on seizure triggers. A systematic and simultaneous implementation of all of these measures is likely to yield a sizable, clinically relevant, improvement. This paper presents an exploratory study on the effects of implementing such an approach, specifically evaluating this method's impact on seizure frequency.

METHODS

I performed a retrospective chart review of 659 consecutive adult patients with epilepsy followed up at the University of Utah and at the Salt Lake City VA Medical center using the multimodal approach described above. I identified 27 patients who had DRE and uncontrolled seizures and in whom a medical management optimization protocol was implemented. I measured these patients' seizure frequency at the beginning and the end of the study period and compared the results with those of a matching control group of 48 patients.

RESULTS

The optimization protocol did not increase the number of seizure-free patients with DRE; however, it was effective in minimizing seizure frequency in patients whose seizures remained uncontrolled. Among these patients, the median seizure frequency dropped by 64% in the optimization group but did not change in the control group.

CONCLUSIONS

Despite the high occurrence of DRE, there is no accepted protocol for the related medical management. This paper describes an effective approach that can be implemented in a clinically relevant and readily achievable manner.

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 Epworth Sleepiness Scale in epilepsy: Internal consistency and disease-related associations

BACKGROUND

The Epworth Sleepiness Scale (ESS) is the most common instrument for measuring subjective sleep propensity in people with epilepsy but has not yet been validated in this population.

STUDY OBJECTIVES

We aimed to systematically assess the validity, performance, and internal consistency of the ESS, as well as correlations between the ESS and disease-specific variables and patient-reported outcome measures in a cohort of adults with epilepsy (AWE).

METHODS

Ninety-five AWE completed sleep and seizure diaries, in-laboratory polysomnography (PSG) and patient-reported outcome measures, including the ESS, Insomnia Severity Index (ISI), and the Beck Depression Inventory (BDI). Demographic information and data from 95 matched controls referred for PSG for suspected obstructive sleep apnea (OSA) was taken from the electronic medical record. Frequencies of high ESS item ratings (item score ≥2) were calculated for each group. Cronbach's α and factor analysis were performed to assess the internal consistency and validity of the ESS within cases and controls. Multivariable linear models were used to assess the association between ESS and predictors of interest, adjusting for demographic and disease-specific variables, including seizure type, frequency, and anti-seizure medication (ASM) therapy.

RESULTS

While suspected OSA controls had significantly greater mean ESS total scores (9.9 vs 7.9, p = 0.004) and proportion with ESS >10 (42% vs 25%, p = 0.014), there were no significant differences in the severity of item responses, with the exception of "lying down to rest in the afternoon when circumstances permit," for which more controls rated as likely/very likely (79% vs 64%), p = 0.024). AWE with ESS >10 had higher mean standardized ASM dose (2.5 vs 1.7, p = 0.026). All ESS items were significantly correlated with the total score within each group. Cronbach's α was 0.75 for cases and 0.85 for controls, indicating good internal consistency of the ESS for both groups. After adjusting for demographic and sleep characteristics, higher ESS scores were associated with greater insomnia scores on the ISI (p = 0.024) and depressive symptoms on the BDI (p = 0.018).

CONCLUSIONS

This study provides validity for the use of the ESS in adult populations with epilepsy.

Bidirectional relationships of sleep and epilepsy in adults with epilepsy

This targeted review addresses the best accepted and most intriguing recent observations on the complex relationships between sleep and epilepsy. Ten to 15% of all epilepsies are sleep-related. Included in these is sleep-related hypermotor epilepsy, renamed from nocturnal frontal lobe epilepsy by a 2016 consensus conference since 30% of cases are extra-frontal, seizures are related to sleep rather than clock time, and the predominant semiology is hypermotor. Stereo-EEG is providing crucial insights into network activation in sleep-related epilepsies and definition of the epileptogenic zone. Pathologic high-frequency oscillations, a promising biomarker for identifying the epileptogenic zone, are most frequent in NREM sleep, lowest in wakefulness and REM sleep, similar to interictal epileptiform discharges (IEDs). Most sleep-related seizures are followed by awakening or arousal and IEDs cause arousals and increase after arousals, likely contributing to sleep/wake complaints. Sleep/wake disorders are 2-3 times more common in adults with epilepsy than the general population; these comorbidities are associated with poorer quality of life and may impact seizure control. Treatment of sleep apnea reduces seizures in many cases. An emerging area of research is in circadian biology and epilepsy. Over 90% of people with epilepsy have seizures with circadian periodicity, in part related to sleep itself, and the majority of SUDEP cases occur in sleep. Recognizing these bidirectional relationships is important for patient and caregiver education and counseling and optimizing epilepsy outcomes.

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.

Experimental chronic sleep fragmentation alters seizure susceptibility and brain levels of interleukins 1β and 6

Brain hyperexcitability in sleep apnea is believed to be provoked by hypoxemia, but sleep fragmentation can also play a significant role. Sleep fragmentation can trigger inflammatory mechanisms. The aim of this research was to investigate the effects of chronic sleep fragmentation on seizure susceptibility and brain cytokine profile. Chronic sleep fragmentation in male rats with implanted EEG electrodes was achieved by the treadmill method. Rats were randomized to: treadmill control (TC); activity control (AC) and sleep fragmentation (SF) group. Convulsive behavior was assessed 14 days later by seizure incidence, latency time and seizure severity during 30 min following lindane administration. The number and duration of EEG ictal periods were determined. Levels of IL-1β and IL-6 were measured in the animals' serum and brain structures (hippocampus, thalamus and cerebral cortex), in separate rat cohort that underwent the same fragmentation protocol except lindane administration. Incidence and severity of seizures were significantly increased, while latency was significantly decreased in SF+L compared with TC+L group. Seizure latency was also significantly decreased in SF+L compared to AC+L group. The number and duration of ictal periods were increased in the SF+L compared to the AC+L group. IL-1β was significantly increased in the thalamus, cortex and hippocampus in the SF compared to the AC and TC groups. IL-6 was statistically higher only in the cortex of SF animals, while in the thalamic or hippocampal tissue, no difference was observed between the groups. It could be concluded that fourteen-day sleep fragmentation increases seizure susceptibility in rats and modulates brain production of IL-1β and IL-6.

Brain hyperexcitability in sleep apnea is believed to be provoked by hypoxemia, but sleep fragmentation can also play a significant role. Sleep fragmentation can trigger inflammatory mechanisms. The aim of this research was to investigate the effects of chronic sleep fragmentation on seizure susceptibility and brain cytokine profile. Chronic sleep fragmentation in male rats with implanted EEG electrodes was achieved by the treadmill method. Rats were randomized to: treadmill control (TC); activity control (AC) and sleep fragmentation (SF) group. Convulsive behavior was assessed 14 days later by seizure incidence, latency time and seizure severity during 30 min following lindane administration. The number and duration of EEG ictal periods were determined. Levels of IL-1β and IL-6 were measured in the animals’ serum and brain structures (hippocampus, thalamus and cerebral cortex), in separate rat cohort that underwent the same fragmentation protocol except lindane administration. Incidence and severity of seizures were significantly increased, while latency was significantly decreased in SF+L compared with TC+L group. Seizure latency was also significantly decreased in SF+L compared to AC+L group. The number and duration of ictal periods were increased in the SF+L compared to the AC+L group. IL-1β was significantly increased in the thalamus, cortex and hippocampus in the SF compared to the AC and TC groups. IL-6 was statistically higher only in the cortex of SF animals, while in the thalamic or hippocampal tissue, no difference was observed between the groups. It could be concluded that fourteen-day sleep fragmentation increases seizure susceptibility in rats and modulates brain production of IL-1β and IL-6.

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.

Subjective and objective hypersomnia highly prevalent in adults with epilepsy

INTRODUCTION

Sleepiness is among the most common complaints of people with epilepsy, but objective documentation is lacking. We systematically investigated subjective and objective sleepiness in an observational cross-sectional cohort of adults with epilepsy (AWE).

METHODS

This is a prospective study of AWE consecutively recruited without foreknowledge of sleep/wake complaints. Polysomnography (PSG) with 18-channel electroencephalography (EEG) followed by multiple sleep latency testing (MSLT) was performed. Patients completed the Epworth Sleepiness Scale (ESS), a single-item question assessing excessive daytime sleepiness (EDS), and a 7-day sleep and seizure diary. Multivariable linear models were used to assess the association between MSLT mean sleep latency (MSL) and interests with adjustment of covariates of interest. Receiver operating characteristics (ROC) analysis was performed to evaluate the discrimination capability of ESS on MSL < 8 min and <5 min and investigate the optimal cutpoints.

RESULTS

Among 127 AWE (mean age: 38.7 ± 13.7 years), abnormal MSL (<8 min) was observed in 49.6% and MSL <5 min in 31.5%. While 78% reported feeling sleepy during the day on a single-item question, only 24% had elevated scores on the ESS (>10/24). The ESS score was associated with MSL even after adjusting for seizure frequency, antiseizure medication (ASM) standardized dose and number, age, gender, depression and insomnia symptom severity, and apnea-hypopnea index (HPI) and total sleep time on PSG (coefficients [95% confidence interval (CI)]: -0.26 [-0.48, -0.05], p = 0.018). The area under the curve (AUC) of the ESS ROC predicting MSL < 8 min and MSL < 5 min were similar: 0.62 (95%CI: 0.52-0.72) and 0.62 (95%CI: 0.51-0.74).

CONCLUSIONS

This is the largest prospective cross-sectional observational study to date using MSLT in AWE. We found subjective and objective daytime sleepiness highly prevalent in AWE and not explained by seizure frequency, ASM burden, symptoms of insomnia/depression, or PSG findings although those with MSL < 5 min were more likely to have obstructive sleep apnea (OSA). Pathologic sleepiness with MSL < 8 min was present in half of AWE. Nearly one-third of AWE unselected for sleep/wake complaints had MSL < 5 min, a range typical of narcolepsy.

Sex differences in factors associated with daytime sleepiness and insomnia symptoms in persons with epilepsy

Clinical factors associated with daytime sleepiness and insomnia in persons with epilepsy (PWE) were examined in this cross-sectional study of 126 participants (men, 50.8%). Excessive daytime sleepiness (EDS; score of ≥11 on the Epworth Sleepiness Scale (ESS)) was noted in 17.5% of participants (mean score, 6.1 ± 4.2), and moderate-to-severe insomnia (Insomnia Severity Index (ISI) scores of ≥15) was noted in 20.6% (mean score, 7.8 ± 6.4). Linear regression analyses revealed that ESS scores were independently associated with obstructive sleep apnea (OSA; snoring, tiredness, observed apnea, high blood pressure, body mass index, age, neck circumference, and gender (STOP-Bang) score of ≥3), an antiepileptic drug (AED) load of >3, depression (Patient Health Questionnaire-9 (PHQ-9) score of ≥10), female sex, and nocturnal seizures. Insomnia Severity Indices were independently associated with depression and anxiety (Generalized Anxiety Disorder-7 (GAD-7) score of ≥7). Notably, significant sex differences were found. Epworth Sleepiness Scale scores were associated with OSA in men but were associated with depression in women. In addition, anxiety was associated with insomnia in women only. Overall, OSA and depression were the most important significant clinical factors associated with daytime sleepiness and insomnia, respectively. However, there were sex differences for the associations between individual factors and sleep disturbances.

Factors contributing to excessive daytime sleepiness in Korean adults with epilepsy: A sleep questionnaire-based study

OBJECTIVES

We determined factors contributing to excessive daytime sleepiness (EDS) in Korean adults with epilepsy (AWE).

METHODS

A total of 147 AWE who had been treated for >1 year were included. Daytime sleepiness was assessed using the Epworth Sleepiness Scale (ESS). Subjective sleep disturbances were assessed with the Sleep Apnea of Sleep Disorder Questionnaire (SA-SDQ) and questionnaires about insomnia and restless legs syndrome (RLS). The Hospital Anxiety and Depression Scale (HADS) was also used. An ESS score >10 was considered indicative of EDS. Multivariate logistic regression analyses using the backward elimination method were performed for variables with a p < 0.10 on univariate analysis.

RESULTS

The mean ESS score was 6.8 (standard deviation [SD]: 4.4). Among the 147 subjects, 36 (24.5%) had EDS. Multivariate logistic regression analysis showed that being employed (odds ratio [OR]: 4.469, p < 0.01), the presence of at least one sleep disturbance (OR: 3.626, p < 0.01), and antiepileptic drug (AED) polytherapy (OR: 2.663, p < 0.05) were independently associated with EDS in the overall group of AWE. In contrast, being employed (p < 0.05) and higher Hospital Anxiety and Depression Scale-Anxiety subscale (HADS-A) scores (p < 0.05) in a model for men with epilepsy, as well as having at least one sleep disturbance (p < 0.05) in a model for women with epilepsy, were identified as independent factors for EDS.

CONCLUSIONS

Excessive daytime sleepiness in AWE may have a multifactorial origin. Being employed, subjective sleep disturbances, and AED polytherapy are independent predictors of EDS. There may be sex differences in factors associated with EDS.

Sleep-disordered breathing among patients admitted for inpatient video-EEG monitoring

Objective

To examine the prevalence and risk factors of sleep-disordered breathing (SDB) in individuals with epilepsy and psychogenic nonepileptic seizures (PNES).

Methods

We conducted a cross-sectional study of consecutive patients admitted for inpatient video-EEG monitoring at The Royal Melbourne Hospital, Australia, between December 1, 2011, and July 31, 2017. Participants underwent routine clinical investigations during their monitoring period including polysomnography, neurocognitive testing, and screening instruments of daytime somnolence, sleep quality, and quality of life.

Results

Our study population consisted of 370 participants who received a diagnosis of epilepsy (n = 255), PNES (n = 93), or both disorders (n = 22). Moderate to severe SDB (defined by an apnea-hypopnea index ≥15) was observed in 26.5% (98/370) of individuals, and did not differ across subgroups: epilepsy 26.3% (67/255), PNES 29.0% (27/93), or both disorders 18.2% (4/22; p = 0.610). Following adjustment for confounders, pathologic daytime sleepiness predicted moderate to severe SDB in epilepsy (odds ratio [OR] 10.35, 95% confidence interval [CI] 2.09–51.39; p = 0.004). In multivariable analysis, independent predictors for moderate to severe SDB in epilepsy were older age (OR 1.07, 95% CI 1.04–1.10; p < 0.001) and higher body mass index (OR 1.06, 95% CI 1.01–1.11; p = 0.029), and in PNES older age (OR 1.10, 95% CI 1.03–1.16; p = 0.002).

Conclusion

Polysomnography during inpatient video-EEG monitoring identified a substantial number of patients with undiagnosed SDB. This was remarkable in the subgroup with PNES, who were often female and obese. Identification of risk factors may improve management of SDB in these populations. The association with pathologic daytime sleepiness suggests that SDB may be an important contributor to these common and disabling symptoms in patients with epilepsy.

Serotonin Reuptake Inhibitors in Obstructive Sleep Apnea: Associations in People with and without Epilepsy

Purpose

Positive airway pressure remains the gold-standard treatment for OSA, but many are intolerant. The neurotransmitter serotonin is involved in respiratory control. Evidence exists for SRIs in reducing OSA severity in the general population and ictal hypoxemia and seizure-induced respiratory arrest in people with epilepsy (PWE). However, the association between SRIs and OSA severity has not been studied in populations consisting of both groups. This study aims to determine if SRIs are associated with OSA severity in both PWE and people without epilepsy (PWO) and whether differences exist between the two groups.

Methods

A retrospective study of adults with OSA was conducted. Subjects were categorized as PWE or PWO and for the use (+SRI) or absence (-SRI) of an SRI. The primary outcome was OSA severity relative to SRI status. OSA severity as a function of SRI status was also compared between PWE and PWO and within the PWE and PWO cohorts. Oxygen saturation nadir was a secondary outcome measure. Statistical adjustment of pertinent characteristics was performed.

Results

There were 125 subjects (57 PWE, 68 PWO, 80 –SRI, and 45 +SRI). +SRI was associated with reduced odds of severe compared to moderate OSA, in unadjusted and adjusted analysis. Compared to PWO, PWE demonstrated a more robust association between OSA severity and +SRI. When analyzed as separate cohorts, only PWE demonstrated reduced OSA severity, with adjustment for age (OR:0.140, CI:0.021-1.116, and p=0.042). Oxygen saturation nadir was not significant in any model.

Conclusions

SRIs represent a potential treatment option for OSA and may demonstrate a more robust association with reduced OSA severity in PWE compared to PWO.

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

OBJECTIVE

We aimed to determine the frequency of probable obstructive sleep apnea (pOSA) in refractory epilepsy monitoring unit inpatients and clinical features associated with pOSA, including risk for sudden unexpected death in epilepsy (SUDEP).

METHODS

We prospectively recruited 49 consecutive adult patients admitted to the Mayo Clinic Epilepsy Monitoring Unit with focal, generalized, or unclassified epilepsy syndromes. pOSA was identified using oximetric oxyhemoglobin desaturation index (ODI) and the Sleep Apnea-Sleep Disorders Questionnaire (SA-SDQ) and STOP-BAG screening tools. Revised SUDEP Risk Inventory (rSUDEP-7) scores were calculated, and epilepsy patients with and without pOSA were compared with Wilcoxon signed-rank tests. Correlation and regression analyses were utilized to determine relationships between pOSA and rSUDEP-7 scores.

RESULTS

Thirty-five percent of patients had pOSA, with a mean ODI of 11.3 ± 5.1/h (range = 5.1-22.8). Patients with pOSA were older and heavier, and more frequently had a focal epilepsy syndrome and longer epilepsy duration, with higher SA-SDQ and STOP-BAG scores (all P < 0.05). Median rSUDEP-7 score was 3 ± 1.4 (range = 0-6). Higher rSUDEP-7 scores were positively correlated with higher ODI (P = 0.036). rSUDEP-7 score ≥ 5 was associated with pOSA by ODI, SA-SDQ, and STOP-BAG questionnaire criteria (P < 0.05).

SIGNIFICANCE

Our pilot study identified a high frequency of pOSA in refractory epilepsy monitoring patients, finding that pOSA patients were older and heavier, with higher screening symptoms for sleep apnea and more frequent focal seizures with a longer epilepsy duration. We also found a possible association between OSA and SUDEP risk. Identification and treatment of OSA in patients with epilepsy could conceivably provide a novel approach toward preventing the risk of SUDEP. Future studies with polysomnography are needed to confirm predictive features for OSA in epilepsy populations, and to determine whether OSA is associated with SUDEP risk.

Sleep-Disordered Breathing

PURPOSE OF REVIEW

Sleep-disordered breathing encompasses a broad spectrum of sleep-related breathing disorders, including obstructive sleep apnea (OSA), central sleep apnea, as well as sleep-related hypoventilation and hypoxemia. Diagnostic criteria have been updated in the International Classification of Sleep Disorders, Third Edition and the American Academy of Sleep Medicine Manual for Scoring Sleep and Associated Events. Neurologic providers should have basic knowledge and skills to identify at-risk patients, as these disorders are associated with substantial morbidity, the treatment of which is largely reversible.

RECENT FINDINGS

OSA is the most common form of sleep-disordered breathing and is highly prevalent and grossly underdiagnosed. Recent studies suggest that prevalence rates in patients with neurologic disorders including epilepsy and stroke exceed general population estimates. The physiologic changes that occur in OSA are vast and involve complex mechanisms that play a role in the pathogenesis of cardiovascular and metabolic disorders and, although largely unproven, likely impact brain health and disease progression in neurologic patients. A tailored sleep history and examination as well as validated screening instruments are effective in identifying patients with sleep-disordered breathing, although sleep testing is necessary for diagnostic confirmation. While continuous positive airway pressure therapy and other forms of noninvasive positive pressure ventilation remain gold standard treatments, newer therapies, including mandibular advancement, oral appliance devices, and hypoglossal nerve stimulation, have become available. Emerging evidence of the beneficial effects of treatment of sleep-disordered breathing on neurologic outcomes underscores the importance of sleep education and awareness for neurologic providers.

SUMMARY

Sleep-disordered breathing is highly prevalent and grossly underrecognized. The adverse medical and psychosocial consequences of OSA and other sleep-related breathing disorders are considerable. The impact of sleep therapies on highly prevalent neurologic disorders associated with substantial morbidity and health care costs is becoming increasingly recognized.

Wake up to sleep: The effects of lacosamide on daytime sleepiness in adults with epilepsy

OBJECTIVE

The objective of the study was to investigate the effects of lacosamide (LCM) on daytime sleepiness ascertained by the Epworth Sleepiness Scale (ESS) in adults with focal epilepsy in a randomized, controlled design.

METHODS

Subjects taking ≤2 AEDs for ≥4weeks underwent polysomnography with EEG followed by the maintenance of wakefulness test (MWT) and completed the ESS and other patient-reported outcomes (PROs) at baseline, LCM 200mg/day, and LCM 400mg/day (Visit 4; V4). Primary endpoint was ESS change (V4 to baseline) between LCM and placebo. Noninferiority test on ESS used a one-sided t-test based on a hypothesized difference of 4-point change between groups. Superiority test used a two-sided t-test to investigate the difference in change in PROs and MWT mean sleep latency (MSL) between groups. Fifty-five subjects provided 80% power to show noninferiority of LCM assuming 10% dropout.

RESULTS

Fifty-two subjects (mean age: 43.5±13.2years, 69% female, median monthly seizure frequency: 1 [0, 4.0]) participated. Baseline group characteristics including age, sex, ethnicity, standardized AED dose, seizure frequency, and ESS were similar. Abnormal baseline ESS scores were found in 35% of subjects. Noninferiority test found a ≤4-point increase in ESS (mean [95% CI]) in LCM subjects vs. placebo (-1.2 [-2.9, 0.53] vs. -1.1 [-5.2, 3.0], p=0.027) at V4. No significant difference in change in PROs, MSL, seizure frequency, or AED standardized dose was observed between groups.

SIGNIFICANCE

Our interventional trial found that LCM is not a major contributor to daytime sleepiness based on subjective and objective measures. Inclusion of sleepiness measures in AED trials is warranted given the high prevalence of sleep-wake complaints in people with epilepsy.

Obstructive sleep apnoea in patients with epilepsy: a meta-analysis

PURPOSE

The aim of this study was to accurately determine the prevalence of obstructive sleep apnoea (OSA) in patients with epilepsy (PWE) and to evaluate the efficacy of seizure control after treating OSA.

METHODS

Articles were identified through a search of both MEDLINE and Embase. The articles were collected and data were extracted independently by two authors. OSA was described using the following terms: Apnoea/hypopnoea index (AHI) and respiratory disturbance index (RDI). The variables were calculated using DerSimonian and Laird's random-effects model and odds ratio (OR).

RESULTS

The prevalence of mild-to-severe OSA in PWE was determined to be 33.4 % (95 % CI 20.8-46.1 %), and PWE are more susceptible to OSA as compared to healthy controls (OR 2.36; 95 % CI 1.33-4.18). Males were shown to be more susceptible to OSA than females (OR 3.00; 95 % CI 2.25-3.99). The results also indicated that the prevalence of OSA in patients with refractory epilepsy is not higher than the prevalence of OSA in PWE overall (17.5 vs 33.4 %). The prevalence of OSA was not found to be significantly different for different seizure types or in the number of antiepileptic drugs (AEDs). Patients that had been treated with continuous positive airway pressure (CPAP) were shown to have better seizure control than those untreated (OR 5.26; 95 % CI 2.04-13.5).

CONCLUSIONS

The prevalence of OSA in PWE is higher than in the general population. Additionally, the results of our study suggest that CPAP treatment results in a reduction of seizures.

Severity of self-reported insomnia in adults with epilepsy is related to comorbid medical disorders and depressive symptoms

BACKGROUND

Few studies have systematically investigated insomnia in adults with epilepsy.

METHODS

We performed a prospective cross-sectional investigation of the prevalence, severity, and comorbidities of insomnia in 90 adults with epilepsy using a battery of self-reported instruments and polysomnography. We quantified insomnia severity using the Insomnia Severity Index (ISI).

RESULTS

Fifty-nine of 90 (65.5%) adults with epilepsy reported insomnia (ISI≥8), moderate or severe (ISI≥15) in 28.9%. Good agreement between standard clinical diagnostic criteria and ISI was found for patients with ISI scores <8 and ≥15. Scores on the modified Beck Depression Inventory (mBDI) (r=0.25, p=0.021), the original BDI (r=0.32, p=0.002), and self-reported total sleep duration (TSD) (r=-0.3, p=0.006) were significantly related to ISI score. A multiple regression model found that decreased TSD (ß=-0.93, p=0.007), head trauma (ß=4.37, p=0.003), sedative-hypnotic use (ß=4.86, p=0.002), AED polytherapy (ß=3.52, p=0.005), and asthma/COPD (ß=3.75, p=0.014) were predictors of a higher ISI score. For 63 patients with focal epilepsy, an increased mBDI (ß=0.24, p=0.015), decreased TSD (ß=-1.11, p=0.008), asthma/COPD (ß=4.19, p=0.02), and epilepsy surgery (ß=5.33, p=0.006) were significant predictors of an increased ISI score. Patients with temporal lobe epilepsy (TLE) showed a trend for greater severity compared with those with extra-TLE (ß=-2.92, p=0.054).

CONCLUSIONS

Our findings indicate that severity of insomnia in adults with epilepsy is more likely to be associated with comorbid medical and depressive symptoms and less likely to be directly related to epilepsy. Good agreement between standard clinical diagnostic criteria for insomnia and the ISI for subjects without insomnia symptoms and for those with moderate-to-severe symptoms supports the use of this instrument in epilepsy research.

The therapeutic dilemma of vagus nerve stimulator-induced sleep disordered breathing

Intermittent vagus nerve stimulation (VNS) can reduce the frequency of seizures in patients with refractory epilepsy, but can affect respiration in sleep. Untreated obstructive sleep apnea (OSA) can worsen seizure frequency. Unfortunately, OSA and VNS-induced sleep disordered breathing (SDB) may occur in the same patient, leading to a therapeutic dilemma. We report a pediatric patient in whom OSA improved after tonsillectomy, but coexistent VNS-induced SDB persisted. With decrease in VNS output current, patient's SDB improved, but seizure activity exacerbated, which required a return to the original settings. Continuous positive airway pressure titration was attempted, which showed only a partial improvement in apnea–hypopnea index. This case illustrates the need for clinicians to balance seizure control and SDB in patients with VNS.

Sudden unexpected death in epilepsy: basic mechanisms and clinical implications for prevention

Sudden unexpected death in epilepsy (SUDEP) is the most common cause of death in patients with intractable epilepsy. The substantial lifetime risk of SUDEP and the lack of a clear pathophysiological connection between epilepsy itself and sudden death have fuelled increased attention to this phenomenon. Understanding the mechanisms underlying SUDEP is paramount to developing preventative strategies. In this review, we discuss SUDEP population studies, case-control studies, witnessed and monitored cases, as well as human seizure cardiorespiratory findings related to SUDEP, and SUDEP animal models. We integrate these data to suggest the most probable mechanisms underlying SUDEP. Understanding the modifiable risk factors and pathophysiology allows us to discuss potential preventative strategies.

Sleep disruption increases seizure susceptibility: Behavioral and EEG evaluation of an experimental model of sleep apnea

Sleep disruption accompanies sleep apnea as one of its major symptoms. Obstructive sleep apnea is particularly common in patients with refractory epilepsy, but causing factors underlying this are far from being resolved. Therefore, translational studies regarding this issue are important. Our aim was to investigate the effects of sleep disruption on seizure susceptibility of rats using experimental model of lindane-induced refractory seizures. Sleep disruption in male Wistar rats with implanted EEG electrodes was achieved by treadmill method (belt speed set on 0.02 m/s for working and 0.00 m/s for stop mode, respectively). Animals were assigned to experimental conditions lasting 6h: 1) sleep disruption (sleep interrupted, SI; 30s working and 90 s stop mode every 2 min; 180 cycles in total); 2) activity control (AC, 10 min working and 30 min stop mode, 9 cycles in total); 3) treadmill chamber control (TC, only stop mode). Afterwards, the animals were intraperitoneally treated with lindane (L, 4 mg/kg, SI+L, AC+L and TC+L groups) or dimethylsulfoxide (DMSO, SIc, ACc and TCc groups). Convulsive behavior was assessed by seizure incidence, latency time to first seizure, and its severity during 30 min after drug administration. Number and duration of ictal periods were determined in recorded EEGs. Incidence and severity of lindane-induced seizures were significantly increased, latency time significantly decreased in animals undergoing sleep disruption (SI+L group) compared with the animals from TC+L. Seizure latency was also significantly decreased in SI+L compared to AC+L groups. Number of ictal periods were increased and duration of it presented tendency to increase in SI+L comparing to AC+L. No convulsive signs were observed in TCc, ACc and SIc groups, as well as no ictal periods in EEG. These results indicate sleep disruption facilitates induction of epileptic activity in rodent model of lindane-epilepsy enabling translational research of this phenomenon.

Sleep, epilepsy, and autism

The purpose of this review article is to explore the links between sleep and epilepsy and the treatment of sleep problems in children with autism spectrum disorder (ASD). Epilepsy and sleep have bidirectional relationships, and problems with both are highly prevalent in children with ASD. Literature is reviewed to support the view that sleep is particularly important to address in the context of ASD. Identification and management of sleep disorders may improve seizure control and challenging behaviors. In closing, special considerations for evaluating and treating sleep disorders in children with ASD and epilepsy are reviewed. This article is part of a Special Issue entitled "Autism and Epilepsy".

Impact of sleep duration on seizure frequency in adults with epilepsy: a sleep diary study

BACKGROUND

Prolonged sleep deprivation activates epileptiform EEG abnormalities and seizures in people with epilepsy. Few studies have addressed the effect of chronic partial sleep deprivation on seizure occurrence in populations with epilepsy. We tested the primary hypothesis that partial sleep deprivation over 24- and 72-hour periods increases seizure occurrence in adults with epilepsy.

METHODS

Forty-four subjects completed a series of self-reported instruments, as well as 1-month sleep and seizure diaries, to characterize their sleep and quality of life. Diaries were used to determine the relationship between seizure occurrence and total sleep time 24 and 72h before seizure occurrence using random effects models and a logistic regression model fit by generalized estimating equations.

RESULTS

A total of 237 seizures were recorded during 1295 diary days, representing 5.5±7.0 (mean±SD) seizures per month. Random effects models for 24- and 72-hour total sleep times showed no clinically or statistically significant differences in the total sleep time between preseizure periods and seizure-free periods. The average 24-hour total sleep time during preseizure 24-hour periods was 8min shorter than that during seizure-free periods (p=0.51). The average 72-hour total sleep time during preseizure periods was 20min longer than that during seizure-free periods (p=0.86). The presence of triggers was a significant predictor of seizure occurrence, with stress/anxiety noted most often as a trigger. Mean total sleep time was 9h, and subjects took an average of 12±10 naps per month, having a mean duration of 1.9±1.2h. Daytime sleepiness, fatigue, and insomnia symptoms were commonly reported.

CONCLUSIONS

Small degrees of sleep loss were not associated with seizure occurrence in our sample of adults with epilepsy. Our results also include valuable observations of the altered sleep times and frequent napping habits of adults with refractory epilepsy and the potential contribution of these habits to quality of life and seizure control.