Continuous positive airway pressure therapy for obstructive sleep apnea reduces interictal epileptiform discharges in adults with epilepsy

Subclinical epileptiform activity and sleep disturbances in Alzheimer's disease

INTRODUCTION

Subclinical epileptiform activity (SEA) and sleep disturbances are frequent in Alzheimer's disease (AD). Both have an important relation to cognition and potential therapeutic implications. We aimed to study a possible relationship between SEA and sleep disturbances in AD.

METHODS

In this cross-sectional study, we performed a 24-h ambulatory EEG and polysomnography in 48 AD patients without diagnosis of epilepsy and 34 control subjects.

RESULTS

SEA, mainly detected in frontotemporal brain regions during N2 with a median of three spikes/night [IQR1-17], was three times more prevalent in AD. AD patients had lower sleep efficacy, longer wake after sleep onset, more awakenings, more N1%, less REM sleep and a higher apnea-hypopnea index (AHI) and oxygen desaturation index (ODI). Sleep was not different between AD subgroup with SEA (AD-Epi+) and without SEA (AD-Epi-); however, compared to controls, REM% was decreased and AHI and ODI were increased in the AD-Epi+ subgroup.

DISCUSSION

Decreased REM sleep and more severe sleep-disordered breathing might be related to SEA in AD. These results could have diagnostic and therapeutic implications and warrant further study at the intersection between sleep and epileptiform activity in AD.

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.

[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.

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.

Drug-Resistant Epilepsy and Obstructive Sleep Apnea: Exploring a Link Between the Two

Drug-resistant epilepsy accounts for approximately one third of all epilepsy cases; yet its exact etiopathogenesis still remains under intense exploration. Several factors have been advocated for predicting drug resistance in patients with epilepsy. Obstructive sleep apnea (OSA) is a commonly prevalent sleep disorder that exhibits a bidirectional and strong comorbidity with epilepsy. The exact pathophysiology of this comorbidity is not yet clearly explained. This study analyzes the relationship between drug-resistant epilepsy and OSA, and the findings indicate a strong role of rapid eye movement sleep (REMS) in the pathogenesis of this relationship. It also emerges from the study that REMS reduction is a prominent feature of OSA, and drug resistance in patients with epilepsy and treatment of OSA has been shown to restore REMS in several studies with concomitant improvement in seizure control.

Factors determining the long-term compliance with PAP therapy in patients with sleep-related epilepsy

INTRODUCTION

In adult patients with epilepsy, treatment of comorbid obstructive sleep apnea syndrome (OSAS) by positive airway pressure (PAP) therapy results in improvements in the control of seizures. This is the first study investigating the long-term compliance with PAP therapy in patients with sleep-related epilepsy and OSAS.

METHODS

In this longitudinal study, patients with sleep-related epilepsy and OSAS were followed-up for five years. The compliance with PAP therapy was defined as the use of PAP therapy for at least four hours per night for more than 70 % of nights.

RESULTS

A total of 58 patients with sleep-related epilepsy and OSAS completed study protocol. Eleven patients (19.0 %) refused PAP treatment for OSAS, and 13 patients (22.3 %) showed irregular use. Remaining 34 patients (58.7 %) were compliant with PAP therapy. Females were found to be more compliant than males (p = 0.027), while the age was not found to correlate with the compliance (p = 0.721). Epilepsy-related factors including the types of seizures, whether pure sleep-related or mixed (p = 0.403), localization (p = 0.920) or lateralization (p = 0.697) of discharges, showed no effect on the compliance with PAP therapy. On the other hand, patients with a lower number of seizures (p = 0.042) or with a lower seizure frequency (p = 0.048) showed better compliance with PAP therapy. Polysomnographic parameters including severity of OSAS failed to show a significant correlation.

CONCLUSION

Our findings showed that about two thirds of the study population was compliant with PAP therapy after a mean follow-up duration of almost three years. Newly-diagnosed patients, mostly females, with a lower number of total seizures and lower seizure frequency seem to be more compliant with PAP therapy, which implies the significance of investigation and treatment of OSAS as early as possible in the patients with sleep-related seizures.

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.

Late-onset unexplained epilepsy: What are we missing?

With the aging of the US population, the incidence of epilepsy will increase, with 25 to 50% of new cases with no identifiable etiology diagnosed as late-onset unexplained epilepsy (LOUE). In the current targeted review, we discuss the possible role of cerebral small vessel ischemic disease, accumulation of amyloidβ and hyperphosphorylated tau, and sleep apnea as potential pathophysiologic mechanisms explaining LOUE. We highlight the impact of these processes on cognition and avenues for diagnosis and treatment.

Brain network alterations of mesial temporal lobe epilepsy with cognitive dysfunction following anterior temporal lobectomy

The aims of this study were to investigate the brain network connectivity alterations of intractable unilateral mesial temporal lobe epilepsy (MTLE) with cognitive dysfunction before and after anterior temporal lobectomy (ATL) using resting-state functional magnetic resonance imaging (rs-fMRI) study and to further observe the correlation between the brain network connectivity with cognitive performance. Fourteen patients with unilateral left MTLE before and after ATL were compared with thirty healthy controls (HCs) on functional connectivity (FC) between resting-state networks (RSNs). The correlation between the neuropsychological tests of patients and abnormal FC was further investigated. When compared with the HCs, patients before surgery showed significantly changed FC between special RSNs. No difference of FC was found between each RSN when patients were compared with the HCs after surgery. Compared with patients before surgery, patients after surgery showed significantly decreased FC between RSNs. Abnormal FC between RSNs significantly correlated with Montreal Cognitive Assessment (MoCA) scores. Our study suggested that dynamic alterations of RSN after ATL in unilateral MTLE may be closely related with seizure generating. However, unchanged FC between RSN before and after ATL may be closely related with cognitive performance. The present findings may help us understand the feature of brain network alterations in patients with left MTLE who became seizure-free following ATL.

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.

Co-morbid sleep disorders and epilepsy: A narrative review and case examples

Co-morbid sleep disorders, including sleep apnea, insomnia, restless legs syndrome, and the parasomnias, occur frequently in people with epilepsy. This article reviews the cardinal presenting symptoms and diagnostic features of each of these disorders to enable epileptologists to readily screen and identify sleep co-morbidities in their patients. It summarizes current evidence concerning the reciprocal relationship between sleep disturbances and epilepsy and available treatment options for common sleep disorders in people with epilepsy. Several illustrative cases demonstrate the practical consequences of co-morbid sleep disorders in epilepsy patients and suggest diagnostic and treatment approaches that may improve daytime functioning, alertness, quality of life, and seizure burden.

Positive Airway Pressure Therapy Is Challenging for Patients With Epilepsy

STUDY OBJECTIVES

To investigate whether patients with epilepsy and comorbid obstructive sleep apnea (OSA) are more likely to be nonadherent to positive airway pressure (PAP) therapy than adults with OSA but without epilepsy.

METHODS

This retrospective study included patients with epilepsy diagnosed with OSA and age-, sex-, and apnea-hypopnea index (AHI)-matched controls with OSA but without epilepsy who started PAP treatment between February 2014 and August 2017. Subjects' adherence to PAP therapy was continuously recorded electronically, and comparisons were made at 1 month, 3 months, and 1 year following PAP initiation. Predictors to poor adherence were also evaluated.

RESULTS

Patients with epilepsy (n = 23) were less adherent to PAP than controls (n = 23) during the first month of treatment (13% versus 78%, P = .03). During this first month, average PAP use was lower in patients with epilepsy (4.7 ± 2.1 hours) relative to controls (6.1 ± 1.2 hours, P = .03). Despite sustained PAP treatment, patients with epilepsy had a greater residual AHI and were five times more likely than controls to have residual apnea events above normal range at 3-month and 1-year follow-up. However, no clinical characteristics could significantly predict poor adherence in patients.

CONCLUSIONS

Patients with epilepsy are less likely to be adherent to PAP therapy during the first month of treatment, as compared to adults with OSA but no epilepsy. Moreover, PAP therapy could not sufficiently reduce AHI in up to 72% of patients. These findings highlight the need for careful monitoring of PAP treatment in patients with epilepsy, as untreated OSA may worsen seizure burden.

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.

Understanding the self-management skills of persons with epilepsy

PURPOSE

To determine whether the self-management skills of persons with epilepsy (PWE) vary across the different domains of the Epilepsy Self-Management Scale (ESMS).

METHODS

172 PWE completed a survey questionnaire as well as the ESMS.

RESULTS

Using ANOVA with pairwise comparison, the mean item scores of the medication, seizure, and safety management subscales of the ESMS were significantly higher than the lifestyle and information management subscales (p<0.01). The mean item score for the lifestyle management subscale was significantly higher than the information management subscale (p<0.01).

CONCLUSION

PWE in our population performed differently across the various domains of the ESMS and did worse on the lifestyle and information management subscales. We discuss the implications of this on patient counseling and education.

High incidence of obstructive sleep apnea syndrome in patients with late-onset epilepsy

OBJECTIVES

The objective of the present study was to evaluate the prevalence of obstructive sleep apnea (OSA) in patients with late-onset epilepsy (LOE) who were considered at higher risk of cardiovascular disease.

METHODS

Polysomnography was performed on 27 patients with LOE. Berlin questionnaires and Epworth sleepiness score were performed on all patients. We compared clinical, demographic and anthropometric characteristics, questionnaire scores on the patients with no or mild OSA (group 1) and the patients with moderate or severe OSA (group 2). Patients eligible for continuous positive airway pressure (CPAP) therapy were reviewed in consultation.

RESULTS

Twenty-four patients (88.9%) had OSA and 55.6% had moderate or severe OSA. Patients in group 2 (n=15) were older than patients in group 1 (n=12). The two groups were similar in terms of body mass index (BMI), neck circumference, nocturnal seizure frequency, vascular cardiovascular risk factors and excessive daytime sleepiness. Leukoaraiosis in MRI was highly prevalent in our patients (40.7%), especially in group 2 patients. Eighty percent of the patients who had begun CPAP therapy experienced decreased seizure frequency.

CONCLUSION

Patients with LOE should be screened for the presence of OSA and treated accordingly.

Sleep Disorders in Neurologic Practice: A Case-based Approach

Sleep disorders are common in neurology practice, but are often undiagnosed and untreated. Specific patient cohorts, such as older adults, patients residing in nursing homes, and patients with underlying chronic neurologic and psychiatric disorders, are at particular risk. If these sleep problems are not properly evaluated and managed the patient may experience exacerbation of the underlying neurologic disorder. This article highlights some of the key sleep disorders relevant to practicing neurologists, emphasizing hypersomnolence, insomnia, and sleep-related movement disorders in the setting of neurologic disorders to enhance the tools available for evaluation, and discusses management strategies.

Changes in Neurocognitive Architecture in Patients with Obstructive Sleep Apnea Treated with Continuous Positive Airway Pressure

Background

Obstructive sleep apnea (OSA) is a chronic, multisystem disorder that has a bidirectional relationship with several major neurological disorders, including Alzheimer's dementia. Treatment with Continuous Positive Airway Pressure (CPAP) offers some protection from the effects of OSA, although it is still unclear which populations should be targeted, for how long, and what the effects of treatment are on different organ systems. We investigated whether cognitive improvements can be achieved as early as one month into CPAP treatment in patients with OSA.

Methods

55 patients (mean (SD) age: 47.6 (11.1) years) with newly diagnosed moderate–severe OSA (Oxygen Desaturation Index: 36.6 (25.2) events/hour; Epworth sleepiness score (ESS): 12.8 (4.9)) and 35 matched healthy volunteers were studied. All participants underwent neurocognitive testing, neuroimaging and polysomnography. Patients were randomized into parallel groups: CPAP with best supportive care (BSC), or BSC alone for one month, after which they were re-tested.

Findings

One month of CPAP with BSC resulted in a hypertrophic trend in the right thalamus [mean difference (%): 4.04, 95% CI: 1.47 to 6.61], which was absent in the BSC group [− 2.29, 95% CI: − 4.34 to − 0.24]. Significant improvement was also recorded in ESS, in the CPAP plus BSC group, following treatment [mean difference (%): − 27.97, 95% CI: − 36.75 to − 19.19 vs 2.46, 95% CI: − 5.23 to 10.15; P = 0.012], correlated to neuroplastic changes in brainstem (r = − 0.37; P = 0.05), and improvements in delayed logical memory scores [57.20, 95% CI: 42.94 to 71.46 vs 23.41, 95% CI: 17.17 to 29.65; P = 0.037].

Interpretation

One month of CPAP treatment can lead to adaptive alterations in the neurocognitive architecture that underlies the reduced sleepiness, and improved verbal episodic memory in patients with OSA. We propose that partial neural recovery occurs during short periods of treatment with CPAP.

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One month of CPAP treatment leads to adaptive alterations in the neuroanatomy and neurocognition in patients with OSA.

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Improvements in sleepiness and verbal episodic memory were demonstrable following only one month of treatment with CPAP.

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Our findings support the clinical rationale for the use of CPAP treatment to relieve sleepiness, even for a short duration.

Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder that has been linked with dementia, stroke and increased risks of cardiovascular disease. Continuous positive airway pressure (CPAP) treatment has been shown to be effective in reducing sleepiness in moderate to severe OSA. However, the evidence for its use to reverse or slow the rate of cognitive decline is unclear. Our findings show that one month of CPAP treatment in patients with moderate to severe OSA leads to adaptive alterations in the brain networks associated with reduced sleepiness and improved memory.

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.

The impact of sleep and hypoxia on the brain: potential mechanisms for the effects of obstructive sleep apnea

PURPOSE OF REVIEW

Obstructive sleep apnea (OSA) is a chronic, highly prevalent, multisystem disease, which is still largely underdiagnosed. Its most prominent risk factors, obesity and older age, are on the rise, and its prevalence is expected to grow further. The last few years have seen an exponential increase in studies to determine the impact of OSA on the central nervous system. OSA-induced brain injury is now a recognized clinical entity, although its possible dual relationship with several other neuropsychiatric and neurodegenerative disorders is debated. The putative neuromechanisms behind some of the effects of OSA on the central nervous system are discussed in this review, focusing on the nocturnal intermittent hypoxia and sleep fragmentation.

RECENT FINDINGS

Recent preclinical and clinical findings suggest that neurogenic ischemic preconditioning occurs in some OSA patients, and that it may partly explain variability in clinical findings to date. However, the distinct parameters of the interplay between ischemic preconditioning, neuroinflammation, sleep fragmentation and cerebrovascular changes in OSA-induced brain injury are still largely unclear, and more research is required.

SUMMARY

Early diagnosis and intervention in patients with OSA is of paramount importance. Future clinical studies should utilize multimodal investigative approaches to enable more reliable referencing for the acuity of the pathological process, as well as its reversibility following the treatment.

Sleep and Epilepsy

Sleep and epilepsy are common bedfellows. Sleep can affect frequency and occurrence of interictal spikes and occurrence, timing, and threshold of seizure. Epilepsy can worsen sleep architecture and severity of sleep disorders. Thus, a vicious cycle is set. Certain epilepsy syndromes are so intertwined with sleep that they are considered sleep-related epilepsies. Poor sleep in epilepsy is multifactorial and is worsened by poorly controlled seizures. On the contrary, poor sleep is associated with worsened quality of life, psychological function, and memory. Improving sleep has been noted to improve seizure frequency and an overall well-being in patients with epilepsy. Hence, an emphasis should be given to address sleep in patients with epilepsy. These interactions are discussed in detail in this review.