Sleep instability and cognitive status in drug-resistant epilepsies

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.

Kullback-Leibler Divergence of Sleep-Wake Patterns Related with Depressive Severity in Patients with Epilepsy

(1) Objective: Whether abnormal sleep-wake rhythms were associated with depressive symptoms in patents with epilepsy had remained unclear. Our study aimed to establish relative entropy for the assessment of sleep-wake patterns and to explore the relationship between this index and the severity of depressive symptoms in patients with epilepsy. (2) Methods: We recorded long-term scalp electroencephalograms (EEGs) and Hamilton Depression Rating Scale-17 (HAMD-17) questionnaire scores from 64 patients with epilepsy. Patients with HAMD-17 scores of 0-7 points were defined as the non-depressive group, while patients with scores of 8 or higher were defined as the depression group. Sleep stages were firstly classified based on EEG data. We then quantified sleep-wake rhythm variations in brain activity using the Kullback-Leibler divergence (KLD) of daytime wakefulness and nighttime sleep. The KLD at different frequency bands in each brain region was analyzed between the depression and non-depression groups. (3) Results: Of the 64 patients with epilepsy included in our study, 32 had depressive symptoms. It was found that patients with depression had significantly decreased KLD for high-frequency oscillations in most brain areas, especially the frontal lobe. A detailed analysis was conducted in the right frontal region (F4) because of the significant difference in the high-frequency band. We found that the KLDs at the gamma bands were significantly decreased in the depression groups compared to the non-depression group (KLD_D = 0.35 ± 0.05, KLD_ND = 0.57 ± 0.05, p = 0.009). A negative correlation was displayed between the KLD of gamma band oscillation and HAMD-17 score (r = -0.29, p = 0.02). (4) Conclusions: Sleep-wake rhythms can be assessed using the KLD index calculated from long-term scalp EEGs. Moreover, the KLD of high-frequency bands had a negative correlation with HAMD-17 scores in patients with epilepsy, which indicates a close relationship between abnormal sleep-wake patterns and depressive symptoms in patients with epilepsy.

Long time polysomnographic sleep and breathing evaluations in children with CDKL5 deficiency disorder

STUDY OBJECTIVES

CDKL5 deficiency disorder (CDD) is a rare developmental and epileptic encephalopathy, developing in the first months of life, caused by a mutation in the cyclin-dependent kinase-like 5 (CDKL5) gene. Children with CDD often have sleep (90%) and breathing disorders in wake (50%). Sleep disorders may have a significant impact emotional wellbeing and quality of life of caregivers of children with CDD and are challenging to treat. The outcomes of these features are unknown in children with CDD.

METHODS

We retrospectively evaluated sleep and respiratory function changes over 5-10 years in a small cohort of Dutch children with CDD, using video-EEG and/or polysomnography (3 × 24 h) and a parental questionnaire, the Sleep Disturbance Scale for Children (SDSC). The present study is a follow-up sleep and PSG study to evaluate if sleep and breathing disturbances persist in children with CDD previously studied.

RESULTS

Sleep disturbances persisted during the study period (5.5-10 years). All five individuals had long sleep latency (SL, range 32-174.5 min) and frequent arousals and awakenings (14-50/night), unrelated to apneas/seizures, corresponding to the SDSC findings. Low sleep efficiency (SE, 41-80%) was present and did not improve. In our participants, total sleep time (TST, 3h52min-7h52min) was short and remained so. Time in bed (TIB) was typical for children aged 2-8 years, but did not adjust with ageing. Low duration (4.8-17.4%) or even absent REM sleep persisted over time. No sleep apneas were noted. Central apneas due to episodic hyperventilation were reported during wakefulness in two of the five.

CONCLUSION

Sleep disturbances were present and persisted in all. The decreased REM sleep and sporadic breathing disturbances in wake may indicate failure of brainstem nuclei. Sleep disturbances can severely affect the emotional wellbeing and quality of life of the caregivers and the individuals with CDD and are challenging to treat. Hopefully our polysomnographic sleep data contribute to find the optimal treatment of the sleep problems in CDD patients.

Evaluation of sleep habits, sleep chronotype, and quality of life in children with drug-resistant epilepsy in Turkey

BACKGROUND/AIM

Drug-resistant epilepsy (DRE) is a condition that affects sleep habits and the quality of life of children unfavorably. The aim of our study was to evaluate the relationship of sleep habits and sleep chronotype with the quality of life and behavioral problems in children with DRE.

MATERIALS AND METHODS

In our study, 2-11-year-old children, who were either healthy or diagnosed with DRE, were evaluated. A sociodemographic data form was filled out to evaluate the general characteristics of children. The Children's Sleep Habits Questionnaire (CSHQ) and the Children's Chronotype Questionnaire (CCTQ) for sleep habits, the Pediatric Quality of Life Inventory (PedsQL) for the quality of life, and the Aberrant Behavior Checklist (ABC) for behavioral problems were filled out through face-to-face interviews with parents.

RESULTS

Thirty children with DRE and 31 healthy children were included in our study. Statistically significant differences were found in children with DRE compared to the control group in terms of the total and the subscale scores of CSHQ, including sleep onset delay, sleep duration, sleep anxiety, parasomnias, and sleep-disordered breathing (p < 0.001). There were no significant differences between the groups in terms of CCTQ total scores and sleep patterns (p > 0.05). Significant differences were found in PedsQL total and subscale scores, and ABC scores in children with DRE compared to the control group (p < 0.001). Children's Sleep Habits Questionnaire, PedsQL, and ABC scores were significantly correlated with each other in children with DRE.

CONCLUSIONS

Our results have shown that sleep habits and the quality of life are poor in children with DRE. Our study has shown that sleep disturbances, quality of life, and behavioral problems are strongly associated with each other in DRE. The recognition and appropriate treatment of sleep disturbances are important for improving the quality of life in children with DRE.

Sleep in children with refractory epilepsy and epileptic encephalopathies: A systematic review of literature

Children with epilepsy have more sleep disorders compared to healthy children. The bidirectional interaction between epilepsy and sleep is not completely understood. However, disruption of sleep architecture during childhood may have consequences for cognitive development. As children with drug-refractory epilepsy often have intellectual disability, sleep disruption could be an important contributing factor in severity of their cognitive impairment. To better understand these interactions, sleep architecture in children with drug-refractory epilepsy and epileptic encephalopathies should be investigated. In this review, we conducted a systematic literature search on this topic. Articles that investigated sleep macro- and/or microstructure by means of electroencephalogram/polysomnography were included, as well as articles that used validated questionnaires. Sixteen articles were reviewed, eight of which used polysomnography. Only 2 articles examined sleep in children with epileptic encephalopathies. Consistent findings on measures of sleep architecture were a reduction in REM percentage and an increase in sleep fragmentation when comparing drug-refractory patients with non-refractory and healthy subjects. The findings on slow wave sleep were less clear. Studies with questionnaires unambiguously confirmed subjectively more sleep problems in children with drug-refractory epilepsy. This is the first review of literature in this patient population. More good quality sleep studies in children with drug-refractory epilepsy are warranted. The use of wearables in the home setting together with automatic sleep staging could provide more insights.

Sleep and Temporal Lobe Epilepsy – Associations, Mechanisms and Treatment Implications

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Sleep disruption in children and adolescents with epilepsy: A systematic review and meta-analysis

This systematic review and meta-analysis aims to assess and quantify putative differences in sleep architecture, sleep efficiency, sleep timing and broadly-defined sleep difficulties between children with and without epilepsy. Databases were searched systematically, and studies identified in PubMed, EMBASE, PsychINFO and Medline. The meta-analysis included 19 studies comparing a total of 901 children with epilepsy to 1470 healthy children. Relative to healthy children, children with epilepsy experienced reduced sleep time, sleeping on average 34 mins less across self-report, actigraphy, 24-h video-EEG and polysomnography measures. They had more sleep difficulties specifically in the domains of night waking, parasomnias and sleep disordered breathing. The analysis also revealed a significantly increased percentage of N2 sleep and decreased sleep efficiency in children with epilepsy compared to healthy children. These results illustrate that children with epilepsy are vulnerable to more sleep difficulties compared to healthy children. This suggests that screening for sleep difficulties should be an integral part in a diagnosis of epilepsy to ensure that clinically relevant sleep difficulties are identified and treated. Such an approach may ultimately aid in the development of treatment strategies which can contribute to improvements in both developmental and diagnostic outcomes for children with epilepsy.

How do children with drug-resistant epilepsy sleep? A clinical and video-PSG study

AIM

The aim of this study was to assess sleep architecture and sleep problems among three homogenous groups of children including children with drug-resistant focal epilepsy, children with newly diagnosed, drug-naïve focal epilepsy, and healthy children using overnight video-polysomnography (V-PSG) and a sleep questionnaire.

METHODS

We compared sleep architecture among 44 children with drug-resistant focal epilepsy, 41 children with newly diagnosed, drug naïve focal epilepsy, and 36 healthy children. All children underwent an overnight V-PSG recording, and their parents completed the Children's Sleep Habits Questionnaire (CSHQ). Sleep recordings were scored according to the American Academy of Sleep Medicine criteria.

RESULTS

Compared with children with newly diagnosed epilepsy and healthy controls, children with drug-resistant epilepsy receiving antiepileptic treatment showed disturbed sleep architecture, a significant reduction in time in bed, total sleep time, sleep efficiency, NREM3%, REM%, and a significant increase in awakenings, wake after sleep onset, and periodic leg movement. Children with drug-naïve, newly diagnosed focal epilepsy showed a statistically significant increase in sleep onset latency, rapid eye movement (REM) latency, N1%, awakenings, and a significant decrease in time in bed when compared with the controls. Children with drug-resistant epilepsy had the highest CSHQ total scores, while children with drug-naïve, newly diagnosed focal epilepsy had higher scores than healthy children.

CONCLUSION

This is one of the few polysomnographic studies adding to the limited research on the sleep macrostructure of children with drug-resistant epilepsy compared with children with drug-naïve, newly diagnosed focal epilepsy and healthy children by obtaining objective measurements of sleep concurrently with a validated questionnaire. Children with drug-resistant epilepsy had a greater incidence of sleep disturbance on the basis of qualitative aspects and architecture of sleep than children with newly diagnosed epilepsy, suggesting the need for referral of children with drug-resistant epilepsy for overnight sleep evaluation in order to improve the clinical management and optimize therapeutic strategies.

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

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

Effects of acute physical exercise in the light phase of sleep in rats with temporal lobe epilepsy

OBJECTIVE

Our aim was to investigate the influence of an acute exercise session on sleep pattern in rats with temporal lobe epilepsy (TLE).

METHODS

Twenty male Wistar rats were randomly assigned to 4 groups: control (C); acute exercise (EX); epilepsy (E) and epilepsy acute exercise (EEX). Two sleep electrocorticography recordings were performed during the light phase [baseline and day 2 (after the acute physical exercise session)]. After baseline recording, the exercise groups (EX and EEX) were submitted to an exercise session on a motor-driven treadmill at 12m/min for 30min. Twelve hours later, the rats were submitted to the second sleep recording.

RESULTS

At baseline, the E group showed a higher wakefulness and a lower Total sleep time, Slow Wave Sleep and REM sleep compared with the C group. After acute exercise, there was an increase in Total sleep time and Slow Wave Sleep and a decrease of wakefulness in EEX (+11.10%, +20.29% and -11.25%, respectively) and EX (+5.20%, +11.60% and -8.12%, respectively) groups.

CONCLUSION

These findings suggest that acute physical exercise positively impacts the sleep pattern of rats with TLE, inducing a more consolidated sleep.

Insomnia in childhood and adolescence: clinical aspects, diagnosis, and therapeutic approach

OBJECTIVES

To review the clinical characteristics, comorbidities, and management of insomnia in childhood and adolescence.

SOURCES

This was a non-systematic literature review carried out in the PubMed database, from where articles published in the last five years were selected, using the key word "insomnia" and the pediatric age group filter. Additionally, the study also included articles and classic textbooks of the literature on the subject.

DATA SYNTHESIS

During childhood, there is a predominance of behavioral insomnia as a form of sleep-onset association disorder (SOAD) and/or limit-setting sleep disorder. Adolescent insomnia is more associated with sleep hygiene problems and delayed sleep phase. Psychiatric (anxiety, depression) or neurodevelopmental disorders (attention deficit disorder, autism, epilepsy) frequently occur in association with or as a comorbidity of insomnia.

CONCLUSIONS

Insomnia complaints in children and adolescents should be taken into account and appropriately investigated by the pediatrician, considering the association with several comorbidities, which must also be diagnosed. The main causes of insomnia and triggering factors vary according to age and development level. The therapeutic approach must include sleep hygiene and behavioral techniques and, in individual cases, pharmacological treatment.

Executive function and sleep problems in childhood epilepsy

Pediatric epilepsy has been reported to be associated with both sleep problems and cognitive deficits. In turn, in healthy children, poorer sleep has been associated with deficits in cognitive functioning. We hypothesized that poor sleep in childhood epilepsy may contribute to cognitive deficits. Using actigraphy, we objectively measured the sleep of children with epilepsy alongside that of healthy controls. In contrast to previous reports, we did not find any differences in objectively measured sleep between children with epilepsy and healthy controls. However, significant deficits in cognitive functioning were demonstrated that were not explained by differences in sleep.

Sleep alterations in children with refractory epileptic encephalopathies: a polysomnographic study

Data on the relationship between sleep disturbances and refractory epileptic encephalopathies (EEs) are scarce. Our aim was to assess, by means of nocturnal polysomnography, if children with EEs present with objective alterations in sleep organization. Twenty-three children with EEs (12 males; mean age: 8.7±1.4years) and 40 healthy controls (22 males; mean age: 8.8±1.1years) underwent an overnight full polysomnography (PSG). Relative to controls, children with EEs showed a significant reduction in all PSG parameters related to sleep duration time in bed (TIB-min p<0.001), total sleep time (TST-min p<0.001), and sleep percentage (SPT-min p<0.001), as well as significantly higher REM latency (FRL-min p<0.001), rate in stage shifting (p=0.005), and number of awakenings/hour (p=0.002). Relative to controls, children with EEs also showed significant differences in respiratory parameters (AHI/h p<0.001, ODI/h p<0.001, SpO2% p<0.001, SpO2 nadir% p<0.001) and a higher rate of periodic limb movements (PLMs% p<0.001). Our findings suggest that sleep evaluation could be considered mandatory in children with refractory epileptic encephalopathy in order to improve the clinical management and the therapeutic strategies.

Sleep cyclic alternating pattern and cognition in children: a review

Several studies have been recently focused on the relationship between sleep cyclic alternating pattern (CAP) and daytime cognitive performance, supporting the idea that the CAP slow components may play a role in sleep-related cognitive processes. Based on the results of these reports, it can be hypothesized that the analysis of CAP might be helpful in characterizing sleep microstructure patterns of different phenotypes of intellectual disability and a series of studies has been carried out that are reviewed in this paper. First the studies exploring the correlations between CAP and cognitive performance in normal adults and children are described; then, those analyzing the correlation between CAP and cognitive patterns of several developmental conditions with neurocognitive dysfunction (with or without mental retardation) are reported in detail in order to achieve a unitary view of the role of CAP in these conditions that allows to detect a particular "sleep microstructure phenotype" of children with neurologic/neuropsychiatric disorders.