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

SPECT/CT imaging of poor sleep quality in people with epilepsy

PURPOSE

To analyze the characteristics of cerebral blood flow changes of poor sleep quality in people with epilepsy(PWE).

METHODS

90 PWE treated in The General Hospital of Ningxia Medical University from December 2021 to September 2023 were divided into poor sleep quality group (PSQG) and good sleep quality group (GSQG) according to the Chinese version of the Pittsburgh Sleep Quality Index (CPSQI), to compare the differences in cerebral perfusion between the two groups of patients, so as to summarize the characteristics of cerebral blood flow changes of poor sleep quality in PWE.

RESULTS

The positive rate of interictal single-photon emission computed tomography/computed tomography (SPECT/CT) was 76.7 %(69/90), which showed localized cerebral hypoperfusion. There was no statistical difference between the two groups of PSQG (N=29) and GSQG (N=61) in terms of the positive rate of SPECT/CT, the number of hypoperfusion foci, and the range of hypoperfusion foci. In PSQG and GSQG, 9 patients(31.0 %) and 6 patients(9.8 %) showed hypoperfusion in the right parietal lobe, respectively, and the difference between the two groups was statistically significant (P=0.017). There was no statistical difference the rate of the interictal epileptiform discharges (IEDs) and the brain area of IEDs in electroencephalography(EEG) between the two groups.

CONCLUSION

SPECT/CT of poor sleep quality in PWE demonstrated hypoperfusion in the right parietal lobe.

The Reciprocal Relationship between Sleep and Epilepsy

The relationship between sleep and epilepsy is bidirectional. Certain epilepsy syndromes predominantly or exclusively manifest during sleep, with seizures frequently originating from non-rapid eye movement (NREM) sleep. Interictal epileptiform discharges observed on electroencephalograms are most likely to be activated during the deep NREM sleep stage known as N3. Conversely, epileptiform discharges, anti-seizure medications (ASMs), as well as other anti-seizure therapies can exert detrimental effects on sleep architecture. Moreover, the co-occurrence of sleep disorders has the potential to exacerbate seizure control. Understating the relationship between sleep and epilepsy is crucial for healthcare providers. Addressing and managing sleep-related problems in individuals with epilepsy can potentially contribute to improved seizure control and overall well-being. At the same time, improving seizure control can improve sleep quality and quantity, thus further improving the health of individuals with epilepsy.

Sleep, oscillations, and epilepsy

Sleep and wake are defined through physiological and behavioral criteria and can be typically separated into non-rapid eye movement (NREM) sleep stages N1, N2, and N3, rapid eye movement (REM) sleep, and wake. Sleep and wake states are not homogenous in time. Their properties vary during the night and day cycle. Given that brain activity changes as a function of NREM, REM, and wake during the night and day cycle, are seizures more likely to occur during NREM, REM, or wake at a specific time? More generally, what is the relationship between sleep-wake cycles and epilepsy? We will review specific examples from clinical data and results from experimental models, focusing on the diversity and heterogeneity of these relationships. We will use a top-down approach, starting with the general architecture of sleep, followed by oscillatory activities, and ending with ionic correlates selected for illustrative purposes, with respect to seizures and interictal spikes. The picture that emerges is that of complexity; sleep disruption and pathological epileptic activities emerge from reorganized circuits. That different circuit alterations can occur across patients and models may explain why sleep alterations and the timing of seizures during the sleep-wake cycle are patient-specific.

Neurologic Disorders in Women and Sleep

Sleep disorders in women remain underrecognized and underdiagnosed mainly because of gender bias in researching and characterizing sleep disorders in women. Symptoms of common sleep disorders are frequently missed in the general female population and are expected to be further overlooked because of overlapping symptoms in women with neurologic disorders. Given the bidirectional relationship with sleep and neurologic disorders, it remains critical to be aware of the presentation and impact of sleep disorders in this patient population. This article reviews available data on sleep disorders in women with neurologic disorders and discusses their distinctive features.

Fear of sleep in people with epilepsy

More than one third of people with epilepsy (PWE) report experiencing insomnia. This is highly concerning given that sleep loss both triggers and exacerbates seizures. It is therefore paramount that we understand the underlying mechanisms of insomnia in PWE. Nevertheless, research in this area remains limited, with little understanding of the emerging or maintaining factors of insomnia in PWE. Therefore, the current study sought to explore fear of sleep as a novel explanation for the increased rate of insomnia in PWE, and whether fear of sleep was related to post-seizure trauma. We recruited 184 PWE and 197 healthy controls via social media and collected data using a series of online questionnaires. We found that fear of sleep did not significantly differ between the epilepsy and control group. In the epilepsy group, fear of sleep seemed to be largely driven by trauma, especially post-seizure trauma but also non-seizure related trauma, along with anxiety and higher seizure frequency. Fear of sleep in the control group was also largely driven by trauma, but also anxiety and depression. Finally, we found more severe and prevalent insomnia in PWE relative to controls, and in both groups, fear of sleep was the most significant contributor to insomnia. Our novel findings carry important clinical implications. First, they point to the central role of trauma in fear of sleep not only in PWE but also in the general population. Our findings also indicate that fear of sleep is an important maintaining factor of insomnia. Ultimately, these results suggest that all individuals with insomnia may benefit from insomnia interventions targeted at trauma, depression, anxiety, and fear of sleep. PWE are likely to benefit from additional treatment components for seizure-related trauma and seizure management. To better understand the reliability and generalisability of our novel findings, future research should further assess fear of sleep and its role in maintaining insomnia in the epilepsy population.

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

Focal epilepsy disrupts spindle structure and function

Sleep spindles are the hallmark of N2 sleep and are attributed a key role in cognition. Little is known about the impact of epilepsy on sleep oscillations underlying sleep-related functions. This study assessed changes in the global spindle rate in patients with epilepsy, analysed the distribution of spindles in relation to the epileptic focus, and performed correlations with neurocognitive function. Twenty-one patients with drug-resistant focal epilepsy (12 females; mean age 32.6 ± 10.7 years [mean ± SD]) and 12 healthy controls (3 females; 24.5 ± 3.3 years) underwent combined whole-night high-density electroencephalography and polysomnography. Global spindle rates during N2 were lower in epilepsy patients compared to controls (mean = 5.78/min ± 0.72 vs. 6.49/min ± 0.71, p = 0.02, d =  − 0.70). Within epilepsy patients, spindle rates were lower in the region of the epileptic focus compared to the contralateral region (median = 4.77/min [range 2.53–6.18] vs. 5.26/min [2.53–6.56], p = 0.02, rank biserial correlation RC =  − 0.57). This decrease was driven by fast spindles (12–16 Hz) (1.50/min [0.62–4.08] vs. 1.65/min [0.51–4.28], p = 0.002, RC =  − 0.76). The focal reduction in spindles was negatively correlated with two scales of attention (r =  − 0.54, p = 0.01; r =  − 0.51, p = 0.025). Patients with focal epilepsy show a reduction in global and local spindle rates dependent on the region of the epileptic focus. This may play a role in impaired cognitive functioning. Future work will show if the local reduction in spindles can be used as potential marker of the epileptic focus.

Seizures and Sleep: Not such strange bedfellows

It has long been recognised that sleep and deprivation of it have important consequences for cortical excitability, the electroencephalogram and seizure control. However, in the management of people with epilepsy, it is also important to recognise that epilepsy and its treatment may also have significant implications for sleep. Lack of consideration for this bidirectional relationship between sleep and epilepsy may have negative consequences on individuals’ seizure control, quality of life, and other aspects of their health.

Circannual incidence of seizure evacuations from the Canadian Arctic

OBJECTIVES

Emerging evidence suggests that circadian rhythms affect seizure propensity in addition to, and possibly independent of, sleep-wake states. Subject to extreme seasonal changes in light and dark, the northerly Arctic can serve as a "natural experiment" to assess the real-life impact of environmental influences on seizure severity. Therefore, we evaluated the timing of seizure evacuations over 11.25 years in a well-defined region of the Canadian Arctic.

METHODS

Retrospective review of EEG database and patient records at the single "bottleneck" hospital to which all patients from the Kivalliq Region in Nunavut, Canada are evacuated for seizure emergencies. We calculated the mean resultant length (MRL) of circular data for circannual analysis, and conducted Rayleigh's test to assess for a statistical departure from circular uniformity.

RESULTS

Screening 40,392 EEGs, we found 117 medical evacuations from 99 distinct individuals from September 2009 to November 2020. Most evacuations occurred month-wise in May (19%); week-wise within a 7-day period in February (5%), June (5%), or November (5%); and day-wise within a 24-hour period in June (3%) or November (3%). Maximal MRL clustering occurred in April no matter if analyzed by day (0.16333, p = 0.04), week (0.16296, p = 0.04), or month (0.1736, p = 0.03).

CONCLUSIONS

A relative circannual increase in seizure evacuations between the winter and summer solstices may be related to increasing sleep loss when day length grows. Fewer evacuations between the summer and winter solstices may be related to decreased daylight and "catching up" on sleep when night length grows. Additional factors likely also play a role in circannual variation of seizure evacuations in the Arctic, which warrants further research.

Changes in Pre- and Postsurgery for Drug Resistant Epilepsy: Cognition and Sleep

BACKGROUND

Most patients with drug-resistant epilepsy (DRE) have cognitive impairment and sleep disturbance. There was a significant correlation between sleep disorders and cognitive dysfunction. This study performed surgical treatment on patients with DRE and observed seizures, sleep, and cognition in patients with DRE in 6th month after operation to clarify the correlation between sleep and cognition in DRE patients.

METHODS

21 individuals with DRE were recruited to enroll in this trial. Each participant completed epileptic focus resection. Seizure frequency was the principle index; the mean seizure frequency was 1 month before surgery and six months after surgery. Cognitive function was assessed by MMSE, and sleep status was assessed by PSQI and ActiGraph; assessments were performed before and 6 months after surgery.

RESULTS

There were significant differences between conditions on all outcome measures; after 6 months of surgery, compared with before treatment, the monthly average seizure frequency of DRE decreased, which was statistically significant (P < 0.001) compared with that before treatment. The MMSE score of DRE patients was significantly higher than before (P < 0.01), especially the ability of attention, calculation, and recall in MMSE score, which was significantly higher than before operation (respectively, P < 0.001 and P < 0.01). The subjective sleep evaluation index PSQI and objective measurement of sleep latency, total sleep time, and sleep efficiency of patients with DRE by ActiGraph were statistically significant (respectively, P < 0.01) compared with that before treatment. There was a correlation between seizure frequency and MMSE (r = -0.8887, P < 0.0001), PSQI (0.5515, P < 0.01), sleep latency (0.5353, P < 0.05), total sleep time (-0.7814, P < 0.0001), and sleep efficiency (-0.4380, P < 0.05).

CONCLUSIONS

Surgery can effectively reduce the epileptic seizures frequency in patients with DRE and indirectly improve the computational power, attention, recall ability, and sleep status of patients. However, this result did not show a correlation between improved cognitive function and sleep, so the patient's cognitive function may be caused by surgery to improve the frequency of seizures. So, whether the improvement of patients' sleep conditions can also significantly improve the frequency of attacks and cognitive function in patients with DRE needs further exploration.

Effects of anti-seizure medications on sleep architecture and daytime sleepiness in patients with epilepsy: A literature review

Anti-seizure medications (ASMs) may improve or be detrimental to sleep. A literature review (as an update to the 2014 review by Jain and Glauser [https://doi.org/10.1111/epi.12478]) of 25 ASMs of interest (articles from 12 ASMs included) on the effect of ASMs/non-drug treatments on sleep in patients with epilepsy was conducted. The most common objective instrument was polysomnography, and the most common subjective measures were the Epworth Sleepiness Scale and the Pittsburgh Sleep Quality Index. Eslicarbazepine acetate, lacosamide, and perampanel improved or had no effect on sleep. Perampanel was associated with low incidence of insomnia, and lacosamide with low incidence of daytime sleepiness adverse events. Clonazepam, felbamate, lamotrigine, oxcarbazepine, and phenobarbital worsened or had no effect on sleep. Lamotrigine may be associated with insomnia risk and phenobarbital with daytime sleepiness. Data for valproic acid were mixed. Overall, cannabidiol, carbamazepine, and levetiracetam had no effect on sleep. Epilepsy surgery may benefit sleep in patients with a good surgical outcome. Some ASMs, and, possibly, epilepsy surgery, may have positive effects on sleep, possibly linked to achieving seizure control. Nonetheless, other ASMs may worsen sleep in some settings. Clinicians should consider such observations when making treatment decisions, particularly for patients with comorbid sleep disorders.

Expert-level automated sleep staging of long-term scalp electroencephalography recordings using deep learning

STUDY OBJECTIVES

Develop a high-performing, automated sleep scoring algorithm that can be applied to long-term scalp electroencephalography (EEG) recordings.

METHODS

Using a clinical dataset of polysomnograms from 6,431 patients (MGH-PSG dataset), we trained a deep neural network to classify sleep stages based on scalp EEG data. The algorithm consists of a convolutional neural network for feature extraction, followed by a recurrent neural network that extracts temporal dependencies of sleep stages. The algorithm's inputs are four scalp EEG bipolar channels (F3-C3, C3-O1, F4-C4, and C4-O2), which can be derived from any standard PSG or scalp EEG recording. We initially trained the algorithm on the MGH-PSG dataset and used transfer learning to fine-tune it on a dataset of long-term (24-72 h) scalp EEG recordings from 112 patients (scalpEEG dataset).

RESULTS

The algorithm achieved a Cohen's kappa of 0.74 on the MGH-PSG holdout testing set and cross-validated Cohen's kappa of 0.78 after optimization on the scalpEEG dataset. The algorithm also performed well on two publicly available PSG datasets, demonstrating high generalizability. Performance on all datasets was comparable to the inter-rater agreement of human sleep staging experts (Cohen's kappa ~ 0.75 ± 0.11). The algorithm's performance on long-term scalp EEGs was robust over a wide age range and across common EEG background abnormalities.

CONCLUSION

We developed a deep learning algorithm that achieves human expert level sleep staging performance on long-term scalp EEG recordings. This algorithm, which we have made publicly available, greatly facilitates the use of large long-term EEG clinical datasets for sleep-related research.

Proceedings of the Sleep and Epilepsy Workgroup: Section 2 Comorbidities: Sleep Related Comorbidities of Epilepsy

Epilepsy is a chronic disease with multiple, complex comorbidities. Bidirectional relationships exist among seizures, sleep, circadian rhythms, and diseases within and outside of the central nervous system. Seizures fragment sleep and can contribute to development of sleep disorders, which in turn leads to worse overall health and more seizures. Moreover, treatment options are often limited by interactions with anti-seizure medications. Advances in the fields of epilepsy and in sleep medicine have been made separately, and therefore treating patients with these comorbidities necessitates interdisciplinary approach. The focus of this section of the Sleep and Epilepsy Workgroup was to identify methods of collaboration and outline investigational, educational, and treatment priorities to mutually advance what we consider a combined field.

The Management and Alternative Therapies for Comorbid Sleep Disorders in Epilepsy

BACKGROUND

There is a complex and interactive relationship between sleep and epilepsy. Sleep disorders are common in patients with epilepsy, and methods for managing sleep disorders in patients with epilepsy are limited.

OBJECTIVE

This review addresses the relationship among sleep, sleep disorders, and epilepsy, focusing on the management of sleep disorders in epilepsy, including some complementary and alternative therapies.

METHODS

The terms related to "sleep" and "epilepsy" were searched in "Pubmed" and "Cochrane Library".

RESULTS

Sleep stages differently affect both seizures and interictal epileptiform discharges. Seizures disrupt sleep architecture greatly, especially when occurring during sleep in the night. Insomnia and obstructive sleep apnea (OSA) are the most frequent types of comorbid sleep disorders in patients with epilepsy. Pharmacological agents with both anti-convulsant and sedative effects are the priorities for comorbid sleep disorders in epilepsy. Continuous positive airway pressure (CPAP) therapy is the most effective non-pharmacological method to improve OSA and reduce seizures. Complementary and alternative therapies such as Chinese traditional medicine, cognitive behavioral therapy, meditation, yoga, neurofeedback, and acupuncture may have benefits in reducing seizures and improving sleep quality simultaneously by alleviating stress and seizure triggers; however, evidence- based therapies are still deficient.

CONCLUSION

Management of sleep disorders in patients with epilepsy is challenging. Large-scale randomized controlled clinical trials are in demand to guide the treatments in the future.

Objectively measured sleep-wake patterns in patients with drug-resistant epilepsy - Interaction with quality of life and antiepileptic treatment

RATIONALE

Patients with epilepsy experience frequent episodes of fragmented sleep which may contribute to chronic sleep loss. Enhancing sleep patterns might lead to improved quality of life in these patients. Currently, unlike some other antiepileptic drugs (AEDs), there are no data on the effects of clobazam, a novel AED on sleep. Therefore, we tested the hypothesis that patients with epilepsy will have longer, more consolidated sleep after treatment with clobazam.

METHODS

In this prospective study, we included adults with drug-resistant epilepsy who were being considered for treatment with clobazam. Patients with known untreated moderate/severe sleep apnea or with major circadian rhythm disorders were excluded. We tested a set of the following subjective sleep measures: Pittsburgh Sleep Quality Inventory (PSQI), Epworth Sleepiness Scale (ESS), Karolinska Sleepiness Scale (KSS), Insomnia Severity Index (ISI), and Quality of Life in Epilepsy (QOLIE) prior to starting the treatment, as well as after achieving a stable clobazam dose. We also measured sleep pattern using wrist actigraphy - before starting therapy and after achieving stable dose.

RESULTS

A total of 12 participants completed all parts of the study. After treatment, a lower number of awakenings and less wake after sleep onset (WASO) were seen, as well as a lower number of seizures. Average pretreatment bedtime was 23:45, and average wake time was 8:24. A higher seizure frequency significantly correlated with all subjective sleep measures, as well as with a higher amount actigraphy measured WASO and less total sleep time (TST) measured both by sleep log and by actigraphy. Those with higher baseline WASO by actigraphy also had more depressive symptoms, worse quality of life, longer duration of epilepsy, and a higher seizure frequency.

CONCLUSION

Both objective and subjective sleep metrics correlate with depressive symptoms and quality of life. After treatment, there were fewer awakenings as well as fewer seizures.

[Sleep and wake disorders in epilepsy]

OBJECTIVE

To summarize published data on the prevalence, characteristics and diagnostic criteria of sleep disorders in epilepsy.

MATERIAL AND METHODS

A search of published articles was performed in Medline (Pubmed), Scopus, Web of Science and e-library databases.

RESULTS

Epidemiologic, clinical and diagnostic aspects of excessive daytime sleepiness, obstructive sleep apnea and central apnea, restless leg syndrome and parasomnias related to slow-wave and REM-sleep in patients with epilepsy were analyzed.

CONCLUSIONS

Further studies are needed to gain an insight into the complex associations of sleep disorders in epilepsy to optimize diagnostic and treatment approaches and to improve the quality of life in that patient population.

Gender Differences in Associated and Predictive Factors of Anxiety and Depression in People With Epilepsy

PURPOSE

Comorbid anxiety and depression in people with epilepsy (PWE) are highly prevalent and contribute to low quality of life (QOL) and may even lead to poor outcomes of epilepsy. Among the various factors that affect these negative emotional comorbidities, possible gender differences remain poorly understood and are often neglected. This research aimed to determine whether there are discrepancies in the incidence and influence factors of anxiety and depression between men and women with epilepsy in a hospital in northwest China.

METHODS

A total of 158 adult PWE (female: N = 65; 41.1%) completed self-report questionnaires, including the Self-rating Anxiety Scale (SAS), the Self-rating Depression Scale (SDS), the Chinese version of the Quality of Life in Epilepsy-31 (QOLIE-31) inventory and the Pittsburgh Sleep Quality Inventory (PSQI). The comparison between male and female PWE was made by regression analysis.

RESULTS

For the prevalence of anxiety and depression in PWE, no gender difference was found in this study. However, the moderating factors of psychiatric comorbidities were significantly different between men and women: male PWE with comorbid anxiety were more likely to be affected by sleep quality, while anxiety symptoms in female PWE were closely associated with the frequency of seizures. Education years and QOL social function were significant indicators of depression in male PWE but not in female PWE. The important and common predictor for anxiety and depressive symptoms in PWE was QOL energy/fatigue, with male patients being more affected.

CONCLUSION

For the PWE included in this study, the incidence of comorbid anxiety and depression in PWE was similar for men and women, but the moderating factors affecting comorbid anxiety and depressive disorders differed between genders: male PWE were more likely to be affected by psychosocial factors, while female PWE were more influenced by epilepsy itself. This exploration suggests that gender-specific health care should be considered in epilepsy therapy to improve the psychiatric condition and QOL of PWE, and different treatments should be conducted for male and female PWE to prevent negative emotional comorbidities.

Breakthrough spikes in rapid eye movement sleep from the epilepsy monitoring unit are associated with peak seizure frequency

Study Objectives

Rapid eye movement sleep (REM) usually suppresses interictal epileptiform discharges (IED) and seizures. However, breakthrough IEDs in REM sometimes continue. We aimed to determine if the amount of IED and seizures in REM, or REM duration, is associated with clinical trajectories.

Methods

Continuous electroencephalogram (EEG) recordings from the epilepsy monitoring unit (EMU) were clipped to at least 3 h of concatenated salient findings per day including all identified REM. Concatenated EEG files were analyzed for nightly REM duration and the “REM spike burden” (RSB), defined as the proportion of REM occupied by IED or seizures. Patient charts were reviewed for clinical data, including patient-reported peak seizure frequency. Logistic and linear regressions were performed, as appropriate, to explore associations between two explanatory measures (duration of REM and RSB) and six indicators of seizure activity (clinical trajectory outcomes).

Results

The median duration of REM sleep was 43.3 (IQR 20.9–73.2) min per patient per night. 59/63 (93.7%) patients achieved REM during EMU admission. 39/59 (66.1%) patients had breakthrough IEDs or seizures in REM with the median RSB at 0.7% (IQR 0%–8.4%). Every 1% increase in RSB was associated with 1.69 (95% CI = 0.47–2.92) more seizures per month during the peak seizure period of one’s epilepsy (p = 0.007).

Conclusions

Increased epileptiform activity during REM is associated with increased peak seizure frequency, suggesting an overall poorer epilepsy trajectory. Our findings suggest that RSB in the EMU is a useful biomarker to help guide about what to expect over the course of one’s epilepsy.

Role of DNA Methylation and Adenosine in Ketogenic Diet for Pharmacoresistant Epilepsy: Focus on Epileptogenesis and Associated Comorbidities

Epilepsy is a neurological disorder characterized by a long term propensity to produce unprovoked seizures and by the associated comorbidities including neurological, cognitive, psychiatric, and impairment the quality of life. Despite the clinic availability of several novel antiepileptic drugs (AEDs) with different mechanisms of action, more than one-third of patients with epilepsy suffer with pharmacoresistant epilepsy. Until now, no AEDs have been proven to confer the efficacy in alteration of disease progression or inhibition of the development of epilepsy. The ketogenic diet, the high-fat, low-carbohydrate composition is an alternative metabolic therapy for epilepsy, especially for children with drug-resistant epilepsy. Recently clinical and experimental results demonstrate its efficacy in ameliorating both seizures and comorbidities associated with epilepsy, such as cognitive/psychiatric concerns for the patients with refractory epilepsy. Of importance, ketogenic diet demonstrates to be a promising disease-modifying or partial antiepileptogenesis therapy for epilepsy. The mechanisms of action of ketogenic diet in epilepsy have been revealed recently, such as epigenetic mechanism for increase the adenosine level in the brain and inhibition of DNA methylation. In the present review, we will focus on the mechanisms of ketogenic diet therapies underlying adenosine system in the prevention of epileptogenesis and disease modification. In addition, we will review the role of ketogenic diet therapy in comorbidities associated epilepsy and the underlying mechanisms of adenosine.