The relationship between sleep and epilepsy: Evidence from clinical trials and animal models

Sleep profiles in epilepsy patients undergoing monotherapy and polytherapy: A comparative cross-sectional study

OBJECTIVE

Sleep disturbances commonly reported among epilepsy patients have a reciprocal relationship with the condition; While epilepsy and anti-seizure medications (ASMs) can disrupt sleep structure, disturbed sleep can also exacerbate the frequency of seizures. This study explored subjective sleep disturbances and compared sleep profiles in patients who underwent ASM monotherapy and polytherapy.

METHODS

We enrolled 176 epilepsy patients who completed a structured questionnaire containing demographic and clinical information and the Persian versions of the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), and Patient Health Questionnaire-9 (PHQ-9) to evaluate sleep quality, insomnia, excessive daytime sleepiness (EDS), and depressive symptoms, respectively. Chi-square and Mann-Whitney U tests were employed to analyze the association between variables, and logistic regression analysis was conducted to identify factors predicting sleep disturbances.

RESULTS

Comparative analysis of mono/polytherapy groups revealed a significantly higher prevalence of insomnia and EDS among patients on polytherapy compared to monotherapy. However, no significant difference was found in sleep quality between the two groups. Logistic regression analysis revealed that a depressive mood serves as a robust predictor for sleep issues, whereas treatment type did not emerge as an independent predictor of sleep disturbances.

CONCLUSION

Our findings suggest that an increased number of ASMs does not inherently result in a higher incidence of sleep issues. Therefore, multiple ASMs may be prescribed when necessary to achieve improved seizure control. Furthermore, this study underscores the importance of comprehensive management that addresses seizure control and treating affective symptoms in individuals 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.

Effect of valproate on sleep patterns disturbed by epilepsy

Nocturnal epilepsy is a neurological disease that has a significant effect on sleep. Various treatments have been implemented to help mitigate these effects and improve patients' quality of life. The use of experimental animal models for epilepsy has facilitated efficacy assessment and the development of different medications to treat the symptoms of this disease. The objective of this study was to evaluate the effect of valproate on sleep patterns altered by epilepsy. Chronically implanted Wistar rats were used to study sleep patterns over three consecutive days under different experimental conditions. The animals were separated into two groups. The first day was considered the control recording; on the second day, one group received pentylenetetrazol (PTZ) alone, and the other group received valproate prior to induction of convulsive seizures with PTZ administration. The results show that in addition to its antiepileptic effect, valproate has hypnotic properties. It is considered to facilitate the action of GABAergic mechanisms to mitigate the effect of convulsive seizures and increase the occurrence of sleep.

Sleep architecture in neonatal and infantile onset epilepsies in the first six months of life: A scoping review

AIM

Epilepsy occurs in approximately 80 per 100,000 infants in the first year of life, ranging in severity from self-limited and likely to spontaneously resolve, to severe developmental and epileptic encephalopathies. Sleep plays a key role in early brain development and the reciprocal relationship between sleep and seizures is not yet fully understood, particularly in young children. We conducted a Scoping Review to synthesise current knowledge of sleep architecture in neonates and infants with epilepsy.

METHOD

Peer-reviewed publications from 2005 to 2022 describing sleep architecture in infants up to six months of age with unprovoked seizures were included. The analysis set was derived from EMBASE, Web of Science and PubMED using key terms "sleep, epilepsy and infant" and related descriptors. Inclusion criteria were prospectively described in a Scoping Review protocol. Sleep architecture was assessed as macro- and micro-structural elements.

RESULTS

21 publications were included in the qualitative analysis. In self-limited familial and genetic epilepsy, sleep macrostructure was generally preserved. In DEEs and in epileptic encephalopathies of genetic or structural aetiology, sleep architecture was significantly disrupted.

INTERPRETATION

Early identification of infants with epilepsy is important to ensure early and effective treatment. In the DEE spectrum, sleep architecture is significantly impacted, and abnormal sleep architecture may be associated with compromised developmental outcome. Further research is needed to identify the sequence of events in abnormal brain development, epilepsy and sleep disruption and potentially help to predict the course of epilepsy towards a self-limited epilepsy versus a DEE.

The interaction between circadian rhythm and epilepsy

Evidence about the interaction between circadian rhythms (CR) and epilepsy has been expanded with the application of advanced detection technology. An adequate understanding of how circadian system and epilepsy interact with each other could contribute to more accurate seizure prediction as well as rapid development of potential treatment timed to specific phases of CR. In this review, we present the reciprocal relationship between CR and epileptic activities from aspects of sleep effect, genetic modulation and brain biochemistry. It has been found that sleep-wake patterns, circadian timing systems and multidien rhythms have essential roles in seizure activities and interictal epileptiform discharge (IED). For instance, specific distribution patterns of seizures and IED have been reported, i.e., lighter non-rapid eye movement (NREM) sleep stage (stage 2) induces seizures while deeper NREM sleep stage (stage 3) activates IEDs. Furthermore, the epilepsy type, seizure type and seizure onset zone can significantly affect the rhythms of seizure occurrence. Apart from the common seizure types, several specific epilepsy syndromes also have a close correlation with sleep-wakefulness patterns. Sleep influences the epilepsy rhythm, and conversely, epilepsy alters the sleep rhythm through multiple pathways. Clock genes accompanied by two feedback loops of regulation have an important role in cortical excitability and seizure occurrence, which may be involved in the mTORopathy. The suprachiasmatic nuclei (SCN) has a rhythm of melatonin and cortisol secretion under the circadian pattern, and then these hormones can feed back into a central oscillator to affect the SCN-dependent rhythms, leading to variable but prominent influence on epilepsy. Furthermore, we discuss the precise predictive algorithms and chronotherapy strategies based on different temporal patterns of seizure occurrence for patients with epilepsy, which may offer a valuable indication for non-invasive closed-loop treatment system. Optimization of the time and dose of antiseizure medications, and resynchronization of disturbed CR (by hormone therapy, light exposure, ketogenic diet, novel small molecules) would be beneficial for epileptic patients in the future. Before formal clinical practice, future large-scale studies are urgently needed to assist prediction and treatment of circadian seizure activities and address unsolved restrictions.

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 Sleep Disturbances in Patients with Nocturnal Epileptic Seizures in a Romanian Cross-Sectional Study

(1) Background: Based on the premise that epilepsy is frequently associated with hypnopathies, in this study we aim to analyze the prevalence of sleep disturbances among patients with epilepsy, with exclusively or predominantly nocturnal seizures, in relation to demographic factors as well as clinical and electroencephalography (EEG) aspects. (2) Methods: 69 patients with nocturnal epilepsy were included in our study. Sleep disturbances were measured with the Pittsburgh Sleep Quality Index (PSQI) questionnaire, followed by a long-term video-EEG monitoring during sleep. We analyzed the PSQI results in relation to patients' gender and age and determined the correlations between the PSQI scores and the modifications on video-EEG recordings, in comparison to a control group of 25 patients with epilepsy but without nocturnal seizures. (3) Results: We found a statistically significant difference between the PSQI of patients with nocturnal seizures compared to those without nocturnal epileptic manifestations. In the experimental group, the mean PSQI score was 7.36 ± 3.91 versus 5.04 ± 2.56 in controls. In women, the average PSQI score was 8.26, whilst in men it only reached 6.41, highlighting a statistically significant difference between genders (p ˂ 0.01). By examining the relationships between the PSQI scores and certain sleep-related factors, evidenced on the nocturnal video-EEG, we found a statistically significant difference between PSQI values of patients who reached the N2 stage, and those who reached the N3 stage of nonrapid eye movement (NREM) sleep, highlighting that those with a more superficial nocturnal sleep also had higher PSQI scores. There were no statistically significant differences regarding the PSQI scores between patients with or without interictal epileptiform discharges, and also in the few patients with nocturnal seizures where we captured ictal activity. (4) Conclusions: we evidenced in this study a poor quality of sleep in patients with nocturnal epilepsy, mostly in women, independent of age. We observed that sleep disturbances were due to superficial and fragmented sleep with frequent microarousals, not necessarily caused by the electrical epileptiform activity.

Sleep disorders and ADHD symptoms in children and adolescents with typical absence seizures: An observational study

OBJECTIVE

To assess the occurrence of sleep disorders (SD) and attention deficit hyperactivity disorder (ADHD) symptoms in children with typical absence seizures (TAS) compared to control children and to evaluate the impact of epilepsy-related factors on sleep and attention in children with TAS.

METHODS

The Sleep Disturbance Scale for Children (SDSC) and the ADHD rating scale were filled in by parents of a cohort composed by 82 children aged from 5 to 15.6 years, 49% of boys (41 with TAS with a syndromic diagnosis of childhood absence epilepsy and 41 controls). For children with TAS, the Pediatric Epilepsy Side Effects Questionnaire was completed. Statistical analyses were conducted in order to compare sleep and attention scores between groups. In children with TAS, a correlation was computed between these scores. Logistics regression models were conducted to identify predictors of excessive diurnal sleepiness and inattention in children with TAS.

RESULTS

Compared to controls, children with TAS had higher total scores for subjective sleep (mean 42.9 vs 38.3, p = 0.05) and attention disorders (mean 16.8 vs 11.6, p = 0.01), especially for excessive diurnal sleepiness (mean 3.9 vs 3.2, p = 0.02) and inattention (mean 9.3 vs 5.6, p = 0.003) components. In children with TAS, sleep problems were significantly under-reported by parents. Sleep disorders symptoms as breathing-related sleep disturbance, excessive diurnal sleepiness or naps at or after 7 years of age were reported. Subjective sleep and attention disorders were significantly correlated (r = 0.43, p = 0.01). Subjective excessive diurnal sleepiness may be the result of a polytherapy (p = 0.05) or a side effect of anti-seizure medication (ASM) (p = 0.03) but children without medication side effects also reported subjective SD. In children with TAS, the risk of inattention symptoms was increased in boys (p = 0.02), with a high BMI (p = 0.05), or with ASM side effects (p = 0.03).

CONCLUSIONS

This study demonstrates that children with TAS are at risk of sleep and attention disorder symptoms. If attention disorders in a context of epilepsy are now widely assessed and identified, sleep disorders are still under-estimated. An accurate identification and management of sleep disorders could improve academic performances, quality of life, and seizure management in children with TAS.

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.

Sleep, neuronal hyperexcitability, inflammation and neurodegeneration: Does early chronic short sleep trigger and is it the key to overcoming Alzheimer's disease?

Evidence links neuroinflammation to Alzheimer's disease (AD); however, its exact contribution to the onset and progression of the disease is poorly understood. Symptoms of AD can be seen as the tip of an iceberg, consisting of a neuropathological build-up in the brain of extracellular amyloid-β (Aβ) plaques and intraneuronal hyperphosphorylated aggregates of Tau (pTau), which are thought to stem from an imbalance between its production and clearance resulting in loss of synaptic health and dysfunctional cortical connectivity. The glymphatic drainage system, which is particularly active during sleep, plays a key role in the clearance of proteinopathies. Poor sleep can cause hyperexcitability and promote Aβ and tau pathology leading to systemic inflammation. The early neuronal hyperexcitability of γ-aminobutyric acid (GABA)-ergic inhibitory interneurons and impaired inhibitory control of cortical pyramidal neurons lie at the crossroads of excitatory/inhibitory imbalance and inflammation. We outline, with a prospective framework, a possible vicious spiral linking early chronic short sleep, neuronal hyperexcitability, inflammation and neurodegeneration. Understanding the early predictors of AD, through an integrative approach, may hold promise for reducing attrition in the late stages of neuroprotective drug development.

Electrophysiological and neurochemical evaluation of the adverse effects of REM sleep deprivation and epileptic seizures on rat's brain

AIM

The current study aims to investigate the impact of paradoxical (REM) sleep deprivation and/or epileptic seizures on rat's cortical brain tissues.

MAIN METHODS

Animals were divided into four groups; control, epileptic, REM sleep deprived and epileptic subjected to REM sleep deprivation. Electrocorticogram (ECoG) signals were recorded and quantitatively analyzed for each group. Concentrations of amino acid neurotransmitters; proinflammatory cytokines; and oxidative stress parameters; and acetylcholinesterase activity were determined in the cortex of the animals in different groups.

KEY FINDINGS

Results showed significant variations in the spectral distribution of ECoG waves in the epilepsy model, 24- and 48-hours of REM sleep deprivation and their combined effects indicating a state of cortical hyperexcitability. Significant increases in NO and taurine and significant decrement in glutamine, GABA and glycine were determined. In REM sleep deprived rats significant elevation in glutamate, aspartate, glycine and taurine and a significant lowering in GABA were obtained. This was accompanied by significant reduction in AchE and IL-β. In the cortical tissue of epileptic rats deprived from REM sleep significant increases in lipid peroxidation, TNF-α, IL-1β, IL-6 and aspartate and a significant reduction in AchE were observed.

SIGNIFICANCE

The present data indicate that REM sleep deprivation induces an increase in lipid peroxidation and storming in proinflammatory cytokines in the cortex of rat model of epilepsy during SRS. These changes are associated with a decreased seizure threshold as inferred from the increase in alpha and Beta waves and a decrease in Delta waves of ECoG.

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.

Changes in Physiological and Pathological Behaviours Produced by Deep Microelectrode Implantation Surgery in Rats: A Temporal Analysis

Physiological behaviours such as the sleep-wake cycle and exploratory behaviours are important parameters in intact and sham-operated animals and are usually thought to be unaffected by experimental protocols in which neurosurgery is performed. However, there is insufficient evidence in the literature on the behavioural and cognitive effects observed after deep microelectrode implantation surgery in animal models of neurological diseases. Similarly, in studies that utilize animal models of neurological diseases, the impact of surgery on the pathological phenomena being studied is often minimized. Based on these considerations, we performed a temporal analysis of the effects of deep microelectrode implantation surgery in the hippocampus of rats on quiet wakefulness, sleep, and exploratory activity and the pathological behaviours such as convulsive seizures according to the Racine scale. Male Wistar rats (210-300 g) were used and grouped in sham and epileptic animals. Single doses of pilocarpine hydrochloride (2.4 mg/2 μl; i.c.v.) were administered to the animals to generate spontaneous and recurrent seizures. Deep microelectrode implantation surgeries in both groups and analysis of Fast ripples were performed. Physiological and pathological behaviours were recorded through direct video monitoring of animals (24/7). Our principal findings showed that in epileptic animals, one of the main behaviours affected by surgery is sleep; as a consequence of this behavioural change, a decrease in exploratory activity was also found as well as the mean time spent daily in seizures of scale 4 and the number of seizure events of scales 4 and 5 was increased after surgery. No significant correlations between the occurrence of FR and seizure events of scale 4 (rho 0.63, p value 0.25) or 5 (rho -0.7, p value 0.18) were observed. In conclusion, microelectrode implantation surgeries modified some physiological and pathological behaviours; therefore, it is important to consider this fact when it is working with animal models.

Progressive cardiorespiratory dysfunction in Kv1.1 knockout mice may provide temporal biomarkers of pending sudden unexpected death in epilepsy (SUDEP): The contribution of orexin

OBJECTIVE

Immediately preceding sudden unexpected death in epilepsy (SUDEP), patients experienced a final generalized tonic-clonic seizure (GTCS), rapid ventilation, apnea, bradycardia, terminal apnea, and asystole. Whether a progressive pathophysiology develops and increases risk of SUDEP remains unknown. Here, we determined (a) heart rate, respiratory rate, and blood oxygen saturation (SaO₂ ) in low-risk and high-risk knockout (KO) mice; and (b) whether blocking receptors for orexin, a cardiorespiratory neuromodulator, influences cardiorespiratory function mice or longevity in high-risk KO mice.

METHODS

Heart rate and SaO₂ were determined noninvasively with ECGenie and pulse oximetry. Respiration was determined with noninvasive airway mechanics technology. The role of orexin was determined within subject following acute treatment with a dual orexin receptor antagonist (DORA, 100 mg/kg). The number of orexin neurons in the lateral hypothalamus was determined with immunohistochemistry.

RESULTS

Intermittent bradycardia was more prevalent in high-risk KO mice, an effect that may be the result of increased parasympathetic drive. High-risk KO mice had more orexin neurons in the lateral hypothalamus. Blocking of orexin receptors differentially influenced heart rate in KO, but not wild-type (WT) mice. When DORA administration increased heart rate, it also decreased heart rate variability, breathing frequency, and/or hypopnea-apnea. Blocking orexin receptors prevented the methacholine (MCh)-induced increase in breathing frequency in KO mice and reduced MCh-induced seizures, via a direct or indirect mechanism. DORA improved oxygen saturation in KO mice with intermittent hypoxia. Daily administration of DORA to high-risk KO mice increased longevity.

SIGNIFICANCE

High-risk KO mice have a unique cardiorespiratory phenotype that is characterized by progressive changes in five interdependent endpoints. Blocking of orexin receptors attenuates some of these endpoints and increases longevity, supporting the notion that windows of opportunity for intervention exist in this preclinical SUDEP model.

Effect of gabapentin on sleep patterns disturbed by epilepsy

For a long time, numerous sleep alterations induced by nocturnal epilepsy have been described. Such alterations include sleep fragmentation, decrement of sleep efficiency, increment of the wake time after sleep onset (WASO), increment of light sleep, and decrement of sleep depth. On the other hand, gabapentin (GBP), an antiepileptic drug analog of γ-aminobutyric acid (GABA) used as adjunctive and eventually, as a monotherapeutic treatment, induces a significant improvement in patients with both focal and secondarily generalized partial seizures. In experimental epilepsy models, this drug protects against pentylenetetrazol (PTZ)-induced convulsions. In consideration of such GBP properties, the aim of this work was to investigate its efficacy to protect against sleep disturbances provoked by convulsive seizures induced by the administration of PTZ. Nine-hour (9-hour) polygraphic studies were carried out in chronically implanted male adult Wistar rats separated into 4 different groups of 6 individuals. Control recordings in each group were done after saline administration. One group received a SC Subcutaneous (SC) injection of 50 mg/kg of PTZ alone while the other three groups were injected with either 15, 30, or 60 mg/kg IP Intraperitoneal (IP) of GBP 30 min prior to PTZ (50 mg/kg SC) administration. Animals displayed the whole range of electrophysiological and behavioral manifestations of the disease during the epileptic episodes induced by PTZ administration, and the states of vigilance were significantly altered. Insomnia occurred immediately after PTZ injection preceding the appearance of the first epileptic symptoms. Thus, both slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) were completely inhibited during a relatively long period of time. The disturbing effects of epilepsy on sleep decreased when animals were under GBP treatment. Improvement of sleep was dependent on the administered dose of this antiepileptic drug.

The impact of sleep characteristics and epilepsy variables on memory performance in patients with focal seizures

Disturbed sleep can negatively affect overnight memory retention as well as new learning the subsequent day. In healthy participants, positive associations between memory performance and sleep characteristics (e.g., time spent in slow-wave sleep [SWS]) have been detected. In a previous study, we found that SWS was much reduced in patients with focal seizures, but when correlations between memory complaints and various sleep characteristics were considered, the only significant relationship was with the time to onset of rapid eye movement (REM) sleep (i.e., REM latency). In this study, we investigated the relationships between sleep, epilepsy, and objective memory performance variables. Twenty-five patients with focal seizures had their memory tested while undergoing a two-day ambulatory electroencephalography (EEG). The sleep variables of interest were the percentage of time spent in SWS (%SWS) and REM latency. Epilepsy variables included the presence of (1) seizures, (2) interictal epileptiform discharges, and/or (3) hippocampal lesions as well as site of seizure origin (temporal vs extratemporal). Overnight retention (of autobiographical events, a story, and a complex geometric figure) and the ability to learn a word list on day 2 were the measures of memory. A significant positive correlation was found between word-list learning and %SWS during the previous night. A significant negative correlation was observed between REM latency and overnight retention of autobiographical events. Overnight retention scores for the story and geometric figure were not related to sleep characteristics but were negatively affected by the presence of epileptiform activity. Story retention was also worse for temporal lobe epilepsy (TLE) than for patients with extratemporal epilepsy (ETE). Those with hippocampal lesions were more impaired than those without lesions on word-list learning, autobiographical events' retention, and story retention. When multiple contributing factors were entered into regression analyses, %SWS was found to be the best predictor of subsequent word-list learning, whereas the presence of a hippocampal lesion was the best predictor of overnight retention of autobiographical events and a story. These findings provide further evidence of the ways in which particular sleep characteristics are associated with memory and suggest that treatment of sleep disturbances in patients with epilepsy might be helpful for improving their performance.

Accumulation of rest deficiency precedes sudden death of epileptic Kv1.1 knockout mice, a model of sudden unexpected death in epilepsy

OBJECTIVE

Chronic sleep deficiency is associated with early mortality. In the epileptic population, there is a higher prevalence of sleep disorders, and individuals with severe refractory epilepsy are at greater risk of premature mortality than the general population. Sudden unexpected death in epilepsy affects 1:1000 cases of epilepsy each year. Ketogenic diet (KD) treatment is one of the few effective options for refractory seizures. Despite KD reducing seizures and increasing longevity in Kv1.1 knockout (KO) mice, they still succumb to sudden death. This study aims to determine whether (1) the rest profiles of KO and KD-treated KO (KOKD) mice resemble each other as a function of either age or proximity to death and (2) the timing of death correlates with acute or chronic changes in rest.

METHODS

Noninvasive actimetry was used to monitor rest throughout the lives of KO and wild-type (WT) littermates administered standard diet or KD.

RESULTS

As KO mice age, rest is reduced (P < .0001). Rest is significantly improved in KDKO mice (P < .0001), resembling WT values at several ages. When age is removed as a variable and data are realigned to the day of death, the rest profiles of KO and KOKD groups worsen to similar degrees as a function of proximity to death. The amount of rest acutely is not sensitive to the timing of death, whereas chronic rest deficiency profiles (10-15 days prior to death) of both groups were indistinguishable. Chronic accumulation of rest deficiency over the final 15 days was associated with 75% of deaths.

SIGNIFICANCE

Our data suggest that the accumulated rest deficiency is associated with sudden death in Kv1.1 KO mice. These data (1) support the proposed clinical hypothesis that chronic sleep deficiency may be associated with early mortality in epileptic patients and (2) warrant future preclinical and clinical studies on sleep monitoring in epileptic patients.

Methodological standards for in vitro models of epilepsy and epileptic seizures. A TASK1-WG4 report of the AES/ILAE Translational Task Force of the ILAE

In vitro preparations are a powerful tool to explore the mechanisms and processes underlying epileptogenesis and ictogenesis. In this review, we critically review the numerous in vitro methodologies utilized in epilepsy research. We provide support for the inclusion of detailed descriptions of techniques, including often ignored parameters with unpredictable yet significant effects on study reproducibility and outcomes. In addition, we explore how recent developments in brain slice preparation relate to their use as models of epileptic activity.

Cntnap2 Knockout Rats and Mice Exhibit Epileptiform Activity and Abnormal Sleep-Wake Physiology

Study Objectives

Although recent innovations have enabled modification of the rat genome, it is unclear whether enhanced utility of rodents as human disease models will result. We compared electroencephalogram (EEG) and behavioral phenotypes of rats and mice with homozygous deletion of Cntnap2, a gene associated with cortical dysplasia-focal epilepsy (CDFE) and autism spectrum disorders (ASD).

Methods

Male contactin-associated protein-like 2 (Cntnap2) knockout (KO) and wild-type (WT) rats and male Cntnap2 KO and WT mice were implanted with telemeters to record EEG, electromyogram, body temperature, and locomotor activity. Animals were subjected to a test battery for ASD-related behaviors, followed by 24-hr EEG recordings that were analyzed for sleep-wake parameters and subjected to spectral analysis.

Results

Cntnap2 KO rats exhibited severe motor seizures, hyperactivity, and increased consolidation of wakefulness and REM sleep. By contrast, Cntnap2 KO mice demonstrated absence seizure-like events, hypoactivity, and wake fragmentation. Although seizures observed in Cntnap2 KO rats were more similar to those in CDFE patients than in KO mice, neither model fully recapitulated the full spectrum of disease symptoms. However, KOs in both species had reduced spectral power in the alpha (9-12 Hz) range during wake, suggesting a conserved EEG biomarker.

Conclusions

Deletion of Cntnap2 impacts similar behaviors and EEG measures in rats and mice, but with profound differences in nature and phenotypic severity. These observations highlight the importance of cross-species comparisons to understand conserved gene functions and the limitations of single- species models to provide translational insights relevant to human diseases.

Parental Perception of Comorbidities in Children With Dravet Syndrome

BACKGROUND

We hypothesized that children with Dravet syndrome may have additional common features beyond seizures and cognitive impairment. To address this gap in knowledge, we conducted a survey of caregivers of children with Dravet syndrome to identify and quantify their perception of associated symptoms in this population.

METHODS

An electronic survey was developed in REDcap (Research Electronic Data Capture) and sent via e-mail to the participants on the Dravet Syndrome Foundation e-mail list. Questions focused on eating, sleep, behavior, and other symptoms that might be related to Dravet syndrome. The questions were assessed using a four-point Likert scale (e.g., strongly agree to strongly disagree). Results were later dichotomized for analysis. Logistic regression was used to calculate odds ratios of various demographic factors potentially associated with symptoms. Multivariable models were constructed using backward elimination to assess the relationship among a variety of symptoms.

RESULTS

There were 202 respondents, 96% were parents of a child with Dravet syndrome (the remainder were grandparents or guardians); 90.5% were female. The median age of the affected child was eight years (interquartile range five to 14), 50% were male, and 90.5% were reported to have a known SCN1A mutation. At least one symptom associated with appetite was reported in 99% of respondents, 82% reported a disturbance of sleep, one third reported autonomic symptoms, and 75% reported problems with gait. Inattention and perseveration were reported more commonly than other behavioral disturbances.

SIGNIFICANCE

Caregivers have the perception of many symptoms in children with Dravet syndrome in addition to those that have been previously reported, including appetite, sleep, gait, and behavior. Many of these can significantly affect quality of life for both the child and the caregiver.

The relationship between epilepsy, sleep disorders, and attention deficit hyperactivity disorder (ADHD) in children: A review of the literature

Objective

To analyze the relationship between epilepsy, sleep disorders, and attention deficit hyperactivity disorder (ADHD).

Bibliographic search

A literature search of the PubMed database was performed using the following key words: epilepsy, sleep, and ADHD. In total, 91 articles were located in PubMed, 34 were selected for abstract reading and twelve articles were reviewed, in which the main objectives were examine the relationship between epilepsy, sleep and ADHD from several perspectives, including epidemiology, effect of comorbidities on academic performance and the factors leading to diagnostic difficulties among these three disorders

Results

Among the main findings, there were difficulties to start and maintain sleep in patients with epilepsy and ADHD, reduction in sleep efficiency, decreased seizure threshold, as well as behavioral and cognitive deficits in both groups.

Conclusions

It is important to know which symptom is the predominant one. For this reason, children and adolescents with epilepsy, ADHD and sleep disorders need to be assessed carefully before initiating treatment. Our review concluded that there is an important link in this pathological triad.

The impact of sleep loss on the facilitation of seizures: A prospective case-crossover study

PURPOSE

The relationship between sleep and seizures is intricate. The aim of this study was to assess whether sleep loss is an independent seizure precipitant in a clinical setting.

METHODS

In this prospective, observational cross-over study, 179 consecutive hospital admissions for epileptic seizures were included. A semi-structured interview regarding several seizure precipitants was performed. The sleep pattern prior to the seizure, as well as alcohol, caffeine and drug use, were recorded. The interview was repeated by telephone covering the same weekday at a time when there had been no recent seizure. The Hospital Anxiety and Depression Scale (HADS) and a visual analogue scale for perceived stress were applied at admission. Student's t-test, Fisher exact test and ANOVA were used for statistical analyses.

RESULTS

Complete data for analysis were retrieved in 144 patients. The sleep-time during the 24h prior to the seizure was lower (7.3h) compared to follow-up (8.3h; p<0.0005). Caffeine consumption and use of relevant non antiepileptic drugs (AED) were not different. HADS and stress scores at admission did not correlate with sleep-time difference. In ANOVA, controlled for alcohol consumption and AED use, the sleep-time difference remained significant (p=0.008). The interaction with alcohol intake was high, but the sleep-time difference remained highly significant also for the non- and low-consumption (≤2 units per day) subgroup (n=121, 7.50h vs 8.42h, p=0.001).

CONCLUSION

Epileptic seizures are often precipitated by a combination of various clinical factors, but sleep loss stands out as an independent seizure trigger.

Effect of temperature on sleep regulation in an animal epilepsy model

Besides recurring seizures, disordered sleep is common in individuals with epilepsy and may present as reduced sleep depth, altered proportions of different stages of sleep, intermittent arousal, and other phenomena. Sleep loss can in turn precipitate seizures, thus sustaining a vicious cycle. It is well known that changes in ambient temperature elicit thermoregulatory responses that alter the dynamics of sleep. As a first step toward therapeutic sleep modulation for epilepsy, we assessed the effect of elevated ambient temperature on sleep dynamics and seizure yield in the chronic pilocarpine mouse model of temporal lobe epilepsy. The results in a small sample indicate that temperature does in fact significantly alter the proportions and durations of each vigilance state in this model, with possibly correlated changes in seizure incidence. Manipulation of ambient temperature therefore offers a simple and relatively unobtrusive way of titrating sleep quality and perhaps alleviating the seizure burden in epilepsy.

Associations of impaired sleep quality, insomnia, and sleepiness with epilepsy: A questionnaire-based case-control study

PURPOSE

The purpose of this study was to document the frequency of sleep problems including poor sleep quality, excessive daytime sleepiness, and insomnia in subjects with epilepsy compared with healthy controls and to determine the factors associated with these sleep disturbances.

METHODS

We recruited 180 patients with epilepsy (age: 43.2 ± 15.6 years, men: 50.0%) and 2836 healthy subjects (age: 44.5 ± 15.0 years, men: 49.8%). Sleep and the anxiety/mood profiles were measured using the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, Insomnia Severity Index, Goldberg Anxiety Scale, and Patient Health Questionnaire-9 depression scale. Associations of sleep problems with epilepsy and other factors were tested by multiple logistic regression analysis, adjusted for age, gender, body mass index, alcohol intake, smoking, perceived sleep insufficiency, and habitual snoring.

RESULTS

Sleep disturbances were more common in the group with epilepsy than in the controls (53.3% vs. 25.5%; p<0.001). Poor sleep quality, excessive daytime sleepiness, and insomnia were significantly associated with epilepsy (odds ratio [95% confidence interval]: 3.52 [2.45-5.05], 2.10 [1.41-3.12], 5.91 [3.43-10.16], respectively). Depressive mood, anxiety, and perceived sleep insufficiency contributed to the presence of sleep disturbances. In the group with epilepsy, seizure remission for the past year related to a lower frequency of insomnia, whereas age, sex, type of epilepsy, and number of antiepileptic drugs were not correlated with sleep problems.

CONCLUSION

Epilepsy was significantly associated with the higher frequency of sleep disturbances, which supports the importance of screening sleep problems in patients with epilepsy and providing available intervention.

Neuropsychological consequences of sleep disturbance in children with epilepsy

A growing body of research reveals strong relationships between sleep disturbance, sleep architecture, and neuropsychological functioning in children. Children with epilepsy experience numerous neuropsychological comorbidities, including cognitive deficiencies and emotional/behavioral difficulties; thus, it is reasonable to consider the moderating role of sleep in this population. This review summarizes findings involving the prevalence and characteristics of sleep problems often experienced by children with epilepsy. The complex and bidirectional relationship between sleep and seizure frequency is discussed. Research pertaining to the relationship between sleep disturbance and daytime cognition as well as behavior reveals a substantial association between these variables. Clinically relevant practices related to the assessment and treatment of sleep-related complications are reviewed, and directions for further research involving intervention and assessment are also reviewed.

Seizures and brain regulatory systems: consciousness, sleep, and autonomic systems

Research into the physiologic underpinnings of epilepsy has revealed reciprocal relationships between seizures and the activity of several regulatory systems in the brain. This review highlights recent progress in understanding and using the relationships between seizures and the arousal or consciousness system, the sleep-wake and associated circadian system, and the central autonomic network.

Genetic effects on sleep/wake variation of seizures

OBJECTIVE

There is a complex bidirectional relationship between sleep and epilepsy. Sleep/wake timing of seizures has been investigated for several individual seizure types and syndromes, but few large-scale studies of the timing of seizures exist in people with varied epilepsy types. In addition, the genetic contributions to seizure timing have not been well studied.

METHODS

Sleep/wake timing of seizures was determined for 1,395 subjects in 546 families enrolled in the Epilepsy Phenome/Genome Project (EPGP). We examined seizure timing among subjects with different epilepsy types, seizure types, epilepsy syndromes, and localization. We also examined the familial aggregation of sleep/wake occurrence of seizures.

RESULTS

Seizures in nonacquired focal epilepsy (NAFE) were more likely to occur during sleep than seizures in generalized epilepsy (GE), for both convulsive (odds ratio [OR] 5.2, 95% confidence interval [CI] 3.59-7.52) and nonconvulsive seizures (OR 4.2, 95% CI 2.48-7.21). Seizures occurring within 1 h of awakening were more likely to occur in patients with GE than with NAFE for both convulsive (OR 2.3, 95% CI 1.54-3.39) and nonconvulsive (OR 1.7, 95% CI 1.04-2.66) seizures. Frontal onset seizures were more likely than temporal onset seizures to occur during sleep. Sleep/wake timing of seizures in first-degree relatives predicted timing of seizures in the proband.

SIGNIFICANCE

We found that sleep/wake timing of seizures is associated with both epilepsy syndrome and seizure type. In addition, we provide the first evidence for a genetic contribution to sleep/wake timing of seizures in a large group of individuals with common epilepsy syndromes.

Sleep impairment and reduced interneuron excitability in a mouse model of Dravet Syndrome

Dravet Syndrome (DS) is caused by heterozygous loss-of-function mutations in voltage-gated sodium channel NaV1.1. Our mouse genetic model of DS recapitulates its severe seizures and premature death. Sleep disturbance is common in DS, but its mechanism is unknown. Electroencephalographic studies revealed abnormal sleep in DS mice, including reduced delta wave power, reduced sleep spindles, increased brief wakes, and numerous interictal spikes in Non-Rapid-Eye-Movement sleep. Theta power was reduced in Rapid-Eye-Movement sleep. Mice with NaV1.1 deleted specifically in forebrain interneurons exhibited similar sleep pathology to DS mice, but without changes in circadian rhythm. Sleep architecture depends on oscillatory activity in the thalamocortical network generated by excitatory neurons in the ventrobasal nucleus (VBN) of the thalamus and inhibitory GABAergic neurons in the reticular nucleus of the thalamus (RNT). Whole-cell NaV current was reduced in GABAergic RNT neurons but not in VBN neurons. Rebound firing of action potentials following hyperpolarization, the signature firing pattern of RNT neurons during sleep, was also reduced. These results demonstrate imbalance of excitatory vs. inhibitory neurons in this circuit. As predicted from this functional impairment, we found substantial deficit in homeostatic rebound of slow wave activity following sleep deprivation. Although sleep disorders in epilepsies have been attributed to anti-epileptic drugs, our results show that sleep disorder in DS mice arises from loss of NaV1.1 channels in forebrain GABAergic interneurons without drug treatment. Impairment of NaV currents and excitability of GABAergic RNT neurons are correlated with impaired sleep quality and homeostasis in these mice.

Does abnormal glycogen structure contribute to increased susceptibility to seizures in epilepsy?

Epilepsy is a family of brain disorders with a largely unknown etiology and high percentage of pharmacoresistance. The clinical manifestations of epilepsy are seizures, which originate from aberrant neuronal synchronization and hyperexcitability. Reactive astrocytosis, a hallmark of the epileptic tissue, develops into loss-of-function of glutamine synthetase, impairment of glutamate-glutamine cycle and increase in extracellular and astrocytic glutamate concentration. Here, we argue that chronically elevated intracellular glutamate level in astrocytes is instrumental to alterations in the metabolism of glycogen and leads to the synthesis of polyglucosans. Unaccessibility of glycogen-degrading enzymes to these insoluble molecules compromises the glycogenolysis-dependent reuptake of extracellular K(+) by astrocytes, thereby leading to increased extracellular K(+) and associated membrane depolarization. Based on current knowledge, we propose that the deterioration in structural homogeneity of glycogen particles is relevant to disruption of brain K(+) homeostasis and increased susceptibility to seizures in epilepsy.

Somatosensory stimulation suppresses the excitability of pyramidal cells in the hippocampal CA1 region in rats

The hippocampal region of the brain is important for encoding environment inputs and memory formation. However, the underlying mechanisms are unclear. To investigate the behavior of individual neurons in response to somatosensory inputs in the hippocampal CA1 region, we recorded and analyzed changes in local field potentials and the firing rates of individual pyramidal cells and interneurons during tail clamping in urethane-anesthetized rats. We also explored the mechanisms underlying the neuronal responses. Somatosensory stimulation, in the form of tail clamping, chan-ged local field potentials into theta rhythm-dominated waveforms, decreased the spike firing of pyramidal cells, and increased interneuron firing. In addition, somatosensory stimulation attenuated orthodromic-evoked population spikes. These results suggest that somatosensory stimulation suppresses the excitability of pyramidal cells in the hippocampal CA1 region. Increased inhibition by local interneurons might underlie this effect. These findings provide insight into the mechanisms of signal processing in the hippocampus and suggest that sensory stimulation might have therapeutic potential for brain disorders associated with neuronal hyperexcitability.

BMAL1 controls the diurnal rhythm and set point for electrical seizure threshold in mice

The epilepsies are a heterogeneous group of neurological diseases defined by the occurrence of unprovoked seizures which, in many cases, are correlated with diurnal rhythms. In order to gain insight into the biological mechanisms controlling this phenomenon, we characterized time-of-day effects on electrical seizure threshold in mice. Male C57BL/6J wild-type mice were maintained on a 14/10 h light/dark cycle, from birth until 6 weeks of age for seizure testing. Seizure thresholds were measured using a step-wise paradigm involving a single daily electrical stimulus. Results showed that the current required to elicit both generalized and maximal seizures was significantly higher in mice tested during the dark phase of the diurnal cycle compared to mice tested during the light phase. This rhythm was absent in BMAL1 knockout (KO) mice. BMAL1 KO also exhibited significantly reduced seizure thresholds at all times tested, compared to C57BL/6J mice. Results document a significant influence of time-of-day on electrical seizure threshold in mice and suggest that this effect is under the control of genes that are known to regulate circadian behaviors. Furthermore, low seizure thresholds in BMAL1 KO mice suggest that BMAL1 itself is directly involved in controlling neuronal excitability.

Validation of actigraphy with continuous video-electroencephalography in children with epilepsy

BACKGROUND

The relationship between epilepsy and sleep is bidirectional as seizures disrupt sleep and coexisting sleep disorders have detrimental effects on seizure control and quality of life for both the children and their families. Previous research has reported on sleep disturbance in children with epilepsy primarily by subjective parental reports. Actigraphy may provide a more accurate objective evaluation of sleep, but the validity of this sleep measure for children with epilepsy has not yet been assessed. The primary objective of this study was to validate the use of actigraphy as a tool in studying sleep patterns in children with epilepsy.

METHODS

This was a prospective study comparing sleep and wake epochs recorded for 24 h simultaneously by actigraphy and by continuous video-electroencephalography (VEEG) monitoring in 27 patients aged 2-18 years with medically refractory epilepsy.

RESULTS

Strong correlations were found between actigraphy and VEEG sleep variables including night sleep period (r = 0.99), night sleep time (r = 0.96), duration of night wake time (r = 0.93) and number of significant wakings during the night (r = 0.81).

CONCLUSION

The study results validate that actigraphy is a reliable and objective clinical and research tool for evaluating sleep and wakefulness in children with epilepsy.

Sleep-dependent memory consolidation and accelerated forgetting

Accelerated long-term forgetting (ALF) is a form of memory impairment in which learning and initial retention of information appear normal but subsequent forgetting is excessively rapid. ALF is most commonly associated with epilepsy and, in particular, a form of late-onset epilepsy called transient epileptic amnesia (TEA). ALF provides a novel opportunity to investigate post-encoding memory processes, such as consolidation. Sleep is implicated in the consolidation of memory in healthy people and a deficit in sleep-dependent memory consolidation has been proposed as an explanation for ALF. If this proposal were correct, then sleep would not benefit memory retention in people with ALF as much as in healthy people, and ALF might only be apparent when the retention interval contains sleep. To test this theory, we compared performance on a sleep-sensitive memory task over a night of sleep and a day of wakefulness. We found, contrary to the hypothesis, that sleep benefits memory retention in TEA patients with ALF and that this benefit is no smaller in magnitude than that seen in healthy controls. Indeed, the patients performed significantly more poorly than the controls only in the wake condition and not the sleep condition. Patients were matched to controls on learning rate, initial retention, and the effect of time of day on cognitive performance. These results indicate that ALF is not caused by a disruption of sleep-dependent memory consolidation. Instead, ALF may be due to an encoding abnormality that goes undetected on behavioural assessments of learning, or by a deficit in memory consolidation processes that are not sleep-dependent.

Eliciting patients' preferences for epilepsy diagnostics: a discrete choice experiment

BACKGROUND

Diagnosing epilepsy is a lengthy and burdensome process for patients and their family. Although the need for a more patient-centered approach in clinical practice is widely acknowledged, empirical evidence regarding patient preferences for diagnostic modalities in epilepsy is missing. The objectives of this study were 1) to identify to what extent important attributes of diagnostic procedures in epilepsy affect preferences for a procedure, 2) to determine the relative importance of these attributes, and 3) to calculate overall utility scores for routine electroencephalography (EEG) and magnetoencephalography (MEG) recordings.

METHODS

A discrete choice experiment was performed to determine patients' preferences, which involved presentation of pairwise choice tasks regarding hypothetical scenarios. Scenarios varied along six attributes: "way of measuring brain activity", "duration", "freedom of movement", "travel time", "type of additional examination", and "chance of additional examination". Choice tasks were constructed using a statistically efficient design, and the questionnaire contained 15 unique unlabeled choice tasks. Mixed multinomial logistic regression was used to estimate patients' preferences.

RESULTS

A total of 289 questionnaires were included in the analysis. McFadden's pseudo R(2) showed a model fit of 0.28, and all attributes were statistically significant. Heterogeneity in preferences was present for all attributes. "Freedom of movement" and "Chance of additional examination" were perceived as the most important attributes. Overall utility scores did not substantially differ between routine EEG and MEG.

CONCLUSION

This study suggests that the identified attributes are important in determining patients' preference for epilepsy diagnostics. It can be concluded that MEG is not necessarily more patient-friendly than a routine EEG in primary diagnostics and, regarding additional diagnostics, patients have a strong preference for long-term 24-h EEG over EEG after sleep deprivation. Furthermore, barring substantial heterogeneity within the parameters in mind, our study suggests that it is important to take individual preferences into account in medical decision-making.

Subjective sleep disturbances in children with partial epilepsy and their effects on quality of life

PURPOSE

The purposes of this study were to explore the prevalence of sleep disturbances in a large cohort of school-aged children with partial epilepsy, to compare the findings with those in children without epilepsy of the same age and gender, and to evaluate the relationship between sleep disturbances and health-related quality of life (HRQoL).

METHODS

One hundred thirty children with partial epilepsy aged 4 to 10years, who were treated in the outpatient setting of a Dutch epilepsy clinic, and 161 age- and sex-matched controls participated in this study. In addition to providing information about their child's demography and health, parents of both groups of children completed three questionnaires to measure their child's sleep [Sleep Disturbance Scale for Children (SDSC), Medical Outcomes Study-Sleep Scale (MOSS-S), and Groningen Sleep Quality Scale (GSQS)] and one questionnaire to measure quality of life (Kidscreen-27). Parents of children with epilepsy also completed the Hague Scales to measure the severity of epilepsy. The prevalence of sleep disturbances and scores on HRQoL in children with and without epilepsy were compared. Additionally, the HRQoL scores were compared between children with and without sleep disturbances in children both with and without epilepsy.

RESULTS

The answers for all three questionnaires suggested worse sleep in children with epilepsy than in children of the same age and gender without epilepsy. Pathological scores (T-value>70) for total SDSC were seen twelve times more frequently in children with epilepsy (36.92% vs. 3.01%, p<0.001). Children with epilepsy also scored significantly lower for all dimensions of HRQoL. Between subgroups of children with and without disturbed sleep, insignificant differences in quality of life were found, with the lowest scores in children with sleep disturbances in both groups.

CONCLUSION

This study confirms the high prevalence of disturbed sleep, as well as its effect on quality of life, in a large group of children with partial epilepsy. The abnormalities are both more prevalent and more severe than in children without epilepsy.

Usefulness of a simple sleep-deprived EEG protocol for epilepsy diagnosis in de novo subjects

OBJECTIVE

In case series concerning the role of EEG after sleep deprivation (SD-EEG) in epilepsy, patients' features and protocols vary dramatically from one report to another. In this study, we assessed the usefulness of a simple SD-EEG method in well characterized patients.

METHODS

Among the 963 adult subjects submitted to SD-EEG at our Center, in the period 2003-2010, we retrospectively selected for analysis only those: (1) evaluated for suspected epileptic seizures; (2) with a normal/non-specific baseline EEG; (3) still drug-free at the time of SD-EEG; (4) with an MRI analysis; (5) with at least 1 year follow-up. SD-EEG consisted in SD from 2:00 AM and laboratory EEG from 8:00 AM to 10:30 AM. We analyzed epileptic interictal abnormalities (IIAs) and their correlations with patients' features.

RESULTS

Epilepsy was confirmed in 131 patients. SD-EEG showed IIAs in 41.2% of all patients with epilepsy, and a 91.1% specificity for epilepsy diagnosis; IIAs types observed during SD-EEG are different in generalized versus focal epilepsies; for focal epilepsies, the IIAs yield in SD-EEG is higher than in second routine EEG.

CONCLUSIONS

This simple SD-EEG protocol is very useful in de novo patients with suspected seizures.

SIGNIFICANCE

This study sheds new light on the role of SD-EEG in specific epilepsy populations.

Sleep and epilepsy: exploring an intriguing relationship with a translational approach

The relationship between sleep and epilepsy has been well established. There is a high prevalence of sleep disturbances in epilepsy, which are associated with a decreased quality of life of individuals with epilepsy. In view of this fact, preclinical research is necessary to address many gaps in knowledge. For instance, it is well known that sleep deprivation can trigger seizures; however, this is a complex pathophysiological event. In this context, there are many valuable animal models of epilepsy that reproduce clinical symptoms and can be used. Investigations using animal models that simulate clinical epilepsy are imperative. Furthermore, preclinical studies that reveal mechanisms related to sleep-epilepsy interactions are very important. Results of such studies can, in turn, improve the understanding of epilepsy itself and can be useful in developing new antiepileptic drugs and preventive measures to control seizures. Preclinical research should be performed using a translational framework with experimental designs that can lead to advances in the quality of life of individuals with epilepsy. In view of the fact that more than 50 million of people are affected by epilepsy around the world, understanding the relationship between sleep and epilepsy is imperative.

Paradoxical sleep deprivation potentiates epilepsy induced by homocysteine thiolactone in adult rats

There is an intriguing and still poorly understood relationship between sleep deprivation and epilepsy. It has recently been shown that paradoxical sleep deprivation decreases levels of homocysteine, an amino acid involved together with its thiolactone metabolite in epileptogenesis. The aim of the present study was to investigate the effects of paradoxical sleep deprivation on homocysteine thiolactone (H)-induced seizures in rats, a model of generalized seizures. Selective deprivation of paradoxical sleep in adult male Wistar rats was achieved by the platform method. Animals with implanted electrodes for electroencephalogram (EEG) registration were assigned to appropriate experimental conditions (dry cage for control, large platform for stress control and small platform for paradoxical sleep deprivation) and 72 h later were intraperitoneally treated with either H (5.5 mmol/kg) or saline (0.9% NaCl). This study showed that paradoxical sleep deprivation increased the incidence and number of H-induced seizure episodes, shortened latency time to seizures and led to significant rates of lethality after H administration, but without effect on the seizure severity. Paradoxical sleep deprivation increased the number and duration of spikes-and-wave discharges, while decreased latency to its appearance in EEG. Judging by the behavioral and EEG findings, it could be concluded that paradoxical sleep deprivation can provoke the expression of factors that can potentiate H-induced seizures in adult rats.

Physiological and electroencephalographic responses to acute exhaustive physical exercise in people with juvenile myoclonic epilepsy

Although the available evidence suggests that exercise may positively affect epilepsy, whether this effect is applicable to different types of epilepsy has not been established. Physiological responses during rest, acute physical effort, and a recovery period were studied by concomitant analysis of cerebral electric activity using EEGs in subjects with juvenile myoclonic epilepsy (JME) and healthy controls. In addition, level of habitual physical activity, body composition, and 1 week of actigraphy monitoring data were evaluated. Twenty-four subjects (12 with JME and 12 controls) participated in this study. Compared with the control group, the JME group had a significantly lower V˙O(2) at rest (13.3%) and resting metabolic rate (15.6%). The number of epileptiform discharges in the JME group was significantly reduced during the recovery period (72%) compared with the resting state. There were no significant differences between the JME and control groups in behavioral outcomes and sleep parameters evaluated by actigraphy monitoring. The positive findings of our study strengthen the evidence for the benefits of physical exercise for people with JME.