Chronotypes in Patients with Epilepsy: Does the Type of Epilepsy Make a Difference?

Chronotype variability in epilepsy and clinical significance: scoping review

PURPOSE

Chronotype, which captures a person's daily preferences for activity and sleep, is still a poorly researched area in epilepsy research. Finding common chronotype characteristics in people with epilepsy (PWE) and explaining possible effects on seizure management are the main goals.

METHODS

Eleven large-scale investigations from 2010 to 2023 were examined in this scoping review. These studies included 1.167 PWE and 4.657 control subjects.

RESULTS

PWE had intermediate chronotypes more often than not. Adult patients were more morning-oriented overall, while pediatric cohorts were variable. Relationships between chronotype and seizure control were limited since only two studies in adults reported this and those results conflicted. An evening-type chronotype was found to be more common in generalized epilepsy than focal. The relationship of chronotype and specific antiseizure medication (ASM) therapy was not investigated.

CONCLUSIONS

The majority of PWE displayed an intermediate chronotype, but analyses based on age showed more nuanced trends, with children displaying variable patterns, adults generally tending toward morningness, and generalized epilepsy being associated with eveningness. This review underscores the importance of more research on the complex connections between epilepsy outcomes and chronotype. It emphasizes the need to study larger samples of PWE with carefully documented seizure control and ASM therapy, including dose and timing of administration to better understand the role of chronotype on epilepsy outcomes.

Seizure control with treatment of delayed sleep-wake phase disorder in juvenile myoclonic epilepsy: A case report

Juvenile Myoclonic Epilepsy (JME) is an idiopathic generalized epilepsy associated with a characteristic sleep/wake rhythm, with the tendency to go to bed later at night, to get up later in the morning. In the pediatric population, we have previously observed specific circadian and sleep/wake patterns of generalized seizures (6 am-12 pm) and myoclonic seizures (in wakefulness, 6 am to noon). Delayed Sleep-Wake Phase Disorder (DSWPD) is characterized by sleep initiation insomnia when attempting sleep at conventional times and difficulty waking at the required time. Here we present the case of a 20-year-old man with JME, diagnosed DSWPD (sleep schedule 3 am to 11 am), presenting with nocturnal seizures out of sleep, always between 5 and 6am. Improvements in seizure control (seizure frequency from 8 per month to 0 per month) were achieved with timed evening melatonin, combined with behavioral sleep-wake scheduling (sleep schedule 10 pm to 6 am) and morning light therapy. Recognition and characterization of DSWPD in JME, together with assessment of circadian and diurnal seizure patterns, may offer therapeutic consideration for better control of seizures.

Sleep quality and architecture in Idiopathic generalized epilepsy: A systematic review and meta-analysis

Idiopathic generalized epilepsies are a group of sleep related epilepsy syndromes with sleep deprivation as a strong trigger for seizures and increased spike-wave activity during sleep and transition to sleep. Neuropsychological deficits are common in Idiopathic generalized epilepsy patients. Learning and memory processes are closely linked to sleep. Therefore, this systematic review and meta-analysis investigates the evidence of sleep disturbances in Idiopathic generalized epilepsy patients. A search of the databases EMBASE, Medline and Scopus identified 22 studies comparing polysomnographic parameters and scores of sleep questionnaires between Idiopathic generalized epilepsy patients and healthy controls. Random effect univariate meta-analyses revealed reduced sleep efficiency, total sleep time, proportion of N2 stage and prolonged REM onset latency in Idiopathic generalized epilepsy patients. Self-assessed sleep quality of patients measured by the Pittsburgh sleep quality index was lower in two thirds of reporting studies. Considering the influence on behavioral issues, cognitive performance and quality of life, the revealed alteration in sleep architecture and lower subjective sleep quality emphasizes the importance of screening for sleep disturbances in the medical care of patients with Idiopathic generalized epilepsy.

The Interaction Between Sleep and Epilepsy

PURPOSE OF REVIEW

To review the mutual interactions between sleep and epilepsy, including mechanisms of epileptogenesis, the relationship between sleep apnea and epilepsy, and potential strategies to treat seizures.

RECENT FINDINGS

Recent studies have highlighted the role of functional network systems underlying epileptiform activation in sleep in several epilepsy syndromes, including absence epilepsy, benign focal childhood epilepsy, and epileptic encephalopathy with spike-wave activation in sleep. Sleep disorders are common in epilepsy, and early recognition and treatment can improve seizure frequency and potentially reduce SUDEP risk. Additionally, epilepsy is associated with cyclical patterns, which has led to new treatment approaches including chronotherapy, seizure monitoring devices, and seizure forecasting. Adenosine kinase and orexin receptor antagonists are also promising new potential drug targets that could be used to treat seizures. Sleep and epilepsy have a bidirectional relationship that intersects with many aspects of clinical management. In this article, we identify new areas of research involving future therapeutic opportunities in the field of epilepsy.

More than sleep and wake disturbances: An actigraphic study showing the sleep-wake pattern dysregulation in epilepsy

OBJECTIVE

This study aimed to assess the sleep-wake pattern in patients with epilepsy compared to controls.

METHODS

Patients with epilepsy and controls underwent a 14-day actigraphic recording to evaluate the rest-activity cycle. A sleep medicine interview was performed to exclude conditions interfering with the sleep-wake cycle in both patients and controls. Patients presenting seizures during the actigraphic recording were excluded. Daytime activity, nocturnal sleep, and non-parametric circadian rhythm activity (NPCRA) were analysed.

RESULTS

Twenty-two patients (mean age 49.5 ± 19.84 years; 50% female) and 17 controls were included. Patients showed lower sleep efficiency and longer sleep latency than controls. NPCRA analysis showed lower inter-daily stability and higher intra-daily variability in patients, who also presented lower daytime activity and a longer central phase measure (CPM) than controls.

CONCLUSIONS

Patients showed a significant alteration of the sleep-wake pattern, featured by lower synchronization and higher fragmentation of the rest-activity rhythm. Moreover, patients showed a delayed CPM compared with controls, corresponding to an evening chronotype tendency. Nocturnal sleep alteration and lower daytime activity were also evident. Therefore, patients with epilepsy present an alteration of the sleep-wake pattern and clinicians should increase their awareness about circadian rhythmicity dysregulation in epilepsy.

The Molecular Genetic Interaction Between Circadian Rhythms and Susceptibility to Seizures and Epilepsy

Seizure patterns observed in patients with epilepsy suggest that circadian rhythms and sleep/wake mechanisms play some role in the disease. This review addresses key topics in the relationship between circadian rhythms and seizures in epilepsy. We present basic information on circadian biology, but focus on research studying the influence of both the time of day and the sleep/wake cycle as independent but related factors on the expression of seizures in epilepsy. We review studies investigating how seizures and epilepsy disrupt expression of core clock genes, and how disruption of clock mechanisms impacts seizures and the development of epilepsy. We focus on the overlap between mechanisms of circadian-associated changes in SCN neuronal excitability and mechanisms of epileptogenesis as a means of identifying key pathways and molecules that could represent new targets or strategies for epilepsy therapy. Finally, we review the concept of chronotherapy and provide a perspective regarding its application to patients with epilepsy based on their individual characteristics (i.e., being a “morning person” or a “night owl”). We conclude that better understanding of the relationship between circadian rhythms, neuronal excitability, and seizures will allow both the identification of new therapeutic targets for treating epilepsy as well as more effective treatment regimens using currently available pharmacological and non-pharmacological strategies.

Impact of repeated kindled seizures on heart rate rhythms, heart rate variability, and locomotor activity in rats

Although an impact of epilepsy on circadian rhythmicity is well-recognized, there are profound gaps in our understanding of the influence of seizures on diurnal rhythms. The effect on activity levels and heart rate is of particular interest as it might contribute to the disease burden. The kindling model with telemetric transmitter implants provides excellent opportunities to study the consequences of focal and generalized seizures under standardized conditions. Data from kindled rats with generalized seizures revealed an increase in activity and heart rate during the resting phase. Total and short-term heart rate variabilities were not affected by electrode implantation or seizure induction. Ictal alterations in heart rate associated with generalized seizures were characterized by a biphasic bradycardia with an immediate drop of heart rate followed by a transient normalization and a second more steady decrease. In conclusion, the findings demonstrate that once daily generalized seizures can exert significant effects on heart rate rhythms. Respective alterations in patients would be of relevance for patient counselling and therapeutic management. Occurrence of biphasic bradycardia associated with seizure induction suggests that the kindling model is suitable to study the consequences and the prevention of ictal bradycardia, which may pose patients at risk for sudden unexpected death.

Circadian rhythm and epilepsy

Advances in diagnostic technology, including chronic intracranial EEG recordings, have confirmed the clinical observation of different temporal patterns of epileptic activity and seizure occurrence over a 24-h period. The rhythmic patterns in epileptic activity and seizure occurrence are probably related to vigilance states and circadian variation in excitatory and inhibitory balance. Core circadian genes BMAL1 and CLOCK, which code for transcription factors, have been shown to influence excitability and seizure threshold. Despite uncertainties about the relative contribution of vigilance states versus circadian rhythmicity, including circadian factors such as seizure timing improves sensitivity of seizure prediction algorithms in individual patients. Improved prediction of seizure occurrence opens the possibility for personalised antiepileptic drug-dosing regimens timed to particular phases of the circadian cycle to improve seizure control and to reduce side-effects and risks associated with seizures. Further studies are needed to clarify the pathways through which rhythmic patterns of epileptic activity are generated, because this might also inform future treatment options.

Juvenile myoclonic epilepsy and sleep

Juvenile myoclonic epilepsy (JME) is a sleep-related epilepsy syndrome, and only a few studies have addressed the relationship between JME and sleep disorders. In this review, the sleep characteristics of patients with JME were summarized based on the features of circadian rhythm, the possible cause of the early morning seizures, the common subjective and objective sleep disorders, the alterations in sleep architecture, and the effect of sleep deprivation and sodium valproate (VPA). The aims of this study were to summarize the interaction between JME and sleep, to reveal JME sleep characteristics, to encourage clinicians to focus on JME and sleep, to heighten the positive diagnosis rate, to guide the treatment, to improve the prognosis, and to enhance the daily life quality of patients with JME. At the same time, this study aimed to present existing controversies, in order to necessitate further studies.