Chronotype in patients with epilepsy: A controlled study in 60 subjects with late-onset focal epilepsy

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.

The Relationship between Anxiety, Subjective and Objective Sleep, Chronotype and Circadian Rhythms with Depressive Symptoms in Insomnia Disorder

Insomnia is a highly prevalent sleep disorder with strong bidirectional associations with depressive symptoms. The circadian preference for eveningness has been shown to be associated with depressive symptoms in insomnia and other mental health conditions. However, there is a lack of studies in insomnia investigating whether objective measures, such as dim light melatonin onset (DLMO) or polysomnographic (PSG) sleep, are associated with depressive symptoms. Therefore, we investigated the associations between subjective measures (questionnaires assessing anxiety, sleep quality and circadian preference, and sleep diary) and depressive symptoms and whether the addition of objective measures (DLMO, PSG parameters) would strengthen the associations with depressive symptoms. In 115 insomnia disorder patients we found that anxiety was strongly associated with depressive symptoms in a model including circadian preference, dysfunctional beliefs of sleep, and self-reported previous depressive symptoms (R² = 0.496, p < 0.001). The addition of sleep diary measures did not strengthen the model. We also found that the addition of objective measures (DLMO, PSG parameters) did not improve the subjective associations with depressive symptoms. Our data suggest that objective circadian markers are less important in the prediction of depressive symptoms in insomnia compared to subjective measures.

Daily rhythms in right-sided and left-sided temporal lobe epilepsy

Introduction

Epilepsy is closely related to daily rhythms, such as the sleep-wake cycle. The objective of this study was to evaluate the relationship between drug-resistant temporal lobe epilepsy (TLE) and the parameters related to the sleep-wake cycle, seizure time and epilepsy laterality.

Methods

Consecutive patients admitted to the video electroencephalogram unit with a diagnosis of TLE were enrolled. Patients were divided into two groups: those with left TLE (LTLE) and those with right TLE (RTLE). They then remained in the conditions of 12-hour light, 12-hour darkness. Demographic data, treatment, number and time of seizure occurrence, sleep diary, morningness-eveningness questionnaire, Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale were recorded.

Results

In total, 74 patients with TLE, 43 with LTLE and 31 with RTLE, were studied. RTLE patients showed a significant preference for morningness. Patients treated with benzodiazepines showed worse sleep quality and greater daytime sleepiness. Patients who did not report any clear predominance and patients who reported seizures during wakefulness had significantly more seizures during wakefulness and patients who reported sleep predominance had more seizures during sleep (p>0.001). The LTLE group had a greater number of seizures from 8 to 16 hours, unlike the RTLE group, which had a uniform distribution (p=0.008).

Conclusions

This was a prospective study of patients with drug-resistant TLE performed in a controlled environment to study the impact of daily rhythms, seizure frequency and seizure distribution. Laterality seems to be a key factor in seizure distribution.

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

BACKGROUND/AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Melatonin (MEL) and its use in neurological diseases and insomnia: Recommendations of the French Medical and Research Sleep Society (SFRMS)

The French Medicine and Research Sleep Society had organized a consensus conference about sleep/wake circadian rhythms and their disorders. During this conference a subgroup of 11 sleep doctors/researchers looked specifically at the use of MEL in different pathologies. This article gives a summary of the main results of MEL therapy in some neurological diseases and insomnia approved by this consensus group. Exogenous MEL, which crosses the blood-brain barrier, has been used as a treatment in its two available forms: an immediate release form that principally shows a chronobiotic action and a long release form that mimics the physiological MEL secretion rhythm and is used to replace reduced physiological secretion. MEL secretion decreases frequently with age, mostly in elderly insomniacs and dementia patients. Results of level A studies show that MEL therapy, used as an add-on treatment, has beneficial effects in mild cognitive impairment (MCI) and Alzheimer patients with sleep disorders in improving sleep quality and in regulating the sleep/wake rhythm. MEL has to be prescribed as early as possible and for a long period, at a dose of 2 to 5 or 10 mg. It may have a beneficial effect on cognitive function in MCI but shows no effect in moderate to severe Alzheimer's disease. It should be emphasized that there are no serious side effects with MEL treatment. In these diseases, light therapy used 12 hours before melatonin treatment has a positive synergic effect. In REM sleep behavior disorder, immediate release MEL should be prescribed first as its side effect profile is much better than clonazepam shortly before bedtime. MEL has a good efficacy on clinical symptoms and PSG REM sleep without atonia episodes and is well tolerated. In Parkinson disease with sleep disorders and without REM sleep behavior disorder, MEL seems to improve subjective sleep quality but no conclusions can be drawn. There is insufficient scientific proof for using MEL as a prophylactic treatment in primary headache, migraine and cluster headache. In epileptic patients, MEL can be safely used to regulate the sleep/wake rhythm and to improve insomnia but more randomized controlled studies are necessary. In primary or no-comorbid insomnia, only a 2 mg dose of slow release MEL, 1 to 2 hours before bedtime, over a period of 3 to 12 weeks, is recommended. It decreases sleep onset latency, improves quality of sleep, morning alertness and quality of life without serious side effects and without withdrawal symptoms.

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.

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

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

Circadian phase typing in idiopathic generalized epilepsy: Dim light melatonin onset and patterns of melatonin secretion-Semicurve findings in adult patients

OBJECTIVE/BACKGROUND

It has been debated in the literature whether patients with idiopathic generalized epilepsy (IGE) have a distinctive, evening-oriented chronotype. The few questionnaire-based studies that are available in the literature have conflicting results. The aim of our study was to define chronotype in patients with IGE by determining dim light melatonin onset (DLMO).

PATIENTS/METHODS

Twenty adults diagnosed with IGE (grand mal on awakening [GM] in 7 cases and juvenile myoclonic epilepsy in 13 cases) were investigated by means of a face-to-face semistructured sleep interview, Morningness-Eveningness Questionnaire (MEQ), Pittsburgh Sleep Quality Index (PSQI) questionnaire, and a melatonin salivary test with DLMO determination. Eighteen healthy subjects (HC) and 28 patients affected with cryptogenic focal epilepsy (FE) served as controls.

RESULTS

The mean MEQ score was significantly lower in patients with IGE than that in patients with FE (49.1±5.9 versus 56.1±8.7 P<0.01) but not significantly lower than that in HC (49.1±5.9 versus 49.3±8.6). Midsleep on free days corrected for sleep duration did not differ significantly between the three subject groups (04:59±01:21h, 04:37±01:17h, 04:29±00:52h). The mean DLMO time in patients with IGE (22:13±01:34h) occurred 49min later than that in HC (21.24±1h), and the melatonin surge within the 30-minute time interval after DLMO in patients with IGE was significantly lower than that in HC (1.51±2.7 versus 3.8±3.6pg/mL P=0.045).

CONCLUSIONS

Subjective measures of chronotype do not indicate a definite evening-oriented chronotype in patients with IGE. However, the data concerning endogenous melatonin secretion indicate that patients with IGE tend to have a late circadian phase. Further studies are warranted in order to better define the late pattern of endogenous melatonin secretion in patients with IGE and to ascertain the role of this pattern in influencing behavioral chronotype in these subjects.