Are seizures in the setting of sleep deprivation provoked?

First seizure from sleep: Clinical features and prognosis

OBJECTIVES

Patients with a first-ever unprovoked seizure commonly have subsequent seizures and identifying predictors of recurrence has important management implications. Both prior brain insult and epileptiform abnormalities on electroencephalography (EEG) are established predictors of seizure recurrence. Some studies suggest that a first-ever seizure from sleep has a higher likelihood of recurrence. However, with relatively small numbers and inconsistent definitions, more data are required.

METHODS

Prospective cohort study of adults with first-ever unprovoked seizure seen by a hospital-based first seizure service between 2000 and 2015. Clinical features and outcomes of first-ever seizure from sleep and while awake were compared.

RESULTS

First-ever unprovoked seizure occurred during sleep in 298 of 1312 patients (23%), in whom the 1-year cumulative risk of recurrence was 56.9% (95% confidence interval [CI] 51.3-62.6) compared to 44.2% (95% CI 41.1-47.3, p < .0001) for patients with first-ever seizure while awake. First-ever seizure from sleep was an independent predictor of seizure recurrence, with a hazard ratio [HR] of 1.44 (95% CI 1.23-1.69), similar to epileptiform abnormalities on EEG (HR 1.48, 95% CI 1.24-1.76) and remote symptomatic etiology (HR 1.47, 95% CI 1.27-1.71). HR for recurrence in patients without either epileptiform abnormalities or remote symptomatic etiology was 1.97 (95% CI 1.60-2.44) for a sleep seizure compared to an awake seizure. For first seizure from sleep, 76% of second seizures also arose from sleep (p < .0001), with 65% of third seizures (p < .0001) also from sleep. Seizures from sleep were less likely to be associated with injury other than orolingual trauma, both with the presenting seizure (9.4% vs 30.6%, p < .0001) and first recurrence (7.5% vs 16.3%, p = .001).

SIGNIFICANCE

First-ever unprovoked seizures from sleep are more likely to recur, independent of other risk factors, with recurrences also usually from sleep, and with a lower risk of seizure-related injury. These findings may inform treatment decisions and counseling after first-ever seizure.

Sleep and seizure risk in epilepsy: bed and wake times are more important than sleep duration

Sleep duration, sleep deprivation and the sleep-wake cycle are thought to play an important role in the generation of epileptic activity and may also influence seizure risk. Hence, people diagnosed with epilepsy are commonly asked to maintain consistent sleep routines. However, emerging evidence paints a more nuanced picture of the relationship between seizures and sleep, with bidirectional effects between changes in sleep and seizure risk in addition to modulation by sleep stages and transitions between stages. We conducted a longitudinal study investigating sleep parameters and self-reported seizure occurrence in an ambulatory at-home setting using mobile and wearable monitoring. Sixty subjects wore a Fitbit smartwatch for at least 28 days while reporting their seizure activity in a mobile app. Multiple sleep features were investigated, including duration, oversleep and undersleep, and sleep onset and offset times. Sleep features in participants with epilepsy were compared to a large (n = 37 921) representative population of Fitbit users, each with 28 days of data. For participants with at least 10 seizure days (n = 34), sleep features were analysed for significant changes prior to seizure days. A total of 4956 reported seizures (mean = 83, standard deviation = 130) and 30 485 recorded sleep nights (mean = 508, standard deviation = 445) were included in the study. There was a trend for participants with epilepsy to sleep longer than the general population, although this difference was not significant. Just 5 of 34 participants showed a significant difference in sleep duration the night before seizure days compared to seizure-free days. However, 14 of 34 subjects showed significant differences between their sleep onset (bed) and/or offset (wake) times before seizure occurrence. In contrast to previous studies, the current study found undersleeping was associated with a marginal 2% decrease in seizure risk in the following 48 h (P < 0.01). Nocturnal seizures were associated with both significantly longer sleep durations and increased risk of a seizure occurring in the following 48 h. Overall, the presented results demonstrated that day-to-day changes in sleep duration had a minimal effect on reported seizures, while patient-specific changes in bed and wake times were more important for identifying seizure risk the following day. Nocturnal seizures were the only factor that significantly increased the risk of seizures in the following 48 h on a group level. Wearables can be used to identify these sleep-seizure relationships and guide clinical recommendations or improve seizure forecasting algorithms.

Association between benzodiazepine outpatient treatment and risk of early seizure recurrence in emergency patients with seizure: A multicenter retrospective study

INTRODUCTION

Seizures are one of the most common neurological reasons for emergency department (ED) visits. The benefit of ED-initiated, short-course outpatient benzodiazepine (BZD) treatment to prevent early recurrent seizure is unknown. This study assesses the risk of early seizure recurrence in patients who were or were not started with outpatient BZD in the ED.

METHODS

This was a multicenter retrospective study conducted in eight French EDs between January 1 and December 31, 2019. All patients admitted for seizure were retrospectively screened and those discharged home from the ED were included. Patients with a history of chronic alcohol intoxication or chronic BZD therapy were excluded. Baseline characteristics, type of seizure, and 30-day outcome were retrospectively collected from the electronic health records. The primary endpoint was a return visit for seizure recurrence within 30 days. Independent factors associated with a seizure recurrence were identified using a multivariable binary logistic regression.

RESULTS

A total of 2,218 patients were included and 1,820 were analyzed. The median age was 39 years and 60% were men. Among them 82% of patients had a generalized tonic-clonic seizure and 47% of seizures were idiopathic. BZD treatment was started in 773 (42%) patients. A total of 154 (8%) patients had an early recurrence at 30 days: 68 (9%) in patients who were treated with BZD versus 86 (8%) in patients who were not (odds ratio [OR] = 1.07, 95% confidence interval [CI] = 0.71 to 1.43). In multivariable analysis, two factors were independently associated with the primary endpoint: chronic epileptic treatment (adjusted OR = 2.58, 95% CI = 1.55 to 4.37) and having had a focal seizure (adjusted OR = 2.16, 95% CI = 1.56 to 4.37).

CONCLUSION

BZD therapy was started in 42% of patients who were discharged home after ED visit for a seizure. This treatment was not an independent factor associated with the risk of return visit for seizure recurrence at 30 days.

Sleep Loss Drives Brain Region-Specific and Cell Type-Specific Alterations in Ribosome-Associated Transcripts Involved in Synaptic Plasticity and Cellular Timekeeping

Sleep and sleep loss are thought to impact synaptic plasticity, and recent studies have shown that sleep and sleep deprivation (SD) differentially affect gene transcription and protein translation in the mammalian forebrain. However, much less is known regarding how sleep and SD affect these processes in different microcircuit elements within the hippocampus and neocortex, for example, in inhibitory versus excitatory neurons. Here, we use translating ribosome affinity purification (TRAP) and in situ hybridization to characterize the effects of sleep versus SD on abundance of ribosome-associated transcripts in Camk2a-expressing (Camk2a+) pyramidal neurons and parvalbumin-expressing (PV+) interneurons in the hippocampus and neocortex of male mice. We find that while both Camk2a+ neurons and PV+ interneurons in neocortex show concurrent SD-driven increases in ribosome-associated transcripts for activity-regulated effectors of plasticity and transcriptional regulation, these transcripts are minimally affected by SD in hippocampus. Similarly, we find that while SD alters several ribosome-associated transcripts involved in cellular timekeeping in neocortical Camk2a+ and PV+ neurons, effects on circadian clock transcripts in hippocampus are minimal, and restricted to Camk2a+ neurons. Taken together, our results indicate that SD effects on transcripts associated with translating ribosomes are both cell type-specific and brain region-specific, and that these effects are substantially more pronounced in the neocortex than the hippocampus. We conclude that SD-driven alterations in the strength of synapses, excitatory-inhibitory (E-I) balance, and cellular timekeeping are likely more heterogeneous than previously appreciated.SIGNIFICANCE STATEMENT Sleep loss-driven changes in transcript and protein abundance have been used as a means to better understand the function of sleep for the brain. Here, we use translating ribosome affinity purification (TRAP) to characterize changes in abundance of ribosome-associated transcripts in excitatory and inhibitory neurons in mouse hippocampus and neocortex after a brief period of sleep or sleep loss. We show that these changes are not uniform, but are generally more pronounced in excitatory neurons than inhibitory neurons, and more pronounced in neocortex than in hippocampus.

Driving eligibility: Implications of studies on seizure recurrence risk

BACKGROUND

Driving is one of the most important issues for patients with seizures. The 2009 European directive provides a framework for evaluating standard situations in assessing the ability to drive. Such a framework may not be sufficient for individual scenarios.

AIMS OF THE STUDY

To analyse current data on seizure recurrence risks (RcRs) focusing on their potential implications for car driving issues (group 1).

METHODS

We evaluated current studies and meta-analyses on RcR.

RESULTS

A meta-analysis of seizure-free patients who withdrew their medication (Lamberink et al Lancet Neurology 2017;16:523) created a nomogram and a web-based tool that allow estimating RcR in individual patients and thus to identify those in whom medication withdrawal is possible without the common driving ban during withdrawal. The 2-year prediction model of that meta-analysis has been recently externally tested and confirmed. A meta-analysis of patients with a first unprovoked seizure (Bonnett et al PloS ONE 2014;9:e99063) determined to which extent RcRs depend on established risk factors. The seizure-free period required to restart driving could be tailored according to the individual RcR.

CONCLUSION

These current studies allow estimating individual RcR more precisely and thus modifying periods of driving bans beyond the existing guidelines.

In vitro Cortical Network Firing is Homeostatically Regulated: A Model for Sleep Regulation

Prolonged wakefulness leads to a homeostatic response manifested in increased amplitude and number of electroencephalogram (EEG) slow waves during recovery sleep. Cortical networks show a slow oscillation when the excitatory inputs are reduced (during slow wave sleep, anesthesia), or absent (in vitro preparations). It was recently shown that a homeostatic response to electrical stimulation can be induced in cortical cultures. Here we used cortical cultures grown on microelectrode arrays and stimulated them with a cocktail of waking neuromodulators. We found that recovery from stimulation resulted in a dose-dependent homeostatic response. Specifically, the inter-burst intervals decreased, the burst duration increased, the network showed higher cross-correlation and strong phasic synchronized burst activity. Spectral power below <1.75 Hz significantly increased and the increase was related to steeper slopes of bursts. Computer simulation suggested that a small number of clustered neurons could potently drive the behavior of the network both at baseline and during recovery. Thus, this in vitro model appears valuable for dissecting network mechanisms of sleep homeostasis.

The Mutual Interaction Between Sleep and Epilepsy on the Neurobiological Basis and Therapy

BACKGROUND

Sleep and epilepsy are mutually related in a complex, bidirectional manner. However, our understanding of this relationship remains unclear.

RESULTS

The literatures of the neurobiological basis of the interactions between sleep and epilepsy indicate that non rapid eye movement sleep and idiopathic generalized epilepsy share the same thalamocortical networks. Most of neurotransmitters and neuromodulators such as adenosine, melatonin, prostaglandin D2, serotonin, and histamine are found to regulate the sleep-wake behavior and also considered to have antiepilepsy effects; antiepileptic drugs, in turn, also have effects on sleep. Furthermore, many drugs that regulate the sleep-wake cycle can also serve as potential antiseizure agents. The nonpharmacological management of epilepsy including ketogenic diet, epilepsy surgery, neurostimulation can also influence sleep.

CONCLUSION

In this paper, we address the issues involved in these phenomena and also discuss the various therapies used to modify them.

The debate: Treatment after the first seizure-The PRO

According to current diagnosis criteria, first seizures constitute beginning epilepsy when they carry recurrence risks of ≥60% over the next 10 years. This is frequently the case and warrants AED treatment. Evidence argues against deferring treatment when provoking factors such as sleep deprivation are reported. There are several characteristics of first seizures which markedly increase recurrence risk but not clearly beyond 60%. This includes status epilepticus or seizure flurries at first manifestation or focal semiology indicating focal epilepsy. In this situation, there are still various medical, social and individual aspects supporting early initiation of AED. Modern AED allow this safely and at low dosages.

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.

Predictive value of S100-B and copeptin for outcomes following seizure: the BISTRO International Cohort Study

Objective

To evaluate the performance of S100-B protein and copeptin, in addition to clinical variables, in predicting outcomes of patients attending the emergency department (ED) following a seizure.

Methods

We prospectively included adult patients presented with an acute seizure, in four EDs in France and the United Kingdom. Participants were followed up for 28 days. The primary endpoint was a composite of seizure recurrence, all-cause mortality, hospitalization or rehospitalisation, or return visit in the ED within seven days.

Results

Among the 389 participants included in the analysis, 156 (40%) experienced the primary endpoint within seven days and 195 (54%) at 28 days. Mean levels of both S100-B (0.11 μg/l [95% CI 0.07–0.20] vs 0.09 μg/l [0.07–0.14]) and copeptin (23 pmol/l [9–104] vs 17 pmol/l [8–43]) were higher in participants meeting the primary endpoint. However, both biomarkers were poorly predictive of the primary outcome with a respective area under the receiving operator characteristic curve of 0.57 [0.51–0.64] and 0.59 [0.54–0.64]. Multivariable logistic regression analysis identified higher age (odds ratio [OR] 1.3 per decade [1.1–1.5]), provoked seizure (OR 4.93 [2.5–9.8]), complex partial seizure (OR 4.09 [1.8–9.1]) and first seizure (OR 1.83 [1.1–3.0]) as independent predictors of the primary outcome. A second regression analysis including the biomarkers showed no additional predictive benefit (S100-B OR 3.89 [0.80–18.9] copeptin OR 1 [1.00–1.00]).

Conclusion

The plasma biomarkers S100-B and copeptin did not improve prediction of poor outcome following seizure. Higher age, a first seizure, a provoked seizure and a partial complex seizure are independently associated with adverse outcomes.

Do reflex seizures and spontaneous seizures form a continuum? - triggering factors and possible common mechanisms

Recent changes in the understanding and classification of reflex seizures have fuelled a debate on triggering mechanisms of seizures and their conceptual organization. Previous studies and patient reports have listed extrinsic and intrinsic triggers, albeit their multifactorial and dynamic nature is poorly understood. This paper aims to review literature on extrinsic and intrinsic seizure triggers and to discuss common mechanisms among them. Among self-reported seizure triggers, emotional stress is most frequently named. Reflex seizures are typically associated with extrinsic sensory triggers; however, intrinsic cognitive or proprioceptive triggers have also been assessed. The identification of a trigger underlying a seizure may be more difficult if it is intrinsic and complex, and if triggering mechanisms are multifactorial. Therefore, since observability of triggers varies and triggers are also found in non-reflex seizures, the present concept of reflex seizures may be questioned. We suggest the possibility of a conceptual continuum between reflex and spontaneous seizures rather than a dichotomy and discuss evidence to the notion that to some extent most seizures might be triggered.