Sleep Disorders and Epilepsy

Complex interplay and reciprocal interactions between sleep and epilepsy have been known for centuries. However, newer technologies and in-depth studies have provided us with better understanding of this relationship. Nocturnal seizures can interrupt sleep, while a number of factors, including antiepileptic drugs and sleep disorders, can aggravate seizures. Interestingly, different epileptic syndromes may trigger increase in seizure frequency at a certain phases of the sleep-wake cycle, while others may not show any correlation with these phases. We aim to provide an overview of the interactions between sleep and epilepsy, and provide better understanding how knowledge of the relationship between these two conditions can help more effective management of both disorders.

Multimodal nocturnal seizure detection in a residential care setting

ObjectiveTo develop and prospectively evaluate a method of epileptic seizure detection combining heart rate and movement.MethodsIn this multicenter, in-home, prospective, video-controlled cohort study, nocturnal seizures were detected by heart rate (photoplethysmography) or movement (3-D accelerometry) in persons with epilepsy and intellectual disability. Participants with >1 monthly major seizure wore a bracelet (Nightwatch) on the upper arm at night for 2 to 3 months. Major seizures were tonic-clonic, generalized tonic >30 seconds, hyperkinetic, or others, including clusters (>30 minutes) of short myoclonic/tonic seizures. The video of all events (alarms, nurse diaries) and 10% completely screened nights were reviewed to classify major (needing an alarm), minor (needing no alarm), or no seizure. Reliability was tested by interobserver agreement. We determined device performance, compared it to a bed sensor (Emfit), and evaluated the caregivers’ user experience.ResultsTwenty-eight of 34 admitted participants (1,826 nights, 809 major seizures) completed the study. Interobserver agreement (major/no major seizures) was 0.77 (95% confidence interval [CI] 0.65–0.89). Median sensitivity per participant amounted to 86% (95% CI 77%–93%); the false-negative alarm rate was 0.03 per night (95% CI 0.01–0.05); and the positive predictive value was 49% (95% CI 33%–64%). The multimodal sensor showed a better sensitivity than the bed sensor (n = 14, median difference 58%, 95% CI 39%–80%, p < 0.001). The caregivers' questionnaire (n = 33) indicated good sensor acceptance and usability according to 28 and 27 participants, respectively.ConclusionCombining heart rate and movement resulted in reliable detection of a broad range of nocturnal seizures.

Sleep and epilepsy: unfortunate bedfellows

The relationship between sleep and seizure disorders is a particularly vicious cycle. Nocturnal seizures can interrupt sleep while a number of factors, including antiepileptics and sleep disorders that cause sleep fragmentation, can worsen seizures. Understanding and managing seizures and related sleep disturbance is therefore an important and treatable intervention target that could potentially improve children’s sleep, but also their learning, mood, behaviour, seizures and parental quality of life.

Nocturnal supervision and SUDEP risk at different epilepsy care settings

ObjectiveTo estimate the incidence of sudden unexpected death in epilepsy (SUDEP) in people with intellectual disabilities in residential care settings and to ascertain the effects of nocturnal seizures and nocturnal supervision on SUDEP risk.MethodsWe conducted a nested case-control study reviewing records of all people who died at 2 residential care settings over 25 years. Four controls per case were selected from the same population, matched on age (±5 years) and residential unit. Nocturnal supervision was graded in 3 categories: (1) no supervision; (2) a listening device or a roommate or physical checks at least every 15 minutes; and (3) 2 of the following: a listening device, roommate, additional device (bed motion sensor/video monitoring), or physical checks every 15 minutes. Outcome measures were compared using Mann-Whitney U tests and Fisher exact tests.ResultsWe identified 60 SUDEP cases and 198 matched controls. People who died of SUDEP were more likely to have nocturnal convulsive seizures in general (77% of cases vs 33% of controls, p < 0.001) and a higher frequency of nocturnal convulsive seizures. Total SUDEP incidence was 3.53/1,000 patient-years (95% confidence interval [CI] 2.73–4.53). The incidence differed among centers: 2.21/1,000 patient-years (95% CI 1.49–3.27) vs 6.12/1,000 patient-years (95% CI 4.40–8.52). There was no significant difference in nocturnal supervision among cases and controls, but there was a difference among centers: the center with a lowest grade of supervision had the highest incidence of SUDEP.ConclusionsHaving nocturnal seizures, in particular convulsions, may increase SUDEP risk. Different levels of nocturnal supervision may account for some of the difference in incidence.