Role of continuous positive airway pressure therapy on the pathogenesis of sleep-related frontal lobe epilepsy in a child with obstructive sleep apnea syndrome

Experimental chronic sleep fragmentation alters seizure susceptibility and brain levels of interleukins 1β and 6

Brain hyperexcitability in sleep apnea is believed to be provoked by hypoxemia, but sleep fragmentation can also play a significant role. Sleep fragmentation can trigger inflammatory mechanisms. The aim of this research was to investigate the effects of chronic sleep fragmentation on seizure susceptibility and brain cytokine profile. Chronic sleep fragmentation in male rats with implanted EEG electrodes was achieved by the treadmill method. Rats were randomized to: treadmill control (TC); activity control (AC) and sleep fragmentation (SF) group. Convulsive behavior was assessed 14 days later by seizure incidence, latency time and seizure severity during 30 min following lindane administration. The number and duration of EEG ictal periods were determined. Levels of IL-1β and IL-6 were measured in the animals' serum and brain structures (hippocampus, thalamus and cerebral cortex), in separate rat cohort that underwent the same fragmentation protocol except lindane administration. Incidence and severity of seizures were significantly increased, while latency was significantly decreased in SF+L compared with TC+L group. Seizure latency was also significantly decreased in SF+L compared to AC+L group. The number and duration of ictal periods were increased in the SF+L compared to the AC+L group. IL-1β was significantly increased in the thalamus, cortex and hippocampus in the SF compared to the AC and TC groups. IL-6 was statistically higher only in the cortex of SF animals, while in the thalamic or hippocampal tissue, no difference was observed between the groups. It could be concluded that fourteen-day sleep fragmentation increases seizure susceptibility in rats and modulates brain production of IL-1β and IL-6.

Brain hyperexcitability in sleep apnea is believed to be provoked by hypoxemia, but sleep fragmentation can also play a significant role. Sleep fragmentation can trigger inflammatory mechanisms. The aim of this research was to investigate the effects of chronic sleep fragmentation on seizure susceptibility and brain cytokine profile. Chronic sleep fragmentation in male rats with implanted EEG electrodes was achieved by the treadmill method. Rats were randomized to: treadmill control (TC); activity control (AC) and sleep fragmentation (SF) group. Convulsive behavior was assessed 14 days later by seizure incidence, latency time and seizure severity during 30 min following lindane administration. The number and duration of EEG ictal periods were determined. Levels of IL-1β and IL-6 were measured in the animals’ serum and brain structures (hippocampus, thalamus and cerebral cortex), in separate rat cohort that underwent the same fragmentation protocol except lindane administration. Incidence and severity of seizures were significantly increased, while latency was significantly decreased in SF+L compared with TC+L group. Seizure latency was also significantly decreased in SF+L compared to AC+L group. The number and duration of ictal periods were increased in the SF+L compared to the AC+L group. IL-1β was significantly increased in the thalamus, cortex and hippocampus in the SF compared to the AC and TC groups. IL-6 was statistically higher only in the cortex of SF animals, while in the thalamic or hippocampal tissue, no difference was observed between the groups. It could be concluded that fourteen-day sleep fragmentation increases seizure susceptibility in rats and modulates brain production of IL-1β and IL-6.

Transient increase in epileptiform discharges after the introduction of nasal continuous positive airway pressure in a patient with obstructive sleep apnea and epilepsy

In patients with obstructive sleep apnea (OSA) and epilepsy, the frequency of generalized spike and wave complexes (GSWCs) usually decreases after the initiation of nasal continuous positive airway pressure (nCPAP) therapy. However, we herein report a patient who had a transient increase in GSWCs following nCPAP treatment. A woman with epilepsy underwent polysomnography, who showed severe OSA and 30 GSWCs during the sleep study. Polysomnography at the introduction nCPAP showed that the GSWCs increased to 94 times during the monitoring period, despite improvement of her OSA. Polysomnography was again performed four months later, and the GSWCs had decreased to 23 times. Physicians should therefore be cautious regarding a possible increase in epileptiform discharges and seizures immediately after the introduction of nCPAP.

Cyclic alternating pattern (CAP): the marker of sleep instability

Cyclic alternating pattern CAP is the EEG marker of unstable sleep, a concept which is poorly appreciated among the metrics of sleep physiology. Besides, duration, depth and continuity, sleep restorative properties depend on the capacity of the brain to create periods of sustained stable sleep. This issue is not confined only to the EEG activities but reverberates upon the ongoing autonomic activity and behavioral functions, which are mutually entrained in a synchronized oscillation. CAP can be identified both in adult and children sleep and therefore represents a sensitive tool for the investigation of sleep disorders across the lifespan. The present review illustrates the story of CAP in the last 25 years, the standardized scoring criteria, the basic physiological properties and how the dimension of sleep instability has provided new insight into pathophysiolology and management of sleep disorders.

Sleep and epilepsy in children and adolescents

Epilepsy and sleep disorders are considered by many to be common bedfellows. Several sleep phenomena may occur during nighttime taking a wide variety of forms and which can mimic seizures. Although most seizure sub-types have the potential to occur during sleep or wakefulness, sleep has a well-documented and strong association with specific epilepsy syndromes. Seizures in sleep also tend to occur during lighter stages of non-REM (NREM) sleep. The neurophysiologic process involved in the deepening of NREM sleep may also facilitate both seizures and IEDs. Epilepsy per se and/or seizures themselves promote sleep disruption and significantly affect the quality, quantity, and architecture of sleep. There are many causes of sleep disruption in patients with epilepsy, including inadequate sleep hygiene, coexisting sleep disorders, and circadian rhythm disturbances. Seizures themselves can disrupt sleep, even when they occur during wakefulness. Anti-epileptic drugs (AEDs) can also alter sleep in positive and negative ways, and these effects are independent of anticonvulsant actions. The end result of sleep disruption is excessive daytime sleepiness, worsening seizures, and poor quality of life. Screening for sleep disorders in the epilepsy population and appropriate intervention strategies will lead to overall improved quality of life and seizure control.

Cyclic alternating pattern: A window into pediatric sleep

Cyclic alternating pattern (CAP) has now been studied in different age groups of normal infants and children, and it is clear that it shows dramatic changes with age. In this review we first focus on the important age-related changes of CAP from birth to peripubertal age and, subsequently, we describe the numerous studies on CAP in developmental clinical conditions such as pediatric sleep disordered breathing, disorders of arousal (sleep walking and sleep terror), pediatric narcolepsy, learning disabilities with mental retardation (fragile-X syndrome, Down syndrome, autistic spectrum disorder, Prader-Willi syndrome) or without (dyslexia, Asperger syndrome, attention-deficit/hyperactivity disorder). CAP rate is almost always decreased in these conditions with the exception of the disorders of arousal and some cases of sleep apnea. Another constant result is the reduction of A1 subtypes, probably in relationship with the degree of cognitive impairment. The analysis of CAP in pediatric sleep allows a better understanding of the underlying neurophysiological mechanisms of sleep disturbance. CAP can be considered as a window into pediatric sleep, allowing a new vision on how the sleeping brain is influenced by a specific pathology or how sleep protecting mechanisms try to counteract internal or external disturbing events.

Relação da epilepsia com a síndrome de apneia obstrutiva do sono: revisão

OBJETIVOS: Avaliar principalmente a relação entre síndrome da apneia obstrutiva do sono (SAOS) e crises epilépticas (CE). MÉTODOS: Pesquisa no Pubmed com publicações de 2000 até 23.11.2009 a partir dos descritores “Sleep Apnea, Obstructive” [Mesh Major Topic] e epilepsy[title/abstract]. Acrescentado também artigo referente à Classificação Internacional de Transtornos do Sono-2005. RESULTADOS: Obtidos 19 artigos (um em alemão, excluído) sendo 1 artigo de revisão, 2 editoriais, 5 relatos de caso, 1 série de casos, 4 transversais, 1 ensaio clínico piloto, 2 longitudinais experimentais sem controle, 1 longitudinal/avaliação polissonográfica em dois momentos, 1 de acurácia. CONCLUSÃO: A SAOS é subnotificada na população epiléptica farmacorresistente e nos pacientes com sonolência excessiva diurna (pode ser consequência da SAOS) bem como nos que serão submetidos a estimulação do nervo vago (pode exacerbar SAOS em pacientes com SAOS pré-existente) para fim de controle de CE. Os dados dessa revisão levantam a hipótese da relação importante entre SAOS e CE, pois alguns estudos sugerem a relação mútua entre os dois fatores, apesar de não haver significância estatística. Existe uma relação inversa em um relato de caso de lobectomia frontal esquerda com resolução de CE e da apneia, levando a sugestão de que descargas epilépticas interictais extensas bem como a CE em si no sono pudessem alterar o controle das vias aéreas superiores. A revisão estabelece também a necessidade da realização de novos estudos com análise multivariada e, idealmente, prospectivos e com controles, com amostra maior, observacionais ou de intervenção, com continuous positive airway pressure (CPAP) para a conclusão mais fundamentada metodologicamente.