Obstructive sleep apnea risk in patients with focal versus generalized epilepsy

Sex differences in variables associated with excessive daytime sleepiness in patients with epilepsy

OBJECTIVE

Excessive daytime sleepiness (EDS) is common in patients with epilepsy (PWE). The Epworth Sleepiness Scale (ESS) is a self-reported measure of sleepiness in widespread use. The purpose of this study was to identify contributors to the ESS score in PWE and to identify variables associated with a high score indicative of EDS.

METHODS

A cross-sectional study was performed on 115 PWE presenting to the epilepsy clinic. Self-reported questionnaires were administered and demographic and clinical information was gathered from the electronic medical record. Regression analyses were performed.

RESULTS

A high ESS score was found in nearly 20% of the cohort. Obstructive sleep apnea (OSA) risk, standardized anti-seizure drug (ASD) dose, and female sex were associated with an increased likelihood of a high ESS score. Assessment of the ESS without the use of a cutpoint showed that standardized ASD dose and OSA risk were associated with the ESS in men, but standardized ASD dose was not associated with the ESS in women. Higher use of valproic acid and oxcarbazepine in men and higher use of lamotrigine in women may be contributing factors.

SIGNIFICANCE

Sex is likely to be a key factor in determining contributors to EDS in PWE.

The role of sleep state and time of day in modulating breathing in epilepsy: implications for sudden unexpected death in epilepsy

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among patients with refractory epilepsy. While the exact etiology of SUDEP is unknown, mounting evidence implicates respiratory dysfunction as a precipitating factor in cases of seizure-induced death. Dysregulation of breathing can occur in epilepsy patients during and after seizures as well as interictally, with many epilepsy patients exhibiting sleep-disordered breathing (SDB), such as obstructive sleep apnea (OSA). The majority of SUDEP cases occur during the night, with the victim found prone in or near a bed. As breathing is modulated in both a time-of-day and sleep state-dependent manner, it is relevant to examine the added burden of nocturnal seizures on respiratory function. This review explores the current state of understanding of the relationship between respiratory function, sleep state and time of day, and epilepsy. We highlight sleep as a particularly vulnerable period for individuals with epilepsy and press that this topic warrants further investigation in order to develop therapeutic interventions to mitigate the risk of SUDEP.

Risk of sudden unexpected death in people with epilepsy and obstructive sleep apnea

This study aimed to determine whether severity of newly diagnosed obstructive sleep apnea (OSA) in people with epilepsy is associated with elevated sudden unexpected death in epilepsy (SUDEP) risk as calculated by the revised SUDEP-7 Inventory (rSUDEP-7). To this aim, a retrospective cross-sectional study was conducted at a single academic center. Adults ≥18 years of age with epilepsy and newly diagnosed OSA were retrospectively identified via electronic health records. Analysis was performed for subjects with confirmed epilepsy, OSA, and complete diagnostic PSG and rSUDEP-7 data. OSA severity was categorized as mild, moderate or severe. Logistic regression analysis was used to determine the association between OSA severity and rSUDEP-7 scores, adjusting for significantly different baseline characteristics. Of 86 subjects, OSA severity was classified as mild 38(44.2 %), moderate 25(29.1 %), and severe 23(26.7 %). Multivariate logistic regression demonstrated that severe OSA was significantly associated with rSUDEP-7 ≥ 5 after adjusting for congestive heart failure and diabetes (OR:4.08,p = 0.046,CI:1.04-16.28), but was attenuated when male gender was added to the model (OR:3.91,p = 0.067,CI:0.91-16.77). In conclusion, severe OSA is associated with elevated SUDEP risk. As a treatable disorder, OSA may thus represent a modifiable SUDEP risk factor. However, future confirmatory studies involving the prospective, longitudinal evaluation of SUDEP from broader populations are required.