Respiratory Arousal Threshold in Patients with Epilepsy and Obstructive Sleep Apnea

Area of Science:

• Neurology
• Sleep Medicine
• Respiratory Physiology

Background:

• Epilepsy is associated with a higher incidence of obstructive sleep apnea (OSA).
• Limited research exists on the specific phenotypes of OSA in patients with epilepsy (PWE).
• Investigating the respiratory arousal threshold (rAT) is crucial for understanding OSA pathophysiology in PWE.

Purpose of the Study:

• To evaluate the respiratory arousal threshold (rAT) in patients with epilepsy and concurrent obstructive sleep apnea (PWE+OSA).
• To compare rAT characteristics between PWE+OSA and patients with OSA only.
• To explore potential differences in CPAP compliance based on rAT in these groups.

Main Methods:

• Adult patients were recruited from a specialized Sleep and Epilepsy Center.
• Overnight in-laboratory polysomnography was performed on all participants.
• Patients with epilepsy and OSA were compared to age-, sex-, and AHI-matched controls with OSA only.
• Low rAT was determined using predictive models derived from polysomnography data.

Main Results:

• The study included 48 PWE (36 with OSA) and 108 OSA-only patients.
• PWE+OSA patients were older and had a later epilepsy onset than PWE without OSA.
• The proportion of patients predicted to have low rAT was similar between PWE+OSA (52.8%) and OSA-only (63.0%) groups.
• Continuous positive airway pressure (CPAP) compliance was lower in the low rAT subgroup within the OSA-only group, but not in the PWE+OSA group.

Conclusions:

• Patients with epilepsy and OSA exhibit a similar prevalence of low respiratory arousal threshold (rAT) compared to OSA-only controls.
• The predictive model for rAT, while informative, has limitations; direct measurement is needed for definitive conclusions.
• Further research is warranted to elucidate the mechanisms underlying the increased prevalence of OSA in PWE.