Nocturnal Hypoxemia and Daytime Sleepiness in Epilepsy With Obstructive Sleep Apnea-Hypopnea Syndrome: A Case–Control Polysomnography Study

Sleep disorders are common in patients with epilepsy, affecting their quality of life. In this study, we aimed to explore the sleep structure of adult patients with epilepsy and determine its correlation with different degrees of obstructive sleep apnea-hypopnea syndrome (OSAHS). We also examined the impact of intermittent hypoxemia on nocturnal sleep structure, respiratory-related events, and excessive daytime sleepiness (EDS). This case–control polysomnography study included 81 patients with epilepsy and 86 healthy controls. Polysomnography combined with video electroencephalography was used to assess sleep structure, respiratory-related events, and factors related to EDS. Patients with epilepsy had a higher prevalence of sleep disorders, hypoxemia, and EDS than controls. Comorbid moderate-to-severe OSAHS was associated with increased risk of severe hypoxemia and awakening. Intermittent and mean hypoxemia worsened with increasing apnea-hypopnea index. The incidence of EDS increased drastically in patients with comorbid moderate-to-severe OSAHS. The total sleep period time was a significant independent predictor of the occurrence of EDS in patients with comorbid moderate-to-severe OSAHS. The study findings indicate that patients with epilepsy experience changes in sleep structure, and the coexistence of OSAHS increases the risk of hypoxemia and EDS. These findings are useful in clinical prognostication of patients with epilepsy comorbid with OSAHS.