Sleep-disordered breathing among patients admitted for inpatient video-EEG monitoring

Objective: Examine the frequency and risk factors of sleep-disordered breathing in individuals with epilepsy and psychogenic non-epileptic events (PNES). Methods: We conducted a cross-sectional study of consecutive patients admitted for inpatient video-EEG monitoring at The Royal Melbourne Hospital, Australia between December 1, 2011 and July 31, 2017. Participants underwent routine clinical investigations during their monitoring period including polysomnography, neurocognitive testing, and screening instruments of daytime somnolence, sleep quality, and quality of life. Results: Our study population consisted of 370 participants who received a diagnosis of epilepsy (n=255), PNES (n=93), or both disorders (n=22). Moderate-to-severe sleep-disordered breathing (defined by an apnea-hypopnea index ≥15) was observed in 26.5% (98/370) individuals, and did not differ across subgroups: epilepsy 26.3% (67/255), PNES 29.0% (27/93) or both disorders 18.2% (4/22; p=0.610). Following adjustment for confounders, pathological daytime sleepiness predicted moderate-to-severe sleep-disordered breathing in epilepsy (OR 10.35, 95% CI: 2.09-51.39; p=0.004). In multivariable analysis, independent predictors for moderate-to-severe sleep-disordered breathing in epilepsy were older age (OR 1.07, 95% CI: 1.04-1.10; p<0.001) and higher body-mass index (OR 1.06, 95% CI: 1.01-1.11; p=0.029), and in PNES older age (OR 1.10, 95% CI: 1.03-1.16; p=0.002). Conclusion: Polysomnography during inpatient video-EEG monitoring identified a substantial number of patients with undiagnosed sleep-disordered breathing. This was notable in the subgroup with PNES, who were often female and obese. Identification of risk factors may improve management of sleep-disordered breathing in these populations. The association with pathological daytime sleepiness suggests that sleep-disordered breathing may be an important contributor to these common and disabling symptoms in patients with epilepsy.