The Epworth Sleepiness Scale in epilepsy: Internal consistency and disease-related associations.

BACKGROUND: The Epworth Sleepiness Scale (ESS) is the most common instrument for measuring subjective sleep propensity in people with epilepsy but has not yet been validated in this population. STUDY OBJECTIVES: We aimed to systematically assess the validity, performance, and internal consistency of the ESS, as well as correlations between the ESS and disease-specific variables and patient-reported outcome measures in a cohort of adults with epilepsy (AWE). METHODS: Ninety-five AWE completed sleep and seizure diaries, in-laboratory polysomnography (PSG) and patient-reported outcome measures, including the ESS, Insomnia Severity Index (ISI), and the Beck Depression Inventory (BDI). Demographic information and data from 95 matched controls referred for PSG for suspected obstructive sleep apnea (OSA) was taken from the electronic medical record. Frequencies of high ESS item ratings (item score ≥2) were calculated for each group. Cronbach's α and factor analysis were performed to assess the internal consistency and validity of the ESS within cases and controls. Multivariable linear models were used to assess the association between ESS and predictors of interest, adjusting for demographic and disease-specific variables, including seizure type, frequency, and anti-seizure medication (ASM) therapy. RESULTS: While suspected OSA controls had significantly greater mean ESS total scores (9.9 vs 7.9, p = 0.004) and proportion with ESS >10 (42% vs 25%, p = 0.014), there were no significant differences in the severity of item responses, with the exception of "lying down to rest in the afternoon when circumstances permit," for which more controls rated as likely/very likely (79% vs 64%), p = 0.024). AWE with ESS >10 had higher mean standardized ASM dose (2.5 vs 1.7, p = 0.026). All ESS items were significantly correlated with the total score within each group. Cronbach's α was 0.75 for cases and 0.85 for controls, indicating good internal consistency of the ESS for both groups. After adjusting for demographic and sleep characteristics, higher ESS scores were associated with greater insomnia scores on the ISI (p = 0.024) and depressive symptoms on the BDI (p = 0.018). CONCLUSIONS: This study provides validity for the use of the ESS in adult populations with epilepsy.

Continuous positive airway pressure therapy for obstructive sleep apnea reduces interictal epileptiform discharges in adults with epilepsy.

Obstructive sleep apnea (OSA) is highly prevalent, affecting 25% of men and 10% of women. We recently reported a prevalence of OSA of 30% among 130 adults with epilepsy unselected for sleep disorder complaints, including 16% with moderate-to-severe disease, rates that markedly exceed general population estimates. Treatment of OSA with continuous positive airway pressure (CPAP) therapy or upper airway surgery reduces seizures in many cases. A single study reported a reduction in interictal spike rate with CPAP in 6 patients with OSA. We explored the effect of CPAP therapy on spike rate in 9 adults with epilepsy and OSA. Interictal epileptiform discharges were quantified during a diagnostic polysomnogram (PSG) and a second PSG using therapeutic CPAP. Spike rates were calculated for each recording during wake and sleep stages. Continuous positive airway pressure therapy was associated with significant reductions in median (quartiles) spike rate overall (77.9 [59.7-90.7] %), in wakefulness (38.5 [0.3-55] %), and in sleep (77.7 [54.8-94.7] %) but not in REM sleep. Continuous positive airway pressure therapy also produced a significant improvement in oxygen saturation and arousals. Our work extends a single prior observation demonstrating beneficial effects of CPAP therapy on interictal EEG in patients with epilepsy with comorbid OSA and supports the hypothesis that sleep fragmentation due to OSA contributes to epileptogenicity.

Effect of positive airway pressure therapy on seizure control in patients with epilepsy and obstructive sleep apnea.

Previous studies suggest that treatment for obstructive sleep apnea (OSA) in patients with epilepsy can improve seizure control. We investigated the effect of positive airway pressure (PAP) therapy on seizures in adults with epilepsy referred to the Cleveland Clinic for polysomnography (PSG) from 1997 to 2010. Seizure outcome at baseline and 1 year later was compared in patients with no OSA (apnea-hypopnea index [AHI] <5), patients with PAP-treated OSA, and patients with untreated OSA. One hundred thirty-two subjects (age: 40.2±13 (18-76) years, 65.4% female) were included. Seventy-six (57.6%) subjects had OSA; of these, 43 (56.6%) were on PAP therapy, and 33 (43.4%) were not on PAP therapy (either PAP-intolerant or refused therapy). Of the group with PAP-treated OSA, 83.7% were adherent (use ≥4 h/night at least 5 nights/week). The percentage of subjects with ≥50% seizure reduction and the mean percentage of seizure reduction were significantly greater in the group with PAP-treated OSA (73.9%; 58.5%) than in subjects with untreated OSA (14.3%; 17.0%). There were significantly more subjects with successful outcomes (with ≥50% seizure reduction or seizure-free at both baseline and follow-up) in the group with PAP-treated OSA (83.7%) than in the groups with no OSA (53.6%) and untreated OSA (39.4%). After adjusting for age, gender, body mass index, AHI, and epilepsy duration, we found that the odds of successful outcomes in subjects in the group with PAP-treated OSA were 9.9 and 3.91 times those of the groups with untreated OSA and no OSA, respectively. The group with PAP-treated OSA had 32.3 times the odds of having a ≥50% seizure reduction compared with the group with untreated OSA and 6.13 times compared with the group with no OSA. Positive airway pressure therapy appears to produce beneficial effects on seizures in adult patients with epilepsy and OSA.

Sleep apnea and epilepsy: who's at risk?

Obstructive sleep apnea (OSA) is highly prevalent, affecting 25% of men and 10% of women. Treatment reduces seizures in some patients. Awareness of the comorbidity of sleep disturbances in epilepsy has been increasing. No study has explored OSA predictors in patients unselected for epilepsy severity and sleep disorder symptoms. We assessed cross-sectional OSA prevalence and predictors (apnea-hypopnea index [AHI] ≥10) in 130 consecutive adults using structured interview, subjective assessments, and polysomnography. Obstructive sleep apnea prevalence was 30%, 16% having moderate-severe disease, rates that markedly exceed general population estimates. Obstructive sleep apnea predictors in multivariate modeling included age, dental problems, and standardized AED dose. Male gender, older age, higher BMI, hypertension, and dental problems were associated with higher AHI. Adults with epilepsy appear at increased risk for OSA, increasing with age and AED load, regardless of gender, BMI, and seizure frequency. These findings support the implementation of routine OSA screening in adult epilepsy clinics.

Dose-response relationship between positive airway pressure therapy and excessive daytime sleepiness: the HomePAP study.

STUDY OBJECTIVES: The clinical benefits of positive airway pressure (PAP) therapy for obstructive sleep apnea are assumed to require adherent PAP usage, defined by the Centers for Medicare & Medicaid Services as ≥ 4 hours of use ≥ 70% of nights. However, this definition is based on early data and does not necessarily capture improvements at subthreshold adherence. We explored dose-response relationships between PAP adherence measures and excessive daytime sleepiness from the HomePAP randomized controlled trial. METHODS: Participants aged ≥ 18 years with an apnea-hypopnea index ≥ 15 events/h and baseline sleepiness (Epworth Sleepiness Scale [ESS] ≥ 12) received PAP therapy. Data were collected at baseline, 1-month follow-up, and 3-months follow-up. Regression models and receiver operating characteristic curves evaluated PAP measures as predictors of ESS change and normalization (ESS < 10). RESULTS: In 119 participants (aged 49.4 ± 12.6 years, 66.4% male, 72.3% White), > 50% were PAP nonadherent per Centers for Medicare & Medicaid Services criteria at 3 months. The percentage of nights with PAP use ≥ 4 hours predicted ESS change (P = .023), but not when controlling for the apnea-hypopnea index. The percentage of nights with ≥ 4 hours and average PAP use provided the best discrimination for predicting ESS normalization; each 10% increase in PAP use ≥ 4 hours increased the odds of ESS normalization by 22% (P = .007); those using PAP ≥ 4 hours had a nearly 3-fold greater odds of ESS normalization (P = .025). PAP use for at least 4 hours and on 70% of nights provided the best balance between specificity (0.50) and sensitivity (0.73). CONCLUSIONS: Although subadherent PAP usage may still confer some benefit for patients with obstructive sleep apnea, adherence to current criteria confers the highest likelihood for ESS change and normalization. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Portable Monitoring for Diagnosis and Management of Sleep Apnea (HomePAP); URL: https://clinicaltrials.gov/ct2/show/NCT00642486; Identifier: NCT00642486. CITATION: Pascoe M, Bena J, Andrews ND, et al. Dose-response relationship between positive airway pressure therapy and excessive daytime sleepiness: the HomePAP study. J Clin Sleep Med. 2022;18(4):1027-1034.

Prevalence of Undetected Sleep Apnea in Patients Undergoing Cardiovascular Surgery and Impact on Postoperative Outcomes.

STUDY OBJECTIVE: We examined the prevalence of obstructive sleep apnea (OSA) among patients undergoing cardiac surgery and its impact on postoperative outcomes. METHODS: Subjects were recruited from inpatient cardiovascular surgery units at two tertiary care centers. Crystal Monitor 20-H recorded polysomnograms preoperatively. Regression analyses were performed to explore associations between OSA using different apnea-hypopnea index (AHI) cutoffs and postoperative outcomes adjusting for key covariates. Prevalence of postoperative outcomes was compared among groups defined by AHI and left ventricle ejection fraction (LVEF) median cutoffs. RESULTS: Of 107 participants, the AHI was ≥ 5 in 79 (73.8%), ≥ 10 in 63 (58.9%), ≥ 15 in 51(47.7%), and ≥ 30 in 29 (27.1%). Patients with AHI ≥ 15 had significantly lower LVEF (p < 0.001). Logistic regression analyses with OSA cutoffs as above adjusting for age, gender, race, BMI, and LVEF found no significant increase in odds for any postoperative outcomes. No significant differences were found in %Total sleep time (TST) with SpO2 < 90% between AHI or LVEF groups, or by presence/absence of complications. Patients with any amount of TST with SpO2 < 90% had greater BMI, longer OR tube time, and greater prevalence of prolonged intubation (p = 0.007, 0.035, 0.038, respectively). CONCLUSIONS: OSA is highly prevalent in patients undergoing cardiovascular surgery. It could not be shown that OSA was significantly associated with adverse postoperative outcomes, but this may have been due to an insufficient number of subjects. AHI ≥ 15 was associated with lower LVEF. Larger samples are required to explore the impact of OSA on key postoperative outcomes that have clinical and economic importance in the care of cardiovascular surgery populations. COMMENTARY: A commentary on this article appears in this issue on page 1081.