Table e-1. Detailed Study Criteria
- Age of 18 years or older.
- A diagnosis of partial or generalized epilepsy (symptomatic or idiopathic) confirmed by the site investigator, with two or more seizures per month indicated on their survey and confirmed by chart review.
- A quantifiable seizure type (subjects were aware they had experienced a seizure or had a reliable caregiver present most of the time who was aware that the patient experienced a seizure). Absence, myoclonic, and other types of seizures with a motor component were included, but sensory simple partial seizures were excluded as these can be difficult to quantify.
- Cutoffs of 26 or higher for women or 29 or higher for men on the Sleep Apnea Scale of the Sleep Disorders Questionnaire (SA/SDQ) or a compelling history supportive of OSA, with a confirmatory evaluation by the site investigator suggesting a high likelihood for OSA. These cutoffs were used based on our prior work in an epilepsy population.1
- Subject was able and willing to provide informed consent and to cooperate with polysomnography. Subjects may withdraw from the study for escalating seizures, inability to tolerate treatment, severe concurrent illness, or at their request.
- Subjects and their physicians agreed to have their medication regimens optimized so that they were on the best regimen that was titrated to therapeutic benefit for 30 days prior to the baseline phase of the study. To avoid the confounding influence of AEDs on seizure frequency and daytime sleepiness, they were required to remain on constant doses of AEDs throughout the study, with AED levels checked at regular intervals.
- Those subjects being considered for other interventions, including epilepsy surgery, vagus nerve stimulation, or investigational medication trials were offered participation in the study if they were willing to defer their other interventions until this study is completed.
- Subjects with effectively treated OSA. Those with prior diagnoses of OSA were included as long as their OSA was not effectively treated and they were CPAP-naïve (as prior exposure to CPAP treatment would potentially interfere with their ability to be blinded to therapeutic vs. sham CPAP treatment).
- Seizures secondary to drugs, alcohol, infection, neoplasia, demyelination, metabolic illness, or progressive degenerative disease.
- Non-epileptic spells (e.g., pseudoseizures) alone or in combination with epileptic seizures.
- Narcolepsy or another primary sleep disorder requiring intervention with medications and potentially affect results of study (e.g., severe periodic limb movement disorder).
- History of poor compliance with AEDs.
- Active treatment with the vagus nerve stimulator, which may affect sleep-disordered breathing.2
- Pregnancy, as hormonal changes can affect seizure frequency, sleep disordered breathing, and daytime sleepiness. Women enrolled in the trial documented that they were using an effective form of birth control.
- A significant history of medical or psychiatric disease impairing participation in the trial.
- A history of alcohol or drug abuse during the one-year period prior to trial participation.
- Evidence of medical instability (e.g., congestive heart failure, cardiac arrhythmias, pulmonary disease) due to obstructive sleep apnea. These patients underwent an expedited evaluation and treatment given their clinical condition.
- Greater than ten seizures a day, as this may interfere with polysomnography or result in apparent apneas.
1.Weatherwax KJ, Lin X, Marzec ML, Malow BA. Obstructive sleep apnea in epilepsy patients: the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) is a useful screening instrument for obstructive sleep apnea in a disease-specific population. Sleep Med 2003;4(6):517-521.
2.Marzec ML, Edwards J, Sagher O, Fromes G, Malow B. Effects of vagus nerve stimulation on sleep-related breathing in epilepsy patients. Epilepsia 2003;44(7):930-935.