Our recommendation to treat patients with OSA using CPAP is consistent with a guideline from the American College of Physicians that recom- mends CPAP as the initial therapy.330 In stud- ies of various populations, treatment with CPAP effectively reduced the AHI and improved mea- sures of sleepiness, BP control, sleep-related quality of life, and physical functioning.302,303 As described in the above synopsis, limited data from small trials specifically among patients with stroke show that treatment with CPAP is CLINICAL STATEMENTS AND GUIDELINES Kleindorfer safe, reduces the AHI, improves sleepiness, and may improve neurological function.304 313 Evidence from 1 trial suggests that treat- ment may improve mood.314 In a planned ancil- lary analysis in the SAVE trial, which enrolled patients with either coronary or cerebrovascu- lar disease, CPAP reduced the risk for stroke in patients with better CPAP adherence.303 The American College of Physicians recommends mandibular advancement devices as an alterna- tive for patients who do not tolerate CPAP or who prefer mandibular advancement.330 These devices, however, have not been specifically tested in patients with stroke. 2. OSA is common among patients with stroke, but most cases are undiagnosed.315 The combined prevalence of known and unknown moderate to severe OSA approaches 40%. Arguing against evaluating patients for undiagnosed OSA is the absence of evidence that treatment improves stroke-related outcomes, including recurrence. 