Specific aim: To test the effects of nasal expiratory positive airway pressure (EPAP) therapy on sleep apnea severity among patients with recent ischemic stroke.

Hypothesis 1: Ischemic stroke patients with sleep apnea will have less severe sleep apnea, as measured by the apnea-hypopnea index (AHI), with nasal EPAP therapy compared with a control night.

Hypothesis 2: Ischemic stroke patients will have higher mean levels of oxygen saturation with nasal EPAP therapy compared with a control night.

Inclusion Criteria:

• adults with an ischemic stroke (including TIA with infarction) within the prior 14 days

Exclusion Criteria:

1. Current use of any transnasal tube (eg dobhoff tube)
2. Current use of CPAP, mechanical ventilation, or supplemental oxygen
3. Known severe breathing disorders including hypercapnic respiratory failure, respiratory muscle weakness, bullous lung disease, bypassed upper airway, pneumothorax, pneumomediastinum
4. Severe heart disease (including severe heart failure)
5. Pathologically low blood pressure
6. An acute upper respiratory (including nasal, sinus or middle ear) inflammation or infection, or perforation of the ear drum
7. Sores, abrasions, or skin or mucosal irritation on or around the nose.
8. Known pregnancy
9. Inability to provide informed consent
10. Use of alpha blockers or short acting nitrates
11. Permanent pacemaker
12. Sustained non-sinus cardiac arrhythmia

All subjects who completed both nights