The primary aims are to determine in TIA patients: 1) the prevalence of sleep-disordered breathing, 2) the feasibility of diagnosing and treating sleep-disordered breathing using an auto-titrating continuous positive airways pressure (auto-CPAP) machine within 24-hours of TIA symptom onset, 3) adherence to auto-CPAP, and 4) the effect of auto-CPAP on blood pressure.