Unexplained Hypoxemia in a Patient With Transient Ischemic Attack.

An 84-year-old woman with a medical history of hypertension, hypothyroidism, and transient ischemic attacks presented with right-sided upper and lower extremity weakness for 1 day. She was a lifetime nonsmoker with no known heart disease or chronic lung disease. She had no occupational exposure or pertinent family history. She denied any fevers, chills, rashes, or shortness of breath. There was no history of recent travel.