A 72-year-old woman with uncontrolled hypertension presents…

A 72-year-old woman with uncontrolled hypertension presents to the emergency department with altered mental status.  His blood pressure is 210/130 mm Hg, pulse is 110/min, and oxygen saturation is 99% on room air.  CT of the head reveals a posterior fossa bleed. One hour later the patient goes into respiratory failure.  Which of the following is the most likely etiology?