A 58-year-old man with a history of hypertension presents to the emergency department with sudden-onset right arm weakness and aphasia. CT head without contrast shows no hemorrhage. MRI performed later demonstrates an ischemic infarct in the left middle cerebral artery territory. Over the next 24 hours, he becomes increasingly somnolent and develops worsening headache. Repeat imaging shows a marked increase in hypodensity of the white matter surrounding the infarct with mass effect and midline shift. Which of the following pathophysiologic changes most directly explains this patient’s worsening cerebral edema?

A. Enhanced carrier-mediated transport of glucose and amino acids into the brain parenchyma B. Disruption of endothelial tight junctions leading to leakage of plasma proteins and fluid into extracellular space C. Increased emetic signaling from a circumventricular organ in the medulla D. Increased permeability of the blood-brain barrier due to hyperosmolar therapy E. Increased Na+ and K+ movement through ion channels across intact blood-brain barrier endothelium