A 60-year-old man with a history of hypertension. diabetes_and hyperlipidemia had a sudden onset or right-sided weakness, by the time the ambulance arrived. he had difficulty speaking. Unfortunately, the patient died within the next 2 hours and an autopsy was performed immediately. The gross examination of the cerebral left hemisphere showed brain swelling. widened gyri and poorly demarcated unction. Which of the following is the most likely cause of this patient's death?