A 62-year-old right-handed man is brought to the emergency department by his family after they noticed a sudden change in his ability to communicate. Earlier in the day, he was speaking normally, but he suddenly began speaking in long, fluent sentences that made little sense. For example, he said, “The table is running in the park with the sky,” which confused his family. He seems unaware that his speech is abnormal and becomes frustrated when others do not understand him. He also has difficulty understanding what others are saying to him, often responding inappropriately to questions or commands. On examination, the patient is alert and cooperative. His speech is fluent but contains paraphasic errors (substituting incorrect words or using nonsensical phrases). He is unable to repeat simple phrases or follow verbal commands, such as “raise your left hand.” Neurological examination reveals no motor deficits, and his vision and hearing appear intact. An MRI of the brain is ordered. Which area of the brain is most likely affected in this patient?
