Encephalitis

A 37-year-old man comes to the clinic because of difficulty with speech for the past month. He was hospitalized with encephalitis 2 months ago. He says it has recently become difficult to name people and places he has known for many years. He vividly describes the White House and Eiffel Tower, but is unable to recall the names. When informed, he promptly recognizes and repeats the names with no difficulty. He speaks in full, fluent sentences with no halting or signs of increased effort. Physical examination shows no abnormalities. Magnetic resonance imaging shows atrophy of the left anterior inferior temporal lobe. Which of the following is the most appropriate diagnosis?