A 64 year-old female, Mrs.Jane, comes to your office for her annual health checkup. For the last few months, she has been having difficulty remembering the names of her friends. She struggles to remember even the names of some of her grandchildren. Sometimes she struggles to find the right words to express her thoughts. Sometimes she wonders whether she has taken her regular blood pressure medication even after she took it. Two weeks ago, her niece called her to attend her birthday party over the weekend, but after two days, she completely forgot about it. She was planning to go to Orlando, Florida for a business conference. She was able to register to attend the conference, was able to buy the plane tickets but forgot to book a hotel room. Until recently, she used to do these things so systematically and effortlessly. She is sleeping well, feeling good about herself and her financial situation. There is no change in sexual life. Her family members have not noticed anything different in her but she feels that ‘something is not right with my memory and planning’. Noone complained about her behavior – no impulsivity, no aggressiveness, no inappropriate conversations. She is still able to take care of herself. She reports that she is able to cook, drive, go to work, go to gym, do gardening and work on her computer. There is no change in her performance at house and work. Her vital signs are normal. As you observe her, you see a well-dressed, well behaved individual. Her physical examination including nervous system is normal. Of the following, which is the most likely explanation for this patient’s symptoms and signs?
