A 69 year old man is brought to the ED after he was found by police trying to break into the back office of a grocery store, claiming that he works there and that he had left his keys in the office. The owner of the grocery store denied that the patient was employed there, but thought that she recognized him a regular patron. The patient's medical problems include hypertension, hyperlipidemia, major depressive disorder, alcohol use disorder, and type 2 DM. Family history is significant for Alzheimer disease on both sides of the family. The patient answers questions without difficulty, but provides conflicting information to different examiners. He is unable to account for how he ended up in the grocery store; however, he does provide detailed accounts of his previous job as an English professor. He does not appear troubled by his inability to recall events initially. The remainder of the exam is normal. Which of the following is the most likely?
A. Alzheimer disease
B. Dissociative amnesia
C. Korsakoff syndrome
D. Marchiafava-Bignami disease
E. Transient global ischemia
F. Vascular dementia
G. wernicke encephalopathy
