A 68 year old man is brought to the clinic by his son complaining of abnormal behavior for one month. Along the last 6 months, he had worsening forgetfulness. He lost his way several times and neighbours brought him home after finding him wondering around his home. His medical, surgical and family histories are unremarkable. He doesn’t smoke, drink or use any recreational drugs. He eats healthy food and takes daily vitamin and mineral supplements. He is happily married for 39 years. His last regular check up was 6 months ago and was completely normal. http://medical-usmle.com/repeated-usmle-question-47
