A 55-year-old man presents to his primary care physician because of what he refers to as "brain fog" and confusion over the logistical parts of his life. Over the past year, he has had difficulty performing simple calculations, such as counting money, calculating a tip at a restaurant, writing checks, and managing his checkbook. He reports increasing difficulty in managing his personal finances and in managing some of his clients' bills; he is an accountant in private practice. He reports difficulty with daily tasks that involve numbers, including dialing the phone and reading the time on a clock, because he is unsure of the digits he is viewing. He often confuses numbers. Last week, he made one of his favorite recipes, but it was inedible because he put in the wrong amount of ingredients. He is extremely frustrated and embarrassed by this. He has made multiple large mistakes with several clients over the past few months that have cost him larger pieces of business and have hurt his revenue. He is unable to prepare spreadsheets as he once was and has had to delegate those responsibilities to an employee. He also is no longer able to do the daily crossword puzzle in the morning paper, something he enjoyed and did every morning for many years.

Physical exam reveals nothing remarkable. Blood pressure and pulse are normal; heart, lung, and bowel sounds are normal on auscultation; liver and spleen are normal on palpation. There is no evidence of lymphadenopathy of any kind. Further investigation into cognitive symptoms reveals moderate agraphia and alexia, and moderate anomia, primarily in spoken language but also in written samples that involve both words as well as numbers and simple calculations. Additionally, there is slight limb apraxia on the right side. There is no evidence of right-left discrimination difficulty. Minor visuospatial difficulties are observed. Routine laboratory studies (complete blood cell count with differential, cobalamin, thyroid panel, liver function tests) reveal nothing remarkable. The patient has no other comorbidities and no family history of dementia.