A 50-year-old man with Down syndrome (DS) presents to his primary care physician for routine checkup. He lives in a small group home with nine other people of varying degrees of disability. He is employed as a packer at a local grocery store and is transported between the group home and his job via accessible van 5 days per week. He is of moderate intellectual disability.

The patient is complaining of being "forgetful" and "clumsy," and he recounts how he got into trouble at work for "not listening" (to instructions) and for dropping and breaking a glass jar of peaches that a customer had purchased. A paid worker at the home in which he lives, reports that she has noticed a marked loss of hand-eye coordination and increased memory loss related to basic functioning and instructions in the past 3 months. She also reports that the patient recently experienced a seizure and has been bumping into furniture and doors in the group home often, which has resulted in several bruises on his body.

Physical exam confirms poor hand-eye coordination and visuospatial dysfunction. Laboratory tests are performed and reveal nothing remarkable.