A 72-year-old man is brought by his wife for evaluation of progressive cognitive decline over the past 18 months. His wife reports that his cognition fluctuates dramatically throughout the day — some mornings he is alert, conversational, and oriented, while other times he appears confused, stares into space, and is difficult to engage. She describes recurrent, detailed visual hallucinations of children playing in the living room, which the patient describes with vivid specificity but acknowledges may not be real. She also notes that he has developed a shuffling gait, stooped posture, resting tremor in his right hand, and has fallen three times in the past month. During the REM sleep behavior disorder screening, his wife confirms he has been physically acting out his dreams for the past two years, once punching her while asleep. His MoCA score is 18/30. He is currently taking no psychotropic medications.