Review Question - QID 109031

A 46-year-old man presents with his wife to his primary care provider for depression and strange movements. His wife reports that her husband has not been himself for the last 2 months. Whereas he was previously outgoing and “the life of the party,” the patient is now irritable and withdrawn. He is a partner at an accounting firm, but his colleagues are threatening to fire him if he continues to perform poorly at work. The patient cannot explain the recent changes to his mood and tearfully admits he fears there is something seriously wrong with him. His wife says that he is getting worse. The patient’s medical history is significant for hypertension, for which he takes lisinopril. His family history is unknown as he was adopted. The patient met his mother once and never knew his father but was told he died in his 50s. He drinks a few glasses of wine per week and has never smoked. His temperature is 98.6°F (37°C), blood pressure is 141/87 mmHg, pulse is 81/min, and respirations are 12/min. On physical exam, the patient has a flat affect with a facial grimace and sudden jerky movements of his upper extremities. Which of the following is most likely to be seen on further workup?