Parkinson disease Quiz: Ace Your Exams

A 65-year-old man comes to the physician’s office due to a recent fall and the feeling of unsteadiness. The patient fell 2 days ago when going down the stairs but did not experience any head trauma. The patient’s partner reports that the patient has been acting differently for the past several months and is often anxious. The patient is healthy with no significant past medical history, and he does not take any medications. Vital signs are within normal limits. On physical examination, there is mild hyperkyphosis, and the patient is walking slowly. The muscle tone is increased bilaterally. There is a mild tremor on the right hand during rest which disappears on a finger-to-nose test. The patient is started on appropriate therapy. Which of the following is most likely to be found on examination of a patient’s brain with this condition?