A patient comes to you with complaints of intense headaches on the left side of his head just behind his eye. He also tells you that lately he has had trouble
concentrating and feels unusually angry and confused. You ordered a variety of
diagnostic tests and have the following results:
• Patient's speech, hearing, and vision appear normal.
• Patient's ability to perform memory tasks is less than expected for his
age.
• Patient's ability to control movement and balance appear normal.
Due to these symptoms, you suspect an issue with his central nervous system.
What additional test or tests would you order to help with the diagnosis and why?