MSFinals-3200

MSFinals-3200

A 68-year-old man came to the Emergency Department following a seizure at home, which he had never experienced before. He experienced moderate weakness on his left side during the initial postictal period, which quickly subsided. He is disoriented, and his wife reports that he has been experiencing dull, throbbing headaches that he can feel throughout his head. He has a medical history of hypertension and type II diabetes, which he manages with an ACE inhibitor and metformin. Upon neurological examination, the patient exhibits reduced strength in his right upper limb.

What is the definitive diagnostic test for this patient?