A 35-year-old male presents to the emergency department with palpitations and an episode of syncope followed by a head injury. There is no prior history of hypertension, diabetes, smoking, or relevant family history. According to the attendants, the patient fell in the washroom 7 days ago, striking his head, and since then has been experiencing persistent headache and episodes of nausea/vomiting. Over the past 2 days, he also reports blurring of vision, particularly when attempting to stand or g