Confusion recurs 2 weeks after fall

A 77-year-old woman presented to the emergency department complaining of a headache following a syncopal episode (while standing) earlier that day. She said that she'd lost consciousness for several minutes, and then experienced several minutes of mild confusion that resolved spontaneously. On physical exam, she was oriented to person and place, but not time. She had a contusion in her left occipitoparietal region without extensive bruising or deformity. The patient had normal cardiopulmonary, abdominal, and neurologic exams. Her past medical history included hypertension and normal pressure hydrocephalus, and her vital signs were within normal limits. She was taking aspirin once daily. The patient's initial head and neck computerized tomography (CT) scans were normal, but she was hospitalized because of her confusion. During her hospitalization, the patient had mild episodic headaches that resolved with acetaminophen. The next day, her confusion resolved, and repeat CT scans were unchanged. She was discharged within 24 hours. Two weeks later, the patient returned to the hospital after her daughter found her on the toilet, unable to stand up from the sitting position. She was confused and experienced a worsening of headache during transport to the hospital. No recurrent falls or additional episodes of trauma were reported. A CT scan was performed. WHAT IS YOUR DIAGNOSIS? HOW WOULD YOU TREAT THIS PATIENT?