system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 66-year-old man comes to the physician because of difficulty walking for the past year. He reports that his gait has become slower and that initiating steps has become more challenging. During the past 6 months, his family has noticed that he is starting to forget important family meetings and holidays. On a number of occasions, he has not been able to get to the bathroom in time in order to urinate. He has hypertension treated with hydrochlorothiazide. His father died of Parkinson's disease at the age of 63 years. The patient had smoked one pack of cigarettes daily for 40 years, but quit 10 years ago. His vital signs are within normal limits. On mental status examination, he is confused and has short-term memory deficits. He has a wide-based, shuffling gait. Muscle strength is normal. Deep tendon reflexes are 2+ bilaterally. An MRI of the head is shown. Which of the following is the most likely underlying cause of this patient's symptoms?
assistant
Decreased cerebrospinal fluid absorption