Given these changes from the original case, what is your diagnosis?
What is your diagnostic explanation?
As compared to the long case, this patient is a 50 year old man who presents to the ED with symptoms of confusion, unsteadiness, and headaches.
HPI: Patient notes that for the past several weeks he has been getting confused (has gotten lost driving to work, put his car keys in the refrigerator and then couldn’t find them). This is not something that he noticed before the past several weeks. He also notes that he feels unsteady on his feet (though he has not fallen) and has been having occipital headaches as well. He has a 30 pack year smoking history.
PMH: Patient has a history of psoriasis for >10 years, and frequent respiratory tract infections (2-3 per year) which often required antibiotic treatment. Uses no medications currently.
SH: Lives by himself since he got divorced. See HPI.
ROS: Noncontributory
PE: 50 year old man looking older than his stated age. BP was 126/80 lying and 130/84 standing. Pulse 88 bpm. Afebrile. Respiration – 20/minute. No edema noted. Rest of PE unremarkable.
Mental Status Exam: Patient could remember 1 object of 3 at 5 minutes. Could spell ‘world,’ but could not do it correctly backwards. (Spelled w-o-w-d-l). Could not immediately repeat more than 3 numbers forward and backward at a time.
Labs: Na=118 mmol/L Serum Osmolality=249 mOsm/kg (normal is 275-300 mOsm/Kg)
CT of abdomen and head were both normal.