A 66 year old man presents with abnormal behavior for 1 month. He has become highly suspicious of his neighbors, without just cause. Further questioning reveals a history of worsening forgetfulness for 6 months, including losing his way in his own neighborhood 3 times.

His medical, psychiatric, and family histories are unremarkable, and he is not on any drugs or over-the-counter medications. He does not smoke, drink, or abuse recreational drugs.

He consumes a normal diet, including red meat and fish. He has been sexually promiscuous throughout his life, with the most recent relationship just 2 years ago.

He underwent a routine check-up 3 months earlier, at which time a complete blood count, serum electrolyte assay, and renal, thyroid, and liver profiles were all found to be normal.

Select Relevant Investigations
Mini Mental State Examination


MMSE Score: 17/30 (moderate cognitive impairment)
MRI Brain


The MRI scan of the brain is only significant for mild age related atrophy.
STI Panel


Rapid Plasma Regain (RPR): positive with a titer of 1:64
Fluorescent Treponemal Antibody Absorption (FTA-ABS): positive
Negative for human immunodeficiency virus (HIV) 1 and 2 and other STDs.
CSF Analysis


Appearance: clear
Opening pressure: 14 cmH2O (10 - 20)
Cell count: 2 cells/mm3 (<5 cells)
Protein: 67.4 mg/dl (15-40)
Glucose: 69.1 mg/dL (½ to ⅔ of blood glucose)
Gram stain: no organisms detected
Culture report: pending
Viral (meningoencephalitis) panel: negative
VDRL test: positive with a titer of 1:4
Fluorescent Treponemal Antibody Absorption (FTA-Abs): positive

Select Relevant Management
IV Penicillin-G
Oral Doxycycline
Electroconvulsive Therapy