Jarvis Garner

A 51-year-old male with a history of AIDS presents with his partner with confusion over one month. Per the patient’s partner, he has not experienced any fevers, chills, cough, congestion, or recent illness and was not complaining of headaches or vision changes. The partner does not know of any other medical history. On exam, he is stable. The patient is alert but not oriented to person, place, or time. Hyporeflexia is noted on patellar DTRs. On ocular examination, constriction of the pupils is noted when the eyes are focused on a nearby object but not when the pupils are illuminated. A broad workup is initiated for altered mental status, including an STD panel, which shows a reactive Venereal Disease Research Laboratory (VDRL) and a negative CT head. Cerebrospinal fluid (CSF) studies are obtained in the recumbent position for opening pressures. The CSF studies return positive for CSF VDRL as well as for CSFfluorescent treponemal antibody-absorption test (FTA-ABS), with 75 WBCs/microL and a CSF protein of 60 mg/dL and elevated opening pressures. Neurology is consulted, treatment is started, and the patient is admitted to the hospital for further management.  What is the most likely diagnosis?