A 58-year-old African American male presented with rapidly progressive dementia over 3-6 months. Upon examination, he was afebrile, tachycardic, nonverbal, and could not follow any commands. Diffuse rigidity with muscle atrophy were observed. He was negative for syphilis, HIV, Hepatitis B or C. MRI of the brain showed hydrocephalus and right cerebellar small diffusion restriction. Electroencephalogram showed mild diffuse slowing.

Lumbar puncture (LP) showed normal opening pressure (8 cm H2O) and lymphocytic leukocytosis (WBC 262 with lymph 70%, RBC 12,000, glucose <20, and protein 1935 mg/dl). Meningitis panel was positive for Cryptococcus and cultures confirmed Cryptococcus neoformans. The patient was initiated on Amphotericin and Flucytosine. In addition, CSF studies also tested positive anti-NDMA receptor antibody with a titer of 1:40 and elevated oligoclonal bands. A repeat LP ten days later revealed similar results to the initial LP including continued positivity for anti-NMDA receptor antibody in CSF. IVIG (2 g/kg over 5 days) was initiated to combat the NMDA receptor encephalitis. CT thorax/abdomen/pelvis was negative for any malignancy. With the above interventions, he had mild improvement in his neurological status and was able to hold simple conversation upon discharge.