A 34-year-old man with HIV is brought to the ED by his brother because of personality change over the past week. He has suddenly started to laugh much of the time, often uncontrollably. He has had two episodes of Pneumocystis pneumonia during the past year. An MRI of the brain shows a ring-enhancing lesion in the frontal lobe. Vitals are normal. Which of the following is the most likely explanation for this patient’s change in personality?
Central nervous system demyelination
Neurocysticercosis
Primary CNS lymphoma
Progressive multifocal leukoencephalopathy
Toxoplasmosis
