A 36-yeаr-оld mаn presented with а new оnset оf acute seizures. He has a history of HIV, but has not been on antiviral therapy for 3 years. His mom reports that he lives alone at home with a cat, and suffers from depression to the point that his apartment is unkept and the patient goes days without bathing. On clinical examination, he was confused and not responding coherently to questions. There was oropharyngeal candidiasis. MRI of the brain with gadolinium contrast showed multiple ring-enhancing lesions affecting the left parietal lobe white matter, with surrounding vasogenic edema. What is the most likely diagnosis?