Leukoencephalopathy, Progressive MultifocalJC VirusLeukoencephalopathiesCADASILPolyomavirus InfectionsMuscle WeaknessPosterior Leukoencephalopathy SyndromeDementia, Multi-InfarctCerebrospinal FluidMagnetic Resonance ImagingT-Lymphocytopenia, Idiopathic CD4-PositiveMianserinBrainTumor Virus InfectionsBrain DiseasesFatal OutcomeAIDS-Related Opportunistic InfectionsDNA, ViralImmune Reconstitution Inflammatory SyndromeHereditary Central Nervous System Demyelinating DiseasesPolyomavirusBK VirusIntegrin alpha4Central Nervous System CystsAkinetic MutismAIDS Dementia ComplexHLA-B18 AntigenOpportunistic InfectionsDemyelinating DiseasesGerstmann SyndromeMultiple Sclerosis, Relapsing-RemittingAntibodies, Monoclonal, HumanizedCapsid ProteinsImmunocompromised HostAcquired Immunodeficiency SyndromeMultiple SclerosisHypertensive EncephalopathyNeurogliaOligodendrogliaOrganophosphonatesAntigens, Viral, TumorDementia, VascularCentral Nervous System DiseasesMefloquinePolymerase Chain ReactionCytosineAntigens, Polyomavirus TransformingUrineCytarabineEncephalitis, ViralHIV InfectionsVirus ActivationGene RearrangementReceptors, NotchAntiretroviral Therapy, Highly ActiveAntibodies, Monoclonal, Murine-DerivedBiopsyCentral Nervous System InfectionsDisease ProgressionAntibodies, MonoclonalImmunosuppressive AgentsBase SequenceViral Regulatory and Accessory ProteinsMolecular Sequence DataAntiviral AgentsSimian virus 40Gene Expression Regulation, ViralSyndromeToxoplasmosis, CerebralRegulatory Sequences, Nucleic AcidCD4 Lymphocyte Count