In the classic presentation of the disease death occurs in 1 to 3 years, but faster and slower progressions can occur. Faster deterioration in cases of acute fulminant<unk>  leads to death within 3 months of diagnosis. Although the prognosis is bleak for<unk>  past stage 1, there is a 5% spontaneous remission rate—this may be either a full remission that may last many years or an improvement in condition giving a longer progression period or at least a longer period with the less severe symptoms.
Subacute sclerosing panencephalitis
Progressive multifocal leukoencephalopathy
Hashimoto's encephalopathy
Hereditary diffuse leukoencephalopathy with spheroids
Intravascular lymphomas
HIV-associated nephropathy
Toxic leukoencephalopathy
Progressive rubella panencephalitis