The Bottom Line: PML frequently presents as hemiparesis, ataxia, visual disturbances or higher cortical dysfunction—dysphasia or agnosia rather than global impairment, unless PML is severe. Cognitive decline without accompanying deficits in motor or sensory function is an uncommon clinical symptom of this disease.
Brew. Progressive multifocal leukoencephalopathy and other forms of JC virus disease. Nature reviews. Neurology 2010 vol:6 iss:12 pg:667 -79
Figure 2: FLAIR images showing progression of progressive multifocal leukoencephalopathy immune reconstitution inflammatory syndrome page 671