Punctate lesion pattern suggestive of perivascular inflammation in acute natalizumab-associated progressive multifocal leukoencephalopathy: productive JC virus infection or preclinical PML-IRIS manifestation?

The article presents a case of a 45-year-old female with relapsing multiple sclerosis (MS). The woman received natalizumab infusions as a treatment and after completing 51 infusions, she complained of subacute slurred speech and mild ataxia of her right arm. The magnetic resonance imaging (MRI) of her brain showed progressive multifocal leukoencephalopathy (PML) lesions in cerebellum and supreatentorial brian. It discusses periventricular inflammation and PML lesions.