"DWI/ADC: peripheral patchy diffusion restriction, particularly at the leading edge 14"
"Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease that results from reactivation of the John Cunningham virus (JC virus), which infects oligodendrocytes in patients with compromised immune systems."
"It is considered the most common clinical manifestation of JC virus infection in the brain, 7, and is mainly seen in three clinical contexts:"
"inflammatory diseases (e.g. SLE, sarcoidosis)"
"CSF JC virus PCR is the standard first-line confirmatory test, with brain biopsy reserved for PCR-negative cases with high clinical suspicion 7,27."
"CSF JC virus PCR is the standard first-line confirmatory test, with brain biopsy reserved for PCR-negative cases with high clinical suspicion 7,27."
"CSF JC virus PCR is the standard first-line confirmatory test, with brain biopsy reserved for PCR-negative cases with high clinical suspicion 7,27."
"enhancement can be seen in PML-IRIS, AIDS with ART, and in patients on natalizumab 16,17"
"enhancement can be seen in PML-IRIS, AIDS with ART, and in patients on natalizumab 16,17"
"MR spectroscopy: according to one study, spectra of PML lesions were characterised by significantly reduced NAA, lactate presence, and by significantly increased choline and lipids compared with control group values 8"
"If PML-IRIS manifests, high-dose glucocorticoid therapy is recommended. Otherwise, pembrolizumab, an inhibitor of the programmed cell death protein 1 (PD-1) receptor on T cells, has also been shown to be an effective treatment for PML in several small case series 24,25,29."
"inflammatory diseases (e.g. SLE, sarcoidosis)"
"differing clinical history (e.g. hypertension)"
"differing clinical history (e.g. recent infection/vaccination)"
"Typically seen as multifocal, asymmetric periventricular and subcortical involvement. There is little or no mass effect or enhancement 10 and the subcortical U-fibres are commonly involved with a predilection for the parieto-occipital regions 17. In fact, even though subcortical U-fibre involvement is an important feature of lesions of multiple sclerosis, these are relatively uncommon. If new lesions have a subcortical U-fibre distribution, this favours PML 21. Typically, the lesion presents with a sharply demarcated peripheral border along the subcortical U fibres and a hazy, ill-defined inner border.22 The corpus callosum may be involved 17."
"early in the disease, MS and PML may appear similar 21"