Table 2

Multivariable prediction model of lesion characteristics differentiating asymptomatic PML from new MS lesions in order of entry in the model

Predictive lesion characteristics*OR for PML†95% CIp Value
Focal lesion appearance‡0.0090.0008 to 0.12<0.001
Periventricular white matter localisation0.00060.00003 to 0.0121<0.001
Presence of punctate T2 lesions§183.211.4 to 2950.7<0.001
Cortical grey matter involvement59.88.4 to 427.6<0.001
  • *The model is corrected for age and treatment duration and the lesion characteristics are listed in order of stepwise entering in the model.

  • †OR>1 is associated with PML lesions; OR<1 is associated with new MS lesions.

  • ‡Compared to ‘non-focal appearance’ (ie, rated as: diffuse, confluent irregular or infiltrative appearance).

  • §Defined as punctiform T2/FLAIR hyperintense lesions in the vicinity of the main PML lesions recently described as ‘milky way appearance’ and/or punctiform T2/FLAIR hyperintense lesions with a perivascular spread (<5 mm in diameter).

  • FLAIR, fluid-attenuated inversion recovery; MS, multiple sclerosis; PML, progressive multifocal leukoencephalopathy.