PPMS may be diagnosed in subjects with One year of disease progression (retrospectively or prospectively determined) PLUS two out of the three following criteria*

1) Evidence for DIS in the brain based on

Compare the 2010 brain DIS criteria to 2005.

2) Evidence for DIS in the spinal cord based on ≥ 2 T2lesions + in the cord

3) Positive CSF (isoelectric focusing evidence of oligoclonal bands and/or elevated IgG index)

* If a subject has a brainstem or spinal cord syndrome, all symptomatic lesions are excluded from the Criteria
+ Gadolinium enhancement of lesions is not required