Table 2.

Descriptions of the classifications of relapsing–remitting and progressive MS, as defined by Lublin et al. in 2013 [2, 3]

Relapsing–remitting disease
CIS	A clear-cut syndrome such as optic neuritis, brain stem/cerebellar dysfunction, or partial myelitis Characteristics of inflammatory demyelination that could be MS are present, but McDonald 2010 criteria [7] of dissemination in time are yet to be fulfilled	Active
		Not active
RRMS	MRI evidence of dissemination in space, as well as gadolinium-enhancing and non-enhancing T2 lesions on a single MRI scan and/or a subsequent event	Active
		Not active

Progressive disease
PPMS	Progressive accumulation of disability from onset	Active and with progression
		Active, but without progression
SPMS	Progressive accumulation of disability after initial relapsing course	Not active, but with progression
		Not active and without progression

Definitions
Active	Clinical relapses and/or MRI activity (gadolinium-enhancing MRI lesions or new/enlarging T2 lesions) assessed at least annually
Not active	Absence of MRI activity (if activity assessments are not available, disease activity is “indeterminate”)
Progression	Measured by clinical evaluation at least annually
Worsening disease	A documented increase in neurologic dysfunction/disability as a result of relapses or progressive disease or both
Disease progression	Reserved solely for patients in a progressive phase of MS
Confirmed progression	An increase in neurologic dysfunction confirmed throughout a defined time interval (e.g. 3, 6, or 12 months)

CIS clinically isolated syndrome, MRI magnetic resonance imaging, MS multiple sclerosis, PPMS primary progressive MS, PRMS progressive relapsing MS, RRMS relapsing–remitting MS, SPMS secondary progressive MS