MRI evidence of dissemination in space | Three out of four of following. a) 1 gadolinium enhancing brain or cord lesion b) 1 or more brain infratentorial or cord lesions c) 1 or more juxtacortical lesions d) 3 or more periventricular lesions |
MRI evidence of dissemination in time | A gadolinium enhancing lesion detected in scan atleast 3 months after the onset of initial clinical event at a site different from initial event |